CA2209944A1 - Packet radio system, and a terminal equipment for a packet radio system - Google Patents
Packet radio system, and a terminal equipment for a packet radio systemInfo
- Publication number
- CA2209944A1 CA2209944A1 CA002209944A CA2209944A CA2209944A1 CA 2209944 A1 CA2209944 A1 CA 2209944A1 CA 002209944 A CA002209944 A CA 002209944A CA 2209944 A CA2209944 A CA 2209944A CA 2209944 A1 CA2209944 A1 CA 2209944A1
- Authority
- CA
- Canada
- Prior art keywords
- point
- protocol
- packet
- data
- terminal equipment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
- H04L69/16—Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
- H04L69/169—Special adaptations of TCP, UDP or IP for interworking of IP based networks with other networks
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
- H04L69/16—Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
- H04L69/168—Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP] specially adapted for link layer protocols, e.g. asynchronous transfer mode [ATM], synchronous optical network [SONET] or point-to-point protocol [PPP]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/40—Network security protocols
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W76/00—Connection management
- H04W76/20—Manipulation of established connections
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L2212/00—Encapsulation of packets
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
- H04L69/16—Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/16—Gateway arrangements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W92/00—Interfaces specially adapted for wireless communication networks
- H04W92/02—Inter-networking arrangements
Abstract
A packet radio system encapsulates data packets of external data networks by a point-to-point protocol PPP (Fig. 4A, 4B), and passes them through one or more sub-networks to a point which supports the protocol of the encapsulated data packet. In addition, a special radio link protocol of the packet radio network is required on the radio interface between a mobile data terminal equipment and a support node. PPP packets are encapsulated in data packets of said radio link protocol. The disadvantage of the arrangement is that the data packets of both the PPP protocol and the radio link protocol contain protocol-specific control fields, which reduces the transmission capacity of user information. Therefore, a PPP packet is compressed (Fig. 4C) before the encapsulation (Fig. 4D) by removing therefrom the unnecessary control fields. After having been transferred over the radio interface, the PPP packet is decompressed into its original format (Fig. 4F, 4G).
Description
WO 96/21984 PCT/1i~96100020 Packet radio system, and a terminal equipment for a packet radio system .~
Field of the Invention ~ 5 The present invention relates to a packet radio system, comprising a digital mobile communication network;
at least one packet radio support node, connected to the mobile communication network and to one or more other packet radio support nodes and/or providing an access point to an external packet data network; a packet data terminal equipment providing an access point for packet data transmission taking place over the radio interface, said access point supporting a universal communication protocol used by an application associated with the terminal equipment.
Bac~ylo~d of the Invention Mobile communication systems have been developed because there has been a need to free people to move away from fixed telephone terminals without this hindering their reachability. While the use of different data transmission services in offices has increased, different data services have also been introduced into mobile communication systems. Portable computers enable efficient data processing everywhere the user moves. As for mobile communication networks, they provide the user with an efficient access network for mobile data transmission, such an access network providing access to actual data networks. In order to do this, different new data services are designed for existing and future mobile communication networks. Digital mobile communication systems, such as the pan-European mobile communication system GSM (Global System for Mobile Communication), support particularly well mobile data transmission.
General Packet Radio Service GPRS is a new service in the GSM system, and it is one the items of the WO96/21984 PCTA~96/00020 standardization work of the GSM phase 2+ in ETSI (European Telecommunication Standard Institute). The GPRS
operational environment consists of one or more sub-network service areas, which are interconnected by a GPRS
backbone network. A sub-network comprises a number of packet data service nodes, which are referred to as GPRS
support nodes (or agents) in this context, each packet data service node being connected to a GSM mobile communication network in such a manner that it is capable of providing a packet data service for mobile data terminal equipments via several base stations, i.e. cells.
The intermediate mobile communication network provides circuit switched or packet switched data transmission between a support node and mobile data terminal equipments. Different sub-networks are connected to an external data network, such as a public switched packet data network PSPDN. The GPRS service thus produces packet data transmission between mobile data terminal equipments and external data networks, a GSM network acting as an access network. One aspect of the GPRS service network is that it operates almost independently of the GSM network.
One of the requirements set for the GPRS service is that it must operate together with external PSPDNs of different types, for instance with Internet or X.25 networks. In other words, the GPRS service and a GSM network should be capable of serving all users, irrespective of which type of data networks they want to register in via the GSM
network or which protocols are used in a data terminal equipment. This means that the GSM network and the GPRS
service have to support and handle different network addressings and data packet formats, and be prepared for new (future) data network protocols.
Disclosure of the Invention r The object of the present invention is a packet radio system, providing reliable and effective data WO96/21984 PCTn~96100020 transmission, which supports several external data networks and protocols and enables new protocols to be supported as flexibly as possible and with minor modifications.
This object is achieved with the packet radio system described in the introduction, characterized according to the invention by using a point-to-point protocol independent of said universal communication protocol in the internal transmission of the packet radio system, a data packet according to said point-to-point protocol containing the control fields used by the protocol, an identification field identifying the protocol used by the terminal equipment, and a data field, a data packet according to the universal protocol being thus encapsulated in the data field of a data packet according to the point-to-point protocol in the internal transmission of the packet radio system, using a special radio link protocol between the packet data terminal equipment and said at least one packet radio support node on the radio interface, said radio link protocol supporting point-to-multipoint addressing and the control of data packet retransmission, a data packet according to said radio link protocol containing the control fields used by the protocol and a data field, arranging the packet data terminal equipment and said at least one support node to compress a data packet according to the point-to-point protocol, transmitted over the radio interface, by removing therefrom at least one control field and to encapsulate the remaining fields in the data field of a data packet according to the radio link protocol, arranging the packet data terminal equipment and said at least one support node to decompress a compressed WO 96/21984 PCT/1;196/00020 data packet according to the point-to-point protocol, received over the radio interface, by adding thereto the fields removed in the compression before the data packet is forwarded further.
The present invention also relates to a terminal equipment for a packet radio system, said terminal equipment providing an access point for packet data transmission taking place over the radio interface, said access point supporting a universal communication protocol used by the application associated with the terminal equipment. The terminal equipment is characterized in that the terminal equipment uses a point-to-point protocol independent of said universal communication protocol in the internal transmission of the packet radio system, a data packet according to said point-to-point protocol containing the control fields used by the protocol, an identification field identifying the protocol used by the terminal equipment, and a data field, the terminal equipment uses, in the transmission taking place over the radio interface, a special radio link protocol used in the inter-nodal transmission of the packet radio system, said protocol supporting point-to-multipoint addressing and the control of data packet retransmission, a data packet according to said radio link protocol containing the control fields used by the protocol and a data field, the terminal equipment is arranged to encapsulate a transmitted data packet according to the universal protocol in the data field of a data packet according to said point-to-point protocol, the terminal equipment is arranged to compress a data packet according to the point-to-point protocol, transmitted over the radio interface, by removing therefrom at least one control field and to encapsulate the r~m~;n;ng fields in a data packet according to the WO96/21984 PCT ~ 6/00020 radio link protocol, the terminal equipment is arranged to decompress a compressed data packet according to the point-to-point protocol, received over the radio interface, by adding ' 5 thereto the fields removed in the compression, the terminal equipment is arranged to release a data packet according to the universal protocol from a decompressed data packet according to the point-to-point protocol.
In the present invention, the packet radio system encapsulates data packets of external data networks and transports them through one or more sub-networks to a point which supports the protocol of the encapsulated data packet. At this interface, the packet of an external network is released from the encapsulation and sent to an external data network. Thus, it is necessary that a general, standardized protocol exist between a mobile data terminal equipment and a support node serving the mobile data terminal equipment, said protocol providing the transmission of user data independently of the network, transport and higher level protocols used. With the implementation of such a single protocol, the data terminal equipment provides a transmission path for all applications irrespective of what type of external data network they are communicating with. According to the invention, for instance the point-to-point protocol PPP
defined in standards RFC 1661 and 1662 of Internet Architecture Board (IAB), and the data encapsulation method thereof, is used as such a packet radio network-internal protocol that encapsulates data packets of external data networks. However, the PPP does not provide all functions required for the operation of the link layer over the radio interface particularly in an environment where the number of transmission errors may be great.
Consequently, a special radio link protocol which can WO96/21984 PCTn~96/00020 provide all the necessary functions is required between a mobile data terminal equipment and a support node on the radio interface of the packet radio network. The two most important aspects provided by this protocol are the support of point-to-multipoint addressing and the control of the data packet retransmission. As a result of this solution, PPP data packets are transferred as encapsulated in data packets of the radio link protocol. A PPP data packet can be arranged in radio link protocol packets in a number of ways: one PPP packet in one radio link protocol packet, several PPP packets in one radio link protocol packet, one PPP packet in several radio link protocol packets. One of the drawbacks of this protocol arrangement is that the data frames of both the PPP and the radio link protocol contain the control fields used by the protocols.
Normally, all this information has to be transferred from end to end. As a result, this overhead control data of the link layer reduces the transmission capacity of user information. To obviate this problem, the amount of the control data of the link layer must be minimized.
According to the invention, this is done by removing part or all of the unnecessary fields from a PPP data frame.
This is possible because in a PPP data frame, the values of flag fields, address field and control field are constant and do not therefore contain any real information. Thus, according to the invention, the PPP
data frames are compressed by removing therefrom at least part of the control fields before they are transmitted over the radio path. Since the removed fields are constant, the fields can easily be returned into the compressed data frame after the transmission over the radio path. Since a data frame according to the radio link protocol contains a dedicated check sum field, the check sum field of a PPP data frame can also be omitted, if necessary, before the transmission over the radio CA 02209944 l997-07-09 WO 96/21984 PCT/FI~6/00020 interface, and the check sum can be recalculated and the check sum field added again to the compressed packet transmitted over the radio interface. The PPP protocol according to the standard may also contain stuffing bytes, which are used for preventing the appearance of the bit patterns used in the control in the data field. Since, according to the invention, PPP frames are transmitted as encapsulated in radio interface packets on the radio interface, these forbidden bit patterns have no effect on the transmission. Thus, according to the invention, these stuffing bytes may be removed from the data before the transmission to the radio interface and returned to the data after the transmission over the radio interface. This is done in order that it would not be necessary to modify the general data network protocols provided in the terminal equipments. By means of the compression of the invention, the transmission capacity of user data can be significantly improved.
A PPP frame contains a protocol identification field, the value of which identifies the protocol used by the application. The packet radio network routes an encapsulated data packet to such a point of the network or a point of an external data network that supports the protocol indicated by the identification field. At this point, the encapsulation is stripped away, and the original data packet is routed to its destination on the basis of the address information contained therein.
