DE10346086B4 - Method for data communication between a user's mobile data terminal (ME) and a destination data network - Google Patents

Abstract

A method for data communication between a mobile terminal (ME) of a user (54, 56) and a destination data network (18, 32), the mobile terminal (ME) having transmitting and receiving means adapted to communicate user and management data with a first one Transmitter and receiver devices (4) of a local area network (2, 20) of an access provider to exchange and the local area network further comprises second transmitting and receiving devices (ZNK, 30) which are suitable, utility and administrative data via a public network (18) exchanged with the destination data network (18, 32), subscriber-specific data records being stored at a first service provider (DLA1), the service provider of the user, in particular his mobile operator, and wherein a second service provider (DLA2) is the contract partner of the access provider,
characterized,
that the user's fees incurred for the use of the access provider's local area network are calculated by the first service provider (DLA1),
a first network element (NE1) is present in the access area of the first service provider (DLA1),
which has access to the subscriber-specific data records, ...

Description

The The invention relates to a method for data communication between a mobile data terminal (ME) of a user and a destination data network, after the generic term of claim 1 and components and control programs for carrying out the Process.

mobile Data communication in which a user uses telecommunications services mobile terminal from different geographical locations especially in the business environment but also increasingly important in the private sphere. It goes the tendency - independent of the nature of the transfer Data, including Language, towards packet data communication. It compares to switched and switched connections much more efficient with the needed Resources around. In addition, it allows higher transmission rates.

It There are several types of public access networks over which a user can operate mobile data communication. In addition to radio networks such as GSM (Global System for Mobile Communications) with GPRS (General Packet Radio Service) and / or UMTS (Universal Mobile Communication System), those of big ones Telecommunications providers are operated, there are wired Additions, which are offered by many hotels and usually the ethernet Standard (IEEE 802.3), and small wireless networks based on technologies such as WLAN (IEEE 802.11, Wireless Local Area Network) or Bluetooth based. Potential access providers of small wireless networks are, for example the operators of airports, Fairs, hotels, restaurants and others publicly accessible Institutions. These local data networks of an access provider, which may be radio networks or wireline networks, have opposite to the huge Mobile networks usually speed advantages. That's what they are for only locally accessible.

at a data communication of a user of such a local Data network, the transmission takes place first from the mobile device the user in the local area network to a data transmission device of the access provider. The connection of these local data transmission devices to the Internet is usually via data lines such as DSL or 2 Mbit leased lines.

packet data are commonly used today over the Internet promoted. Each package passes on average between 11 and 15 intermediate stations, so-called hops. These hops can skip national borders, if sender and receiver stay in the same country. The hops are different Controlled by service providers.

For data security is in IP (Internet Protocol) networks usually the user self-responsible. Only for certain services, the service is provided by the provider. exceptions are the radio links in the public digital Mobile networks. They are in contrast to the old analog mobile networks via a special encryption between terminal or the SIM (Subscriber Identity Module) contained therein Secured card and the network elements of the mobile service providers. These, network-controlled encryption is optional, but in practice everywhere used.

The Situation for small public WLAN networks, so-called hotspots, is different. Although exists Again, a standardized in IEEE 802.11 encryption option on the so-called WEP (Wired Equivalent Privacy) algorithm for the air interface, however, the encryption is weak and the algorithm therefore uncertain. This weighs heavier, as WLAN networks in contrast to conventional digital mobile networks through normal terminals abusively can be used. Even with advanced standards such. IEEE 802.11i introduces continue to face the problem of key exchange, because of the missing User authentication can only be solved manually. It would be straight a frequent change in WEP of the key necessary, to alleviate the problems.

Next the backup of the data are in contrast to the big public ones Networks with the local data networks also the topics billing, automatic Cost control and legal telecommunications monitoring not or only insufficiently implemented.

• 1 Eine praktikable und sichere Lösung für die Gebührenerfassung und Abrechnung;
• 2 Geringe Kosten;
• 3 Einfache Bedienbarkeit durch den Anwender;
• 4 Sicherheit der übertragenen Daten.

