Patent Publication Number: US-2011075660-A1

Title: Dynamic network selection

Description:
The invention relates to a telecommunication network and a method for controlling the allocation of a telecommunication user equipment to a terminal network. 
     Telecommunication is currently undergoing a revolution. It is an improvement, for instance, that the handover from conventional CS-based telecommunication (CS=circuit switching) to Internet-based PS telecommunication (PS=packet switching) is applied increasingly more frequently. 
     This improvement, however, requires that a certain cooperation (interworking) must take place between these systems as long as these different systems are used in parallel with each other. 
     Such an interworking appears necessary in particular for all services that contain voice. 
     Such an interworking between these systems is required because
         voice in the PSTN/ISDN is predominantly CS-based;   voice on the Internet is predominantly PS-based;   most current cellular mobile radio systems support CS voice;   future generation cellular mobile radio systems no longer support CS services, since all voice services will be based on VoIP (Voice over Internet Protocol).       

     This interworking is normally carried out by means of an interworking server, which implements a one-to-one transcoding of the voice signals where necessary. 
     The problem that arises in this context is when and how it is decided and controlled within a network whether voice is implemented via the conventional CS service or via VoIP. In the known solutions this is done using predefined static scenarios. 
     The object of the present invention can therefore be considered that of avoiding or circumventing this fixed allocation of the type of voice signal. 
     This object is achieved according to the invention by the technical teaching of the independent claims. 
     Advantageous embodiments and improvements of the invention will become apparent from the dependent claims, the content of which is hereby referenced. 
     More particularly, the inventive dynamic allocation control allows various criteria to be taken into account. 
     The following criteria are taken into account, with the following list not being intended to limit the scope of the invention. On the contrary, all other known possible criteria for taking into account such criteria for a dynamic access control are claimed also. 
     For outgoing calls the following criteria can be taken into account:
         service   destination network   subscriber preferences   network operator preferences       

     For incoming calls the following criteria can be taken into account:
         service   originating network   subscriber preferences   network operator preferences       

     A further embodiment of the invention provides for introducing an additional information exchange between the existing radio infrastructure and the selected domain. 
     Through this information exchange operator-specific radio parameters and user equipment properties can be integrated into the decision process. Consequently, this results in new criteria for the allocation. 
     The question of when and how a decision is made within a network with respect to controlling voice can be answered such that that the access network control is carried out under incorporation of operator-specific radio parameters and user equipment properties, the objective being that of deciding and controlling whether voice is implemented via the conventional CS service or via VoIP. 
     For outgoing calls the resulting criteria are as follows:
         service   destination network   static and dynamic user equipment properties for subscribers A and B   subscriber preferences   network operator preferences       

     For mobile incoming calls the resulting criteria are as follows:
         service   originating network   static and dynamic user equipment properties for subscribers A and B   subscriber preferences   network operator preferences       

     The invention will be described in more detail below in conjunction with drawings that illustrate one possible embodiment. Additional features that are essential to the invention and advantages of the invention will become apparent from the drawings and their description. 
    
    
     
       In the drawings, 
         FIG. 1  shows an access control according to the prior art; 
         FIG. 2  shows an inventive dynamic access control. 
     
    
    
     The access control depicted in  FIG. 1  shows a handoff from a circuit-switching (CS) telecommunication to a packet-switching (PS) telecommunication, which is known, for example, from telecommunication on the Internet. 
     Such a packet-switched communication is carried out by means of various protocols, such as for example 2G or 3G, in which it is necessary for a handoff from CS communication to PS communication that the two communication systems are capable of cooperating with one another. 
     This cooperation for the handoff between these systems is known from the prior art as so-called interworking, which is carried out by means of an interworking server. 
     From a mobile user equipment (UE) voice signals are transmitted circuit-switched ( 1 ,  2 ) or packet-switched ( 3 ,  4 ,  5 ) to an interworking server in the particular access network ( 10 ). 
     This server recognizes from the incoming voice signals whether the voice signals are circuit-switched ( 1 ,  2 ) or packet-switched ( 3 ,  4 ,  5 ). 
     After the appropriate transcoding in the access network ( 10 ) these voice signals are relayed to the appropriate network either circuit-switched CS ( 11 ) or packet-switched PS ( 12 ). 
     It is possible to relay such voice signals to a service portal ( 14 ) comprising a virtual network VPN ( 15 ), an intelligent network IN ( 16 ), or an IP multimedia subsystem IMS ( 17 ). 
     Additionally, the voice signals can be relayed as circuit-switched CS ( 11 ) or packet switched PS ( 12 ) voice signals to a mobile radio network PLMN ( 18 ). 
     Additionally, the voice signals can be relayed as circuit-switched CS ( 11 ) signals to a public switched telephone network PSTN ( 19 ) or as packet switched PS ( 12 ) signals to the Internet ( 20 ). 
     The inventive solution for controlling voice signals that is shown in  FIG. 2  illustrates that voice signals are relayed by means of a corresponding controller ( 23 ) from a CS access network ( 24 ) or from a PS access network ( 25 ) directly to the Internet ( 20 ), to the public switched telephone network ( 19 ), to a service portal ( 14 ), or to a mobile radio network ( 18 ), with the controller ( 23 ) dynamically making the decision to relay the voice signals to the respective network by means of the aforementioned decision criteria. 
     It is important in this context that the respective voice signals are transmitted to the controller ( 23 ) via an access network ( 24 ) with circuit switched CS voice signals or from an access network ( 25 ) with packet-oriented PS voice signals. 
     The subject matter of the present invention is attained not only from the subject of the individual claims but also from the combination of the individual claims with one another. 
     All of the specifications and features disclosed herein, including in the abstract, especially the three-dimensional embodiment depicted in the drawings, are claimed as essential to the invention to the extent that they are novel either individually or in combination over the prior art. 
     LIST OF REFERENCE NUMERALS 
     
         
           1 . 2G CS (CS=2nd generation circuit switching) 
           2 . 3G CS (CS=3rd generation circuit switching) 
           3 . 2G PS (PS=2nd generation packet switching) 
           4 . 3G PS (PS=3rd generation packet switching) 
           6 . Selection 
           7 . 2G (2 nd  generation) 
           8 . 3G (3 rd  generation) 
           9 . LTE (Long Term Evolution (working term for the radio portion of the next generation mobile networks) 
           10 . Access network 
           11 . CS (CS=circuit switching) 
           12 . PS (PS=packet switching) 
           13 . Selection 
           14 . Service portal 
           15 . VPN (virtual private network) 
           16 . IN (intelligent network) 
           17 . IMS (IP multimedia subsystem) 
           18 . PLMN (public land mobile network) 
           19 . PSTN (public switched telephone network)
       ISDN (integrated services digital network)     
           20 . Internet 
           21 . Control data base 
           22 . Control logic 
           23 . Controller 
           24 . CS access network 
           25 . PS access network