Abstract:
A method for determining if a call, corresponding to a mobile terminal located in a cell of a base station of a wireless telecommunication network is permitted to be routed through the base station. The method includes receiving a command representative of a level of acceptance of calls permitted to be routed through the base station, obtaining a class of service associated with the call, and deciding if the call is permitted to be routed through the base station according to the class of service of the call and the level of acceptance of calls permitted to be routed through the base station.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority under 35 U.S.C. §119 from European Patent Application No. 07000994.9, filed Jan. 18, 2007, the entire contents of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to methods and devices for determining if a call, in which a mobile terminal located in a cell of a base station of a wireless telecommunication network is involved, has to go through the base station. 
     2. Description of Related Art 
     Today, there is a trend to put base stations of inside home and offices. Recently, some Fixed-Mobile Convergence (FMC) solutions are proposed, where Public Land Mobile Network (PLMN) signals are relayed inside homes/offices. 
     However, the only customers to which an access can be offered to the cells of these base stations are the one being the owner of the base station. 
     If the owner of the base station authorizes calls from other mobile terminals to go through its base station, it may occur sometimes that these calls require most of the resources of the base station. In such case, the owner may not be able to establish or receive a communication through its own base station. 
     Furthermore, if the owner of the base station unplugs its base station, this will affect the communication of its mobile terminal and other mobile terminals. 
     This situation is not satisfactory. 
     BRIEF SUMMARY OF THE INVENTION 
     The aim of the invention is therefore to propose methods and devices which make it possible to enable to limit the use of the resources of a base station for the transfer of communication through the base station. 
     To that end, the present invention concerns a method for determining if a call, in which a mobile terminal located in a cell of a base station of a wireless telecommunication network is involved, has to go through the base station, characterised in that the method comprises the steps of:
         receiving a command representative of a level of acceptance of calls going through the base station,   obtaining a class of service associated to the call,   deciding if the call has to go through the base station according to the class of service of the call and the level of acceptance of calls going through the base station.       

     The present invention concerns also a device for determining if a call, in which a mobile terminal located in a cell of a base station of a wireless telecommunication network is involved, has to go through the base station, characterised in that the device comprises:
         means for receiving a command representative of a level of acceptance of calls going through the base station,   means for obtaining a class of service associated to the call,   means for deciding if the call has to go through the base station according to the class of service of the call and the level of acceptance of calls going through the base station.       

     Thus, the use of the resources of a base station for the transfer of communication through the base station can be restricted, according to the level of acceptance of calls. 
     Furthermore, the level of acceptance can be varied so as to adapt the restriction of access to various usages of the base station. The resources of the base station can be reserved for prioritised calls, having the appropriate class of service. 
     According to a particular feature, the method is executed by the base station or the device is the base station and the command representative of a level of acceptance is received from a keyboard associated to the base station. 
     Thus, the control of the use of the resources of a base station is not centralized and doesn&#39;t need an important transfer of data through the telecommunication network. It is easy to adapt, in real time, the restrictions when the usage of the base station varies. 
     According to a particular feature, the call is an ongoing call going through the base station or a new call in which the mobile terminal is involved, or is an ongoing call going through another base station of the wireless telecommunication network and for which a handover procedure is requested in order to allow the ongoing call to go through the base station. 
     Thus, the restriction of access can apply both to ongoing and new calls. It is not necessary to wait for the end of ongoing calls to get free resource when the level of acceptance of calls is changed according to the invention. 
     According to a particular feature, the base station establishes an handover procedure with another base station for one ongoing call going through the base station if the class of service of the ongoing call is not compatible with the level of acceptance of calls going through the base station. 
     Thus, each ongoing call going through the base station having a class of service which is not compatible with the level of acceptance of calls going through the base station can continue the communication through another base station. There is no interruption of the communication. The resource of the base station previously used for such ongoing calls can be reassigned to other ongoing calls or new calls with a class of service that is compatible with the level of acceptance of calls. 
     Such case is particularly effective when the owner of the base station authorizes calls from other mobile terminals to go through its base station. The owner of the base station can restrict the usage of its base station for the usage of the sole mobile terminals which are also owned by the owner of the base station. The quality of the communication of the mobile terminals of the owner of the base station can be enhanced. 
     According to a particular feature, the command representative of a level of acceptance of calls going through the base station is a power off command of the base station. 
     Thus, even if the base station is powered off, each ongoing call going through the base station can continue the communication. There is no interruption of the communication. It is easy for the owner of the base station to achieve basic handling of the base station, such as switching off the base station. The communications of tiers mobile terminals, going through the base station prior to the switching off, can be maintained after the switch off. 
     According to a particular feature, the base station is powered off once an handover has been executed for each ongoing call going through the base station or after a timer duration. 
     Thus, an important number of ongoing calls going through the base station can continue the communication. Furthermore, the owner of the base station needs not wait an undefined time, when it is necessary to manually power off the base station. 