Basic requirements for a method for data communication are from the perspective of the user:

• 1 A workable and secure solution for billing and billing;
• 2 low costs;
• 3 Easy to use by the user;
• 4 security of transmitted data.

Out The view of the access provider of the local data network should be reliable Protection against misuse as well as safe and simple solutions for the calculation of fees and the fee collection be given.

Further demands on data networks are made by legislators demanding that authorized authorities prevent and prosecute them offenses can monitor the traffic of certain users. A fundamental problem here is that a multitude of prerequisites such as the reliable identification of the users, the operation of the various interfaces with the authorities and the qualification of the discharging body, for example by means of certification, are necessary.

It there are several approaches at least to solve the problems of access providers. So Methods and systems are known in which the user of the access provider provided a specific access hardware for the local network becomes. Here, e.g. a hotel offers its guests special network cards (WLAN cards) available the user to one for it at his mobile data terminal plugged in slot (PCMCIA slot). The billing These systems are either flat rate or over the period of time the data connection. The system only provides network hardware certain MAC addresses access. MAC address stands for "Media Access Control address "and labeled a hardware address that uniquely identifies each node of an IP network identified.

The Main disadvantages of this solution are the high price and the high administrative costs. This solution is even limited applicable and also not sure because there are possibilities in the Communication used to manipulate MAC addresses. By the Increasing integration of WLAN hardware in laptops makes them obsolete.

at other methods are provided by the access provider of the local network a so-called WEP key (Wired Equivalent Privacy) to secure communication from and charged by credit or prepaid cards. Again, there is a relatively high administrative burden. Prepaid cards work specifically only with certain access providers from local networks; a user who is traveling while traveling would like to serve local data networks, needs accordingly a variety of prepaid cards, which only conditionally accepted. The use of credit cards in one Environment in which numbers may be poorly secured via a Transmit air interface be, carries high security risks. In addition, the anonymity of the user can across from the access provider of the local network.

Besides, they are also methods are known in which an access only to a certain, specified Internet provider possible is. The billing takes place over time and an account, the Internet provider led becomes.

These newer idea reduces the billing effort considerably. For that she restricts the possible Customer circle drastically and potential customers are dependent on the few local data networks that come from this Providers are offered.

The DE 10043203 A1 discloses a method in which subscriber data sets exchanged with a mobile service provider are used for billing the services of the access provider of the local area network. The user has a subscription both in the local data network of the access provider and in a mobile network. It can be compared to the user a common billing of mobile services and the services of the local access provider. The identification of the subscriber is based on data of the SIM card (Subscriber Identification Module.), Which is provided to the user by his mobile service provider. In this system, it is necessary for the user to carry his SIM card with him. The card must then be inserted into the local access provider in a SIM card reader, or the user must have facilities with which he can transfer the data of the SIM card to his mobile terminal, such as his laptop. Such devices may be, for example, infrared interfaces on the mobile phone and on the laptop.

The document "3GPP TS 23.234 V2.0.0 (2003-09). 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; 3GPP system to Wireless Local Area Network (WLAN) Interworking; System Description (Release 6) [online]. 3GPP, Sophia Antipolis Valbonne, France. September 2003 <URL:
http://www.3gpp.org/ftp/Specs/archive/23_ series / 23.234 / 23234-200.zip>"discloses a method of data communication between a user's mobile terminal and a destination data network, the mobile terminal being transmitted and transmitted Receiving devices, which are adapted to exchange user and management data with first transmitting and receiving devices of a local area network of an access provider and the local area network further comprises second transmitting and receiving devices, which are useful and administrative data over a public network with the destination data network subscriber-specific records are deposited with a service provider, in particular mobile operator of the user and charges incurred by the user for the use of the local data network of the access provider by its service provider become

Of the Invention is based on the object of specifying a method at a high data security is ensured, in which the Legislative requirements are easily met can, in which the fee calculation for all parties can be done safely and easily, and existing systems can be used with only minor adjustments. It should also be possible that a user of a mobile terminal in a simple way very much many different local data networks from different access providers can use.