Brief Description of the Figures In the following, the invention will be described by means of the preferred embodiments with reference to the accompanying drawing, in which Figure 1 is a block diagram which illustrates a packet radio system of the invention, Figure 2 is a diagram which illustrates the encapsulation of data packets, CA 02209944 l997-07-09 WO 96/2 1984 PCT/l;l~G,r ~ 20 Figure 3 shows a PPP data frame, Figures 4A, B, C, D, E, F and G illustrate different protocol frames at the encapsulation, compression, transmission, decompression and de-encapsulation stage.
Description of the Preferred ~bodiments The present invention can be used in packet radio systems of different types. The invention is particularly well suited for implementing the general packet radio service (GPRS) in the pan-European mobile communication system GSM (Global System for Mobile Communication) or in corresponding digital systems such as DCS1800 and PCN
(Personal Communication Network). In the following, the preferred embodiment of the invention will be described by means of the GPRS service and the GSM system, without restricting the invention to such a particular packet radio system, however.
Figure 1 illustrates the basic structure of a GPRS packet radio network. The GPRS packet radio system consists of one or more sub-network service areas, such as SA1 and SA2, which are interconnected by a GPRS backbone network 1 (Backbone). Typically, the backbone network is the local network of the operator of the packet radio network, for instance an IP network. The sub-network service area SA1 and SA2 comprises one or more packet data service nodes, which are referred to as agents or GPRS
support nodes. Figure l shows GPRS support nodes SN1 and SN2. One or more of the GPRS support nodes may also act as gateway support nodes towards an external data network, for instance towards a public switched packet data network PSPDN. The backbone network 1 may also be provided with special gateway nodes for connecting to data networks.
Each GPRS support node controls a packet data service within the area of one or more cells in a cellular packet radio network. For this, each support node SNl and , WO96/219X4 PCT ~ 6/00020 SN2 is connected to a certain local part of the GSM mobile system. This connection is typically established in a mobile exchange MSC via an interworking function IWF, but in some situations it may be advantageous to provide the connection directly in the base station system BSS, i.e.
in a base station controller BSC or one of the base stations BTS. The mobile station MS located in a cell communicates over the radio interface with a base station BTS and further through the mobile communication network with the GPRS support node SNl, SN2, SN3 to the service area of which the cell belongs. In principle, the mobile communication network existing between the GPRS support node and the mobile data terminal equipment MS merely delivers packets between these two. In order to do this, the mobile communication network may provide either a circuit switched connection or packet switched data packet transmission between the terminal equipment MS and the serving support node SN. An example of a circuit switched connection between a terminal equipment MS and a support node (agent) is given in Finnish Patent Application 934115. An example of packet switched data transmission between a terminal equipment MS and a support node (agent) is given in Finnish Patent Application 940314. However, it should be noticed that the mobile communication network provides merely a physical connection between the terminal equipment MS and the support node, and the exact operation and structure thereof do not have essential significance as regards the invention. As for more detailed description of the GSM system, reference is made, however, to ETSI/GSM
specifications and to "The GSM System for Mobile Communications", M. Mouly and M. Pautet, Palaiseau, France, 1992, ISBN:2-9507190-07-7.
A typical mobile data terminal equipment consists of a mobile station 3 in a mobile communication network, and a portable computer 4 connected to the data interface WO 96/21984 PCT/~il96/00020 of the mobile station. The mobile station 3 may be for instance a Nokia 2110, which is manufactured by Nokia Mobile Phones Ltd., Finland. By means of a PCMCIA-type Nokia Cellular Datacard, which is manufactured by Nokia Mobile Phones Ltd., Finland, the data interface of the mobile station can be connected to any portable PC which is provided with a PCMCIA card location. The PCMCIA card thus provides the PC with an access point, which supports the protocol of the telecommunication application used in the computer 4, for instance CCITT X.25 or Internet Protocol IP. Alternatively, the mobile station 3 may directly provide an access point which supports the protocol used by the application of the PC 4. Furthermore, it is possible that the mobile station 3 and the PC are integrated into one unit within which the application program is provided with an access point supporting the protocol used by it.
It is apparent that mobile users will require access to various data networks through a packet radio network. This requires that for instance the GPRS system must be capable of operating together with external data networks PSPDN of different types, such as Internet and X.25 networks. This means that the GPRS system has to support different network addressing schemes (and network addresses) and the data packet formats of different protocols.
The general mechanism by which data transmission supporting many external PSPDN networks can be implemented in a GPRS data network is shown in Figure 2. The idea is that for instance a data packet of the protocol used by an external PSPDN, sent by the application of a data terminal equipment MS, is encapsulated in the data terminal equipment in the frame format used by the GPRS network, said frame format being independent of the protocol of the application of the data terminal equipment or that of the CA 02209944 l997-07-09 WO 96/21984 PCT/FI~'C~A20 external PSPDN. The GPRS packet also contains information on the protocol used by the terminal equipment or the application, and data sent by the terminal equipment. The GPRS packet is routed and transmitted from the data terminal equipment MS to the GPRS support node serving it, said GPRS support node forwarding the GPRS packet further to such a point of the GPRS network or the external PSPDN
network that supports the protocol of the application.
When the GPRS packet has arrived in such a point, the GPRS
packet and the encapsulation are released, and the original packet is forwarded further by means of the address data provided therein. Due to the encapsulation, the GPRS network can forward packets of different protocols even if the GPRS network did not directly support said protocols itself.
To achieve the object according to the present invention, a general, standardized protocol must be provided between a data terminal equipment MS and the support node SN serving it, said protocol providing the above-described transmission protocol which is independent of PSPDN networks and the transport layer and upper layer communication protocols used by said PSPDN neLworks. With the implementation of such a single independent protocol, the data terminal equipment MS is capable of providing a transmission path for all the applications associated with it. According to the preferred embodiment of the invention, the internal packet format of a GPRS network is essentially in accordance with the data encapsulation format of Point-to-Point Protocol (PPP) defined in standards RFC 1661 and 1662 of Internet Architecture Board (IAB). The PPP uses the principles, terminology and frame structure of IS0-3309-1979 High-level Data Link Control (HDLC) procedures. The PPP protocol will be described briefly in the following.
The PPP is an encapsulation protocol for both WO96/21984 PCTn~96/00020 bit-oriented synchronous links and asynchronous links with 8 bits of data and no parity bit. The PPP is carefully designed to maintain compatibility with the most commonly used software. In addition, it is provided with a specified escape mechanism, which enables arbitrary data to be transmitted over the link (without the characters provided in the data being interpreted as the control characters of the frame, for instance a start/stop flag).
This is done in such a manner that data characters corresponding to the control characters of the frame are replaced with two-character pairs in transmission and returned as the original special characters in reception.
The PPP encapsulation also multiplexes different network layer protocols simultaneously over a single link.
It is thus intended that the PPP provide a common solution for interconnecting a wide variety of different computers, bridges and routers.
Point-to-Point Protocol PPP defines more than merely an encapsulation principle. In order for it to be sufficiently versatile to be transferred to different environments, the PPP provides Link Control Protocol (LCP). The LPC is used to automatically negotiate encapsulation format options, handle varying limits on packet size, authenticate the identity of its peers on the link, determine when a link is operating properly and when it is not operating properly, detect a looped-back link and other common configuration errors, and terminate the link.
A summary of a standard PPP frame structure is shown in Figure 3. However, Figure 3 does not include start/stop bits (for asynchronous links), nor bits or octets inserted in the frame for transparency. The fields of the frame are transmitted in succession from left to right.
The flag sequence FLAG is a single octet, and it WO 96t21984 PCT/F196/00020 indicates the beginning or end of a frame. Only one flag is required between the frames. Two successive flags constitute an empty frame, which is ignored. The address field ADDRESS is a single octet, and it contains a binary sequence 11111111 (hexadecimal 0xff), which is a so-called All Stations address. In other words, the PPP provides all stations with the same address and does not provide addresses of individual stations. The control field CONTROL is a single octet, and it contains a binary sequence 00000011 (hexadecimal 0x03). The control field contains an unnumbered information (UI) command, in which the P/F bit is set to zero. The protocol field PROTOCOL
contains comprises two octets, and its value identifies the protocol of that data packet which is encapsulated in the information field of the UI frame. This protocol field is defined by the PPP, and it is not defined in HDLC.
However, the protocol field is consistent with the ISO
3309 extension mechanism for address fields.
Even though the PPP is selected as the data encapsulation method within the GPRS network in the preferred embodiment of the invention, the PPP does not provide, however, all those functions which are required in link layer operation over the radio interface. This means that a special GPRS-specific radio link protocol GLP, which can provide all necessary functions, is required on the radio interface between a terminal equipment MS and a support node SN. The GLP may be an HDLC
based protocol, very similar to the radio link protocol RLP already used by the GSM system. The two most important aspects to be provided by the GLP are the support of point-to-multipoint addressing and control of data frame retransmission. It should be noticed that the exact implementation of the GLP protocol is not essential as regards the invention. The frame structure of the GLP
(packet format) contains, however, similar fields as PPP
WO 96/21984 PCT/1il~6/C~,~20 frames do, i.e. data field, control field, address field, flag fields and check sum field. PPP frames are transferred over the radio path as encapsulated in the data field of these GLP frames between a terminal equipment MS and a support node SN. One of the disadvantages of this protocol arrangement is that both PPP and GLP data frames contain control fields, address fields, flags, check sums, etc. Normally, all this information must be transferred from end to end. This overhead data of the link layer reduces the transmission capacity of user information.
According to the invention, this problem is avoided by m;n;m;zing the amount of control data transferred over the radio interface. This is carried out by removing a part, or preferably all, of the unnecessary fields from the PPP data frame before it is encapsulated in a GLP data frame. This is possible because the values of flag, address and control fields used in PPP data frames are constant, and thus contain no real information.
The check sum field FCS of the PPP data frame can also be omitted, because the GLP data frame uses its own check sum, by means of which errors occurring on the radio interface are detected and corrected. On the whole, the terminal equipment MS and the support node SN compress the PPP data frames before they are encapsulated in GLP data frames and transferred over the radio interface.
Correspondingly, the terminal equipment MS and the support node SN decompress the compressed PPP data frames transferred over the radio interface by removing them from the GLP data frames, adding the removed fields thereto, the contents of these fields being constant and thus known, and by calculating a new check sum for the returned PPP data frame by a known check sum calculation algorithm.