     The present invention concerns also a method for enabling the determination if a call, in which a mobile terminal located in a cell of a base station of a wireless telecommunication network is involved, has to go through the base station, characterised in that the method comprises the steps of executed by a server of the wireless telecommunication network:
         determining a class of service associated to the call,   transferring the determined class of service associated to the call to the base station.       

     The present invention concerns also a server of the wireless telecommunication network enabling the determination if a call, in which a mobile terminal located in a cell of a base station of the wireless telecommunication network is involved, has to go through the base station, characterised in that the server comprises:
         means for determining a class of service associated to the call,   means for transferring the determined class of service associated to the call to the base station.       

     Thus, the use of the resources of a base station for the transfer of communication through a base station can be restricted and defined for each call. 
     According to a particular feature, the class of service is determined from the call priority and/or according to the type of service associated to the call. 
     Thus, by prioritizing the calls, the selection of the calls which can go through the base station is very effective. 
     According to a particular feature, the class of service is determined considering if the mobile terminal involved in the call belongs to the owner of the base station which is handling the call or if the mobile terminal involved in the call is registered as a preferred mobile terminal for the base station. 
     Thus, the mobile terminal which belongs to the owner of the base station which is handling the call has some higher priority in comparison with other mobile terminals. The owner of the base station can optimise the usage of its base station. 
     Furthermore, it can be set some preferred mobile terminals for a base station. These mobile terminals have some priority in comparison with other mobile terminals. 
     According to a particular feature, the class of service is determined according to the subscription level of the mobile terminal to the wireless telecommunication operator. 
     Thus, the mobile terminals which have a high subscription level have some priority in comparison with other mobile terminals. 
     According to a particular feature, the class of service is determined considering if the mobile terminal involved in the call belongs to the owner of the base station which is handling the call and according to the number and/or the class of service of calls abruptly terminated due to at least one power off of the base station and/or according to the number and the class of service of calls abruptly terminated due to at least one power off of at least one different base station, the at least one different base station belonging to the owner of the base station. 
     Thus, if the mobile terminal involved in the call belongs to the owner of a base station, the class of service is adjusted according to the contribution by the base stations belonging to the owner for the wireless telecommunication network. 
     According to a particular feature, the class of service is determined considering the level of acceptance of calls of at least one base station BTS belonging to the owner of the mobile terminal. 
     Thus, it is possible to encourage owners of base stations to set high level of acceptance of calls going through the base stations. The access to the telecommunication network through these base stations is more likely to be opened to mobile terminals not owned by the owner of the base stations. The coverage of the telecommunication is likely to be enhanced. 
     According to a particular feature, the server determines a financial compensation for the base station according to the level of acceptance of calls going through the base station. 
     Thus, it is possible to encourage owners of base stations to set high level of acceptance of calls going through the base stations. The access to the telecommunication network through these base stations is more likely to be opened to mobile terminals not owned by the owner of the base stations. The coverage of the telecommunication is likely to be enhanced. 
     According to a particular feature, the server determines a billing formula for the calls of a mobile terminal according to the determined class of service and/or at least one level of acceptance of calls going through a base station owned by the owner of the mobile terminal. 
     Thus, it is possible to encourage owners of base stations to set high level of acceptance of calls going through the base stations. The access to the telecommunication network through these base stations is more likely to be opened to mobile terminals not owned by the owner of the base stations. The coverage of the telecommunication is likely to be enhanced. 
     According to still another aspect, the present invention concerns computer programs which can be directly loadable into a programmable device, comprising instructions or portions of code for implementing the steps of the methods according to the invention, when said computer programs are executed on a programmable device. 
     Since the features and advantages relating to the computer programs are the same as those set out above related to the methods and devices according to the invention, they will not be repeated here. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The characteristics of the invention will emerge more clearly from a reading of the following description of an example embodiment, the said description being produced with reference to the accompanying drawings, among which: 
         FIG. 1  is a diagram representing the architecture of a wireless telecommunication network in which the present invention is implemented; 
         FIG. 2  is a block diagram of a server according to the present invention; 
         FIG. 3  is a block diagram of a base station according to the present invention; 
         FIGS. 4   a  and  4   b  represent an algorithm executed by a base station according to the present invention; 
         FIG. 5  represents an algorithm executed by a server according to the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a diagram representing the architecture of a wireless telecommunication network in which the present invention is implemented. 
     In the wireless telecommunication network according to the present invention, plural base stations BTSa, BTSb and BTSc, manage respectively the cells  15   a ,  15   b  and  15   c  in which mobile terminals  30   a ,  30   b  and  30   c  are located. The base stations BTS are linked through a telecommunication network  50  to a server  10 . 
     The telecommunication network  50  is, as example and in a non limitative way, a dedicated wired network, part of public network like a public switched network, an IP based network, a wireless network, an Asynchronous Transfer Mode network or a combination of above cited networks. 