The Invention is achieved by a method having the features of the main claim solved. Advantageous embodiments as well as components and control programs to carry out of the method are given by the dependent claims.

According to the invention So is in a generic method in the access area of the service provider DLA1, which is typically the mobile operator the user is a network element NE1 through which at least the entire user data is passed between the mobile data terminal ME of the user and the destination data network ZDN are exchanged.

The So data is not directly between the local data network of the Exchanged access provider and the target data network, but over the Network element at the service provider. Target data network can a public one Network like the internet or even a non-public one Corporate network.

At the Service providers thus have the ability to determine when a data network use has taken place by the user and which He transfers data volumes. Furthermore the network element at the service provider has access to subscriber-specific Data, in particular identity of the user and tariffs agreed with him. This information can then a fee calculation be based on.

Especially, if the service provider is a conventional provider of telecommunications services As is (for example, a mobile operator), it can be ensured that the Network element over the user data is routed in a secure way Environment stands. Corresponding security structures are in such Providers already exist due to legal regulations. On the other hand, this environment is also particularly suitable for the discharge of certain data to be monitored Users to authorities.

at In an advantageous embodiment of the invention, user data, which from the mobile data terminal of the user to the network element at the service provider be in the data terminal encoded and decrypted in the network element for the first time and in the opposite direction payload data, which is transmitted from the network element to the data terminal are encrypted in the network element and in the data terminal decrypted for the first time.

Thereby it is achieved that the user data in the network element is unencrypted, making access through authorized sites particularly easy is. Nevertheless, the payload on the data links between the Transmitting and receiving devices of the mobile terminal and the first transmitting and receiving means of the local area network (e.g. WLAN) and the data transmission links between the second transmitting and receiving means of the local area network and the public Network in encrypted State transmitted, so that a high data security can be achieved.

A Discharge of data to authorized agencies can be beneficial Way done by the fact that the network element via an interface to authorized body, that deposited with the service provider of the user subscriber-specific data records an exam the identity allow the user to and that depends on Result of an identity check of user data of the user the interface to the authorized body are discharged.

Especially, if the destination network is a nonpublic network such as Company network is that is used by multiple users it is advantageous if the payload of multiple users of the destination data network between the network element and the destination data network via a common secured tunnel to be transferred.

Usually, so-called IPSec routers are used in company networks. IPSec (Internet Protocol Security) is a family of protocols that describes secure encrypted traffic over computer networks. IPSec provides a so-called tunnel for the communication partners, in which the data is encrypted and for this reason transported 'invisibly'. The advantage of this embodiment of the invention is that between the network element at the service provider and the corporate network only one ziger tunnel that several users can share. This reduces costs, since only a small amount of hardware is needed to produce a high number of secure data connections.

The The invention will be explained in more detail with reference to the accompanying figures. Show in it

1 a representation of physically networked components of various network subscribers of a public data network,

2 a representation of logical data connections between (network nodes?), which are produced in one embodiment of the method according to the invention,

3 a flow chart of a first part of a method according to the invention,

4 a flow diagram of the second part of a method according to the invention

5 a flowchart of a third part of a method according to the invention and

6 a flowchart of a fourth part of a method according to the invention.

In 1 is with 2 a wireless, local IP based Bluetooth or wireless data network called. This comprises a transmitting and receiving station which is intended to communicate data with mobile data terminals of users, such as a laptop computer 6 , a palmtop computer 8th or a mobile phone 10 exchange. For this purpose, the mobile data terminals also have an interface which supports the protocol of the local data network. The transmitting and receiving station 4 is via a data line 12 connected to an access control module ZNK, which comprises an interface card, not shown, via a data line 16 with a public data network 18 , the Internet, is connected.

In 1 is another local data network with 20 designated. It is a wired data network LAN (Local Area Network) of a hotel 22 using the ethernet protocol. Hotel guests can use their mobile data terminals, laptop computers 24 . 26 , connect to it. In the same network is also a stationary computer 28 connected. Between the devices ( 24 . 26 . 28 ) of the local network and the public data network 18 Once again there is an access control module 30 with an interface card, not shown.

