Patent Publication Number: US-11388668-B2

Title: Method for controlling, via a terminal and a server, a standby mode of a communication module of the terminal

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part application of U.S. application Ser. No. 15/763,117 filed Mar. 25, 2018, which is a § 371 application from PCT/FR2016/052509 filed Sep. 30, 2016, which claims priority from French Patent Application No. 15 59262 filed Sep. 30, 2015, each of which is incorporated herein by reference in its entirety 
    
    
     TECHNICAL FIELD 
     The present invention belongs to the field of telecommunications, and relates more particularly to the management of the electrical consumption of a terminal of a wireless communication system. 
     BACKGROUND OF THE INVENTION 
     The present invention is applied particularly advantageously, although without any limitation, to wireless communication systems for M2M (acronym for “Machine-to-Machine”) or “Internet of Things” (IoT) applications. 
     In the context for example of the IoT, every everyday object is able to become a communicating object, and is equipped for this purpose with a terminal designed to transmit data to a wireless access network of a wireless communication system. 
     In such a context, it is important to have solutions that are both inexpensive (and therefore not very complex) and at the same time consume little electric power. This makes it possible for example to make many everyday objects able to communicate, without having a significant impact on their production cost, and above all without having too much of an impact on their autonomy when they are battery-operated. 
     Wireless communication systems are known that are optimized for M2M or IoT applications, and that make it possible to simultaneously serve, in a given zone, a very large number of terminals equipped with suitable communication modules, and that furthermore exhibit very low electrical consumption. 
     For example, ultra-narrowband wireless communication systems are known. The term “Ultra Narrow Band” (UNB) is understood to mean that the instantaneous frequency spectrum of the signals exchanged between the terminals and the wireless access network has a frequency width of less than two kilohertz, or even less than one kilohertz. Such signals are able to be transmitted with very low electrical consumption. The electrical consumption is also reduced by the fact that the terminals transmit signals without having to associate themselves beforehand with one or more base stations of said wireless access network. Thus, the terminal does not need to perform regular measurements to determine the most suitable base station for receiving its signals. The complexity hinges on the wireless access network, which must be capable of receiving signals that can be transmitted at arbitrary instants in time and on arbitrary frequencies. 
     Such UNB wireless communication systems therefore have, on the terminal side, an electrical consumption that is perfectly suitable for M2M or IoT applications. 
     By contrast, the use of ultra-narrowband signals limits the maximum throughput that can be achieved for exchanging data between a terminal and the wireless access network of a UNB wireless communication system. 
     Although such a limitation of the maximum throughput does not necessarily pose a problem for the majority of M2M and IoT applications, there may however be scenarios where it is necessary to be able to have a higher maximum throughput, in order in particular to be able to exchange a large amount of data more easily between said terminal and the wireless access network. For example, on a downlink of the wireless access network to the terminal, a higher maximum throughput would make it possible to transfer a firmware update for said terminal. 
     Numerous wireless communication systems are known that have a maximum throughput far higher than that of UNB wireless communication systems. 
     Mention may be made in particular of the GPRS, EDGE, UMTS, HSPA, HSPA+, LTE, CDMA2000, etc. wireless communication systems, which may be termed “high-throughput” in comparison with UNB wireless communication systems, which, by contrast, may be termed “low-throughput”. 
     However, one drawback of high-throughput wireless communication systems lies in the fact that they are accompanied, on the terminal side, by an electrical consumption that may prove to be too high for battery-operated objects. Furthermore, the number of terminals able to be connected simultaneously, in a given zone, to a high-throughput wireless communication system is generally limited, and far lower than the number of terminals able to be served, in this same zone, by a low-throughput wireless communication system. In addition, the associated cost is generally too high for M2M or IoT applications, insofar as each terminal has to have a personal identification code, for example an IMSI (“International Mobile Subscriber Identity”) subscriber number, enabling it to connect to the wireless access network of the high-throughput wireless communication system. 
     To benefit from the respective advantages offered by low-throughput wireless communication systems (for example UNB) and by high-throughput wireless communication systems (GPRS, EDGE, UMTS, HSPA, HSPA+, LTE, CDMA2000, etc.), it has been contemplated to equip some terminals with two communication modules, namely a low-throughput communication module and a high-throughput communication module. Although the electrical consumption of the high-throughput communication module may then be reduced by limiting use only to those exchanges requiring a high throughput, it may still remain too high for some battery-operated objects, in particular if the intended autonomy is long, of the order of a few years. Furthermore, the cost associated with using the high-throughput communication module remains too high for M2M or IoT applications. 