     The server  10  is classically named a Mobility Management Entity or a Serving GPRS Support Node or a Foreign Agent or a Visitor Location Register or a Public Land Mobility Network server. 
     The server  10  comprises means for authenticating each mobile terminal  30  which intends to establish a communication through the wireless telecommunication network, means for memorizing the location of each mobile terminal  30  within the wireless telecommunication network and means for determining a class of service for each call transferred through the wireless telecommunication network to each mobile terminal  30  or received through the wireless telecommunication network by each mobile terminal  30 . 
     Only one server  10  is shown in the  FIG. 1  for the sake of clarity but in practice, a more important number of server  10  are comprised in the wireless telecommunication network. 
     The base stations BTSa, BTSb and BTSc comprise means for enabling the establishment or the continuation of a communication with each mobile terminal  30  which is located in the respective cells  15   a ,  15   b  and  15   c  each base station BTSa, BTSb and BTSc manages. 
     The base stations BTS are also named a node or a node B or an enhanced node B or an access point. 
     Only three base stations BTSa, BTSb and BTSc are shown in the  FIG. 1  for the sake of clarity. The base station BTSa manages the cell  15   a , the base station BTSb manages the cell  15   b  and the base station BTSc manages the cell  15   c.    
     According to the invention, each base station BTS comprises means for limiting the access by the mobile terminals  30  to the wireless telecommunication network according to the class of service determined by the server  10  for each call transferred through the wireless telecommunication network to each mobile terminal  30  located in the cell of the base station BTS or received through the wireless telecommunication network by each mobile terminal  30  located in the cell of the base station BTS. 
     The base stations BTS are as example preferably located in homes or offices. 
     The base stations BTS belong to partners of the wireless telecommunication network. As example, the base station BTSa belongs to a first partner Pa and the base stations BTSc and BTSb belong to a second partner Pcb. 
     A partner of the wireless telecommunication network is a company or a person which authorizes the mobile terminals  30  which are located in the cell  15  of its base station or base stations BTS to establish calls through one of its base station BTS and through the telecommunication network  50 . 
     In return of such service, the partner of which the base station BTS which is used by a mobile terminal  30  for the establishment or the continuation of a communication, preferably receives a financial compensation from the wireless telecommunication network operator. The financial compensation can be a discount on the subscription fee for the base station BTS, or a discount for communications with mobile terminals  30  owned by the partner, or a discount for subscription of access to the telecommunication network  50  or a payment. 
     The financial compensation is as example proportional to the amount of communications established or continued through the base station BTS, or proportional to the number of bits transferred by the base station BTS for the communication. 
     The mobile terminals  30  are terminals like mobile phones, personal digital assistants, or personal computers. The mobile terminals  30  can be either the mobile terminals of a partner of the wireless telecommunication network, or mobile terminals owned by clients of the wireless telecommunication network. 
     A client of the wireless telecommunication network is a person which subscribed to the wireless telecommunication network operator, the access to the wireless cellular telecommunication network comprising the base stations BTS according to the present invention. A client of the wireless telecommunication network is not necessary a partner of the wireless telecommunication network. 
     Only three mobile terminals  30   a ,  30   b  and  30   c  are shown in the  FIG. 1  for the sake of clarity but in practice, a more important number of mobile terminals  30  are located in the cells  15  of the wireless telecommunication network. 
       FIG. 2  is a block diagram of a server according to the present invention. 
     The server  10  has, for example, an architecture based on components connected together by a bus  201  and a processor  200  controlled by the programs as disclosed in the  FIG. 5 . 
     It has to be noted here that the server  10  is, in a variant, implemented under the form of one or several dedicated integrated circuits which execute the same operations as the one executed by the processor  200  as disclosed hereinafter. 
     The bus  201  links the processor  200  to a read only memory ROM  202 , a random access memory RAM  203 , a database  205  and a network interface  204 . 
     The RAM memory  203  contains registers intended to receive variables, and the instructions of the programs related to the algorithm as disclosed in the  FIG. 5 . 
     The read only memory  202  contains the instructions of the programs implementing the algorithm of the  FIG. 5 . 
     The processor  200  controls the operation of the network interface  204 . 
     The server  10  is connected to the telecommunication network  50  through the network interface  204 . As example, the network interface  204  is a DSL (Digital Subscriber Line) modem, or an ISDN (Integrated Services Digital Network) interface, etc. 
     The database  205  memorises, for each mobile terminal  30  comprised in the cells of the wireless telecommunication network, information related to the mobile terminal  30  like authentication parameters, subscription parameters, the identifier of the area in which the mobile terminal  30  is supposed to be located, information indicating if the mobile terminal  30  is a mobile terminal of a partner, if the mobile terminal  30  is associated to at least one community of base stations BTS. 
       FIG. 3  is a block diagram of a base station according to the present invention. 
     Each base station BTS has, for example, an architecture based on components connected together by a bus  301  and a processor  300  controlled by the programs as disclosed in the  FIGS. 4   a  and  4   b.    
