WO2009071802A1

WO2009071802A1 - Management of the consumption of a hybrid mobile terminal

Info

Publication number: WO2009071802A1
Application number: PCT/FR2008/052086
Authority: WO
Inventors: Alain Abinakhoul; Bruno Bouchoir
Original assignee: France Telecom
Priority date: 2007-11-20
Filing date: 2008-11-19
Publication date: 2009-06-11

Abstract

The invention relates to the management of a communication between a mobile hybrid terminal (TER) and a local network. The terminal can communicate simultaneously with at least: a first local network including at least one access point (PA), and a second cellular network that geographically covers said access point. In particular, the invention includes the locating of the terminal by the cellular network (BSC) and the authorisation of the connection of the terminal (TER) to the local network at least if the terminal is located in a coverage area (ZPA) of the access point.

Description

Managing the consumption of a hybrid mobile terminal

The present invention relates to a hybrid mobile terminal, capable of communicating via at least: - a first network, local, and a second network, cellular.

By "cellular network" is meant here a network comprising a plurality of zones of covers (or "cells") which are juxtaposed and / or which partially overlap.

The cellular network may be for example (but not limited to) a GSM-type network (for "Global System for Mobile Communications"), comprising, with reference to FIG. 1, BS1 ... BSN base stations capable of covering each at least one geographical area defining a cell C 1 ... CN of the network. Thus, in a mobility situation, the terminal TER can continue its communication by being located in a first cell C1, then in a second cell C2 adjacent to the first cell, and so on (the management of the communication of a cell to another being provided by a so-called "handover" technique).

It will then be understood that the cellular network is an "extended" network in the sense that the terminal can, in communication, travel a great distance covered by several base stations.

This concept is substantially opposed to that characterizing the first network, of "local network", typically providing short-range communication to the terminal. An example of a first network is a network comprising a wireless termination, for example between a Wi-Fi terminal and the terminal. Such a Wi-Fi terminal then acts as an access point of the terminal to the local network. Thus, if the only access to the local network, for the terminal, is constituted by a single Wi-Fi terminal, the terminal can communicate via the first network only in a restricted area, delimited by the coverage offered by the Wi-Fi terminal. Aforementioned Fi. The hybrid mobile terminal, meanwhile, is not limited to a particular type of communication means. It can be a mobile phone handset capable of communicating via both types of network, local and cellular. It may also be a personal assistant or PDA (for "Personal Digital Assistant"), a laptop, or any other terminal with at least one interface capable of communicating with the two types of networks mentioned above.

A problem posed by such terminals is the energy consumption due to the permanent search of the local network. For example, looking for a terminal

Wi-Fi, this type of terminal incorporates a wireless network card that seeks to detect the availability of a Wi-Fi wireless network. However, a major disadvantage of this type of terminal is its reduced autonomy in Wi-Fi communication mode. Fi, this mode results in increased power consumption. The energy consumption of Wi-Fi chips is indeed one of the problems posed by such hybrid terminals where autonomy is a paramount criterion. Thus, laptops and / or hybrid mobile phones (including GSM and Wi-Fi) offer an option to manually disable the search for Wi-Fi terminal when it is not desired to connect to the Wi-Fi network , in order to avoid the consequences of unnecessary energy consumption of the battery. When a Wi-Fi chip is in operation, it is necessary to count a consumption between 700 and 1300 mW, against 100 m W for the same chip at rest.

Another problem related to the permanent search of a local network relates to the data security that a mobile terminal can communicate with a gateway. The permanent search for a local network results in a possible attack in a Wi-Fi type network, the attack consisting, for an attacker, of masquerading as an access point for retrieving data from the terminal . It is then desired to dispense with validity checks of the access point (in particular in secure protocols according to developments in the IEEE-802.1 1 standard), these verifications increasing the communications in such networks. The present invention improves the situation.

For this purpose, the invention proposes a communication management method of a mobile terminal, this terminal being hybrid and therefore capable of communicating with both:

a first network, local, comprising at least one access point, and

a second, cellular network, geographically covering this access point.

The method in the sense of the invention comprises a location of the terminal by the cellular network and a connection authorization of the terminal to the local network at least if the terminal is located in a coverage area of the access point.

As indicated above, the term "local area network" means that the access point of the first network has a relatively limited scope relative to the extent covered by the cellular network. Moreover, here is meant by "geographically covering the access point" the fact that at least one cell of the cellular network can include at least part of the coverage area of the access point.