     Patent application EP 2755429 A1 provides a solution making it possible to reduce the electrical consumption of such a terminal, in which the high-throughput communication module is put into standby mode and is woken by way of the low-throughput communication module. However, this solution does not address the problem of cost associated with using a high-throughput communication module for M2M or IoT applications. 
     SUMMARY OF THE INVENTION 
     The aim of the present invention is to rectify all or some of the limitations of the prior art solutions, in particular those outlined above, by providing a solution that makes it possible both to reduce the electrical consumption of the high-throughput communication module of the terminal and to reduce the cost associated with using said high-throughput communication module. 
     To this end, and according to a first aspect, the invention relates to a method for controlling, by a processor-based terminal, a standby mode of a first communication module of the terminal. The first communication module is configured to exchange data with a first wireless access network. The terminal furthermore comprises a second communication module configured to exchange data with a second wireless access network, with a maximum throughput lower than a maximum throughput of the first communication module. Furthermore, the terminal belongs to a group of terminals sharing a set of one or several identification codes for connecting to the first wireless access network. The control method includes:
         listening, by way of the second communication module, to a downlink between the second wireless access network and the terminal in response to a determination that the first communication module is in standby mode,   receiving, via the second communication module, an activation request, transmitted by a processor-based server linked to the second wireless access network, wherein the activation request comprises an indication of an available identification code: activation of the first communication module from among the set of shared identification codes, and   activating the first communication module to connect to the first wireless access network using the indicated identification code.       

     The terminal thus listens to the downlink by way of the second communication module. If the server transmits an activation request, the terminal activates the first communication module, which then exits standby mode and is available to exchange data with the first wireless access network. In the opposite case, the first communication module remains in standby mode. 
     As a result, the activation of the first communication module is controlled remotely by the server. Such provisions are advantageous in that a server remote from the terminal may have access to information to which the terminal does not have access and that can be taken into account to decide whether the first communication module should be activated. 
     In particular, in order to reduce the cost associated with using the first communication module, the latter uses, to connect to the first wireless access network, an identification code that is shared by a group of terminals. Specifically, it is understood that such a solution is more economical than the prior art solutions, in which each terminal has to have a personal identification code. By contrast, the first communication module of said terminal will not be able to connect to the first wireless access network if the shared identification code is already being used by another terminal of the group, and there is therefore no need to activate the first communication module in such a case. Advantageously, the server remotely controls the activation of the first communication module of the terminal depending on the availability, or lack thereof, of said shared identification code. 
     For example, the server may know whether a large amount of data, for example a firmware update for the terminal, has to be transferred to said terminal by way of the first wireless access network. According to another example, it is possible for the number of terminals that are already connected to the first wireless access network to be equal to a maximum number of terminals able to be connected simultaneously. In such a case, there is no need to activate the first communication module, even if said terminal has a large amount of data to transmit, since said terminal will not be able to connect to the first wireless access network. 
     In particular modes of implementation, the control method may furthermore include one or more of the following features, taken alone or in any technically feasible combination. 
     In particular modes of implementation, the identification codes shared by the group of terminals are IMSI subscriber numbers, MAC addresses, IP addresses or multicast group identifiers. 
     In particular modes of implementation, the method for controlling a standby mode by the terminal includes:
         evaluating a criterion for transmitting a request to confirm activation of the first communication module,   when the criterion for transmitting an activation confirmation request is met: transmitting, by way of the second communication module, an activation confirmation request to the server,
 
the terminal listening to the downlink after having transmitted the activation confirmation request, waiting for an activation request transmitted by the server in response to said activation confirmation request.
       

     In such a case, although the activation of the first communication module is controlled remotely by the server, the procedure that leads, or does not lead, to the activation of said first communication module is initiated by the terminal, through the transmission of the activation confirmation request. Such provisions are advantageous in that the electrical consumption associated with using the second communication module can also be controlled. Specifically, it is not necessary to listen to the downlink at all times waiting for an activation request, since the latter is transmitted in response to an activation confirmation request transmitted by the terminal. As a result, the second communication module can also be put into standby mode often. 
     In particular modes of implementation, evaluating the criterion for transmitting an activation confirmation request includes comparing the instant in time of the evaluation of said criterion for transmitting an activation confirmation request with a predetermined date. 
     In particular modes of implementation, evaluating the criterion for transmitting an activation confirmation request includes determining whether data have to be transmitted by way of the first communication module. 
     In particular modes of implementation, the control method includes, when the first communication module is in active mode, evaluating a criterion for returning to standby mode and, when said criterion for returning to standby mode is met, deactivating said first communication module. 