     It has to be noted here that each base station BTS is, in a variant, implemented under the form of one or several dedicated integrated circuits which execute the same operations as the one executed by the processor  300  as disclosed hereinafter. 
     The bus  301  links the processor  300  to a read only memory ROM  302 , a random access memory RAM  303 , a network interface  304 , a radio interface  305 , displaying mean  307  and a keyboard  308 . 
     The memory  303  contains registers intended to receive variables, and the instructions of the programs related to the algorithm as disclosed in the  FIGS. 4   a  and  4   b.    
     The read only memory  302  contains the instructions of the programs implementing the algorithm of the  FIGS. 4   a  and  4   b.    
     The processor  300  controls the operation of the network interface  304  and of the radio interface  305 . 
     The base station BTS is connected to the telecommunication network  50  through the network interface  304 . As example, the network interface  304  is a DSL (Digital Subscriber Line) modem, or an ISDN (Integrated Services Digital Network) interface, etc. 
     The communications established or received by the mobile terminals  30  located in the cell  15  managed by the base station BTS go through the network interface  304  and the radio interface  305 . 
     The displaying mean  307  is a display which informs the partner of different messages generated by the processor  300  as it will described later on. The displaying mean  305  is in a variant composed of LEDs. 
     The keyboard  308  is constituted of at least one key and enables the partner to enter a level modification command according to the invention or to switch off the base station BTS. 
     It has to be noted here that, in a variant, the displaying mean  307  and/or the keyboard  308  can be external to the base station BTS. In such case, they are included totally or partially as example, in a personal computer. 
       FIGS. 4   a  and  4   b  represent an algorithm executed by a base station according to the present invention. 
     The present algorithm is executed by the processor  300  of each base station BTS. 
     According to the invention, each base station BTS has three states, a running state, a frozen state and a shut down state. The running state corresponds to a state wherein the base station BTS limits the access by the mobile terminals  30  to the wireless telecommunication network according to the class of service determined by the server  10 . The frozen state corresponds to a state wherein the base station BTS intends to proceed to handover procedure of the communications currently going through it, prior to be powered off. The shut down state corresponds to a state wherein the base station is powered off. 
     At step S 400  of the  FIG. 4   a , the processor  300  configures the base station BTS in the running state. 
     At step S 401 , the processor  300  checks if a level modification command has been entered through the keyboard  308  by the partner of which the base station BTS belongs to. 
     If no level modification command has been entered through the keyboard  308 , the processor  300  returns to step S 400 . 
     If a level modification command has been entered through the keyboard  308 , the processor  300  moves to step S 402 . 
     At step S 402 , the processor  300  sets the variable level to the corresponding level modification entered at step S 401 . 
     At next step S 403 , the processor  300  commands the transfer of a message through the network interface  304  informing the server  10  that the variable level has been modified. Preferably, the message comprises the value of the variable level. 
     At next step S 404 , the processor  300  commands the displaying of a message on the displaying mean  307  comprising information representing the new value of the variable level. 
     At next step S 405 , the processor  300  builds a set of rejected classes according to the value of the variable level. 
     As example, four different level values can be set. 
     A first level value authorizes all the calls transferred through the wireless telecommunication network to each mobile terminal  30  located in the cell of the base station BTS or received through the wireless telecommunication network by each mobile terminal  30  located in the cell of the base station BTS. 
     A second level value authorizes only the calls which have a class of service ranked as a gold or a silver class. 
     A third level value authorizes only the calls which have a class of service ranked as a gold class. 
     A fourth level value rejects all the calls transferred through the wireless telecommunication network to each mobile terminal  30  located in the cell of the base station BTS or received through the wireless telecommunication network by each mobile terminal  30  located in the cell of the base station BTS. 
     At next step S 406 , the processor  300  forms a list of ongoing calls which have a rejected class of service. 
     For that, the processor  300  reads in the RAM memory  303 , the class of service which is associated to each ongoing call. 
     At next step S 407 , the processor  300  checks if the base station BTS stops to transfer, through its radio interface  305  and its network interface  304 , all the ongoing calls listed in the list of ongoing calls which have a rejected class. 
     If the base station BTS stops to transfer all the ongoing calls listed in the list of ongoing calls which have a rejected class of service through its radio interface  305  and its network interface  304 , the processor  300  moves to step S 413 . Otherwise, the processor  300  moves to step S 408 . 
     At step S 408 , the processor  300  selects an ongoing call of the list of ongoing calls and checks if that call is in an handover list. 
     The handover list comprises all the calls comprised in the list of ongoing calls for which an handover procedure has been started with a neighbour base station BTS in order to transfer the handling of the call to the neighbour base station BTS. 
     If the call is in the handover list, the processor  300  moves to step S 412 , otherwise, the processor  300  moves to step S 409 . 