Furthermore, it is specified here that the terminal can communicate "at least" with the first and second networks in the sense that the terminal can communicate further with a third network, or even a fourth network, and so on, without leaving the of the present invention.

In addition, the term "at least (if the terminal is located in a coverage area of the access point)" is meant here that, of course, it is possible to condition the connection of the terminal to the local area network. other factors, for example the fact that this access point is authorized for a telephony communication but is not authorized for a data transmission (files or other) from the terminal. Thus, one relies on the cellular network to locate the terminal and if the latter is located within range of an authorized access point, then one can initiate its connection to the local network.

It is then possible to draw up a list of the cells of the second network at least partially covering the authorized access points of the first network and thus allow the connection of the terminal to the first network if it is located in at least one of the cells of this list. .

Thus, a terminal within the meaning of the invention can store in memory such a list and include test and decision means to check if a cell in which it is located is part of this list and possibly allow the connection of the terminal to the first. network.

The present invention thus also aims at a module intended to equip a hybrid terminal within the meaning of the invention and comprising at least such test and decision means.

The present invention also aims at a computer program intended to be stored in memory of such a module and then comprising instructions for the implementation of the method in the sense of the invention, when they are executed by a processor of such a device. module.

Advantageously, the implementation of the invention already makes it possible to avoid a connection to access points of the local network that are not listed as authorized, in correspondence of the predetermined cells of the aforementioned list.

Advantageously also, it can be provided that the connection authorization comprises at least an activation authorization, from the terminal, of the search for connection to the local network. Thus, the search of the local network by the terminal is only active if it is certain that the terminal is within the range of an authorized access point or at least close to the range of a point of access. authorized access, as will be seen in one of the examples of embodiments described below. It then follows a notable energy saving, which must provide the battery of the terminal, since the communication mode with the local network is finally activated only very occasionally, in situation of mobility of the terminal.

Other features and advantages of the invention will emerge on examining the detailed description below, and the appended drawings in which, in addition to FIG. 1, general, described above: FIG. 2 illustrates a situation where a cell partially encompasses the range of an access point of the local network, Figure 3 illustrates a system within the meaning of the invention comprising a hybrid terminal and a local network access point, Figure 4 illustrates the main stages of the network. FIG. 5 illustrates a situation where a plurality of cells partially encompassing the range of an access point of the local network, FIG. 6 illustrates a situation where the access point is situated. at the intersection of a plurality of cells, FIG. 7 illustrates a situation where several cells cover together several authorized points of access to the local network; FIG. 8 illustrates a terminal in the sense of the invention, equipped with a e SIM card having a MEM memory that can store a list of cell identifiers and possibly a computer program in the sense of the invention, Figure 9 illustrates a module of the terminal, in an environment suitable for the implementation of the invention .

Referring first to Figure 2, a TER hybrid terminal is capable of communicating with both a first, local, and a second, cellular network. The TER terminal, if its design allows, could also communicate via a third type of network, for example the switched network by planning to equip a wired interface. The first network, local, has at least one AP access point. This AP access point has a ZPA coverage area having a predetermined geographic position and extent.

The second network, cellular, has, as illustrated in Figure 1 described above, a global geographical coverage defined by a plurality of cells each having a predetermined geographical position and extent.

It will be noted in FIG. 2 that at least part of the AP access point coverage area PA is included in the overall coverage of the second network.

(cellular), and more particularly in the CC cell that covers a current base station BSC. Specifically, in the example of Figure 2, the cell CC has a geographic extent including a portion of the coverage area ZPA of the access point. Hereinafter, the term "cell covering the access point" will be understood to mean that a cell at least partially includes the coverage area ZPA of the access point, as illustrated in FIG. 2.

Typically, with reference to FIG. 3, it is proposed for sale systems in which a TER hybrid telephone can communicate via: a local network (for example wireless Wi-Fi), with a gateway MOD acting as a PA access point (Wi-Fi terminal), this MOD gateway is also connected to an INT wide-area network such as the Internet to provide in particular "Voice over IP" (IP for "Internet Protocol") communications, the the gateway itself being capable of supporting other applications, in particular data transfers from the internet network to a PC, and a cellular network, of the GSM or UMTS type, capable of still offering the services, in particular telephony services, via a radio station. BSC base, when the user of the phone is out of range of the gateway of his home for example, especially in a mobility situation. In this implementation example, the gateway may be the only Wi-Fi access point on which the hybrid terminal can connect. The terminal comprises, for communication with the local network, a card associated with the local network, for example an integrated wireless network card. When the terminal is not in the coverage area near the MOD gateway, the integrated wireless network card, if left on, unnecessarily consumes power from the terminal's battery by searching for available wireless networks, and this, to no avail since the terminal is out of reach of the AP access point.