The encapsulation, compression, decompression and de-encapsulation stages of the invention are illustrated WO96/2l984 PCT ~ "~~~20 in Figure 4. In Figure 4A, the terminal equipment MS
receives a data frame according to the protocol used by the application associated with said terminal equipment, for instance an X.25 frame (or an IP frame or some other ~ 5 frame). The terminal equipment MS performs an encapsulation by inserting the X.25 data frame in the data field of a PPP data frame, as shown in Figure 4B. At the same time, a value in the protocol field PROTOCOL of the PPP data frame is set to indicate the protocol of the encapsulated data packet, i.e. X.25. Thereafter, the terminal equipment MS compresses the PPP data frame by removing therefrom the flag, address, control and check sum fields. The resulting compressed PPP data frame, shown in Figure 4C, is encapsulated by inserting it in the data field of a GLP data frame, as shown in Figure 4D. The GLP
data frame is transferred from the terminal equipment MS
over the radio interface to a base station BTS and routed therefrom further through the mobile communication network to the support node SN which serves the current cell of the MS. In Figure 4E, the support node SN removes the compressed PPP data frame from the GLP data frame according to Figure 4D and performs a decompression by returning to the PPP data frame the flag, address and control fields removed therefrom, the contents of these fields being constant. In addition, the support node SN
calculates a new check sum FCS for the PPP data frame formed in this manner by means of a calculation algorithm reserved for this purpose. The result is the decompressed PPP data frame according to Figure 4F. If the serving support node SN does not support the protocol indicated in the PROTOCOl field itself, it routes the PPP data frame forward to such a point in the GPRS network or in an external data network that supports said protocol. When the PPP data frame arrives in such a point, the encapsulation is stripped away by removing the X.25 frame CA 02209944 l997-07-09 WO 96/21984 PCT11il96/00020 from the data field of the PPP data frame. Thereafter, the X.25 frame is treated according to its own address and control fields.
If the serving support node SN supports the protocol indicated by the PROTOCOL field, the serving node strips the encapsulation away itself and delivers the X.25 frame forward on the basis of the control and address information of the X.25 frame.
The stages according to Figures 4A - 4G also appear in transmission taking place towards the terminal equipment MS. The encapsulation of the X.25 frame in a PPP
data frame takes place either in the serving node SN or in some place on the interface of the GPRS network and the external data network. The compression of the PPP data frame according to Figure 4C and the insertion of the compressed PPP frame in the GLP data frame according to Figure 4D are performed in the serving support node SN.
The decompression and the de-encapsulation according to Figures 4E, 4F and 4G are performed in the terminal equipment MS, whereafter the X.25 frame is forwarded to the application associated with the terminal equipment MS.
It should be noticed that the standard PPP
protocol has its own method for compressing fields. This method is optional so that the use of the compression can be negotiated during the link configuration procedure.
However, this standard PPP compression cannot be used in connection with the present invention.
The standard PPP protocol also includes a so-called byte stuffing protocol. Certain bit patterns, such as the contents reserved for the flag field, in the data field of a PPP frame are thus converted into a two-byte chain. This a way of ensuring that for instance these bit patterns reserved for the flag field do not appear anywhere else in the message and lead to malfunctions.
These stuffing bytes cause problems in the GPRS network, WO96/21984 PCTn~96/00020 however, since the amount of data transmitted over the air interface is not independent of the data but is related to the contents of the data. In the worst case, the length of the data may be twice the length it should be due to the - 5 stuffing bytes. Since the PPP data transmitted over the radio interface is in GLP frames in a GPRS network, such "forbidden" control bit patterns in the data field do not cause malfunctions, such as an erroneous detection of the start/stop of a frame, as in a serial line. Therefore, in the preferred embodiment of the invention, all stuffing bytes are removed at the compression stage before the transmission over the radio interface, and the stuffing bytes are returned at the decompression stage on the other side of the radio interface. The data can also be compressed by other methods, for instance by using the V42.bis method used in modems.
It is also possible to combine several PPP
packets in one GLP frame, which is transmitted over the radio interface, if the PPP packets are smaller than the size of the data field of the GLP packets. It is also possible to transmit one PPP packet in several GLP
packets.
It is also possible that the compression and/or decompression according to the invention are only performed in the gateway node, and the compressed data packets are forwarded via the support node serving the mobile station.
The figures and the description relating thereto are merely intended to illustrate the present invention.
In their details, the packet radio system and the terminal equipment of the invention may vary within the scope and spirit of the appended claims.
Field of the Invention ~ 5 The present invention relates to a packet radio system, comprising a digital mobile communication network;
at least one packet radio support node, connected to the mobile communication network and to one or more other packet radio support nodes and/or providing an access point to an external packet data network; a packet data terminal equipment providing an access point for packet data transmission taking place over the radio interface, said access point supporting a universal communication protocol used by an application associated with the terminal equipment.
Bac~ylo~d of the Invention Mobile communication systems have been developed because there has been a need to free people to move away from fixed telephone terminals without this hindering their reachability. While the use of different data transmission services in offices has increased, different data services have also been introduced into mobile communication systems. Portable computers enable efficient data processing everywhere the user moves. As for mobile communication networks, they provide the user with an efficient access network for mobile data transmission, such an access network providing access to actual data networks. In order to do this, different new data services are designed for existing and future mobile communication networks. Digital mobile communication systems, such as the pan-European mobile communication system GSM (Global System for Mobile Communication), support particularly well mobile data transmission.
General Packet Radio Service GPRS is a new service in the GSM system, and it is one the items of the WO96/21984 PCTA~96/00020 standardization work of the GSM phase 2+ in ETSI (European Telecommunication Standard Institute). The GPRS
operational environment consists of one or more sub-network service areas, which are interconnected by a GPRS
backbone network. A sub-network comprises a number of packet data service nodes, which are referred to as GPRS
support nodes (or agents) in this context, each packet data service node being connected to a GSM mobile communication network in such a manner that it is capable of providing a packet data service for mobile data terminal equipments via several base stations, i.e. cells.
The intermediate mobile communication network provides circuit switched or packet switched data transmission between a support node and mobile data terminal equipments. Different sub-networks are connected to an external data network, such as a public switched packet data network PSPDN. The GPRS service thus produces packet data transmission between mobile data terminal equipments and external data networks, a GSM network acting as an access network. One aspect of the GPRS service network is that it operates almost independently of the GSM network.
One of the requirements set for the GPRS service is that it must operate together with external PSPDNs of different types, for instance with Internet or X.25 networks. In other words, the GPRS service and a GSM network should be capable of serving all users, irrespective of which type of data networks they want to register in via the GSM
network or which protocols are used in a data terminal equipment. This means that the GSM network and the GPRS
service have to support and handle different network addressings and data packet formats, and be prepared for new (future) data network protocols.
Disclosure of the Invention r The object of the present invention is a packet radio system, providing reliable and effective data WO96/21984 PCTn~96100020 transmission, which supports several external data networks and protocols and enables new protocols to be supported as flexibly as possible and with minor modifications.
This object is achieved with the packet radio system described in the introduction, characterized according to the invention by using a point-to-point protocol independent of said universal communication protocol in the internal transmission of the packet radio system, a data packet according to said point-to-point protocol containing the control fields used by the protocol, an identification field identifying the protocol used by the terminal equipment, and a data field, a data packet according to the universal protocol being thus encapsulated in the data field of a data packet according to the point-to-point protocol in the internal transmission of the packet radio system, using a special radio link protocol between the packet data terminal equipment and said at least one packet radio support node on the radio interface, said radio link protocol supporting point-to-multipoint addressing and the control of data packet retransmission, a data packet according to said radio link protocol containing the control fields used by the protocol and a data field, arranging the packet data terminal equipment and said at least one support node to compress a data packet according to the point-to-point protocol, transmitted over the radio interface, by removing therefrom at least one control field and to encapsulate the remaining fields in the data field of a data packet according to the radio link protocol, arranging the packet data terminal equipment and said at least one support node to decompress a compressed WO 96/21984 PCT/1;196/00020 data packet according to the point-to-point protocol, received over the radio interface, by adding thereto the fields removed in the compression before the data packet is forwarded further.
The present invention also relates to a terminal equipment for a packet radio system, said terminal equipment providing an access point for packet data transmission taking place over the radio interface, said access point supporting a universal communication protocol used by the application associated with the terminal equipment. The terminal equipment is characterized in that the terminal equipment uses a point-to-point protocol independent of said universal communication protocol in the internal transmission of the packet radio system, a data packet according to said point-to-point protocol containing the control fields used by the protocol, an identification field identifying the protocol used by the terminal equipment, and a data field, the terminal equipment uses, in the transmission taking place over the radio interface, a special radio link protocol used in the inter-nodal transmission of the packet radio system, said protocol supporting point-to-multipoint addressing and the control of data packet retransmission, a data packet according to said radio link protocol containing the control fields used by the protocol and a data field, the terminal equipment is arranged to encapsulate a transmitted data packet according to the universal protocol in the data field of a data packet according to said point-to-point protocol, the terminal equipment is arranged to compress a data packet according to the point-to-point protocol, transmitted over the radio interface, by removing therefrom at least one control field and to encapsulate the r~m~;n;ng fields in a data packet according to the WO96/21984 PCT ~ 6/00020 radio link protocol, the terminal equipment is arranged to decompress a compressed data packet according to the point-to-point protocol, received over the radio interface, by adding ' 5 thereto the fields removed in the compression, the terminal equipment is arranged to release a data packet according to the universal protocol from a decompressed data packet according to the point-to-point protocol.
In the present invention, the packet radio system encapsulates data packets of external data networks and transports them through one or more sub-networks to a point which supports the protocol of the encapsulated data packet. At this interface, the packet of an external network is released from the encapsulation and sent to an external data network. Thus, it is necessary that a general, standardized protocol exist between a mobile data terminal equipment and a support node serving the mobile data terminal equipment, said protocol providing the transmission of user data independently of the network, transport and higher level protocols used. With the implementation of such a single protocol, the data terminal equipment provides a transmission path for all applications irrespective of what type of external data network they are communicating with. According to the invention, for instance the point-to-point protocol PPP
defined in standards RFC 1661 and 1662 of Internet Architecture Board (IAB), and the data encapsulation method thereof, is used as such a packet radio network-internal protocol that encapsulates data packets of external data networks. However, the PPP does not provide all functions required for the operation of the link layer over the radio interface particularly in an environment where the number of transmission errors may be great.
Consequently, a special radio link protocol which can WO96/21984 PCTn~96/00020 provide all the necessary functions is required between a mobile data terminal equipment and a support node on the radio interface of the packet radio network. The two most important aspects provided by this protocol are the support of point-to-multipoint addressing and the control of the data packet retransmission. As a result of this solution, PPP data packets are transferred as encapsulated in data packets of the radio link protocol. A PPP data packet can be arranged in radio link protocol packets in a number of ways: one PPP packet in one radio link protocol packet, several PPP packets in one radio link protocol packet, one PPP packet in several radio link protocol packets. One of the drawbacks of this protocol arrangement is that the data frames of both the PPP and the radio link protocol contain the control fields used by the protocols.
Normally, all this information has to be transferred from end to end. As a result, this overhead control data of the link layer reduces the transmission capacity of user information. To obviate this problem, the amount of the control data of the link layer must be minimized.