     At next step S 409 , the processor  300  selects the neighbour base station BTS which is susceptible to handle the selected call. For that the processor  300  reads in the RAM memory  303  information related to past measurement reports received from the mobile terminal  30  which is involved in the selected call. 
     At next step S 410 , the processor  300  commands the establishment of an handover procedure with the neighbour base station BTS selected at step S 409  in order to transfer the handling of the call to the neighbour base station BTS. 
     At next step S 411 , the processor  300  registers the selected ongoing call in the handover list. 
     At next step S 412 , the processor  300  selects another ongoing call in the list of ongoing calls of rejected classes and returns to step S 407 . 
     At step S 413 , the processor  300  checks if the variable level is equal to the fourth level value. If the variable level is different from the fourth level value, the processor  300  returns to step S 400 . If the variable level is equal to the fourth level value, the processor  300  moves to step S 414 . The fourth level value corresponds to the state wherein the base station BTS rejects all the calls transferred through the wireless telecommunication network to each mobile terminal  30  located in the cell of the base station BTS or received through the wireless telecommunication network by each mobile terminal  30  located in the cell of the base station BTS or the fourth level value corresponds to a switch off command. 
     At step S 414 , the processor  300  commands the transfer, through the network interface  304 , of a leave notification message to each neighbour base station BTS. 
     A leave notification message informs that the base station BTS intends to stop or to reject all the calls transferred through the wireless telecommunication network to each mobile terminal  30  located in the cell of the base station BTS or received through the wireless telecommunication network by each mobile terminal  30  located in the cell of the base station BTS. 
     At next step S 415 , the processor  300  activates a timer noted Tmax. 
     After that, the processor  300  moves to step S 490  of the  FIG. 4   b  which is representative of the frozen state of the base station BTS. 
     At step S 420 , the processor  300  checks if a switch off command has been entered through the keyboard  308  by the partner of which the base station BTS belongs to. 
     If no switch off command has been entered, the processor  300  returns to step S 400 . 
     If a switch off command has been entered, the processor  300  moves to step S 421 . 
     At step S 421 , the processor  300  memorizes the value of the variable level in the RAM memory  303 . 
     At next step S 422 , the processor  300  sets the value of the variable level to the fourth level value, as example to null value. 
     After that, the processor  300  moves to step S 403  already described. 
     At step S 430 , the processor  300  checks if a leave or a join notification message is received through the network interface  304  from a neighbour base station BTS. 
     If a leave or a join notification message is received from a neighbour base station BTS, the processor  300  moves to step S 431 . Otherwise, the processor  300  returns to step S 400 . 
     At step S 431 , the processor  300  removes or add the identifier of the neighbour base station BTS which sent the message received at step S 430  in or from the list of neighbour base stations BTS. The processor  300  also removes cells of the neighbour base station BTS in the lists of neighbour cells of cells of the base station BTS. 
     After that, the processor  300  returns to step S 400 . 
     At step S 440 , the processor  300  checks if a message representative of a new call establishment for a mobile terminal  30  located in the cell managed by the base station BTS is received or if a message representative of an establishment of an handover procedure is received or if a message comprising a modification of the class of service for one ongoing call is received. 
     If no message representative of a new call establishment for a mobile terminal  30  located in the cell managed by the base station BTS is received and no message representative of an establishment of an handover procedure is received and no message comprising a modification of the class of service for one ongoing call is received, the processor  300  returns to step  400 . 
     If a message representative of a new call establishment for a mobile terminal  30  located in the cell managed by the base station BTS is received or a message representative of an establishment of an handover procedure is received or a message comprising a modification of the class of service for one ongoing call is received, the processor  300  moves to step S 441 . 
     At step S 441 , the processor  300  commands the transfer of a message, through the network interface  304 , requesting the server  10  to transfer in response, a class of service to be associated to the new call or to the call for which the handover procedure is established or to the ongoing call for which the class of service is modified. In a variant of realisation, when the message is representative of an establishment of an handover procedure, the class of service is received from the base station BTS which transferred the message representative of an establishment of an handover procedure. 
     At next step S 442 , the processor  300  checks if the class of service associated to the new call establishment or the call for which the handover procedure is established is compatible with the variable level. 
     If the class of service associated to the new call establishment or the call for which the handover procedure is established is compatible with the value of the variable level, the processor  300  moves to step S 444 . 
     If the class of service associated to the new call establishment or the call for which the handover procedure is established is not compatible with the value of the variable level, the processor  300  moves to step S 443 . 
     At step S 443 , the processor  300  rejects the new call or rejects the establishment of the handover procedure. After that, the processor  300  returns to step S 400 . 
     At step S 444 , the processor  300  commands the establishment of the new call through its radio interface  305  and its network interface  304  or proceeds to the handover of the call. 
     At next step S 445 , the processor  300  commands the update of the list of mobile terminals which are currently using the base station BTS for ongoing calls and commands at step S 446  the display of the list of mobile terminals  30  which are currently using the base station BTS on the displaying mean  307 . In a variant of realisation, the number of mobile terminals  30  which are currently using the base station BTS is displayed. 