     In particular modes of implementation, evaluating the criterion for returning to standby mode includes determining whether data have to be exchanged by way of the first communication module. 
     In particular modes of implementation, evaluating the criterion for returning to standby mode includes comparing the instant in time of the evaluation of said criterion for returning to standby mode with a predetermined date. 
     In particular modes of implementation, evaluating the criterion for returning to standby mode includes analyzing a level of electrical energy stored in a battery of the terminal. 
     In particular modes of implementation, the first wireless access network and the second wireless access network are both wireless wide area networks. 
     In particular modes of implementation, the first communication module is compatible with at least one of the following wireless communication protocols: GPRS, EDGE, UMTS, HSPA, HSPA+, LTE, CDMA2000, IEEE 802.11, WiFi, Bluetooth, NB-IoT. 
     In particular modes of implementation, the second communication module transmits data in the form of ultra-narrowband signals. 
     According to a second aspect, the present invention relates to a terminal of a wireless communication system, including a first communication module configured to exchange data with a first wireless access network, a second communication module configured to exchange data with a second wireless access network, with a maximum throughput lower than a maximum throughput of the first communication module. The terminal belongs to a group of terminals sharing a set of one or several identification codes to connect to the first wireless network. The terminal furthermore comprises a processor configured:
         listen, via the second communication module, to a downlink between the second wireless access network and the terminal in response to a determination that the first communication module is in standby mode;   receive, via the second communication module, an activation request, transmitted by a processor-based server linked to the second wireless access network, wherein the activation request comprises an indication of an available identification code from among the set of shared identification codes; and   activate the first communication module to connect to the first wireless access network using the indicated identification code.       

     According to a third aspect, the present invention relates to a method for remotely controlling, by a processor-based server, a standby mode of a first communication module of a processor-based terminal. The server is linked to the second wireless access network, and the first communication module of the terminal is controlled in accordance with a control method according to any one of the embodiments of the invention. The remote control method comprises:
         evaluating a criterion for transmitting an activation request to activate the first communication module of the terminal, including determining whether an identification code, among a set of one or several identification codes shared by the group of terminals to which said terminal belongs, is available for use by said terminal to connect to the first wireless access network; and   when the criterion for transmitting an activation request is met:       

     transmitting, by way of the second wireless access network, the activation request to the terminal, wherein the activation request comprises an indication of available identification code from among the set of shared identification codes. 
     In particular modes of implementation, the remote control method may furthermore include one or more of the following features, taken alone or in any technically feasible combination. 
     In particular modes of implementation, the identification codes shared by the group of terminals are IMSI subscriber numbers, MAC addresses, IP addresses or multicast group identifiers. 
     In particular modes of implementation, the remote control method includes listening to an uplink between the terminal and the second wireless access network, and the server evaluates the criterion for transmitting an activation request after having received an activation confirmation request transmitted by said terminal. 
     In particular modes of implementation, evaluating the criterion for transmitting an activation request includes determining whether data have to be transmitted to the terminal by way of the first wireless access network. 
     In particular modes of implementation, evaluating the criterion for transmitting an activation request includes comparing a level of use, by other terminals, of the first wireless access network and/or of the server with a predetermined maximum level. 
     According to a fourth aspect, the present invention relates to a server comprising a processor configured to remotely control a standby mode of a first communication module of a terminal in accordance with a remote control method according to any one of the modes of implementation of the invention. 
     According to a fifth aspect, the present invention relates to a wireless communication system including at least one terminal according to any one of the embodiments of the invention and a server according to any one of the embodiments of the invention. 
     In particular embodiments, the system includes a group of terminals sharing one and the same identification code to connect to the first wireless access network. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention will be better understood on reading the following description, given by way of wholly nonlimiting example and made with reference to the figures, in which: 
         FIG. 1  shows a schematic depiction of a wireless communication system; 
         FIG. 2  shows a diagram illustrating the main steps of a method for controlling, by a terminal, a standby mode of a communication module of said terminal; 
         FIG. 3  shows a diagram illustrating a preferred mode of implementation of a method for controlling, by a terminal, a standby mode of a communication module of said terminal; 
         FIG. 4  shows a diagram depicting the main steps of a method for remotely controlling, by a server, a standby mode of a communication module of a terminal; 
       and 
         FIG. 5  shows a diagram depicting a preferred mode of implementation of a method for remotely controlling, by a server, a standby mode of a communication module of a terminal. 
     
    
    
     In these figures, identical references from one figure to another denote identical or analogous elements. For the sake of clarity, the elements shown are not to scale, unless stated otherwise. 
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIG. 1  schematically shows a wireless communication system  10  including a terminal  20 . 
     The terminal  20  includes a first communication module  21  suitable for exchanging data with base stations  310  of a first wireless access network  31 , and a second communication module  22  suitable for exchanging data with base stations  320  of a second wireless access network  32 . In the example illustrated by  FIG. 1 , the base stations  310  of the first wireless access network  31  are all separate from the base stations  320  of the second wireless access network  32 . However, in other examples, there is nothing to rule out having base stations belonging both to the first wireless access network  31  and to the second wireless access network  32 , that is to say that are suitable for exchanging data with both the first communication module  21  and the second communication module  22 . 
     The terminal  20  exchanges data with the first wireless access network  31  and the second wireless access network  32  in the form of radio signals. The term “radio signal” is understood to mean an electromagnetic wave propagating via non-wired means, the frequencies of which are contained within the traditional radio wave spectrum (a few hertz to several hundred gigahertz). 
     The first communication module  21  has a maximum throughput higher than that of the second communication module  22 . For this reason, the first communication module  21  and the first wireless access network  31  may be termed “high-throughput” in comparison with the second communication module  22  and with the second wireless access network  32 , which, by contrast, may be termed “low-throughput” in comparison with the first communication module  21  and with the first wireless access network  31 . On account of this difference between their respective maximum throughputs, the second communication module  22  in principle has an electrical consumption lower than that of the first communication module  21 . 
     The first communication module  21  and the first wireless access network  31  are for example compatible with at least one of the following wireless communication protocols: GPRS, EDGE, UMTS, HSPA, HSPA+, LTE, CDMA2000, etc. 
     The second communication module  22  and the second wireless access network  32  are low-throughput in comparison with the first communication module  21  and with the first wireless access network  31 . For example, if the first communication module  21  and the first wireless access network  31  are compatible with the LTE wireless communication protocol, the second communication module  22  and the second wireless access network  32  may be compatible with the GPRS and/or EDGE communication protocol. 
     In preferred embodiments, the second communication module  22  of the terminal  20  and the second wireless access network  32  of the wireless communication system  10  exchange data in the form of ultra-narrowband (UNB) signals. Such provisions are particularly advantageous in that the electrical consumption of the second communication module  22  is then very low, and is particularly suitable for M2M or IoT applications. 
     In preferred embodiments of the wireless communication system  10 , the first wireless access network  31  and the second wireless access network  32  are both wireless wide area networks, also called WWAN. In such a case, the terminal  20  is almost always in a zone covered both by the first wireless access network  31  and by the second wireless access network  32 . 
     As illustrated by  FIG. 1 , the wireless communication system  10  also includes a server  30 . In the nonlimiting example illustrated by  FIG. 1 , the server  30  is linked both to the first wireless access network  31  and to the second wireless access network  32 . As a result, the terminal  20  is able to exchange data with the server  30  by way of said first wireless access network  31  (by way of the first communication module  21 ) and by way of the second wireless access network  32  (by way of the second communication module  22 ). 
     As indicated previously, the present invention relates in particular to the management of the electrical consumption of the terminal  20 , and in particular the electrical consumption associated with using the first communication module  21 . 
     In order in particular to limit the electrical consumption, the terminal  20  is able to put said first communication module  21  into standby mode. The term “standby mode” is understood to mean any mode of operation of the first communication module  21  in which it is not permitted to exchange data with the first wireless access network  31 , including a flight mode or a complete shutdown of said first communication module  21  by ceasing to supply it with electric power. 
     Advantageously, the terminal  20  may also be adapted to put the second communication module  22  into standby mode, in order to reduce the electrical consumption of said terminal  20  to an even greater extent. 
     The present invention relates more particularly to the control of the standby mode of the first communication module  21  of the terminal  20 , that is to say the control of the transitions from the standby mode to an active mode (in which the first communication module  21  is permitted to exchange data with the first wireless access network  31 ), and vice versa. 
     More particularly, the control of the standby mode of the first communication module  21  of the terminal  20  is distributed between the terminal  20  and the server  30 , and is primarily broken down into:
         a control method  50  whose steps are executed locally by the terminal  20 ,   a remote control method  60  whose steps are executed by the server  30 .       

     In its general principle, the control of the standby mode of the first communication module  21  of the terminal  20  is based, when said first communication module  21  is in standby mode, on transmitting an activation request, by the server  30 , by way of the second wireless access network  32 , to the terminal  20 . When the terminal  20  receives the activation request by way of the second communication module  22 , said terminal  20  activates the first communication module  21 . In the opposite case, the first communication module  21  remains in standby mode. 
     A) Method for Controlling a Standby Mode by the Terminal 
       FIG. 2  schematically shows the main steps of a method  50  for controlling, by the terminal  20 , a standby mode of the first communication module  21  of said terminal  20 . 
     To this end, the terminal  20  includes in particular a control device (not shown in the figures), including one or more processors and memory storage means (magnetic hard disk, electronic memory, optical disk, etc.) in which a computer program product, in the form of a set of program code instructions to be executed in order to implement the various steps of the standby mode control method  50 , is stored in memory. In one variant, the control device includes one or more programmable logic circuits (FPGA, PLD, etc.), and/or one or more specialized integrated circuits (ASIC), and/or a set of discrete electronic components, etc., designed to implement all or some of said steps of the standby mode control method  50 . 
     In other words, the terminal  20  includes a set of means that are configured as software (specific computer program product) and/or hardware (FPGA, PLD, ASIC, discrete electronic components, etc.) in order to implement the steps of the standby mode control method  50 . 
     As indicated previously, the control of the standby mode of the first communication module  21  of the terminal  20  is based in particular, when said first communication module  21  is in standby mode, on transmitting an activation request, by the server  30 , by way of the second wireless access network  32 , to the terminal  20 . 
     On the side of the terminal  20 , the standby mode control method  50  consequently includes a step  53  of listening to a downlink between the second wireless access network  32  and said terminal  20 , by way of the second communication module  22 . 
     When the terminal  20  receives, by way of the second communication module  22 , an activation request transmitted by the server  30  (reference  530  in  FIG. 2 ), the standby mode control method  50  then includes a step  54  of activating, by the terminal  20 , the first communication module  21 . During the activation step  54 , the first communication module  21  exits standby mode for active mode, in which it can connect to the first wireless access network  31  in order to exchange data. The second communication module  22  can advantageously be put into standby mode during the step  54  of activating the first communication module  21  in order to reduce its electrical consumption. 
     By contrast, if no activation request is received by the terminal  20  (reference  531  in  FIG. 2 ), the first communication module  21  is not activated and consequently remains in standby mode. 
     In preferred modes of implementation, and as illustrated by  FIG. 2 , the method  50  for controlling a standby mode by the terminal  20  may include, when the first communication module  21  is in active mode, a step  55  of evaluating a predetermined criterion for returning to standby mode. When said criterion for returning to standby mode is met (reference  550  in  FIG. 2 ), the standby mode control method  50  includes a step  56  of deactivating said first communication module  21  by the terminal  20 , during which step said first communication module  21  exits active mode for standby mode. In the opposite case (reference  551  in  FIG. 2 ), the first communication module  21  of the terminal  20  remains in active mode. 
     Specifically, in order to limit the electrical consumption of the terminal  20 , the first communication module  21  is again put into standby mode as soon as predetermined conditions are satisfied, and step  55  of evaluating said criterion for returning to standby mode is intended precisely to determine whether these conditions are indeed satisfied. 
     For example, the return to standby mode may be carried out at predetermined dates. In particular, it is possible to force a return to standby mode when no exchange of data is carried out by way of the first communication module  21  for a predetermined maximum period. 
     As an alternative or in addition, the criterion for returning to standby mode may be considered to be met when there are no more data to be exchanged by way of the first communication module  21 . 
     It is also possible, as an alternative or in addition, to take account of the level of electrical energy stored in a battery (not shown in the figures) of the terminal  20 . In particular, it is possible to force a return to standby mode when the level of electrical energy stored in the battery falls below a predetermined minimum level. 
     It should be noted that, as an alternative or in addition, the server  30  may force the first communication module  21  of the terminal  20  to return to standby mode by sending a deactivation request by way of the first wireless access network  31  or by way of the second wireless access network  32 . If the terminal  20  receives such a deactivation request, the criterion for returning to standby mode is considered to be met and said terminal  20  deactivates the first communication module  21 . 
     Other types of criteria for returning to standby mode may be considered, and the choice of a particular criterion constitutes only an implementation variant of the invention. 
       FIG. 3  shows a preferred mode of implementation of the method  50  for controlling a standby mode by the terminal  20 . In the preferred mode of implementation illustrated by  FIG. 3 , the server  30  remotely controls the activation of the first communication module  21  of the terminal  20 , but upon the initiative of said terminal  20 . Specifically, when the terminal  20  contemplates activating its first communication module  21 , it transmits, by way of the second communication module  22 , an activation confirmation request to the server  30 . Using this request, said terminal  20  asks the server  30  whether the first communication module  21  may or has to be activated. If the server  30  responds to this activation confirmation request with an activation request, the terminal  20  activates the first communication module  21 . In the opposite case, the first communication module  21  of the terminal  20  remains in standby mode. 
     As illustrated by  FIG. 3 , the standby mode control method  50  includes, first of all, when the first communication module  21  is in standby mode, a step  51  of evaluating a predetermined criterion for requesting confirmation of activation of the first communication module  21 . 
     Specifically, in order to limit the electrical consumption of the terminal  20 , an activation confirmation request is advantageously transmitted only if predetermined conditions are satisfied, and the step  51  of evaluating said criterion for transmitting an activation confirmation request is intended precisely to determine whether these conditions are indeed satisfied. 
     For example, an activation confirmation request may be transmitted at predetermined dates. In particular, it is possible to transmit an activation confirmation request in a substantially periodic fashion, with a period Te. In this case, the criterion for transmitting an activation confirmation request is considered to be met when a period Te has elapsed since the previous transmission of an activation confirmation request. According to another example, it is also possible, as an alternative or in addition, to transmit an activation confirmation request when a validity limit date for data stored in memory in the terminal  20 , for example firmware, has been exceeded. In this case, the activation of the first communication module  21  is intended to update said data whose validity limit date has been exceeded. 
     As an alternative or in addition, the criterion for transmitting an activation confirmation request may be considered to be met when it is determined that data for the terminal  20  have to be transmitted by way of the first communication module  21 . The exchanges of data for the terminal  20  preferably take place mainly by way of the second communication module  22 , and use of the first communication module  21  is limited to exchanges of a large amount of data, for example greater than a predetermined threshold value. However, in other examples, there is nothing to rule out using the second communication module  22  only to control the standby mode of the first communication module  21 , which may then be used to carry out all of the other exchanges of data. 
     Other types of criteria for transmitting an activation confirmation request may be considered, and the choice of a particular criterion constitutes only an implementation variant of the invention. 
     As illustrated by  FIG. 3 , when the criterion for transmitting an activation confirmation request is met (reference  510  in  FIG. 3 ), the standby mode control method  50  includes a step  52  of transmitting, by way of the second communication module  22 , an activation confirmation request to the server  30 . 
     In the opposite case, that is to say when the criterion for transmitting an activation confirmation request is not met (reference  511  in  FIG. 3 ), no activation confirmation request is transmitted. 
     The second communication module  22  is also preferably in standby mode during the step  51  of evaluating the criterion for transmitting an activation confirmation request, in order to reduce the electrical consumption of the terminal  20 . As the case may be, said second communication module  22  is activated when the criterion for transmitting an activation confirmation request is considered to be met, prior to step  52  of transmitting the activation confirmation request to the server  30 . 
     As illustrated by  FIG. 3 , after having transmitted an activation confirmation request, the steps of the method  50  for controlling a standby mode by the terminal  20  correspond to the steps of the mode of implementation described with reference to  FIG. 2 . 
     It should be noted that the terminal  20  may be capable of implementing only one of the modes of implementation described with reference to  FIGS. 2 and 3 , or else be capable of implementing the two modes of implementation described with reference to  FIGS. 2 and 3 , that is to say be capable:
         of transmitting an activation confirmation request, and   of receiving an activation request without having transmitted an activation confirmation request.
 
B) Method for Remote Control by the Server
       

     As indicated previously, the server  30  remotely controls the activation of the first communication module  21  of the terminal  20 , and  FIG. 4  schematically shows the main steps of the remote control method  60  implemented by said server  30 . 
     To this end, the server  30  includes for example one or more processors and memory storage means (magnetic hard disk, electronic memory, optical disk, etc.) in which a computer program product, in the form of a set of program code instructions to be executed in order to implement the various steps of the remote control method  60 , is stored in memory. In one variant, the server  30  includes one or more programmable logic circuits (FPGA, PLD, etc.), and/or one or more specialized integrated circuits (ASIC), and/or a set of discrete electronic components, etc., designed to implement all or some of said steps of the remote control method  60 . 
     In other words, the server  30  includes means that are configured as software (specific computer program product) and/or hardware (FPGA, PLD, ASIC, discrete electronic components, etc.) in order to implement the various steps of the remote control method  60 . 
     As illustrated by  FIG. 4 , the method  60  for remote control by the server  30  includes a step  62  of evaluating a predetermined criterion for transmitting an activation request to the terminal  20 . 
     Specifically, in order to limit the electrical consumption of the terminal  20 , an activation request is advantageously transmitted by the server  30  only if predetermined conditions are satisfied, and step  62  of evaluating said criterion for transmitting an activation request is intended precisely to determine whether these conditions are indeed satisfied. 
     When the criterion for transmitting an activation request is met (reference  620  in  FIG. 4 ), the method  60  for remote control by the server  30  includes a step  63  of transmitting, by way of the second wireless access network  32 , an activation request to the terminal  20 . 
     In the opposite case, that is to say when the criterion for transmitting an activation request is not met (reference  621  in  FIG. 4 ), no activation request is transmitted (step  64  in  FIG. 3 ). 
       FIG. 5  shows the main steps of the remote control method  60 , in the case where the terminal  20  initiates the activation procedure by transmitting an activation confirmation request, as described with reference to  FIG. 3 . In this case, and as illustrated by  FIG. 5 , the remote control method  60  includes a step  61  of listening to the uplink between the terminal  20  and the second wireless access network  32 . 
     Step  61  of listening to the uplink is executed for as long as no activation confirmation request is received (reference  611  in  FIG. 5 ). 
     When the server  30  receives an activation confirmation request (reference  610  in  FIG. 5 ), said server  30  executes step  62  of evaluating the criterion for transmitting an activation request. 
     As before, when the criterion for transmitting an activation request is met (reference  620  in  FIG. 5 ), the server  30  transmits, by way of the second wireless access network  32 , an activation request to the terminal  20 . In the opposite case, that is to say when the criterion for transmitting an activation request is not met (reference  621  in  FIG. 5 ), no activation request is transmitted (step  64  in  FIG. 5 ), that is to say no response is transmitted by the server  30 , or else the server  30  responds to the terminal  20  but indicates that the first communication module  21  should not be activated. 
     Various types of criteria for transmitting an activation request may generally be considered, and the choice of a particular criterion constitutes only an implementation variant of the invention. 
     For example, if the terminal  20  does not have data to transmit by way of the first communication module  21 , the transmission of an activation request may be conditional upon the presence, at the server  30 , of data to be transmitted to the terminal  20  by way of the first wireless access network  31 . In such a case, the activation may be initiated by the server  30  ( FIGS. 2 and 4 ) or, if it is initiated by the terminal  20  ( FIGS. 3 and 5 ), the transmission of the activation confirmation request by the terminal  20  is intended primarily to determine whether the server  30  has data to convey to it by way of the first wireless access network  31 . 
     As an alternative or in addition, the transmission of an activation request may be conditional upon the ability of the server  30  to exchange data with the terminal  20  by way of the first wireless access network  31 . For example, the first wireless access network  31  and/or the server  30  may be configured to accept the connection of a new terminal  20  to the first wireless access network  31  as long as the level of use, by other terminals, is lower than a predetermined maximum level. Thus, if the maximum level is reached, the terminal  20  will not be able to connect to the first wireless access network  31  and/or to the server  30 , such that there is no need to activate the first communication module  21 . In such a case, if the activation is initiated by the terminal  20  ( FIGS. 3 and 5 ), the transmission of the activation confirmation request by the terminal  20  is intended primarily to check the availability of the first wireless access network  31  and of the server  30  before activating its first communication module  21 . 
     It should be noted that, in preferred modes of implementation, the terminal  20  may belong to a group of terminals  20  sharing one and the same identification code for the first wireless access network  31 . In other words, the terminals  20  belonging to this group use the same identification code to connect to the first wireless access network  31 . 
     Such provisions are particularly advantageous in that they make it possible to greatly reduce the costs associated with using the first communication module  21 , as these costs are shared between all of the terminals  20  of said group. In such a case, the standby mode is also intended to enable said identification code to be shared by a group of terminals  20 . Specifically, as a terminal  20  in standby mode is not permitted to exchange data with the first wireless access network  31 , it has released the shared resource, i.e. the identification code, which can be used by one of the other terminals  20  belonging to the same group. 
     In the remainder of the description, a case is considered, in a nonlimiting manner, in which the terminals  20  of said group use one and the same IMSI subscriber number to connect to the first wireless access network  31 . However, in other examples, there is nothing to rule out considering other types of identification codes (like for example, MAC addresses, IP addresses or multicast group identificers), and the choice of a particular type of identification code to be shared between the various terminals  20  of the group constitutes only an implementation variant of the invention. 