According to the invention, this is done by removing part or all of the unnecessary fields from a PPP data frame.
This is possible because in a PPP data frame, the values of flag fields, address field and control field are constant and do not therefore contain any real information. Thus, according to the invention, the PPP
data frames are compressed by removing therefrom at least part of the control fields before they are transmitted over the radio path. Since the removed fields are constant, the fields can easily be returned into the compressed data frame after the transmission over the radio path. Since a data frame according to the radio link protocol contains a dedicated check sum field, the check sum field of a PPP data frame can also be omitted, if necessary, before the transmission over the radio CA 02209944 l997-07-09 WO 96/21984 PCT/FI~6/00020 interface, and the check sum can be recalculated and the check sum field added again to the compressed packet transmitted over the radio interface. The PPP protocol according to the standard may also contain stuffing bytes, which are used for preventing the appearance of the bit patterns used in the control in the data field. Since, according to the invention, PPP frames are transmitted as encapsulated in radio interface packets on the radio interface, these forbidden bit patterns have no effect on the transmission. Thus, according to the invention, these stuffing bytes may be removed from the data before the transmission to the radio interface and returned to the data after the transmission over the radio interface. This is done in order that it would not be necessary to modify the general data network protocols provided in the terminal equipments. By means of the compression of the invention, the transmission capacity of user data can be significantly improved.
A PPP frame contains a protocol identification field, the value of which identifies the protocol used by the application. The packet radio network routes an encapsulated data packet to such a point of the network or a point of an external data network that supports the protocol indicated by the identification field. At this point, the encapsulation is stripped away, and the original data packet is routed to its destination on the basis of the address information contained therein.
Brief Description of the Figures In the following, the invention will be described by means of the preferred embodiments with reference to the accompanying drawing, in which Figure 1 is a block diagram which illustrates a packet radio system of the invention, Figure 2 is a diagram which illustrates the encapsulation of data packets, CA 02209944 l997-07-09 WO 96/2 1984 PCT/l;l~G,r ~ 20 Figure 3 shows a PPP data frame, Figures 4A, B, C, D, E, F and G illustrate different protocol frames at the encapsulation, compression, transmission, decompression and de-encapsulation stage.
Description of the Preferred ~bodiments The present invention can be used in packet radio systems of different types. The invention is particularly well suited for implementing the general packet radio service (GPRS) in the pan-European mobile communication system GSM (Global System for Mobile Communication) or in corresponding digital systems such as DCS1800 and PCN
(Personal Communication Network). In the following, the preferred embodiment of the invention will be described by means of the GPRS service and the GSM system, without restricting the invention to such a particular packet radio system, however.
Figure 1 illustrates the basic structure of a GPRS packet radio network. The GPRS packet radio system consists of one or more sub-network service areas, such as SA1 and SA2, which are interconnected by a GPRS backbone network 1 (Backbone). Typically, the backbone network is the local network of the operator of the packet radio network, for instance an IP network. The sub-network service area SA1 and SA2 comprises one or more packet data service nodes, which are referred to as agents or GPRS
support nodes. Figure l shows GPRS support nodes SN1 and SN2. One or more of the GPRS support nodes may also act as gateway support nodes towards an external data network, for instance towards a public switched packet data network PSPDN. The backbone network 1 may also be provided with special gateway nodes for connecting to data networks.
Each GPRS support node controls a packet data service within the area of one or more cells in a cellular packet radio network. For this, each support node SNl and , WO96/219X4 PCT ~ 6/00020 SN2 is connected to a certain local part of the GSM mobile system. This connection is typically established in a mobile exchange MSC via an interworking function IWF, but in some situations it may be advantageous to provide the connection directly in the base station system BSS, i.e.
in a base station controller BSC or one of the base stations BTS. The mobile station MS located in a cell communicates over the radio interface with a base station BTS and further through the mobile communication network with the GPRS support node SNl, SN2, SN3 to the service area of which the cell belongs. In principle, the mobile communication network existing between the GPRS support node and the mobile data terminal equipment MS merely delivers packets between these two. In order to do this, the mobile communication network may provide either a circuit switched connection or packet switched data packet transmission between the terminal equipment MS and the serving support node SN. An example of a circuit switched connection between a terminal equipment MS and a support node (agent) is given in Finnish Patent Application 934115. An example of packet switched data transmission between a terminal equipment MS and a support node (agent) is given in Finnish Patent Application 940314. However, it should be noticed that the mobile communication network provides merely a physical connection between the terminal equipment MS and the support node, and the exact operation and structure thereof do not have essential significance as regards the invention. As for more detailed description of the GSM system, reference is made, however, to ETSI/GSM
specifications and to "The GSM System for Mobile Communications", M. Mouly and M. Pautet, Palaiseau, France, 1992, ISBN:2-9507190-07-7.
A typical mobile data terminal equipment consists of a mobile station 3 in a mobile communication network, and a portable computer 4 connected to the data interface WO 96/21984 PCT/~il96/00020 of the mobile station. The mobile station 3 may be for instance a Nokia 2110, which is manufactured by Nokia Mobile Phones Ltd., Finland. By means of a PCMCIA-type Nokia Cellular Datacard, which is manufactured by Nokia Mobile Phones Ltd., Finland, the data interface of the mobile station can be connected to any portable PC which is provided with a PCMCIA card location. The PCMCIA card thus provides the PC with an access point, which supports the protocol of the telecommunication application used in the computer 4, for instance CCITT X.25 or Internet Protocol IP. Alternatively, the mobile station 3 may directly provide an access point which supports the protocol used by the application of the PC 4. Furthermore, it is possible that the mobile station 3 and the PC are integrated into one unit within which the application program is provided with an access point supporting the protocol used by it.
It is apparent that mobile users will require access to various data networks through a packet radio network. This requires that for instance the GPRS system must be capable of operating together with external data networks PSPDN of different types, such as Internet and X.25 networks. This means that the GPRS system has to support different network addressing schemes (and network addresses) and the data packet formats of different protocols.
The general mechanism by which data transmission supporting many external PSPDN networks can be implemented in a GPRS data network is shown in Figure 2. The idea is that for instance a data packet of the protocol used by an external PSPDN, sent by the application of a data terminal equipment MS, is encapsulated in the data terminal equipment in the frame format used by the GPRS network, said frame format being independent of the protocol of the application of the data terminal equipment or that of the CA 02209944 l997-07-09 WO 96/21984 PCT/FI~'C~A20 external PSPDN. The GPRS packet also contains information on the protocol used by the terminal equipment or the application, and data sent by the terminal equipment. The GPRS packet is routed and transmitted from the data terminal equipment MS to the GPRS support node serving it, said GPRS support node forwarding the GPRS packet further to such a point of the GPRS network or the external PSPDN
network that supports the protocol of the application.
When the GPRS packet has arrived in such a point, the GPRS
packet and the encapsulation are released, and the original packet is forwarded further by means of the address data provided therein. Due to the encapsulation, the GPRS network can forward packets of different protocols even if the GPRS network did not directly support said protocols itself.
To achieve the object according to the present invention, a general, standardized protocol must be provided between a data terminal equipment MS and the support node SN serving it, said protocol providing the above-described transmission protocol which is independent of PSPDN networks and the transport layer and upper layer communication protocols used by said PSPDN neLworks. With the implementation of such a single independent protocol, the data terminal equipment MS is capable of providing a transmission path for all the applications associated with it. According to the preferred embodiment of the invention, the internal packet format of a GPRS network is essentially in accordance with the data encapsulation format of Point-to-Point Protocol (PPP) defined in standards RFC 1661 and 1662 of Internet Architecture Board (IAB). The PPP uses the principles, terminology and frame structure of IS0-3309-1979 High-level Data Link Control (HDLC) procedures. The PPP protocol will be described briefly in the following.
The PPP is an encapsulation protocol for both WO96/21984 PCTn~96/00020 bit-oriented synchronous links and asynchronous links with 8 bits of data and no parity bit. The PPP is carefully designed to maintain compatibility with the most commonly used software. In addition, it is provided with a specified escape mechanism, which enables arbitrary data to be transmitted over the link (without the characters provided in the data being interpreted as the control characters of the frame, for instance a start/stop flag).
This is done in such a manner that data characters corresponding to the control characters of the frame are replaced with two-character pairs in transmission and returned as the original special characters in reception.
The PPP encapsulation also multiplexes different network layer protocols simultaneously over a single link.
It is thus intended that the PPP provide a common solution for interconnecting a wide variety of different computers, bridges and routers.
Point-to-Point Protocol PPP defines more than merely an encapsulation principle. In order for it to be sufficiently versatile to be transferred to different environments, the PPP provides Link Control Protocol (LCP). The LPC is used to automatically negotiate encapsulation format options, handle varying limits on packet size, authenticate the identity of its peers on the link, determine when a link is operating properly and when it is not operating properly, detect a looped-back link and other common configuration errors, and terminate the link.
A summary of a standard PPP frame structure is shown in Figure 3. However, Figure 3 does not include start/stop bits (for asynchronous links), nor bits or octets inserted in the frame for transparency. The fields of the frame are transmitted in succession from left to right.
The flag sequence FLAG is a single octet, and it WO 96t21984 PCT/F196/00020 indicates the beginning or end of a frame. Only one flag is required between the frames. Two successive flags constitute an empty frame, which is ignored. The address field ADDRESS is a single octet, and it contains a binary sequence 11111111 (hexadecimal 0xff), which is a so-called All Stations address. In other words, the PPP provides all stations with the same address and does not provide addresses of individual stations. The control field CONTROL is a single octet, and it contains a binary sequence 00000011 (hexadecimal 0x03). The control field contains an unnumbered information (UI) command, in which the P/F bit is set to zero. The protocol field PROTOCOL
contains comprises two octets, and its value identifies the protocol of that data packet which is encapsulated in the information field of the UI frame. This protocol field is defined by the PPP, and it is not defined in HDLC.
However, the protocol field is consistent with the ISO
3309 extension mechanism for address fields.
Even though the PPP is selected as the data encapsulation method within the GPRS network in the preferred embodiment of the invention, the PPP does not provide, however, all those functions which are required in link layer operation over the radio interface. This means that a special GPRS-specific radio link protocol GLP, which can provide all necessary functions, is required on the radio interface between a terminal equipment MS and a support node SN. The GLP may be an HDLC
based protocol, very similar to the radio link protocol RLP already used by the GSM system. The two most important aspects to be provided by the GLP are the support of point-to-multipoint addressing and control of data frame retransmission. It should be noticed that the exact implementation of the GLP protocol is not essential as regards the invention. The frame structure of the GLP
(packet format) contains, however, similar fields as PPP
WO 96/21984 PCT/1il~6/C~,~20 frames do, i.e. data field, control field, address field, flag fields and check sum field. PPP frames are transferred over the radio path as encapsulated in the data field of these GLP frames between a terminal equipment MS and a support node SN. One of the disadvantages of this protocol arrangement is that both PPP and GLP data frames contain control fields, address fields, flags, check sums, etc. Normally, all this information must be transferred from end to end. This overhead data of the link layer reduces the transmission capacity of user information.