     After that, the processor  300  returns to step S 400 . 
     At step S 450 , the processor  300  checks if a message representative of an end of call is received for a mobile terminal  30  located in the cell  15  managed by the base station BTS or if a message representative of an handover procedure completion is received. 
     If no message representative of an end of call is received for a mobile terminal  30  located in the cell managed by the base station BTS and no message representative of an handover procedure completion is received, the processor  300  returns to step S 400 . 
     If a message representative of an end of call is received for a mobile terminal  30  located in the cell managed by the base station BTS or a message representative of an handover procedure completion is received, the processor  300  moves to step S 451 . 
     At step S 451 , the processor  300  removes the call from the handover list and commands at step S 452  the display of the handover list on the displaying mean  307 . In a variant of realisation, the number of mobile terminals  30  which are currently using the base station BTS is displayed. 
     After that, the processor  300  returns to step S 400 . 
     At step S 460 , the processor  300  checks if a measurement report is received through the radio interface  305  from a mobile terminal  30  which is located in the cell  15  of the base station BTS. 
     A measurement report comprises information representative of the signals received by the mobile terminal  30  from the base station BTS and neighbour base stations BTS. 
     If a measurement report is received, the processor  300  moves to step S 461 . Otherwise, the processor  300  returns to step S 400 . 
     At step S 461 , the processor  300  checks if an handover procedure has to be triggered for the mobile terminal  30 . 
     If an handover procedure has to be triggered for the mobile terminal  30 , the processor  300  moves to step S 462 . An handover procedure is triggered when the information representative of the signals received by the mobile terminal  30  from the base station BTS is lower than the information representative of the signals received by the mobile terminal  30  from at least one neighbour base station BTS which is included in the list of neighbour base stations BTS. 
     If no handover procedure has to be triggered for the mobile terminal  30 , the processor  300  moves to step S 464  and memorises the information representative of the largest signals received by the mobile terminal  30  from a neighbour base station BTS. 
     After that, the processor  300  returns to step S 400 . 
     At step S 462 , the processor  300  adds the call in the handover list and commands, at step S 463 , the establishment of an handover procedure with the selected neighbour base station BTS in order to transfer the handling of the call to the neighbour base station BTS. 
     After that, the processor  300  returns to step S 400 . 
     At step S 490  of the  FIG. 4   b , the processor  300  configures the base station BTS in the frozen state. 
     At step S 470 , the processor  300  checks, for the mobile terminals  30  identified in the handover list disclosed at step S 411 , if a message representative of an end of call is received for a mobile terminal  30  located in the cell  15  managed by the base station BTS or if a message representative of an handover procedure completion is received. 
     If no message representative of an end of call is received for a mobile terminal  30  located in the cell  15  managed by the base station BTS and no message representative of an handover procedure completion is received, the processor  300  returns to step S 490 . 
     If a message representative of an end of call is received for a mobile terminal  30  located in the cell  15  managed by the base station BTS or a message representative of an handover procedure completion is received, the processor  300  moves to step S 472 . 
     At step S 472 , the processor  300  removes the call from the handover list and commands at step S 473  the display of the handover list on the displaying mean  307 . In a variant of realisation, the number of mobile terminals  30  which are currently using the base station BTS is displayed. 
     At next step S 474 , the processor  300  checks if there is still one ongoing call which go through the base station BTS. 
     If there is at least one ongoing call which goes through the base station BTS, the processor  300  returns to step S 490 . 
     If no ongoing call is going through the base station BTS, the processor  300  moves to step S 475 . 
     At step S 475 , the processor  300  commands the transfer, through the network interface  304 , of a leave notification message to the server  10 . The leave notification message informs that the base station BTS rejects any new call establishment or stops to transfer all the calls transferred through the wireless telecommunication network to each mobile terminal  30  located in the cell of the base station BTS or received through the wireless telecommunication network by each mobile terminal  30  located in the cell of the base station BTS. 
     At next step S 476 , the processor  300  resets the timer Tmax. 
     At next step S 477 , the processor  300  activates a timer noted Tmin. 
     After that, the processor  300  returns to step S 490 . 
     At step S 478 , the processor  300  checks if the timer Tmin or the timer Tmax is expired or if another switch off command has been entered through the keyboard  308  by the partner of which the base station BTS belongs to. 
     If the timer Tmin or the timer Tmax is expired or if another switch off command has been entered through the keyboard  308 , the processor  300  moves to step S 479 . Otherwise, the processor  300  returns to step S 490 . 
     At step S 479 , the processor  300  commands the switch off of the power supply of the base station BTS. 
     At step S 480 , the processor  300  checks if a level modification command has been entered through the keyboard  308  by the partner of which the base station BTS belongs to. 
     If no level modification command has been entered through the keyboard  308 , the processor  300  returns to step S 490 . 