     To this end, the terminals  20  of said group may be equipped with respective SIM (“Subscriber Identity Module”) cards that are identical in that they all store the same IMSI subscriber number in memory. Each terminal  20  of the group is thus able to connect to the first wireless access network  31  using the shared IMSI subscriber number, and therefore the associated MSISDN (“Mobile Station International Subscriber Directory Number”) number. By contrast, at any instant in time, there may not be more than one terminal  20  of said group connected to said first wireless access network  31  using said shared IMSI subscriber number, and the server  30  advantageously controls access, by the terminals  20  of said group, to the use of the shared IMSI subscriber number. In such a case, the transmission of an activation request by the server  30  may be conditional upon the availability of the shared IMSI subscriber number. To this end, the server  30  stores in memory for example a list of the terminals  20  of said group and the IMSI subscriber number associated with said group, and also, when said IMSI subscriber number is being used by a terminal  20  of said group, the identity of this terminal  20 . As a result, evaluating the criterion for transmitting an activation request in this case includes determining whether the IMSI subscriber number associated with the terminal  20  to which the activation request has to be sent is being used by another terminal of the same group, and the criterion for transmitting an activation request is considered to be met if it is determined that said IMSI subscriber number is available. By transmitting the activation request, the server  30  therefore indicates to the terminal  20  that the shared IMSI subscriber number is available. In such a case, if the activation is initiated by the terminal  20  ( FIGS. 3 and 5 ), the transmission of the activation confirmation request by the terminal  20  is intended primarily to check the availability of the shared IMSI subscriber number before activating its first communication module  21 . 
     It should be noted that, if one and the same IMSI subscriber number is shared by a group of terminals  20 , the server  30  should preferably be informed when a terminal  20  stops using said shared IMSI subscriber number. This is the case when the server  30  transmits, by way of the first wireless access network  31  or of the second wireless access network  32 , a request to deactivate the first communication module  21 . By contrast, when the terminal  20  decides to deactivate the first communication module  21 , for example when the criterion for returning to standby mode is met, it may inform the server  30  of this deactivation, by way of the first communication module  21  (before the deactivation) or by way of the second communication module  22 . As an alternative or in addition, the server  30  may be linked to the first wireless access network  31  such that it is able to be informed of the disconnection between the terminal  20  and the first wireless access network  31 . 
     It should also be noted that one and the same group of terminals  20  may, in particular modes of implementation, share a plurality of IMSI subscriber numbers (or a plurality of identification codes if another type of identification codes are used like MAC addresses, IP addresses or multicast group identifiers) in order to connect to the first wireless access network  31 . Such provisions make it possible to facilitate access to the first wireless access network  31 , in particular in the case of a group containing a large number N T  of terminals  20 , while at the same time lowering the cost associated with using the first communication module  21  when the number N C  of shared IMSI subscriber numbers is lower than the number N T  of terminals of the group. In such a case, evaluating the criterion for transmitting an activation request includes determining whether at least one of the N C  shared IMSI subscriber numbers is available, and said criterion for transmitting an activation request is considered to be met if it is determined that one of said N C  shared IMSI subscriber numbers is available. As the case may be, the transmitted activation request may indicate which available IMSI subscriber number said terminal  20  should use to connect to the first wireless access network  31 . 
     More generally, it should be noted that the modes of implementation and embodiments considered above have been described by way of non-limiting example, and that other variants are therefore conceivable. 
     In particular, the invention has been described considering that the first wireless access network  31  and the second wireless access network  32  are both wireless wide area networks (WWAN). However, the invention may be applied to other types of wireless networks, including in particular wireless local area networks (IEEE 802.11, WiFi, Bluetooth, etc.) or NB-IOT networks. The use of wireless wide area networks is however advantageous in that it makes it possible to limit needless waking of the first communication module  21  and/or of the second communication module  22 . 
     Furthermore, the invention has been described considering that the server  30  is linked both to the first wireless access network  31  and to the second wireless access network  32 . However, if the data exchanged by the first communication module  21  and the first wireless access network  31  should not transit by the server  30 , then said server  30  may be linked only to the second wireless access network  32 . This is the case in particular if the server  30  manages only the remote control of the standby mode of the first communication module  21  of the terminal  20 . 
     It should furthermore be noted that an activation request transmitted by the server  30  to a terminal  20  may also include, in particular modes of implementation, additional information for the attention of said terminal  20 . In particular, the server  30  may indicate that said terminal  20  should comply with a delay before activating the first communication module  21  and/or before attempting to connect to the first wireless access network  31 , in order for example to enable the first wireless access network  31  and the server  30  to be available again to exchange data with the terminal  20 . The duration of said delay may be predetermined and/or included in the activation request transmitted by the server  30 . 
     The above description clearly illustrates that, through its various features and the advantages thereof, the present invention achieves the aims that it set itself. In particular, the present invention makes it possible in particular to avoid activating the first communication module  21  of the terminal  20  when there are no data to be received by way of the first wireless access network  31 , but also when the first wireless access network  31  and/or the server  30  are not available to exchange data, or when an identification code of the terminal  20  for the first wireless access network  31 , which code is shared with other terminals, is not available.