According to the invention, this problem is avoided by m;n;m;zing the amount of control data transferred over the radio interface. This is carried out by removing a part, or preferably all, of the unnecessary fields from the PPP data frame before it is encapsulated in a GLP data frame. This is possible because the values of flag, address and control fields used in PPP data frames are constant, and thus contain no real information.
The check sum field FCS of the PPP data frame can also be omitted, because the GLP data frame uses its own check sum, by means of which errors occurring on the radio interface are detected and corrected. On the whole, the terminal equipment MS and the support node SN compress the PPP data frames before they are encapsulated in GLP data frames and transferred over the radio interface.
Correspondingly, the terminal equipment MS and the support node SN decompress the compressed PPP data frames transferred over the radio interface by removing them from the GLP data frames, adding the removed fields thereto, the contents of these fields being constant and thus known, and by calculating a new check sum for the returned PPP data frame by a known check sum calculation algorithm.
The encapsulation, compression, decompression and de-encapsulation stages of the invention are illustrated WO96/2l984 PCT ~ "~~~20 in Figure 4. In Figure 4A, the terminal equipment MS
receives a data frame according to the protocol used by the application associated with said terminal equipment, for instance an X.25 frame (or an IP frame or some other ~ 5 frame). The terminal equipment MS performs an encapsulation by inserting the X.25 data frame in the data field of a PPP data frame, as shown in Figure 4B. At the same time, a value in the protocol field PROTOCOL of the PPP data frame is set to indicate the protocol of the encapsulated data packet, i.e. X.25. Thereafter, the terminal equipment MS compresses the PPP data frame by removing therefrom the flag, address, control and check sum fields. The resulting compressed PPP data frame, shown in Figure 4C, is encapsulated by inserting it in the data field of a GLP data frame, as shown in Figure 4D. The GLP
data frame is transferred from the terminal equipment MS
over the radio interface to a base station BTS and routed therefrom further through the mobile communication network to the support node SN which serves the current cell of the MS. In Figure 4E, the support node SN removes the compressed PPP data frame from the GLP data frame according to Figure 4D and performs a decompression by returning to the PPP data frame the flag, address and control fields removed therefrom, the contents of these fields being constant. In addition, the support node SN
calculates a new check sum FCS for the PPP data frame formed in this manner by means of a calculation algorithm reserved for this purpose. The result is the decompressed PPP data frame according to Figure 4F. If the serving support node SN does not support the protocol indicated in the PROTOCOl field itself, it routes the PPP data frame forward to such a point in the GPRS network or in an external data network that supports said protocol. When the PPP data frame arrives in such a point, the encapsulation is stripped away by removing the X.25 frame CA 02209944 l997-07-09 WO 96/21984 PCT11il96/00020 from the data field of the PPP data frame. Thereafter, the X.25 frame is treated according to its own address and control fields.
If the serving support node SN supports the protocol indicated by the PROTOCOL field, the serving node strips the encapsulation away itself and delivers the X.25 frame forward on the basis of the control and address information of the X.25 frame.
The stages according to Figures 4A - 4G also appear in transmission taking place towards the terminal equipment MS. The encapsulation of the X.25 frame in a PPP
data frame takes place either in the serving node SN or in some place on the interface of the GPRS network and the external data network. The compression of the PPP data frame according to Figure 4C and the insertion of the compressed PPP frame in the GLP data frame according to Figure 4D are performed in the serving support node SN.
The decompression and the de-encapsulation according to Figures 4E, 4F and 4G are performed in the terminal equipment MS, whereafter the X.25 frame is forwarded to the application associated with the terminal equipment MS.
It should be noticed that the standard PPP
protocol has its own method for compressing fields. This method is optional so that the use of the compression can be negotiated during the link configuration procedure.
However, this standard PPP compression cannot be used in connection with the present invention.
The standard PPP protocol also includes a so-called byte stuffing protocol. Certain bit patterns, such as the contents reserved for the flag field, in the data field of a PPP frame are thus converted into a two-byte chain. This a way of ensuring that for instance these bit patterns reserved for the flag field do not appear anywhere else in the message and lead to malfunctions.
These stuffing bytes cause problems in the GPRS network, WO96/21984 PCTn~96/00020 however, since the amount of data transmitted over the air interface is not independent of the data but is related to the contents of the data. In the worst case, the length of the data may be twice the length it should be due to the - 5 stuffing bytes. Since the PPP data transmitted over the radio interface is in GLP frames in a GPRS network, such "forbidden" control bit patterns in the data field do not cause malfunctions, such as an erroneous detection of the start/stop of a frame, as in a serial line. Therefore, in the preferred embodiment of the invention, all stuffing bytes are removed at the compression stage before the transmission over the radio interface, and the stuffing bytes are returned at the decompression stage on the other side of the radio interface. The data can also be compressed by other methods, for instance by using the V42.bis method used in modems.
It is also possible to combine several PPP
packets in one GLP frame, which is transmitted over the radio interface, if the PPP packets are smaller than the size of the data field of the GLP packets. It is also possible to transmit one PPP packet in several GLP
packets.
It is also possible that the compression and/or decompression according to the invention are only performed in the gateway node, and the compressed data packets are forwarded via the support node serving the mobile station.
The figures and the description relating thereto are merely intended to illustrate the present invention.
In their details, the packet radio system and the terminal equipment of the invention may vary within the scope and spirit of the appended claims.
Claims (16)
1. A packet radio system comprising a digital mobile communication network;
at least one packet radio support node, connected to the mobile communication network and to one or more other packet radio support nodes and/or providing an access point to an external packet data network;
a packet data terminal equipment providing an access point for packet data transmission taking place over the radio interface, said access point supporting a universal communication protocol used by an application associated with the terminal equipment, c h a r a c t e r i z e d by using a point-to-point protocol independent of said universal communication protocol in the internal transmission of the packet radio system, a data packet according to said point-to-point protocol containing the control fields used by the protocol, an identification field identifying the protocol used by the terminal equipment, and a data field, a data packet according to the universal protocol being thus encapsulated in the data field of a data packet according to the point-to-point.
protocol in the internal transmission of the packet radio system, using a special radio link protocol between the packet data terminal equipment and said at least one packet radio support node on the radio interface, said radio link protocol supporting point-to-multipoint addressing and the control of data packet retransmission, a data packet according to said radio link protocol containing the control fields used by the protocol and a data field, arranging the packet data terminal equipment and said at least one support node to compress a data packet according to the point-to-point protocol, transmitted over the radio interface, by removing therefrom at least one control field and to encapsulate the remaining fields in the data field of a data packet according to the radio link protocol, arranging the packet data terminal equipment and said at least one support node to decompress a compressed data packet according to the point-to-point protocol, received over the radio interface, by adding thereto the fields removed in the compression before the data packet is forwarded further.
at least one packet radio support node, connected to the mobile communication network and to one or more other packet radio support nodes and/or providing an access point to an external packet data network;
a packet data terminal equipment providing an access point for packet data transmission taking place over the radio interface, said access point supporting a universal communication protocol used by an application associated with the terminal equipment, c h a r a c t e r i z e d by using a point-to-point protocol independent of said universal communication protocol in the internal transmission of the packet radio system, a data packet according to said point-to-point protocol containing the control fields used by the protocol, an identification field identifying the protocol used by the terminal equipment, and a data field, a data packet according to the universal protocol being thus encapsulated in the data field of a data packet according to the point-to-point.
protocol in the internal transmission of the packet radio system, using a special radio link protocol between the packet data terminal equipment and said at least one packet radio support node on the radio interface, said radio link protocol supporting point-to-multipoint addressing and the control of data packet retransmission, a data packet according to said radio link protocol containing the control fields used by the protocol and a data field, arranging the packet data terminal equipment and said at least one support node to compress a data packet according to the point-to-point protocol, transmitted over the radio interface, by removing therefrom at least one control field and to encapsulate the remaining fields in the data field of a data packet according to the radio link protocol, arranging the packet data terminal equipment and said at least one support node to decompress a compressed data packet according to the point-to-point protocol, received over the radio interface, by adding thereto the fields removed in the compression before the data packet is forwarded further.
2. A packet radio system according to claim 1, c h a r a c t e r i z e d in that said at least one support node comprises a support node serving the mobile station and a gateway support node, which provides an access point towards an external packet data network, and that said compression and decompression are performed in the gateway support node on data packets which are forwarded via the support node serving the mobile station.
3. A packet radio system according to claim 1 or 2, c h a r a c t e r i z e d in that the point-to-point protocol comprises a protocol identification field, data field, check sum field, and constant address, control and flag fields.
4. A packet radio system according to claim 3, c h a r a c t e r i z e d in that said point-to-point protocol is essentially the point-to-point protocol PPP
according to standards RFC 1661 and 1662.
according to standards RFC 1661 and 1662.
5. A packet radio system according to claim 3 or 4, c h a r a c t e r i z e d in that the compression in the packet data terminal equipment or in said at least one support node comprises the removal of at least one constant field from a packet according to the point-to-point protocol, the decompression in the packet data terminal equipment and in said at least one node comprises the returning of the removed constant fields to the packet according to the point-to-point protocol.
6. A packet radio system according to claim 3, 4 or 5, c h a r a c t e r i z e d in that the compression in the packet data terminal equipment or in said at least one support node also comprises the removal of the check sum field from a packet according to the point-to-point protocol, the packet data terminal equipment and said at least one node comprise a calculation algorithm for calculating a check sum field according to the point-to-point protocol, the decompression in the packet data terminal equipment and in said at least one node comprises the returning of the removed constant fields to the packet according to the point-to-point protocol, and thereafter, the calculation of a check sum field by means of said calculation algorithm.
7. A packet data radio system according to any one of the preceding claims, c h a r a c t e r i z e d in that the compression in the packet data terminal equipment or in said at least one support node also comprises the removal of stuffing bytes from the data field of a packet according to the point-to-point protocol, the decompression in the packet data terminal equipment and in said at least one node comprises the adding of the removed stuffing bytes to the data field of a data packet according to the point-to-point protocol.
8. A packet data radio system according to any one of the preceding claims, c h a r a c t e r i z e d in that the compression in the packet data terminal equipment or in said at least one support node comprises the encapsulation of two or more data packets according to the point-to-point protocol in a compressed form in one data packet according to the radio link protocol.
9. A packet radio system according to any one of the claims 1 to 7, c h a r a c t e r i z e d in that the compression in the packet data terminal equipment or in said at least one support node comprises the division of a data packet according to the point-to-point protocol in a compressed form into two or more data packets according to the radio link protocol.