     If a level modification command has been entered through the keyboard  308 , the processor  300  moves to step S 481 . 
     At next step S 481 , the processor  300  checks if the new level value is equal to the fourth level value. If the new level value is different from the fourth level value, the processor  300  moves to step S 482 . If the new level value is equal to the fourth level value, the processor  300  returns to step S 490 . 
     At step S 482 , the processor  300  sets the variable level to the corresponding level modification value entered at step S 480  or the value read at step S 487  which will be disclosed hereinafter. 
     At next step S 483 , the processor  300  commands the display of the handover list on the displaying mean  307 . In a variant of realisation, the number of mobile terminals  30  which are currently using the base station BTS is displayed. 
     At next step S 476 , the processor  300  resets the timer Tmax. 
     At next steps S 484  and S 485 , the processor  300  resets the timers Tmin and Tmax. 
     After that, the processor  300  returns to step S 400 . 
     At step S 486 , the processor  300  checks if a switch off cancellation command has been entered through the keyboard  308  by the partner of which the base station BTS belongs to. 
     If a switch off cancellation command has been entered through the keyboard  308  by the partner of which the base station BTS belongs to, the processor  300  moves to step S 487 . Otherwise the processor  300  returns to step S 490 . 
     At step S 487 , the processor  300  reads the value of the variable level in the RAM memory  303  memorized at step S 421 . 
     After that, the processor  300  moves to step S 482  already described. 
       FIG. 5  represents an algorithm executed by a server according to the present invention. 
     At step S 500  of the  FIG. 5 , the processor  500  configures the server  10  in a running state. 
     At step S 501 , the processor  200  checks, through the network interface  204 , if a message informing that the value of the variable level of a base station BTS has been modified. 
     If no message informing that the value of the variable level of a base station BTS has been modified, the processor  200  returns to step S 500 . Otherwise, the processor  200  moves to step S 502 . 
     At step S 502 , the processor  200  memorizes the identifier of the base station BTS which sent the message received at step S 501  in combination with the value of the variable level comprised in the received message. 
     At next step S 503 , the processor  200  updates the credit for the partner of which the base station BTS belongs to. If the value of the variable level is increased, the credit is increased. If the level is decreased, the credit is decreased. It has to be noted here that a switch off command corresponds to the lowest level value, i.e. the fourth level value which preferably corresponds to null value. 
     At next step S 504 , the processor  200  updates the refund policy for the partner of which the base station BTS belongs to. If the level is increased, the refund policy is increased. If the level is decreased, the refund policy is decreased. 
     At next step S 505 , the processor  200  updates the billing for the partner of which the base station BTS belongs to. The billing formula is updated for any communication transferred by the base stations BTS which belong to the partner or only for the communications transferred by the base station BTS which sent the message received at step S 501 . The billing formula is determined according to the class of service of calls of the mobile terminal or terminals of the owner of the base station and/or according the level or levels of acceptance of at least one base station of the owner of the base station BTS. 
     At next step S 506 , the processor  200  gets the list of all the ongoing calls for which the mobile terminals of the partner are involved. 
     At next step S 507 , the processor  200  checks if all the ongoing calls referenced in the list of ongoing call got at step S 506  have been processed. 
     If all the ongoing calls referenced in the list of ongoing calls got at step S 506  have been processed, the processor  200  returns to step S 500 . 
     If at least one ongoing call referenced in the list of ongoing calls got at step S 506  has not been processed, the processor  200  moves to step S 508 . 
     At next step S 508 , the processor  200  starts the process of an ongoing call in the list of ongoing calls and gets the identifier of the base station BTS which is managing that call. 
     At next step S 509 , the processor  200  commands the transfer of a message through the network interface  204  to the base station identified at step S 508 . The message comprises a modification of the class of service for the ongoing calls under process. If the level received at step S 501  is increased, the class of service is increased. If the level received at step S 501  is decreased, the class of service is decreased. 
     At next step S 510 , the processor  200  selects another ongoing call in the list of ongoing calls and moves to step S 507 . 
     At step S 520 , the processor  200  checks, through the network interface  204 , if a message informing that a base station BTS is switched off. 
     If no message informing that a base station BTS is switched off, the processor  200  returns to step S 500 . Otherwise, the processor  200  moves to step S 521 . 
     At step S 521 , the processor  200  checks if they are some ongoing calls going through the base station BTS which sent the message received at step S 520  which have been interrupted when the base station BTS has been switched off. 
     If they are some ongoing calls going through the base station BTS which sent the message received at step S 520  which have been interrupted when the base station BTS has been switched off, the processor  200  moves to step S 522 . Otherwise, the processor  200  moves to step S 503 . 
     At step S 522 , the processor  200  memorizes in the database the call details, such as the time of end of communication and the abrupt communication termination cause. An abrupt communication termination is an interruption of an ongoing call without any request from the mobile terminal  30  or the remote telecommunication device involved in the call. 
