WO2007003856A2

WO2007003856A2 - Method for qualifying mobile terminals, device, programme and support

Info

Publication number: WO2007003856A2
Application number: PCT/FR2006/050655
Authority: WO
Inventors: Benoît Fourestie; Sébastien BARET; Alain Le Cornec; Zwi Altman
Original assignee: France Telecom
Priority date: 2005-06-30
Filing date: 2006-06-30
Publication date: 2007-01-11
Also published as: EP1905257A2; WO2007003856A3; FR2888072A1

Abstract

The invention concerns a method (1) for qualifying identifiable mobile terminals, whereof the identity includes one type. Said terminals are connected to an access network via at least one transmission link. The method includes the following steps: for a given type of communication: associating (2) a power level emitted (Pe) by the network addressed to a mobile terminal with the type of terminal until at least two lists (L1, L2) of power levels associated each with a different type of terminal is obtained, comparing (3) the at least two lists (L1, L2) to determine a classification of the types of terminals associated with the compared lists.

Description

METHOD FOR QUALIFYING MOBILE TERMINALS, DEVICE, PROGRAM AND SUPPORT

The present invention relates to the field of telecommunications, that is to say to the field of data transmission and reception. Within this field, the invention relates more particularly to the radio quality of a mobile terminal operating in mobile networks implementing spread spectrum techniques. These techniques include code-allocation techniques, commonly referred to as CDMA, Code Division Multiple Access, or Code Division Multiple Access Equivalent.

The radio quality of a mobile terminal designates: in reception, its ability to reproduce a signal from a signal received in the presence of interference in order to access the network and maintain good quality communication, in transmission, its ability to emit the power just needed to ensure good network access and good quality communication without unduly disrupting other communications.

This quality can be measured from indicators such as the call success rate, or the block error rate BLER, the acronym for the English words Block Error Rate.

The radio quality in reception of a mobile terminal in a CDMA network is all the more important as it impacts the quality of the network as a whole. Indeed, in a CDMA system, each user is seen as a source of interference by the other users: if a mobile terminal requests a low SIR interference signal report for a given BLER, the power transmitted by the station to this terminal remains low, and therefore limits the amount of interference for other mobile devices. The quality of a mobile terminal is therefore essential to not penalize other users. Mobile network standards define requirements on network interfaces, including the radio interface. Mobile devices that comply with these standards and therefore certified, meet these minimum performance requirements and theoretically have a minimum radio quality and a proper interoperability with the network. However, the radio quality of a terminal depends not only on the hardware, typically peripheral elements such as the antenna, low noise receivers but in addition to processing software implemented in the terminal. Thus, significant differences in radio quality can be observed between mobile terminals of different types or between different software versions of the same type of mobile terminal. The use of "software defined radio" techniques in mobile terminals introduces a risk of introducing multiple versions of the same mobile terminal or a risk of introducing "unknown" mobile terminals onto the network, ie that is, terminals whose radio quality is unrecognized and which may potentially degrade the service offered by the network.

Currently, the characterization of the radio quality of mobile terminals in CDMA networks is evaluated in two different ways: by using test benches integrating simulated environments, on which the terminals are evaluated unitarily according to a standardized test plan, plan used for certification, to which are added tests defined by the operator or - by setting up routes in mobile networks in operation according to a test plan defined by the operator, courses that allow to measure the quality of the terminals in a real operating environment. This method is complementary to the previous one.

The disadvantages of the above methods are as follows. On the one hand, the simulated environment (propagation, interference and mobility) on the test benches is not always representative of the actual conditions that are seen by the terminal operating in the network. On the other hand, these tests are long, tedious and often have insufficient coverage that does not always detect major problems. In addition, the use of route data requires a complex and expensive implementation. Indeed, to achieve statistical reliability to compare terminals, a large number of paths is necessary, which requires mobilizing many testers. In addition, the results depend on the conditions in the network at the time of the course, and it is impossible to conduct courses at all times. The temporal evolution of the network can not, therefore, be taken into account correctly. In addition, the behavior of terminals that are not marketed by the operator, in the case where the latter markets terminals, is poorly known thereof. Indeed, the certification of mobile terminals, if properly performed, relies on standardized tests only. These tests theoretically guarantee an interoperability but certainly not a good quality of the terminal, Indeed, the termina! is tested once, at a given moment, in general before its introduction into the network. Successive software versions of a terminal are rarely tested. The object of the invention is to propose a method for qualifying mobile terminals in a frequency-spread access network that makes it possible to overcome the drawbacks of the preceding methods.

To this end, the invention proposes a terminal qualification process for classifying them.

Thus, the subject of the invention is a method of qualifying identifiable mobile terminals, whose identity comprises a type, connected to an access network via at least one transmission link.

The qualification can be made from the downlink, that is to say from the network to the terminal. In this case, the method comprises the steps which consist, for a given type of communication: to associate a power level transmitted by the access network to a terminal with ϋe type of the terminal and that, until at least two lists of power levels each associated with a different type of terminal, - comparing the at least two lists to determine a classification of terminal types associated with the compared lists.

The qualification can be done from the link up, that is to say the termina! to the network. In this case, the method comprises the steps which consist, for at least one terminal: determining values of a given metric of a signal received by the access network and coming from the terminal, for a type of communication, comparing the different values of the metric to a threshold to obtain deviation values and to classify the terminal.

The invention further relates to an electronic device adapted to be connected to an access network of a cellular network. The device comprises, in the case of a qualification performed from the downlink, that is to say from the network to the terminal: a module for associating a power level transmitted by the access network destined for a mobile terminal with the type of the terminal, until at least two lists of power levels each associated with a different type of terminal, a module for comparing the at least two lists to determine a classification of the associated terminal types compared lists. The device comprises, in the case of a qualification performed from the uplink, ^that is to say the terminai ^ ers IE network: a module for determining values of a given metric of a signal received by the access network and coming from at least one terminal, for a type of communication, a module for comparing, by terminal, the different values of 3a metric to a threshold to obtain deviation values and to classify the terminal.

Typically, this device is an element of an access network, for example a base station or a base station control device.

The invention further relates to a computer program product directly loadable in the internal memory of a device according to the previous object. The computer program product includes portions of software code for executing the steps of a method according to one of the objects of the invention, when the program is executed on the device. The modules of the device are typically software modules.

The invention further relates to a support that can be used in a device according to an object of the invention and on which a computer program product is recorded according to another object of the invention.

The invention, which concerns the characterization of the radio quality of mobile terminals, uses data available during the operation of the network; no specific measurement action during field tests is necessary. Thus, when establishing a communication with a mobile, and, once the communication is established, the identity information of the mobile terminal is transmitted by the terminal to the network. In addition, the access network has either directly the transmitted power levels, in particular the transmission power of the base station, or it determines a metric that it compares to a target value, the result of the comparison being an indicator of the ability of the mobile terminal to respond to a power setpoint sent by the base station.

Depending on the access network, the method can be implemented by the mobile server base station, by a controller device of the base station, or by a measurement device connected to the access network via measuring probes. Depending on the configuration of the access network, these probes are connected to input / output ports of the base stations or a control device.

Thus in the case of a UTRAN access network of a UMTS network, the method can be implemented by a NodeB, that is to say the equipment that provides the radio link to the mobile terminal II can Io It should also be implemented by an RNC. Radio Network Coatrolier, who are! an access network device that controls radio links and the use of radio resources, or is implemented by a C) MC, Operation and Centralized Maintenance which is a device that performs functions for controlling the proper functioning of the access network.

This qualification method enables an operator to automatically and regularly characterize, in a real environment, the quality of the different types of mobile terminals present in the network, and connected to the access network, both on an uplink and on a link down. Such a character! one, which can be described as "real-time", can be used to launch low-cost actions to improve the functioning of the network such as the selection of better mobile terminals for, for example, to promote them within the network or can make it possible to launch actions with the mobile terminal suppliers to improve the radio quality of the terminals marketed. By favoring higher quality terminals at the expense of lower quality terminals, the operator improves the quality perceived by users who no longer suffer the excessive interference caused by the most troublesome terminals; the operator improves the quality of his network.

A characterization of the radio quality according to the invention advantageously makes it possible to evaluate the quality of the mobile terminals which are not marketed by the operator, assuming that the operator markets mobile terminals. A characterization of the radio quality according to the invention also makes it possible to classify the terminals according to their level of hardware version, hardware in English, as well as according to their level of software version. The hardware and software version levels are typically extracted respectively from the identifiers IMEI and IMEÏSV which are present in the messages sent by a mobile terminal to the network during an already established communication or during the establishment of the communication.

A computer program according to the invention, in particular a computer program on or in an information carrier, is adapted to implement a method according to an object of the invention when it is executed by an electronic device. This electronic device is an object of the invention, it is typically a base station or NodeB, a base station controller or RNC, a measuring device with probes or a maintenance device or OMC. This program can use any programming language, and be in the form of source code, object code, or intermediate code between source code and object code such as in a partially compiled form, or in any other form desirable to implement a method according to the invention. The information carrier may be any entity or device capable of storing the program. For example, the medium may comprise storage means, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or a magnetic recording means, for example a floppy disk or a disk. hard.

Alternatively, the information carrier may be an integrated circuit in which the program is incorporated, the circuit being adapted to execute or to be used in the execution of the method in question.

On the other hand, the terminal qualification computer program can be translated into a transmissible form such as an electrical or optical signal, which can be routed via an electrical or optical cable, by radio or by other means. The program according to the invention can in particular be downloaded on a network of the type

Internet.

Other characteristics and advantages of the invention will become apparent from the description which follows, given with reference to appended figures given by way of non-limiting examples.

Figure 1 is a diagram of a UTRAN access network of a UMTS network.

Figure 2 is a flowchart of a method for qualifying mobile terminals according to the invention for a downlink. Figure 3 is a flowchart of a particular implementation of a step of comparing a method according to the invention, for a downlink.

Fig. 4 is a flowchart of a method for qualifying mobile terminals according to the invention for an uplink.

A method according to the invention implemented by an access network proceeds as follows.

The method for qualifying mobile terminals applies to identifiable terminals by means of an identity. This identity includes a type.

In the case of mobile terminals adapted to a UTRAN access network, the acronym for the Universal Terrestrial Radio Access Network words, the identity corresponds to the IMEI information whose TAC, FAC and SRN fields constitute the terminal type. The TAC field contains a code for the country of assembly and the model of the terminal. The FAC field contains a manufacturer code. The SRN field contains a serial number. A UTRAN access network, shown in Figure 1, is the portion of a UMTS mobile network, which stands for the United Kingdom Mobile Mobile Telecommunications System equivalent to a third-generation mobile telecommunication system, consisting of one or more controllers. RNC {Radio Network Controller) and one or more base stations called Node B. A mobile terminal TM connects to the access network via a NodeB. The UTRAN access network is connected to an RC core network of the UMTS network.

In the case of mobile terminals adapted to a CDMA access network ₅ IS95 type for example, the identity information corresponds to the ESN. ESN stands for Electronic Serial Number, so it's an electronic serial number.

The method makes it possible to qualify the terminals connected to the access network, this network implementing a spectrum spreading technique typically of the CDMA type, via at least one transmission link. The link is typically of the radio link type or equivalent. The terminal can equally well be connected to the network via multiple links, for example in a context or macrodiversity in a MIMO system ₅ SLMO or MlSO. MMI, the acronym for the words Multiple Input Multiple Output, denotes a system with multiple inputs and outputs. SlMO, the acronym for the English words Single Input Multiple Output, refers to a system with single input and multiple outputs. MISO, acronym for the English words Multiple Input Single Output, refers to a system with multiple inputs and single output.

The access network knows the type of communication relating to the connection established with a terminal by generally exploiting the content of the exchanges on the common radio channels between the mobile terminal and the access network. In particular, for a UTRAN access network of a UMTS network, the type of communication is accessible by exploiting the MS_SERV1CE_REQUEST field.

In the case of a downlink, the method 1 comprises the following steps described with reference to the flowchart of FIGS. 2 and 3.

A first step 2 consists in associating a level of power transmitted Pe by the access network intended for a mobile terminal, with the type of the terminal.

According to one particular embodiment, the power Pe refers to the size "TX Code Power" of the 3GPP document ₅ "Physical Laver Measurements (FDD)." Release 5, 25.215, v5.0 ₅ 2002-2003.

The association is made for a given type of communication, for example communication carries voice, or data. Step 2 proceeds to obtain, for the same type of communication, at least two lists Li, L- _z of power levels each associated with a different type of terminal between the lists. Thus, each list Li, L ₂ typically contains the different power levels transmitted for the different terminals of the same type and for the same type of communication, Scion a first real! one, the different power levels included in the different lists are relative to the same instant, The lists can be supplemented with power levels emitted at different times, but, preferably, a power level sampling for a terminal of a given type is accompanied at the same time as many power level samples than different lists , In the case of a UTRAN access network of a UMTS network, the power control transmitted by the access network to a terminal may be in steps of 0.5, 1, 1.5, or 2 dB. The mobile terminal receiving the transmitted power Pe, generates TPC commands to control the power level sent by the network and sends them in the TPC field of the uplink on the DPCCH dedicated physical channels. The UTRAN network adjusts the downlink transmitted power in accordance with this command.

Thus, the first step 2 leads to the development of several lists Li, L ₂ consisting of transmitted power levels Pe. Each list Li, L ₂ relates to a type of communication and a type of terminal. And among these lists Li, L ₂ , at least two Li, L ₂ relate to different types of terminals, for the same type of communication.

Each list Li, L ₂ may comprise the power levels relative to all mobile terminals of the same type active in a cell, active in several cells of the access network or active in a given area different from a cell. Such a zone may for example be delimited by a location criterion. For example, lists may relate to an area delimited by two latitudes and two longitudes, in which case these lists contain only levels of power transmitted to terminals located between the three latitudes and the two longitudes. This requires knowing the location of the terminals. According to a particular embodiment, in the case of several transmission links between the network and a mobile terminal, the transmitted power level must be understood as being the sum of the power levels transmitted for each of the links.

A second phase 3 is to compare at least two lists _Î L, L ₂ relating to different types of terminals but to the same type of communication. The comparison makes it possible to determine a classification of the types of terminals associated with the lists L ₁ , L ₂ compared, for a given type of communication. According to one preferred implementation, the comparison is based on statistical tests.

A first statistical test 4 relates to the geographical distribution identity of the terminals between the different lists, and therefore between different types of terminals. When the first test 4 concludes the identity of geographical distribution between mobile terminals of different types, first case, the comparison takes place as follows. In this first case, the lists of power levels relate to terminals positioned according to an identical geographical distribution between the different lists. The comparison then consists in performing statistical tests of equality of means and / or equality of the variances between the power level distributions contained in the lists. For example, let us quote the tests of Fisher, of Student of which a description is given in the document of G.Saporta having for reference: "Probabilities, Data analysis and Statistics", Technip Publishing: Paris, pp342-344, 1990. In function the result of the tests, it is possible to conclude 6 if a population of terminals, corresponding to a list, and therefore to a given type of terminal, is of better quality or of lower quality than another population of another list, therefore of another type, or of equivalent quality.

When the first test 4 concludes that there is no geographical identity identity between mobile terminals of different types, the second case, an intermediate step 7 consists in determining sub-lists of power levels relating to terminals whose geographical distribution is identical between the terminals. different sub lists. This intermediate step takes place as long as the first test does not conclude the geographical distribution identity between the mobile terminals of different types. When the sub-lists are determined, the comparison continues as described for the first case but on the basis of these sub-lists.

In the case of an uplink, the method 10 comprises the following steps described with reference to FIG.

A first step 11 consists in associating values of a given metric of a signal received by the network, originating from a terminal, with the type of the terminal. The association is made for a given type of communication, for example communication conveys voice, or data.

In the case of a UTRAN access network, this metric is typically the SIR, which stands for the English word Signal Integral Ratio, ie the signal-to-interference ratio that is defined in the 3GPP document. Physical Layer Measurements (FDD) ", Release 5, 25.215, v5.0 pl i, 2002-2003.

In the particular case of a MIMO or SIMO system, the signal received by the network must be understood as being the result of a sum of the received signals corresponding to the multiple signals transmitted by the terminal. Indeed in this case, the terminal is connected to the network by several transmission links. A second step 12 consists in comparing the different values of the metric with a threshold for classifying the terminal. Typically, the comparison consists in determining values of deviations between the metric and the threshold.

In the case of a UTRAN access network, this threshold is typically the

relative to the terminal, data defined in the previous 3GPP document. A mobile terminal is able to change its transmission power, therefore uplink, in steps of 1, 2 or 3 dB, in the slot immediately following a TPC command from the server cell, so downlink, and this to keep the signal-to-interference ratio received in the uplink, either the SIR at a given target level or the SIR-call. The server cell estimates the SIR, said SIR _e5b of the power received on the uplink from the terminal, generates a TPC command and transmits this command to the dedicated physical channels DPCCH according to the following rules: if the SIRyst is strictly greater than the SIR _terg et_avc then the TPC command is set to zero, whereas if the SIR _is strictly lower than the SIR _your iget then the TPC command is set to one. After receiving one or more TPC commands in a slot, the mobile terminal determines a single command per slot by combining the multiple commands if more than one command is received per slot. The determination is made by means of an algorithm whose choice depends on a parameter designated by the words "PowerControlAlgorithm". Depending on the positioning of the command, the terminal decreases, maintains or increases its transmitted power.

Typically, if the SIR _& T is greater than the _width SIR eι_ave handheld power waste and is seen as an interference by the other terminals; it can be classified 13 in a category including mobile terminals deemed of poor quality. According to a particular embodiment, the method repeats the two steps 1 1 and

12 for different terminals connected to the access network by at least one transmission link. The method can then compare the terminals to each other to rank the terminals. The comparison consists in comparing, between terminals, the different values of the differences calculated by terminal. This comparison can be based on a comparison of average.

According to a particular embodiment, the method further comprises a step of determining at least two different terminal lists by their type, a step of comparing the lists with each other and a step of classifying the lists.

According to a mode of realization; In particular, the comparison of the lists between them consists in carrying out tests of equal importance of means and or equality he

variances between the lists. The comparison step is similar to step 3 described with reference to FIG.

Claims

A method (1) for qualifying identifiable mobile terminals (TM) whose identity includes a type connected to an access network (UTRAN) via at least one transmission link (It) which includes the steps of, for a given type of communication: associating (2) a power level (Pe) transmitted by the access network (UTRAN) to a terminal (TM) with the type of the terminal ( TM), until at least two lists (Lj, L ₂ ) of power levels (Pe) each associated with a different type of terminal (TM), - to compare (3) the at least two lists ( Li, L ₂ ) to determine a ranking

(6) types of terminals (TM) associated with lists (Li, L ₂ ) compared.

2. Method (1) of mobile terminal qualification (TM) according to the preceding claim wherein, for a terminal (TM) connected to the network (UTRAN) access via several links (It) transmission, the Transmitted power level (Pe) is the sum of the power levels emitted for each transmission link (It).

3. Method (1) for qualifying mobile terminals (TM) according to one of the preceding claims, in which: the lists (L ₁ , L ₂ ) of power levels (Pe) relate to terminals (TM) positioned according to a identical geographical distribution between the different lists (Li, L ₂ ) and in which: the comparison (3) consists of performing statistical (5) tests of equality of the variances and / or equality of the means between the lists (L) , L ₂ ).