An advantage of the present invention is to disable the wireless network card of the terminal as long as it is not likely to be within the ZPA coverage area of the wireless LAN access point.

Thus, in one embodiment, it is sufficient that the terminal is located in a current cell CC (DET arrow entering the cell CC), covered by the current base station BSC which detects the terminal TER, to allow a terminal connection to the local network (dotted arrow R-PA), if the PA access point giving access to this local network has previously been listed as having a ZPA coverage area that is at least partially included in the current cell CC . Advantageously, such an embodiment is facilitated by the fact that the positions and geographical extent of the cells and the coverage area of the access point are generally predetermined (known in advance).

The connection authorization can consist simply of activating the aforementioned wireless network card by triggering in particular its power supply to initiate a connection search to the local network or to authorize a communication of the terminal (for example secure data), if the terminal is detected by a given base station, defined beforehand.

More particularly, with reference to FIG. 2, when the terminal TER enters a current cell CC, the current base station BSC which covers this cell CC locates the terminal. A signal indicating that cellular network communications can be supported by the BSC station is usually notified to the terminal. For the purposes of the invention, a computer routine is then triggered at the terminal, on reception of this signal, to check whether the cell covered by this base station BSC is one of the cells likely to include the coverage area of a terminal. PA access point to the local network, and, if necessary, allow a connection of the terminal to the local network.

Thus, with reference to FIG. 4, two main steps are generally envisaged: a step S i prior to identifying at least one predetermined cell

C1, C2, ..., CN, of the cellular network, covering the access point PA to the local network, and following a location of the terminal in at least one current cell Cj of the cellular network (step S22 of FIG. 4) a test and decision step S23 is carried out to compare the current cell Cj with one of the predetermined cells C1, C2,..., CN and to authorize a connection of the terminal to the local network (step S24) if the current cell Cj corresponds for example to one of the predetermined cells (arrow O at the output of test S23).

More particularly, in an exemplary embodiment where a routine is implemented with the terminal before allowing a connection to the local network, is built in step S 1 1 list of cells likely to cover the AP access point to the local network.

Thus, an LST list of cell identifiers of the cellular network C1, C2,..., CN covering the access point PA can be constructed (step S1) and then saved (step S12) in a memory of the terminal, by example in the SIM card of the terminal (SIM for Subscriber Identity Module).

For example, when the terminal is first connected to the local area network in the coverage area of the access point PA (for example the gateway MOD in the embodiment illustrated in FIG. 3), the identifiers of the cells covering the access point AP are saved on the SIM card. Alternatively, it is also possible to obtain the identifiers of the cells for example through the home address of the user of the terminal if the access point (in particular the MOD gateway of Figure 3) home team of the user.

When the terminal enters into connection with the cellular network via a new current base station BSC (step S21 of FIG. 4), the terminal receives, as described above, a signal indicating a base station identifier characterizing a cell. in which the terminal is located.

A computer application (aforementioned routine), installed on the terminal (stored in a memory of the terminal for example in the SIM card) receives this cell identifier Cj in which the terminal is located (step S22). It then compares (test 23): the identifier of the current cell CC in which the terminal is located with the cells contained in the LST list of cell identifiers saved on the SIM card.

This comparison can be done regularly or on reception of the aforementioned signal indicating the current base station BSC with which the terminal is connected.

If no identifier of the list LST corresponds to the identifier of the cell Cj where the terminal is located (arrow N at the output of the test S23), the terminal is considered out of coverage of the access point PA and the computer application for example, disabling the integrated wireless network card.

If the identifier of the cell Cj where the terminal is located belongs to the list LST (saved on its SIM card) of all the identifiers of cells that cover the access point (arrow O at the output of the test S23), the terminal is then considered in the coverage area of the access point and the computer application for example controls the activation of the integrated wireless network card so that the Wi-Fi connection can be established with the access point PA (step S24). Of course, it can be provided in practice to directly store base station identifiers BS1, BS2,..., BSN and then directly compare these identifiers with the current base station identifier BSC which is received in the signal indicating to the terminal by which base station it is being connected to the cellular network.