The local data networks 2 . 20 allow users of mobile data terminals 6 . 8th . 10 . 24 . 26 To exchange data with a target data network without having their own direct access to the public network 18 to have. Target network can be the public network 18 , the Internet, his or even a non-public company network 32 , The company network 32 has a network component 34 that have a data line 36 with the public network 18 connected is. In the corporate network is a variety of computers 38 networked through an Ethernet LAN network.

Furthermore, the service providers DLA1, DLA2, which are preferably mobile service providers, are also connected to the public network 18 with corresponding data lines 44 . 46 connected. The mobile service providers operate mobile communications systems 48 . 50 , which, however, are not the subject of the present invention. In the access area of the mobile service providers are network elements NE1, NE2, which are over the data lines 44 . 46 to the public network 18 are connected.

Finally shows 1 also still monitoring devices 52 an authority tasked with monitoring the traffic of certain users of terminal equipment, in particular to prevent and prosecute offenses.

The user of the mobile data terminal ME has a service provider DLA1. In this subscriber-specific data are stored, such as the identity of the user, agreed tariffs or even data on the basis of which a derivation of the user data to the monitoring devices 52 the authority is effected. The network element NE1 has access to this subscriber-specific data. According to the invention, at least the entire user data of the user of the mobile terminal ME is routed through the network element NE1, and the user data are unencrypted during transmission in the network element NE1.

In contrast to 1 , which shows the physical connections of each network over the public network, are in 2 the data connections are shown at the logical level. A logical data connection can physically exist over a large number of nodes and devices.

at a secure (logical) data connection, the data on the path between transmitter and receiver encrypted transfer.

1

das mobile Datenendgerät des Anwenders mit ME,

2

das Zugangskontrollmodul des Zugangsanbieters des lokalen Datennetzes mit ZNK,

3

das Netzelement des Dienstleistungsanbieters DLA1 mit NE1,

4

das Netzelement des Dienstleistungsanbieters DLA2 mit NE2,

5

das Firmennetzwerk mit 32,

6

das öffentliche Netzwerk mit 18 und

7

die Überwachungsgeräte der Behörde mit 52 bezeichnet.

In 2 is again

1

the user's mobile data terminal with ME,

2

the access control module of the access provider of the local data network with ZNK,

3

the network element of the service provider DLA1 with NE1,

4

the network element of the service provider DLA2 with NE2,

5

the company network with 32 .

6

the public network with 18 and

7

the surveillance equipment of the authority 52 designated.

The flowchart, which consists of the parts of the 3 , of the 4 , of the 5 and the 6 composed, includes the individual process steps that can be traversed in a method according to the invention from connection establishment to disconnection. 2 shows the individual secured data connections, which are symbolized by tubes and the communication addresses symbolized by diamonds.

In step 1 the user's mobile terminal ME logs in to the access network ZN.

In step 2 switches the access control module ZNK the access provider the mobile data terminal ME for the communication address KA1 access to the access control module ZNK and transmits the communication address ZNK KA2 for further communication to the mobile data terminal ME.

In step 3 the mobile terminal ME builds a first secure connection GV1 to the first communication address KA2 of the access control module ZNK and transmits a unique identifier DLA1_ID of the first service provider DLA1 that is the mobile operator of the user of the mobile data terminal ME.

In step 4 the access control module ZNK constructs a second secure connection GV2 to the network element NE2 at the second service provider DLA2 and transmits the identifier DLA1_ID of the first service provider DLR1. The second service provider DLA2 is the contract partner of the access provider.

In step 5 In the network element NE2, the check takes place as to whether there is a contract between the service providers DLA2 and DLA1 which is a prerequisite for the access provider being compensated for the service used by the user.

If "no", the network element NE2 transmits the access control module ZNK via the second secure connection GV2 in step 5a1 the rejection of communication. The access control module ZNK refuses in step 5a2 opposite the mobile terminal ME from the further communication, the first secure connection GV1 degrades and blocks the communication for the address KA1 and thus for the mobile terminal ME, whereby the data connection is terminated.

If "yes", the network element NE2 transmits the access control module ZNK in step 5b1 via the second secure connection GV2, the third communication address KA3 of the network element NE1. Then build in step 5b2 the ZNK transmits a third secure connection GV3 to the KA3 at NE1 on its tariff information T1, location data, a unique, the ZNK designating identifier ZNK-ID and a transaction identification TID.

In step 6 checks the NE1 at the DLA1 on the basis of participant-specific data to which the NE1 has access, whether the user is authorized.

If "no", the network element NE1 transmits the access control module ZNK via the third secure connection GV3 in step 6a1 the rejection of communication. The access control module ZNK refuses in step 6a2 opposite the mobile terminal ME from the further communication, the first secure connection GV1 and the third secure connection GV3 degrades and blocks the communication for the address KA1 and thus for the mobile terminal ME, whereby the data connection is terminated.

If "yes", the network element NE1 transmits the access control module ZNK in step 6b1 via the third secure connection GV3, the fourth communication address KA4 of the network element NE1. The access control module ZNK transmits in step 6b2 this fourth communication address KA4 and the transaction identification TID via the first secure connection GV1 to the mobile terminal ME and releases the communication address KA4 for the mobile terminal ME.

Arriving at point A, the representation of the procedure in 4 continued.

In step 7 the mobile terminal ME builds a fourth secure connection GV4 to the communication address KA4 of the network element NE1 at the first service provider DLA1 and transmits the TID and a secure authentication AT_ME for the user. This can be done via so-called "preshared keys" using an asymmetric encryption method.

In step 8th transmits the network element NE1 the mobile terminal ME via the fourth secure connection GV4 a previously calculated tariff T2. The tariff T2 was calculated in the network element NE1 from the tariff information T1 from the access control module ZNK and a tariff agreed between the user of the mobile terminal ME and its service provider DLR1. For this purpose, the network element NE1 has access to the subscriber-specific tariff data of the user.

In step 9 In the network element NE1, a check takes place as to whether the data traffic of the user of the mobile terminal is to be monitored.

If yes, the network element transmits NE1 in step 9a the location, information about the communication setup as well as a correlation ID to monitoring devices 52 with an authorized authority.

If "no" becomes step 9a skipped.

In step 10 after a manual input by the user, the mobile terminal ME transmits the confirmation of the tariff T2 to the network element NE1 via the fourth secure connection GV4. At this point, the user also has the option of terminating the connection setup, for example, if the tariff T1 transmitted to him by his service provider DLA1 through the network element NE1 appears too high. The process steps for the connection termination are in 4 not shown.

In step 11 the network element NE1 reduces the fourth secure connection GV4 and transmits an acknowledgment of the tariff T1 as well as a fifth communication address KA5 of the network element NE1 via the third secure connection GV3 to the access control module ZNK. The fifth communication address KA5 is provided for the payload data which is to be transmitted securely from the mobile terminal ME to the network element NE1.

In step 12 finds on the basis of the subscriber-specific data of the user, to which the network element NE1 has access, in the network element NE1 a check whether the target data network of the mobile terminal ME the non-public home network 32 is. The home network may be, for example, a corporate network. If yes, the network element NE1 builds in step 12a a fifth secure connection GV5 to a communication address KA6 stored in the NE1 in the non-public home network 32 if not, step will be 12a skipped.

In step 13 the access control module ZNK transmits the communication address KA5 received from the network element NE1 to the mobile terminal ME, releases the communication address KA5 for the mobile data terminal ME and blocks the communication address KA4 for the mobile terminal ME.

In step 14 the mobile terminal establishes a sixth secure connection GV6 to the communication address KA5 of the network element NE1.

Arrived at point B, the representation of the procedure in 5 continued.

In step 15 the access control module starts its charge counter. Basis for the fee collection is the sixth secured connection over which the user data of the user are transferred. For example, fees may be charged depending on a period of time during which the connection is made or depending on the amount of data transferred.

In step 16 In the network element NE1, another check takes place as to whether the data traffic of the user of the mobile terminal is to be monitored.