10. A packet radio system according to claim 1 or 2, c h a r a c t e r i z e d in that a data packet according to the protocol used by the application, said data packet being encapsulated in a data packet according to the point-to-point protocol in the data terminal equipment, is de-encapsulated in such a point of the packet radio system or the external data network that supports the protocol indicated by said protocol identification field.
11. A packet radio system according to claim 1, c h a r a c t e r i z e d in that a data packet according to the protocol used by the application is also compressed by using generally used compression methods, such as the V.21.bis algorithm.
12. A terminal equipment for a packet radio system, said terminal equipment providing an access point for packet data transmission taking place over the radio interface, said access point supporting a universal communication protocol used by the application associated with the terminal equipment, c h a r a c t e r i z e d in that the terminal equipment uses a point-to-point protocol independent of said universal communication protocol in the internal transmission of the packet radio system, a data packet according to said point-to-point protocol containing the control fields used by the protocol, an identification field identifying the protocol used by the terminal equipment, and a data field, the terminal equipment uses, in the transmission taking place over the radio interface, a special radio link protocol used in the inter-nodal transmission of the packet radio system, said protocol supporting point-to-multipoint addressing and the control of data packet retransmission, a data packet according to said radio link protocol containing the control fields used by the protocol and a data field, the terminal equipment is arranged to encapsulate a transmitted data packet according to the universal protocol in the data field of a data packet according to said point-to-point protocol, the terminal equipment is arranged to compress a data packet according to the point-to-point protocol, transmitted over the radio interface, by removing therefrom at least one control field and to encapsulate the remaining fields in a data packet according to the radio link protocol, the terminal equipment is arranged to decompress a compressed data packet according to the point-to-point protocol, received over the radio interface, by adding thereto the fields removed in the compression, the terminal equipment is arranged to release a data packet according to the universal protocol from a decompressed data packet according to the point-to-point protocol.
13. A terminal equipment according to claim 12, c h a r a c t e r i z e d in that said point-to-point protocol is essentially the point-to-point protocol PPP
according to standards RFC 1661 and 1662.
according to standards RFC 1661 and 1662.
14. A terminal equipment according to claim 12 or 13, c h a r a c t e r i z e d in that said point-to-point protocol comprises a protocol identification field, data field, check sum field, and constant address, control and flag fields.
15. A packet radio system according to claim 14, c h a r a c t e r i z e d in that the compression comprises the removal of at least one fixed-value field from a packet according to the point-to-point protocol, the decompression comprises the returning of the removed fixed-value fields to a packet according to the point-to-point protocol.
16. A packet radio system according to claim 14 or 15, c h a r a c t e r i z e d in that the compression in the packet data terminal equipment or in said at least one support node also comprises the removal of the check sum field from a packet according to the point-to-point protocol, the packet data terminal equipment and said at least one node comprise a calculation algorithm for calculating a check sum field according to the point-to-point protocol, the decompression in the packet data terminal equipment and in said at least one node comprises the returning of the removed constant fields to the packet according to the point-to-point protocol, and thereafter, the calculation of a check sum field by means of said calculation algorithm.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI950117 | 1995-01-10 | ||
| FI950117A FI98027C (en) | 1995-01-10 | 1995-01-10 | Packet radio system and terminal equipment for a packet radio system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2209944A1 true CA2209944A1 (en) | 1996-07-18 |
Family
ID=8542251
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002209944A Abandoned CA2209944A1 (en) | 1995-01-10 | 1996-01-08 | Packet radio system, and a terminal equipment for a packet radio system |
Country Status (10)
| Country | Link |
|---|---|
| US (1) | US5978386A (en) |
| EP (1) | EP0804845B1 (en) |
| JP (1) | JPH10512120A (en) |
| AT (1) | ATE437501T1 (en) |
| AU (1) | AU699246B2 (en) |
| CA (1) | CA2209944A1 (en) |
| DE (1) | DE69637972D1 (en) |
| FI (1) | FI98027C (en) |
| NO (1) | NO973176L (en) |
| WO (1) | WO1996021984A2 (en) |
Families Citing this family (142)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7936664B2 (en) | 1991-03-26 | 2011-05-03 | Nokia Corporation | Multi-carrier radio link protocol supervision in a radio communication system |
| US7298701B2 (en) | 2002-10-31 | 2007-11-20 | Nokia Corporation | Apparatus, and associated method, for requesting data retransmission in a packet radio communication system |
| FI101921B (en) * | 1996-06-07 | 1998-09-15 | Nokia Telecommunications Oy | Implementation of ATM virtual channels in a packet network |
| US5905719A (en) * | 1996-09-19 | 1999-05-18 | Bell Communications Research, Inc. | Method and system for wireless internet access |
| WO1998026557A1 (en) * | 1996-12-10 | 1998-06-18 | Ntt Mobile Communications Network Inc. | Mobile communication device, mobile data communication method, and recording medium |
| JP3735168B2 (en) * | 1996-12-11 | 2006-01-18 | 富士通株式会社 | Simple routing method |
| US6137791A (en) * | 1997-03-25 | 2000-10-24 | Ericsson Telefon Ab L M | Communicating packet data with a mobile station roaming within an incompatible mobile network |
| IT1293882B1 (en) * | 1997-04-14 | 1999-03-11 | Sip | DEVICE AND PROCEDURE FOR THE TRANSMISSION OF DIGITAL SIGNALS, ESPECIALLY ON DECT SYSTEMS. |
| US6393014B1 (en) | 1997-06-03 | 2002-05-21 | At&T Wireless Services, Inc. | Method and system for providing data communication with a mobile station |
| US6122263A (en) * | 1997-06-10 | 2000-09-19 | Telefonaktiebolaget Lm Ericsson | Internet access for cellular networks |
| US6694372B1 (en) * | 1997-06-17 | 2004-02-17 | Advanced Micro Devices, Inc. | Method and system for effective network communication of an unsupported media standard by encapsulated packet tagging |
| US6396820B1 (en) * | 1997-06-24 | 2002-05-28 | Lucent Technologies Inc. | Wireless telecommunications system for improving performance and compatibility |
| DE19728033A1 (en) * | 1997-07-01 | 1999-01-07 | Alsthom Cge Alcatel | Mobile network with connection device for connection to communication networks |
| US6405049B2 (en) * | 1997-08-05 | 2002-06-11 | Symbol Technologies, Inc. | Portable data terminal and cradle |
| FI105874B (en) | 1997-08-12 | 2000-10-13 | Nokia Mobile Phones Ltd | Multiple mobile broadcasting |
| GB2329550A (en) * | 1997-09-22 | 1999-03-24 | Northern Telecom Ltd | Transporting multi-protocol datagrams over an asynchronous virtual channel |
| US6512754B2 (en) * | 1997-10-14 | 2003-01-28 | Lucent Technologies Inc. | Point-to-point protocol encapsulation in ethernet frame |
| US6577643B1 (en) * | 1997-10-14 | 2003-06-10 | Lucent Technologies Inc. | Message and communication system in a network |
| FI105760B (en) * | 1997-10-30 | 2000-09-29 | Nokia Mobile Phones Ltd | Cellular Subnet Dependent Convergence Protocol |
| US6876634B1 (en) * | 1997-11-26 | 2005-04-05 | Lg Information & Communications, Ltd. | Architecture of mobile communication systems network and method for transmitting packet data using the same |
| DE69822516T2 (en) | 1997-12-17 | 2005-02-03 | British Telecommunications Public Ltd. Co. | MOBILE DATENLEITWEG |
| WO1999031846A1 (en) | 1997-12-17 | 1999-06-24 | British Telecommunications Public Limited Company | Proxy routing |
| KR100272567B1 (en) * | 1997-12-31 | 2000-11-15 | 서평원 | Mobile Internet in Mobile Communication Network |
| DE19800772C2 (en) * | 1998-01-12 | 2000-04-06 | Ericsson Telefon Ab L M | Method and device for connection to a packet exchange network |
| KR100281083B1 (en) * | 1998-01-23 | 2001-02-01 | 서평원 | Method of Performing Wireless Data Communication Between the Mobile Data Cellular-Phone |
| US6208633B1 (en) * | 1998-02-05 | 2001-03-27 | Telefonaktiebolaget Lm Ericsson | System and method for mobile data services |
| US6192041B1 (en) * | 1998-02-18 | 2001-02-20 | Qualcomm Incorporated | Transmission of data packets over CDMA type cellular telephone |
| DE19818006A1 (en) * | 1998-04-22 | 1999-10-28 | Siemens Ag | Periphery apparatus for interactive message exchange in intelligent network |
| GB2383504A (en) * | 1998-06-03 | 2003-06-25 | Orange Personal Comm Serv Ltd | A video telephone for conferencing |
| DE19849578A1 (en) * | 1998-10-27 | 2000-01-13 | Siemens Ag | Method and cellular network for handling a packet data service |
| EP0975123A1 (en) * | 1998-07-15 | 2000-01-26 | Telefonaktiebolaget L M Ericsson (Publ) | Communication device and method for reliable and low-delay packet transmission |
| FI106503B (en) * | 1998-09-21 | 2001-02-15 | Nokia Networks Oy | IP mobility mechanism for packet radio network |
| US6233718B1 (en) | 1998-10-19 | 2001-05-15 | Dolby Laboratories Licensing Corporation | Avoiding forbidden data patterns in coded audio data |
| WO2000027077A1 (en) * | 1998-11-03 | 2000-05-11 | Motorola Inc. | Combined mobile and information network communication system |
| CA2349251A1 (en) * | 1998-11-06 | 2000-05-18 | Telefonaktiebolaget Lm Ericsson | Layer 2 tunneling for data communications in wireless networks |
| US6539237B1 (en) * | 1998-11-09 | 2003-03-25 | Cisco Technology, Inc. | Method and apparatus for integrated wireless communications in private and public network environments |
| FI982490A0 (en) | 1998-11-18 | 1998-11-18 | Nokia Corp | Procedures and systems for communication |