The aforementioned computer application is a means advantageously allowing the implementation of the method within the meaning of the invention. In this respect, the present invention also aims at a computer program corresponding to such an application and the general algorithm of which may be, for example, represented by the flowchart of FIG. 4. The present invention also aims at a module comprising a MEM memory (such as the SIM card shown in Figure 8) including storing such a computer program and, optionally, the aforementioned list of cell identifiers covering the AP access point.

With reference to FIG. 9, the aforementioned module may comprise: access to a memory 12 storing at least one predetermined cell identifier covering the access point, such as the memory MEM of the SIM card of FIG. 8, an input 1 1 to receive a current cell identifier Cj by which the terminal is connected to the cellular network, and test and decision means 10 for comparing the identifier of the current cell with at least one predetermined cell identifier stored in memory 12 and decide a connection authorization of the terminal to the local network at least in case of coincidence of the respective identifiers of current cell and predetermined cell.

Thus, such means 10 can control a power supply circuit 16

15 of the wireless network card 13 to activate it, if necessary. Thus, the connection authorization defined in generic terms above (step S24 of FIG. 4) can comprise a power supply control of the card 13 associated with the network. local, while a non-authorization connection may include a power supply cut command of this card 13.

Thus, the aforementioned module 10 can issue: a power supply control of the card 13 in case of coincidence of the respective identifiers of current cell and predetermined cell, and a power supply cut-off command of the card 13 , if not. For this purpose, the module may furthermore comprise control means (arrow 17 of FIG. 9) of the power supply circuit 15 of the wireless network card 13 for: controlling the power supply of the card in case coincidental identification of current cell and predetermined cell identifiers, and control a power failure of the card, otherwise.

In practice, the module of Figure 9 further comprises a processor 14 for executing the computer program within the meaning of the invention, stored in a memory of the module of Figure 9 which could correspond to a MEM memory of the SIM card. Thus, a memory of the SIM card can store both the list of cell identifiers covering the access point and the aforementioned computer program. In a variant, they are stored in separate memories.

The present invention also aims at a hybrid terminal comprising:

a memory 12 storing at least one predetermined cell identifier covering the access point, and a module such as the module 10 of FIG. 9, then arranged to receive a current cell identifier Cj through which the terminal is connected to the cellular network, and to cooperate with the memory 12 to compare the identifier of the current cell Cj to the predetermined cell identifier (s) (s) and decide a connection authorization of the terminal to the local network at least in case of coincidence of the respective identifiers of current cell and predetermined cell. As indicated above, this module 10 can then control (arrow 17) a power supply circuit 15 of the card associated with the local network 13.

Of course, the memory MEM of the SIM card can correspond to this memory 12 of FIG. 9 and can then be an integral part of the module of FIG. 9.

The present invention also aims at a communication system, of the type shown in FIG. 3, comprising a PA access point to a local area network (via a MOD gateway in the embodiment of FIG. 3) and a hybrid mobile terminal. TER comprising at least: an interface IN1 (FIG. 3) for communication with a local network comprising the access point PA, and an interface IN2 (FIG. 3) for communication with a cellular network, and in particular a memory and a module such as described above with reference to FIG. 9.

Thus, with reference again to FIG. 2, the TER terminal initially comes from a C-INIT cell which does not cover the access point. The base station associated with this cell provides the terminal with a cell identifier. The computer application stored for example in the SIM card can thus test that this identifier is not part of the list of LST cell identifiers covering the access point, and decide, therefore, the deactivation of the integrated wireless card in the terminal. On the other hand, when the mobile terminal has moved and enters the cell CC covering the access point PA, the processing based on the identifier of the current cell CC makes it possible to determine (arrow DET) that the terminal has entered a zone (the cell CC) covering the AP access point. The wireless network card is then activated for a local network search (arrow R-PA) and the TER terminal can then establish a Wi-Fi connection with the AP access point.

Thus, it is prejudiced here that the carrier of the mobile terminal, entering the cell CC covering the access point to the wireless network, is moving towards his home (in particular for home applications) or more generally to a point where it is likely to require a communication service via the wireless local area network.

In the example of Figure 2, it appears that the access point is covered only by a single cell CC. In a variant, the access point PA may be covered by several cells of both the cellular network. In one embodiment, during the aforementioned prior step SI 1, a plurality of such cells covering the access point are identified. The connection to the local network is then authorized if the current cell, at least, in which the terminal is located corresponds to one of these predetermined cells of the LST list. This situation is illustrated in FIG. 5 in which two CCI and CC2 cells cover, at the same time, the access point PA. Thus, if the terminal is located in one and / or the other of the CCI and CC2 cells, the search of the local network is activated. It is disabled otherwise.

As soon as the terminal can receive several cell identifiers if it is in an area of intersection of cells (as the common area between cells CCI and CC2 of Figure 5), the activation of the wireless network search can be conditioned to the presence of the terminal in a specific intersection area. This embodiment can be advantageous especially in urban context when a plurality of base stations can cover the same area. FIG. 6 shows such an embodiment on which three cells CCI, CC2 and CC3 cover, at the same time, the access point. Thus, following a fine localization of the terminal in such an intersection of respective coverage areas of a plurality of current cells CCI, CC2, CC3, provision can be made for the connection of the terminal to the wireless network is authorized if each current cell corresponds to one of the predetermined cells of the LST list.

Thus, it is possible for the terminal to finely determine its position and if this position corresponds to that of an authorized access point (for example the access point associated with the home gateway of the mobile terminal holder) , then the wireless network connection can be activated. The implementation of this realization can be advantageous if several access points are likely to be covered by the same cell, in which case the selectivity of the authorized access points is increased by determining the intersections of cells. One advantage of this selectivity includes the security of communication with an authorized access point (such as the home gateway of the terminal carrier). It will be noted that it is also possible to authorize a connection to the local network only if the terminal is located in a complementary zone of an intersection (zone excluding an intersection with one or more other cells), for example if the terminal receives Cell IDs that are not part of the LST list. In this way, the fineness of location of the terminal is increased in an equivalent manner in an area where an authorized access point is located.

Of course, it can be expected to offer the terminal the ability to communicate with a plurality of authorized access points (called "hotspots"), which can be public, available to users. Thus, it can be stored in memory, for example in a memory of the SIM card of the terminal, in addition to one or more cell identifier (s) covering the access point corresponding to the personal gateway of the terminal. user, the list of cell identifiers covering the other authorized access points (Wi-Fi hotspots mentioned above).

This list saved in memory of the SIM card can be easily updated by a remote operator, for example by sending a message type SMS (for "Short Message Service").

This situation is illustrated in FIG. 7. Since the wireless network comprises a plurality of access points covering zones ZPA1, ZP A2, ZP A3, ZP A4,..., ZPAN, it is possible to identify, in the course of prior step IF l, a plurality of predetermined cells

C1, C2, C3, C4, ..., CM, covering together this plurality of access points

ZPAl, ..., ZPAN (with M, in the notation "CM", greater than or equal to N, in the notation "ZPAN"). The connection of the terminal to the wireless network is authorized if at least one current cell in which the terminal is located corresponds to one of these cells C1, ..., CM. Thus, following a location of the terminal in an intersection respective coverage areas of a plurality of current cells (CCI, CC2, CC3) of the second network, when at least two access points are present in this same intersection of cells, the variant illustrated with reference to FIG. to allow access to a wireless network included in the intersection only if all access points included in the intersection are authorized for access.

In addition to the offer of increased security of communication via the local network, the present invention also provides other advantages, including a very low battery power consumption. In particular, no consumption is unnecessarily spent by the integrated wireless network card to continuously search wireless local area networks. The activation of the network card is optimally limited to use within a coverage area of an authorized access point (gateway) or predetermined public access points (Hotspots).

Of course, the present invention is not limited to the embodiment described above by way of example; it extends to other variants.

For example, the aforementioned "local" network is not necessarily a wireless network with an access point supporting communications in Wi-Fi mode. For example, an access point capable of receiving data in communication may be provided. infrared, the main point being that the range of the local network is limited and included in the coverage of the cellular network.

Furthermore, the cellular network is not necessarily a GSM type network, but it may also be, for example, a satellite network covering an access point to a local area network.

Claims

claims

A method for managing the communication of a mobile terminal (TER), said terminal being hybrid and capable of communicating with at least both: a first, local network comprising at least one access point (AP), and a second cellular network, geographically covering said access point, characterized in that it comprises a location of the terminal by the cellular network (S21, S22) and a connection authorization of the terminal (S24) to the local network at least if (S23) the terminal is located in an access point coverage area (APA).

2. Method according to claim 1, characterized in that it comprises: a preliminary step (Sl 1) identification of at least one predetermined cell of the second network, covering said access point, and following a localization of the terminal in at least one current cell of the second network, a test and decision step (S23) for comparing the current cell to said predetermined cell and allowing a connection (S24) of the terminal to the first network at least if the current cell corresponds to the predetermined cell.

3. Method according to claim 2, characterized in that, during said preliminary step (SU), a plurality of predetermined cells (CCI, CC2) covering said access point (PA) are identified, and the connection to the first network is allowed at least if the current cell (CCI, CC2), at least, corresponds to one of said predetermined cells.

4. Method according to claim 3, characterized in that, following a location of the terminal in an intersection of respective coverage areas of a plurality of current cells (CCI, CC2, CC3) of the second network, the connection of the terminal to the first network is allowed at least if each current cell corresponds to one of said predetermined cells.

5. Method according to one of claims 2 to 4, the first network comprising a plurality of access points (ZPAl, ..., ZAPN), characterized in that, during the prior step (SU), identifying a plurality of predetermined cells (C1, ..., CM) covering said plurality of access points together, and connecting the terminal to the first network is allowed at least if the current cell, at least, corresponds to the one of said plurality of predetermined cells.

6. Method according to one of claims 2 to 5, characterized in that the prior step (SU) comprises storage in memory (12) of the terminal of at least one identifier (Cj) of predetermined cell.

7. Method according to one of the preceding claims, characterized in that the connection authorization comprises an activation authorization, from the terminal, the search connection to the local network (S24).

8. Method according to claim 7, characterized in that the connection authorization comprises a power supply control of a card (13) associated with the local network, while a connection non-authorization includes a control of cutoff power supply of said card (13).

Mobile communication terminal, hybrid and having at least one communication interface with at least: a first network, local, having at least one access point, and a second cellular network, geographically covering said access point, characterized in that it further comprises: a memory (12) storing at least one predetermined cell identifier covering said access point, and a module (10) arranged to receive a current cell identifier (Cj) by which the terminal is connected to the cellular network, and to cooperate with said memory (12) to compare the identifier of the current cell and the identifier of the predetermined cell and decide a connection authorization of the terminal to local network at least in case of coincidence of the respective identifiers of current cell and predetermined cell.

10. Terminal according to claim 9, comprising a card (13) associated with the local area network and a circuit (16) for power supply (15) of said card, characterized in that said module (10) emits: a control of supplying power to said card (13) in case of coincidence of the respective current cell and predetermined cell identifiers, and power supply cutoff control of said card (13), otherwise.

1 1. module of a hybrid terminal according to one of claims 9 and 10, for the communication management of the terminal with the local network, characterized in that it comprises: access to a memory (12) storing at least a predetermined cell identifier covering said access point, an input (1 1) for receiving a current cell identifier (Cj) through which the terminal is connected to the cellular network, and test and decision means (10) for compare the identifier of the current cell with the identifier of the predetermined cell and decide a connection authorization of the terminal to the local network at least in case of coincidence of the respective identifiers of current cell and predetermined cell.

12. Module according to claim 1 1, characterized in that it further comprises control means (17) of a circuit (16) for power supply (15) of a card (13) associated with the network. local, for: controlling the power supply of said card (13) in case of coincidence of the respective identifiers of current cell and predetermined cell, and control a power supply cutoff of said card (13), otherwise.

13. Computer program intended to be stored in memory of a module according to one of claims 1 1 and 12, characterized in that it comprises instructions for the implementation of the method according to one of claims 1 to 8, when they are executed by a processor (14) of such a module (10).

14. A communication system comprising a local area network access point (MOD) and a hybrid mobile terminal (TER) comprising at least one communication interface (IN1, IN2) with at least: a first network, local, comprising at least one least said access point (AP), and a second cellular network, geographically covering said access point, characterized in that the terminal further comprises: - a memory (12) storing at least one predetermined cell identifier covering said access point, and a module (10) arranged to receive a current cell identifier (Cj) by which the terminal is connected to the cellular network, and to cooperate with said memory (12) to compare the identifier of the cell current and the identifier of the predetermined cell and decide a connection authorization of the terminal to the local network, via said access point, at least in case of coincidence of the respective identifiers of current cell and cell ule predetermined.

15. System according to claim 14, characterized in that the terminal comprises a card (13) associated with the local area network and a power supply circuit (16) of said card, and in that the module (10) ) of the terminal transmits: a power supply control of said card (13) in case of coincidence of the respective identifiers of current cell and predetermined cell, and a power supply cut-off command of said card (13), if not.