If "yes", the network element NE1 transmits information about the communication start of the mobile terminal ME and starts the packet data extraction via the secure connection GV7 to the monitoring devices 52 the Authority.

In step 17 the network element NE1 starts its charge counter.

In step 18 Based on the user-specific data of the user, to which the network element NE1 has access, the network element NE1 again checks whether the target data network of the mobile terminal ME the non-public home network 32 is.

If "yes", the network element NE1 in step 18a a connection between the fifth and the sixth secure data connection GV5, GV6 ago. This is the user of the mobile terminal with his home network 32 connected. In step 18b the user of the mobile terminal ME authenticates with his home network 32 ,

If "no", the steps become 18a and 18b skipped. The target data network of the user is then the public network 18 which is achieved via the -unsecured connection V8.

In step 19 takes place the actual data traffic in which the user data between the mobile terminal ME of the user and the destination data network, the public network 18 or the home network 32 be replaced. While lukewarm the fee counters both in the access control module ZNK of the access provider and in network element NE1 of the service provider DLA1 the user.

Arrived at point C, the representation of the procedure in 6 continued.

In step 20 At the end of the data traffic, the sixth secure connection GV6 between the mobile terminal ME and the network element NE1 is reduced. This can be done in step 20a done by the mobile terminal in step 20b by the network element NE1 when no data traffic has occurred during a predetermined period of time. It may also be the case that the mobile terminal is in step 20c1 from a new access network ZN (see step 7 ) authenticated out. The network element NE1 then builds in step 20c2 the sixth secure connection GV6.

In step 21 the network element NE1 stops its charge counter and transmits the charging data calculated on the basis of the tariff information T1, which are assigned to the transaction identification TID, to the access control module ZNK via the third secured connection GV3. In addition, information for reducing the data connection to the access control module ZNK is transmitted.

In step 22 In the network element NE1, another check takes place as to whether the data traffic of the user of the mobile terminal was to be monitored. If "yes", the network element NE1 transmits information about the communication end to the monitoring devices 52 the Authority in step 22a , If "no" becomes step 22a skipped.

In step 23 the access control module ZNK acknowledges via the secure connection GV3 and stops its charge counter. ZNK dismantles the secured connections GV1 and GV3, blocks the communication address KA5 and transmits the charge data calculated on the basis of tariff information T1, which are associated with the transaction identification TID together with the transaction identification TID and the unique identifier DLA1_ID of the first service provider DLA1 via the secured connection GV2 to the network element NE2 at the service provider DLA2 of the access provider.

In addition to a first user 54 of a mobile terminal ME shows 2 another user 56 , The connection establishment of the user 56 is identical to the user 54 , The secured connections of the second user are indexed with "a." The target user network of the first user 54 is the home network 32 while the destination network of the second user 56 the public network 18 - the internet - is. The first user can connect to the Internet from his home network. This is not shown in the drawing.

The data of the first user 54 are transmitted from the mobile terminal to the network element NE1 via the sixth secure connection GV6 and from the network element NE1 to the non-public home network 32 encrypted and thus securely transmitted via the fifth secure connection GV5.

Everyone A user of a mobile data terminal remains opposite Access provider anonymous, as he authentication over the secured connection GV4 directly to the network element NE1 at his Service provider DLA1 sends.

A surveillance Traffic through authorized authorities is possible because of the service provider DLA1 of the user's identity User is known and the user data present during transmission unencrypted.

Although the user of the mobile data terminal contractually only its service provider DLA1 and the operator of the local data network bound only to another service provider DLA2 is both the use of the local data network as also billing services, as the two service providers exchange the corresponding data.

The Process steps are controlled by a device installed on the mobile data terminal ME Control program, installed on the access control module ZNK Control program and a control program installed on the network element automated from. For these control programs as well as for Computer program products on which these control programs are stored protection is sought after.

2

local data network

4

Send- and receiving device

8th

Palmtop computer

10

mobile phone

12

data line

16

data line

18

public data network

20

local data network

22

hotel

24 26

Laptop

28

stationary computer

30

Access Module

32

Company network

39

Network component

36

data line

38

computer

44

data line

46

data line

48

mobile plant

50

mobile plant

52

monitoring equipment

54 56

user

ME

mobile data terminal

ZNK

Access Module

DLA1

Service providers

DLA2

Service providers

GV1-GV7

secure data connections

V8

Data Connection

KA1-KA6

communication addresses

Claims (11)

Method for data communication between a user's mobile data terminal (ME) ( 54 . 56 ) and a destination data network ( 18 . 32 ), wherein the mobile data terminal (ME) has transmitting and receiving devices which are suitable, useful and administrative data with first transmitting and receiving devices ( 4 ) of a local data network ( 2 . 20 ) of an access provider and the local data network further comprises second transmitting and receiving devices (ZNK, 30 ), which are capable of providing useful and administrative data via a public network ( 18 ) with the target data network ( 18 . 32 ), wherein at a first service provider (DLA1), the service provider of the user, in particular its mobile operator, subscriber-specific records are deposited and wherein a second service provider (DLA2) is a contract partner of the access provider, characterized in that for the use of the local data network of The first service provider (DLA1) charges the access provider of the first service provider (DLA1) that a first network element (NE1) has access to the subscriber-specific data records, the first network element passing through at least the entire user data, which between the user's mobile data terminal (ME) and the destination data network ( 18 . 32 ), wherein during a user data transmission in the first network element (NE1) at the first service provider (DLA1) a charge meter is running, and that the user data during transmission at least in the first network element (NE1) at the first service provider are available unencrypted. Method according to claim 1, characterized in that that user data, which from the data terminal (ME) to the first network element (NE1) at the first service provider (DLA1) be in the data terminal (ME) encrypted be decrypted for the first time in the first network element (NE1) and that user data, which are transmitted from the first network element (NE1) to the data terminal (ME), encrypted in the first network element (NE1) and in the data terminal (ME) for the first time be decrypted. Method according to claim 1 or 2, characterized in that the first network element (NE1) has at least one direct or indirect interface to monitoring devices ( 52 ) has at least one authorized body, in particular authority that the deposited with the first service provider (DLA1) subscriber records allow an examination of the identity of the user, and depending on the result of an identity check user data of the user and / or accompanying information via the interface to the Monitoring devices ( 52 ) to the authorized agency. Method according to one of claims 2 or 3, characterized in that the target data network is a non-public home network ( 32 ), in particular a company network, and that the user data are transmitted by several users of the destination data network between the network element and the destination data network via a shared tunnel. Method according to one of the preceding claims, characterized characterized in that a second network element (NE2), which the second service provider (DLA2), transaction-specific Exchanging data (TID, DLA1_ID) with the first network element (NE1), that while of the connection establishment the mobile terminal (ME) an identifier (DLA1_ID) the first service provider to an access control module (ZNK) transmitted to the access provider, the access control module (ZNK) sends this identifier to the second network element (NE2) transmitted to the second service provider, the second network element (NE2) checks, whether between the first service provider (DLA1) and the second Service Provider (DLA2) has a contract, and a connection of the mobile terminal for Target data network is only established if the result of exam is positive. Method according to one of the preceding claims, characterized in that in the first network element (NE1) at the first service provider (DLA1) at least from subscriber-specific tariff data, a tariff (T2) is determined before the establishment of a data connection (GV6) for user data the mobile terminal ( ME) and from the user ( 54 . 56 ) of the mobile terminal is to be confirmed manually. Method according to claim 5 or 6, characterized the access control module (ZNK) belongs to the first network element (NE1) while a tariff information (T1) is transmitted to a connection setup, and that this tariff information (T1) in addition to the subscriber-specific Tariff data used to calculate the tariff (T2). Access control module (ZNK) for use in one Method according to one of the preceding claims. Network element (NE1, NE2) for use in a method according to one of the claims 1 to 7. Control program for use in a method according to one of the claims 1 to 7 on a mobile terminal (ME) of a user, an access control module (ZNK) or a Network element (NE1, NE2) in which the method steps after a the claims 1 through 7 are automatically run. Computer program product on which a program code a control program according to claim 10 is stored.