| US6434140B1 (en) * | 1998-12-04 | 2002-08-13 | Nortel Networks Limited | System and method for implementing XoIP over ANSI-136-A circuit/switched/packet-switched mobile communications networks |
| EP1014641A1 (en) | 1998-12-22 | 2000-06-28 | Telefonaktiebolaget Lm Ericsson | Method and system for reducing the processing time of data in communication networks |
| FI106499B (en) * | 1998-12-29 | 2001-02-15 | Nokia Networks Oy | Data transfer method and network elements |
| FI106591B (en) * | 1999-01-15 | 2001-02-28 | Nokia Mobile Phones Ltd | Method of transmitting data transfer flows |
| US6587441B1 (en) * | 1999-01-22 | 2003-07-01 | Technology Alternatives, Inc. | Method and apparatus for transportation of data over a managed wireless network using unique communication protocol |
| US6721555B1 (en) * | 1999-02-19 | 2004-04-13 | Qualcomm Incorporated | System and method for facilitating device authentication in a wireless communications system |
| US6370118B1 (en) * | 1999-02-24 | 2002-04-09 | Qualcomm Incorporated | Simultaneous set up of PPP on AUM and a RM interface |
| WO2000057284A1 (en) * | 1999-03-25 | 2000-09-28 | Motorola Inc. | Point to point protocol multiplexing/demultiplexing method and apparatus |
| AU4603800A (en) | 1999-05-10 | 2000-11-21 | Nokia Networks Oy | Header compression |
| GB2352929A (en) * | 1999-05-24 | 2001-02-07 | Nec Corp | Packet handling in a mobile network |
| EP1056258A1 (en) * | 1999-05-27 | 2000-11-29 | TELEFONAKTIEBOLAGET L M ERICSSON (publ) | Data unit sending means and control method in wireless networks |
| KR20000075358A (en) * | 1999-05-27 | 2000-12-15 | 윤종용 | Variable-length data transmitting and receiving apparatus in accordance with radio link protocol for a mobile telecommunication system and method thereof |
| US6542504B1 (en) * | 1999-05-28 | 2003-04-01 | 3Com Corporation | Profile based method for packet header compression in a point to point link |
| GB9913102D0 (en) | 1999-06-04 | 1999-08-04 | Nokia Telecommunications Oy | An element for a communications system |
| US7062574B1 (en) * | 1999-07-01 | 2006-06-13 | Agere Systems Inc. | System and method for selectively detaching point-to-point protocol header information |
| US6377556B1 (en) * | 1999-07-14 | 2002-04-23 | Qualcomm Incorporated | Method and apparatus to resynchronize ppp on um interface without affecting ppp on a rm interface and to resynchronize ppp on a rm interface without affecting ppp on a um interface |
| US6625164B1 (en) * | 1999-07-14 | 2003-09-23 | Qualcomm, Incorporated | Selectively framing and unframing PPP packets depending on negotiated options on the Um and Rm interfaces |
| JP2003529232A (en) * | 1999-08-02 | 2003-09-30 | クゥアルコム・インコーポレイテッド | Cell Broadcast in Hybrid GSM / CDMA Network |
| EP1079643A1 (en) * | 1999-08-23 | 2001-02-28 | Lucent Technologies Inc. | Improved GTP header |
| US6934276B1 (en) * | 1999-09-08 | 2005-08-23 | Qualcomm Inc | Methods for efficient early protocol detection |
| US6853648B1 (en) * | 1999-09-08 | 2005-02-08 | Telefonaktiebolaget Lm Ericsson (Publ) | Method, apparatus, and system for enabling communication between second generation and third generation packet data networks |
| WO2001019027A2 (en) * | 1999-09-08 | 2001-03-15 | Qualcomm Incorporated | Methods for efficient early protocol detection |
| DE19944334C1 (en) * | 1999-09-15 | 2000-12-21 | Bosch Gmbh Robert | Mobile radio network operating method has data delivered from user and accompanying protocol control information compressed in first convergence protocol layer before grouping into protocol data units |
| KR100367657B1 (en) | 1999-09-21 | 2003-01-10 | 가부시키가이샤 엔.티.티.도코모 | Data conversion apparatus, signal, data conversion method, dce, gateway and communication apparatus |
| US6370399B1 (en) * | 1999-09-29 | 2002-04-09 | Qualcomm Incorporated | Determination of mobile service option via phone number |
| JP3387041B2 (en) | 1999-09-30 | 2003-03-17 | 富士通株式会社 | Protocol conversion device, communication device, communication program storage medium, and communication system |
| DE19950653B4 (en) | 1999-10-21 | 2020-01-16 | Ipcom Gmbh & Co. Kg | Method for operating a cellular network |
| US6622019B1 (en) * | 1999-11-17 | 2003-09-16 | Eci Telecom, Ltd. | Increasing channel capacity in fixed cellular networks |
| US6577596B1 (en) * | 1999-11-30 | 2003-06-10 | Telefonaktiebolaget Ln Ericsson (Publ) | Method and apparatus for packet delay reduction using scheduling and header compression |
| DE19957642C2 (en) | 1999-11-30 | 2002-03-28 | Bosch Gmbh Robert | Method for transmitting data by means of radio transmission systems between transmitting / receiving stations and computer for assigning radio transmission systems for transmitting data between transmitting / receiving stations |
| FI19992593A (en) | 1999-12-02 | 2001-06-03 | Nokia Networks Oy | Call routing in a telecommunications system |
| US6879568B1 (en) | 1999-12-20 | 2005-04-12 | Cisco Technology, Inc. | Quick layer-3 message multiplexing |
| US6424639B1 (en) * | 1999-12-22 | 2002-07-23 | Qualcomm, Incorporated | Notifying a mobile terminal device of a change in point of attachment to an IP internetwork to facilitate mobility |
| DE10007012B4 (en) † | 2000-02-16 | 2010-07-01 | Ipcom Gmbh & Co. Kg | Method for bidirectional data transmission via a packet-oriented network device |
| US6718491B1 (en) * | 2000-03-06 | 2004-04-06 | Agilent Technologies, Inc. | Coding method and coder for coding packetized serial data with low overhead |
| DE10010974A1 (en) * | 2000-03-07 | 2001-09-13 | Bosch Gmbh Robert | Process for the transmission of data |
| US7469142B2 (en) * | 2000-04-28 | 2008-12-23 | Cisco Technology, Inc. | Method and apparatus for inter-cell handover in wireless networks using multiple protocols |
| DE60034319T2 (en) * | 2000-05-19 | 2007-12-20 | Lucent Technologies Inc. | System and method for real-time data transmission |
| DE60044999D1 (en) * | 2000-05-19 | 2010-11-04 | Lucent Technologies Inc | Phone systems |
| US6665722B1 (en) * | 2000-05-31 | 2003-12-16 | Bbnt Solutions Llc | Store-and-forward packet radio system and method |
| JP3525869B2 (en) * | 2000-07-12 | 2004-05-10 | 日本電気株式会社 | Connection apparatus and method for packet communication system |
| DE10034687A1 (en) * | 2000-07-17 | 2002-02-07 | Siemens Ag | Method and transmission device for a communication system for transmitting data using a point-to-point protocol (SCTP) |
| US6879581B1 (en) * | 2000-08-22 | 2005-04-12 | Qualcomm Incorporated | Method and apparatus for providing real-time packetized voice and data services over a wireless communication network |
| KR100689473B1 (en) * | 2000-08-29 | 2007-03-08 | 삼성전자주식회사 | Apparatus and method for compressing protocol header in communication system |
| US7120172B1 (en) * | 2000-09-15 | 2006-10-10 | Lucent Technologies Inc. | Radio link protocol framing system for high speed data transfer over digital cellular mobile telecommunication networks |
| GB2367459A (en) * | 2000-09-28 | 2002-04-03 | Roke Manor Research | Method of compressing data packets |
| US20020064164A1 (en) * | 2000-10-06 | 2002-05-30 | Barany Peter A. | Protocol header construction and/or removal for messages in wireless communications |
| DE20018926U1 (en) * | 2000-11-07 | 2001-02-01 | Walter Andre | Universal platform for GPRS / UMTS services |
| US7046646B2 (en) * | 2001-01-29 | 2006-05-16 | Ipr Licensing, Inc. | Method and apparatus for simple PPP handoff for mobile users |
| GB2371954B (en) * | 2001-02-01 | 2003-02-19 | 3Com Corp | Interface system for wireless node and network node |
| JP3543322B2 (en) * | 2001-02-02 | 2004-07-14 | 日本電気株式会社 | Mobile communication system and data transfer method in mobile communication system |
| BR0208493A (en) * | 2001-03-28 | 2005-12-13 | Qualcomm Inc | Power control for point-to-multipoint services provided in communication systems |
| US8121296B2 (en) | 2001-03-28 | 2012-02-21 | Qualcomm Incorporated | Method and apparatus for security in a data processing system |
| US7693508B2 (en) * | 2001-03-28 | 2010-04-06 | Qualcomm Incorporated | Method and apparatus for broadcast signaling in a wireless communication system |
| US8077679B2 (en) | 2001-03-28 | 2011-12-13 | Qualcomm Incorporated | Method and apparatus for providing protocol options in a wireless communication system |
| US9100457B2 (en) | 2001-03-28 | 2015-08-04 | Qualcomm Incorporated | Method and apparatus for transmission framing in a wireless communication system |
| US7039033B2 (en) * | 2001-05-07 | 2006-05-02 | Ixi Mobile (Israel) Ltd. | System, device and computer readable medium for providing a managed wireless network using short-range radio signals |
| US6909714B2 (en) | 2001-07-03 | 2005-06-21 | Qualcomm Incorporated | Method and apparatus for determining configuration options negotiated for a communications link employing a network model |
| US20040081129A1 (en) * | 2001-08-17 | 2004-04-29 | Amit Haller | Device, system, method and computer readable medium for selectively attaching to a cellular data service |
| US20050030917A1 (en) * | 2001-08-17 | 2005-02-10 | Amit Haller | Device, system, method and computer readable medium obtaining a network attribute, such as a DNS address, for a short distance wireless network |
| US7016334B2 (en) * | 2001-08-17 | 2006-03-21 | Ixi Mobile ( Israel) Ltd. | Device, system, method and computer readable medium for fast recovery of IP address change |
| US7295532B2 (en) * | 2001-08-17 | 2007-11-13 | Ixi Mobile (R & D), Ltd. | System, device and computer readable medium for providing networking services on a mobile device |
| US20040125762A1 (en) * | 2001-08-17 | 2004-07-01 | Amit Haller | Device, system, method and computer readable medium for attaching to a device identifited by an access point name in a wide area network providing particular services |
| US7697523B2 (en) * | 2001-10-03 | 2010-04-13 | Qualcomm Incorporated | Method and apparatus for data packet transport in a wireless communication system using an internet protocol |
| US7352868B2 (en) | 2001-10-09 | 2008-04-01 | Philip Hawkes | Method and apparatus for security in a data processing system |
| US7649829B2 (en) | 2001-10-12 | 2010-01-19 | Qualcomm Incorporated | Method and system for reduction of decoding complexity in a communication system |