     At next step S 523 , the processor  200  interrupts the billing of the call. 
     At next step S 524 , the processor  200  updates the refund policy for the partner of which the base station BTS belongs to. 
     At next step S 525 , the processor  200  updates the historic of the partner of which the base station BTS belongs. The historic of a partner memorises a list of calls, and associated class of service, which have been abruptly interrupted due to a switch off of a base station owned by the partner. 
     At next step S 526 , the processor  200  selects in the list of ongoing calls another ongoing call which has been interrupted when the base station BTS has been switched off and moves to step S 521 . 
     At step S 530 , the processor  200  checks, through the network interface  204 , if a request for a class of service for a call is received from a base station BTS. 
     If no request for a class of service for a call is received from a base station BTS, the processor returns to step S 500 . Otherwise, the processor  200  moves to step S 531 . 
     At next step S 531 , the processor  200  determines the class of service of that call. 
     As example and in a non limitative way, three classes of services are determined. The highest class of service is named the gold class of service, the middle class of service is named the silver class of service and the lowest class of service is named the bronze class of service. 
     The class of service is determined from multiple parameters. Among parameters which can be used by the processor  200  to derive the class of service, we have:
         the call priority. For instance emergency call can be given the highest class of service. Else, different class of service can be given according to the type of service associated to the call, such as video, speech, packet data. Speech service has a higher class of service than the video service and the video service has a higher class of service than the packet service,   if the user of the mobile terminal involved in the call is the owner of the base station which is handling the call, the class of service is set as the highest class of service,   if the mobile terminal  30  involved in the call is registered as a preferred mobile terminal  30  by the partner of which the base station BTS belongs to, the class of service is set as silver class of service,   the subscription level of the mobile terminal  30  to the wireless telecommunication operator,   if the user of the mobile terminal  30  involved in the call is a partner, the historic of the base station or stations  30  belonging to the partner if the user of the mobile terminal  30  involved in the call is a partner. The class of service is determined considering if the mobile terminal involved in the call belongs to the owner of the base station which is handling the call and according to the number and/or the class of service of calls abruptly terminated due to at least one power off of the base station and/or according to the number and the class of service of calls abruptly terminated due to at least one power off of at least one different base station, the at least one different base station belonging to the owner of the base station.   the credit of partner, if the user of the mobile terminal  30  involved in the call is a partner. The credit of the partner is determined as disclosed in step S 503  from the level of acceptance of calls of at least one base station BTS belonging to the partner.       

     At step S 532 , the processor  200  memorizes in the database the call details such as the class of service determined at step S 531 , the time when the class of service was determined, the identity of the partner who owns the base station, which emitted the request for a class of service. 
     At next step S 533 , the processor  200  commands the transfer of the determined class of service for the call to the base station BTS which sent the message received at step S 530 . 
     After that, the processor  200  returns to step S 500 . 
     At step S 540 , the processor  200  checks, through the network interface  204 , if a message representative of an end of call is received from a base station BTS. 
     If no message representative of an end of call is received from a base station BTS, the processor  200  returns to step S 500 . Otherwise, the processor  200  moves to step S 541 . 
     At step S 541 , the processor  200  memorizes in the database the call details such as time of the end of the call. 
     At next step S 542 , the processor  200  interrupts the billing of the call. 
     At next step S 543 , the processor  200  updates the refund policy for the partner of which the base station BTS belongs to. 
     After that, the processor  200  returns to step S 500 . 
     At step S 550 , the processor  200  checks, through the network interface  204 , if a message representative of the establishment of a new call is received from a base station BTS. 
     The steps S 550  to S 554  are in a variant executed instead of the steps S 442  to S 444 . 
     If no message representative of a call is received from a base station BTS, the processor  200  returns to step S 500 . Otherwise, the processor  200  moves to step S 551 . 
     At step S 551 , the processor  200  determines the class of service of that call on the same way as the one disclosed at step S 531 . 
     At next step S 552 , the processor  200  checks if the class of service associated to the new call establishment is compatible with the value of the variable level of the base station BTS which send the message received at step S 550 . 
     If the class of service associated to the new call establishment or the call for which the handover procedure is established is compatible with the value of the variable level, the processor  200  moves to step S 554 . 
     If the class of service associated to the new call establishment or the call for which the handover procedure is established is not compatible with the value of the variable level, the processor  300  moves to step S 553  and rejects the incoming call. After that, the processor  200  returns to step S 500 . 
     At step S 554 , the processor  200  memorizes in the database the call details the class of service determined at step S 551 , the time when the call was started, the identity of the partner who owns the base station BTS, which emitted message representative of the establishment of a new call. 
     At next step S 555 , the processor  200  commands the transfer of the determined class of service for the call to the base station BTS which sent the message received at step S 530 . 
     After that, the processor  200  returns to step S 500 . 
     Naturally, many modifications can be made to the embodiments of the invention described above without departing from the scope of the present invention.