4. Method (1) for qualifying mobile terminals scion of one of claims 1 and 2, wherein: lists (Li, L ₂ ) of power levels are relative to terminals (TM) positioned in a different geographical distribution between the different lists

(L1, L2), and wherein the method further comprises a step of: determining (7) sub-lists of power levels (Pe) relating to terminals (TM) whose geographical distribution is identical between different sub-lists, the process being here that the comparison (3) consists in performing (5) statistical tests of equality of means and / or equality of the variances between the sub-lists.

A method (10) for qualifying identifiable mobile terminals (TM) whose identity comprises a type connected to an access network (UTRAN) via at least one transmission link (It) which comprises the steps of, for at least one terminal (TM): associating (11) values (S1R ^ _SI ) of a given metric (SlR) of a signal received by the access network (UTRAN) and from the terminal (TM) with the type terminai to a type of communication, comparing (12) the various values (SLR _eit) metric (SIR) with a threshold (SIRtarget ave) to obtain values of deviations and to classify (13) the terminal (TM), to repeat the two preceding steps (1, 1.12) for different terminals (TM) each connected to the access network (UTRAN) via at least one link (It) of transmission, to obtain different values (SlR _eil ) of the same metric (SIR) for the same type of communication and for the different types of communication. rminals (TM), to compare between terminals (TM), for the same metric (SIR), the different values of deviations to establish a classification of terminals (TM).

6. Method (10) for qualifying mobile terminals (TM) according to the preceding claim, further comprising a step of determining at least two different terminal lists by their type, a step of comparing (3) the lists between them. and a ranking step of the lists.

7. The method (10) of mobile terminal qualification according to the preceding claim, wherein the comparison (3) consists of performing statistical tests (5) equality of means and / or equality of variances between the lists.

Mobile terminal qualification (TM) method (1, 10) according to one of the preceding claims, in which the identification of a terminal (TM) consists of extracting a message received by the network (UTRAN). access and from the terminal (TM), information (IME1, IMEISV) for determining an identity and type of terminai (TM) at the origin of the message,

9. The method (1, 10) for mobile terminal qualification (TM) according to the preceding claim, wherein the extracted information comprises an identifier (IMElSV) of a software version embedded in the terminal (TM).

An electronic device (NodeB, RNC) adapted to be connected to a network (UTRAN) for accessing a cellular network (UMTS), characterized in that it comprises: a module for associating a power level (Pe) transmitted by the access network (UTRAN) to a mobile terminal (TM) with the terminal type (TM) until at least two lists (Li, L ₂ ) of power levels are obtained

(Pe) each associated with a different type of terminal (TM), a module for comparing the at least two lists (L], L ₂ ) to determine a classification of the terminal types (TM) associated with the lists (L ₁ , L ₂ ) compared.

An electronic device (NodeB, RNC) adapted to be connected to an access network of a cellular network, characterized in that it comprises:

- a module for determining, for a communication type, a metric values (SIR _est) to a data signal received by the access network and from different terminals, identifiable, whose identity comprises a type, and to associate the values obtained for a terminal with the type of the terminal, a module for comparing, by terminal, the different values of the metric at a threshold (SIR _targc t_avJ to obtain values of deviations and to compare between terminals, for the same metric, the different values of differences to classify the terminals.

Base station (NodeB) comprising an electronic device according to one of claims 11 and 12.

13. Base station control device (RNC) (NodeB) comprising an electronic device according to one of claims 1 1 and 12.

14. A computer program product loadable directly into the internal memory of an electronic device (NodeB, RNC) adapted to be connected to a cellular network (UMTS) access network (UTRAN), comprising portions of software code ^for executing the steps of a method H OJ) according one of claims 1 to 10, when the program is executed by the electronic device (NodeB, RNC).

15. Support usable in an electronic device (NodeB, RNC) adapted to be connected to a cellular network (UMTS) access network (UTRAN) on which a computer program product is loaded directly into memory internal device (NodeB, RNC) electronic, comprising portions of software code for performing the steps of a method (1, 10) according to one of claims 1 to 10, when the program is executed by the device ( NodeB, RNC) electronic.