| US6957045B2 (en) | 2001-10-26 | 2005-10-18 | Ixi Mobile (Israel) Ltd. | Device, system, computer readable medium and method for providing status information of devices in a short distance wireless network |
| US6845097B2 (en) | 2001-11-21 | 2005-01-18 | Ixi Mobile (Israel) Ltd. | Device, system, method and computer readable medium for pairing of devices in a short distance wireless network |
| US7013112B2 (en) * | 2001-12-18 | 2006-03-14 | Ixi Mobile (Israel) Ltd. | Method, system and computer readable medium for making a business decision in response to information from a short distance wireless network |
| US7016648B2 (en) * | 2001-12-18 | 2006-03-21 | Ixi Mobile (Israel) Ltd. | Method, system and computer readable medium for downloading a software component to a device in a short distance wireless network |
| US7729322B2 (en) | 2002-02-28 | 2010-06-01 | Qualcomm Incorporated | HDLC hardware accelerator |
| EP1359721A1 (en) * | 2002-04-30 | 2003-11-05 | Siemens Aktiengesellschaft | Method and apparatus for packet transfer in a communication system |
| KR100446508B1 (en) * | 2002-06-26 | 2004-09-04 | 삼성전자주식회사 | Apparatus for processing packet data in a packet data communication system |
| US6909878B2 (en) | 2002-08-20 | 2005-06-21 | Ixi Mobile (Israel) Ltd. | Method, system and computer readable medium for providing an output signal having a theme to a device in a short distance wireless network |
| US7110371B2 (en) | 2002-08-28 | 2006-09-19 | Intel Corporation | System and method to communicate between a host and a modem |
| US7356571B2 (en) | 2002-10-07 | 2008-04-08 | Ixi Mobile (R&D), Ltd. | System, method and processor readable medium for downloading information within a predetermined period of time to a device in a network responsive to price selection |
| US7599655B2 (en) | 2003-01-02 | 2009-10-06 | Qualcomm Incorporated | Method and apparatus for broadcast services in a communication system |
| US7167680B2 (en) * | 2003-02-05 | 2007-01-23 | Ixi Mobile (Israel) Ltd. | Method, system and computer readable medium for adjusting output signals for a plurality of devices in a short distance wireless network responsive to a selected environment |
| US20040259585A1 (en) * | 2003-06-04 | 2004-12-23 | Avi Yitzchak | Wireless device having dual bus archeticure for interfacing with cellular signals and short-range radio signals |
| US8098818B2 (en) | 2003-07-07 | 2012-01-17 | Qualcomm Incorporated | Secure registration for a multicast-broadcast-multimedia system (MBMS) |
| US8718279B2 (en) | 2003-07-08 | 2014-05-06 | Qualcomm Incorporated | Apparatus and method for a secure broadcast system |
| US7366901B2 (en) * | 2003-08-01 | 2008-04-29 | Ixi Mobile (R&D), Ltd. | Device, system, method and computer readable medium for identifying and authenticating a cellular device using a short-range radio address |
| US8724803B2 (en) | 2003-09-02 | 2014-05-13 | Qualcomm Incorporated | Method and apparatus for providing authenticated challenges for broadcast-multicast communications in a communication system |
| JP4143547B2 (en) * | 2004-01-21 | 2008-09-03 | Ｎｅｃアクセステクニカ株式会社 | Data communication system |
| SE528195C2 (en) * | 2004-07-14 | 2006-09-19 | Teliasonera Ab | Method and device in a telecommunication system |
| US8964765B2 (en) * | 2004-11-12 | 2015-02-24 | Broadcom Corporation | Mobile handheld multi-media gateway and phone |
| JP3993869B2 (en) * | 2004-12-06 | 2007-10-17 | 株式会社エヌ・ティ・ティ・ドコモ | Data conversion device, signal, data conversion method, DCE, and gateway |
| US7446678B2 (en) * | 2005-04-18 | 2008-11-04 | Research In Motion Limited | Method and system for encoding communications between wireless and other devices |
| KR100923391B1 (en) | 2005-06-21 | 2009-10-23 | 주식회사 케이티 | Inter-network connection relay device and method for different kind of networks |
| US8284711B2 (en) * | 2005-06-28 | 2012-10-09 | Worcester Polytechnic Institute | Apparatus and methods for addressable communication using voice-grade radios |
| US7899004B2 (en) * | 2005-08-22 | 2011-03-01 | Qualcomm Incorporated | Distributed protocol over a wireless connection |
| US7975071B2 (en) * | 2008-01-18 | 2011-07-05 | Microsoft Corporation | Content compression in networks |
| US7793001B2 (en) * | 2008-05-09 | 2010-09-07 | Microsoft Corporation | Packet compression for network packet traffic analysis |
| KR101649764B1 (en) * | 2009-04-10 | 2016-08-19 | 삼성전자주식회사 | Method and apparatus for providing mobile advertising service in mobile advertising system |
| US9083708B2 (en) | 2010-05-17 | 2015-07-14 | Microsoft Technology Licensing, Llc | Asymmetric end host redundancy elimination for networks |
| JP2012099933A (en) * | 2010-10-29 | 2012-05-24 | Fujitsu Ltd | Electronic device, image management method, and image management program |
| RU2491719C1 (en) * | 2012-02-06 | 2013-08-27 | Общество с ограниченной ответственностью "Интеллектуальные технологии мониторинга" (ООО "Интеллектуальные технологии мониторинга") | Method and apparatus for transmitting and receiving information over power supply networks |
| WO2014134538A1 (en) | 2013-02-28 | 2014-09-04 | Xaptum, Inc. | Systems, methods, and devices for adaptive communication in a data communication network |
| US11057352B2 (en) | 2018-02-28 | 2021-07-06 | Xaptum, Inc. | Communication system and method for machine data routing |
| US10965653B2 (en) | 2018-03-28 | 2021-03-30 | Xaptum, Inc. | Scalable and secure message brokering approach in a communication system |
| US10805439B2 (en) | 2018-04-30 | 2020-10-13 | Xaptum, Inc. | Communicating data messages utilizing a proprietary network |
| US10924593B2 (en) | 2018-08-31 | 2021-02-16 | Xaptum, Inc. | Virtualization with distributed adaptive message brokering |
| US10938877B2 (en) | 2018-11-30 | 2021-03-02 | Xaptum, Inc. | Optimizing data transmission parameters of a proprietary network |
| US10912053B2 (en) | 2019-01-31 | 2021-02-02 | Xaptum, Inc. | Enforcing geographic restrictions for multitenant overlay networks |
| JP6762546B1 (en) * | 2019-07-12 | 2020-09-30 | 多摩川精機株式会社 | Serial communication method and serial communication system |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4755992A (en) * | 1986-06-06 | 1988-07-05 | Racal Data Communications Inc. | Transparent packet access over d-channel of ISDN |
| US5157672A (en) * | 1989-03-15 | 1992-10-20 | Nec Corporation | Interference detection apparatus for use in digital mobile communications system |
| DE3910739C3 (en) * | 1989-04-03 | 1996-11-21 | Deutsche Forsch Luft Raumfahrt | Method for generalizing the Viterbi algorithm and means for performing the method |
| GB2232854A (en) * | 1989-06-06 | 1990-12-19 | Marconi Gec Ltd | Determining channel quality |
| SE465697B (en) * | 1989-09-19 | 1991-10-14 | Ericsson Telefon Ab L M | PROVIDED IN A DIGITAL RADIO TRANSMISSION SYSTEM FOR TRANSMISSION OF SIGNALS BETWEEN SENDING AND RECEIVING RADIO STATION ALSTRA GOODS FOR THE RECEIVING RADIO STATION RECEIVED BINARY FIGURES |
| US5144644A (en) * | 1989-10-13 | 1992-09-01 | Motorola, Inc. | Soft trellis decoding |
| US5446736A (en) * | 1993-10-07 | 1995-08-29 | Ast Research, Inc. | Method and apparatus for connecting a node to a wireless network using a standard protocol |
| AU2902095A (en) * | 1994-06-24 | 1996-01-19 | Metricom, Inc. | Method for using point-to-point protocol over an imperfect mesh network |
| US5535199A (en) * | 1994-09-06 | 1996-07-09 | Sun Microsystems, Inc. | TCP/IP header compression X.25 networks |
-
1995
- 1995-01-10 FI FI950117A patent/FI98027C/en active IP Right Grant
-
1996
- 1996-01-08 AT AT96900337T patent/ATE437501T1/en not_active IP Right Cessation
- 1996-01-08 EP EP96900337A patent/EP0804845B1/en not_active Expired - Lifetime
- 1996-01-08 WO PCT/FI1996/000020 patent/WO1996021984A2/en active Application Filing
- 1996-01-08 DE DE69637972T patent/DE69637972D1/en not_active Expired - Lifetime
- 1996-01-08 JP JP8521460A patent/JPH10512120A/en active Pending
- 1996-01-08 CA CA002209944A patent/CA2209944A1/en not_active Abandoned
- 1996-01-08 US US08/860,827 patent/US5978386A/en not_active Expired - Lifetime
- 1996-01-08 AU AU43929/96A patent/AU699246B2/en not_active Ceased
-
1997
- 1997-07-09 NO NO973176A patent/NO973176L/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| JPH10512120A (en) | 1998-11-17 |
| NO973176D0 (en) | 1997-07-09 |
| NO973176L (en) | 1997-09-09 |
| FI950117A (en) | 1996-07-11 |
| EP0804845A2 (en) | 1997-11-05 |
| DE69637972D1 (en) | 2009-09-03 |
| ATE437501T1 (en) | 2009-08-15 |
| FI98027C (en) | 1997-03-25 |
| WO1996021984A2 (en) | 1996-07-18 |
| EP0804845B1 (en) | 2009-07-22 |
| AU4392996A (en) | 1996-07-31 |
| FI98027B (en) | 1996-12-13 |
| WO1996021984A3 (en) | 1996-09-12 |
| US5978386A (en) | 1999-11-02 |
| AU699246B2 (en) | 1998-11-26 |
| FI950117A0 (en) | 1995-01-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5978386A (en) | Packet radio system, and a terminal equipment for a packet radio system | |
| US6400712B1 (en) | Fast circuit switched data architecture and method | |
| CA2329457C (en) | Header compression for general packet radio service tunneling protocol (gtp)-encapsulated packets | |
| EP0804844B1 (en) | Packet radio system and methods for a protocol-independent routing of a data packet in packet radio networks | |
| KR100642116B1 (en) | Simultaneous setup of ppp on a um and rm interface | |
| US6229823B1 (en) | System and method for the compression of proprietary encapsulations | |
| CA2384162C (en) | Methods for efficient early protocol detection | |
| EP1238510B1 (en) | Data call routing on ip connections | |
| KR100689473B1 (en) | Apparatus and method for compressing protocol header in communication system | |
| EP1142236B1 (en) | A data transmission method and a network element | |
| CN1169806A (en) | Package radio system, and terminal equipment for a package radio system | |
| RU2438243C2 (en) | Method and apparatus for providing levels with multiple quality of service indicators in wireless packet data transmission connections | |
| US20030156571A1 (en) | Communications network and method for framing point-to-point frame structures | |
| KR100746866B1 (en) | Methods for efficient early protocol detection |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |