Method and System For Establishing A Connection Between Network Elements

Abstract

The invention provides a method and system for establishing or handling a connection between a first and a second network element connected to different networks such as GPRS/UMTS and IP-based networks. The connection is established by means of at least one third network element such as a SGSN or GGSN arranged in one of the networks. The third network element is adapted to send, when receiving information on an establishment of a connection, a request to a fourth network element which may be a Call State Control Function (CSCF), a Policy Control Function (PCF), or a Call Processing Server (CPS). The request requests permission for establishing a requested type of connection, or requests a check of a connection parameter, and specifies the first and/or second network element and/or the connection or connection type to be established. The fourth network element returns a response specifying a permission for establishing a connection or connection type, or specifying a connection parameter.

1 . Method for establishing or handling a connection between a first and a second network element connected to different networks, the connection being established by means of at least one third network element arranged in one of the networks, wherein the third network element, when receiving information on an establishment of a connection, sends a request to a fourth network element, the request requesting permission for establishing a requested type of connection, or requesting a check of a connection parameter, the request specifying the first and/or second network element and/or the connection or connection type to be established, the fourth network element returning a response specifying a permission for establishing a connection or connection type, or specifying a connection parameter, the establishment or handling of the connection being controlled in dependence on the response. 
     
     
         2 . Method according to  claim 1 , wherein the third network element is a support node. 
     
     
         3 . Method according to  claim 2 , wherein the support node is a gateway node, in particular a GGSN (Gateway GPRS Support Node). 
     
     
         4 . Method according to any one of the preceding claims, wherein the fourth network element is a Call State Control Function (CSCF). 
     
     
         5 . Method according to any one of the preceding claims, wherein the fourth network element is a Policy Control Function (PCF). 
     
     
         6 . Method according to any one of the preceding claims, wherein the fourth network element is a Call Processing Server (CPS). 
     
     
         7 . Method according to any one of the preceding claims, wherein the fourth network element is at least partly implemented as part of the third network element. 
     
     
         8 . Method according to any one of the preceding claims, wherein the request is a permission request requesting permission to activate or modify a PDP Context for the first and/or second network element. 
     
     
         9 . Method according to any one of the preceding claims, wherein the request is a check request requesting a check of at least one connection parameter. 
     
     
         10 . Method according to any one of the preceding claims, wherein the response indicates call characteristics, preferably accepted QoS values, and/or accepted information on the second network element, and/or an indication indicating whether the connection is a normal call or an emergency call. 
     
     
         11 . Method according to any one of the preceding claims, wherein the first network element addresses a fifth network element when trying to establish a call, the fifth network element sending an authorization message to the fourth network element characterizing at least one call parameter, the fourth network element forming its response to the third network element based on the contents of the authorization message. 
     
     
         12 . Method according to any one of the preceding claims, wherein subscription information stored for the first network element includes a parameter defining the necessity of sending a request from the third to the fourth network element when establishing a connection between the first and second network element, this parameter being sent to the third network element when establishing a connection between the first and second network element, the third network element deciding on the necessity of sending the request to the fourth network element depending on the contents of this parameter. 
     
     
         13 . Method according to  claim 12 , wherein, when the parameter indicates no necessity for sending a request from the third to the fourth network element, the third network element does not send such a request and proceeds with the establishing of the connection between the first and second network elements. 
     
     
         14 . Method according to any one of the preceding claims, wherein a common identifier is provided for identifying a network element requesting the establishment to another network element, or for identifying a call, both in an IP-based network and an GPRS- or UMTS-based network. 
     
     
         15 . Method according to  claim 14 , wherein the common identifier is used for mapping connection parameter, in particular PDP Context information, to a call, and is transmitted to both the third and the fourth network element when establishing a connection between the first and second network element. 
     
     
         16 . Method according to  claim 14  or  15 , wherein the common identifier is NSAPI, or a Call Identifier provided in a connection initiating protocol, preferably SIP (Session Intitiation Protocol). 
     
     
         17 . Method according to any one of the preceding claims, wherein an address of the fourth network element is contained in subscription information stored for the first network element, the address being transmitted to the third network element when establishing a connection being the first and second network element. 
     
     
         18 . Method according to any one of the preceding claims, wherein a charging record for charging for the connection is provided taking account of the result of a check of the connection parameter. 
     
     
         19 . Method according to any one of the preceding claims, wherein the connection parameter indicates requested or accepted QoS, and the QoS information provided in both the signalling and user traffic is checked, a charging record being provided taking account of the check result. 
     
     
         20 . Method according to  claim 19 , wherein the QoS check is effected in response to a check request. 
     
     
         21 . Method according to any one of the preceding claims, wherein the connection parameter indicates call characteristics, preferably accepted QoS values, and/or information about the second network element, and/or an indication indicating whether the connection is a normal call or an emergency call. 
     
     
         22 . Method according to any one of the preceding claims, wherein the connection involves at least two networks of different types, preferably a GPRS/UMTS-based network and an IP-based network, and QoS values provided provided in both networks for the connection are checked and compared for gaining charging-related information. 
     
     
         23 . Method according to any one of the preceding claims, wherein a check request for checking a charging-related parameter is sent from the first network element to the fourth or another network element when sending a call establishment request. 
     
     
         24 . System for establishing or handling a connection between a first and a second network element connected to different networks, the connection being established by means of at least one third network element arranged in one of the networks, wherein the third network element is adapted to send, when receiving information on an establishment of a connection, a request to a fourth network element, the request requesting permission for establishing a requested type of connection, or requesting a check of a connection parameter, the request specifying the first and/or second network element and/or the connection or connection type to be established, the fourth network element returning a response specifying a permission for establishing a connection or connection type, or specifying a connection parameter, the establishment or handling of the connection being controlled in dependence on the response. 
     
     
         25 . System according to  claim 24 , wherein the third network element is a support node. 
     
     
         26 . System according to  claim 25 , wherein the support node is a gateway node, in particular a GGSN (Gateway GPRS Support Node). 
     
     
         27 . System according to any one of the preceding system claims, wherein the fourth network element is a Call State Control Function (CSCF). 
     
     
         28 . System according to any one of the preceding system claims, wherein the fourth network element is a Policy Control Function (PCF). 
     
     
         29 . System according to any one of the preceding system claims, wherein the fourth network element is a Call Processing Server (CPS). 
     
     
         30 . System according to any one of the preceding system claims, wherein the fourth network element is at least partly implemented as part of the third network element. 
     
     
         31 . System according to any one of the preceding system claims, wherein the request is a permission request requesting permission to activate or modify a PDP Context for the first and/or second network element. 
     
     
         32 . System according to any one of the preceding system claims, wherein the request is a check request requesting a check of at least one connection parameter. 
     
     
         33 . System according to any one of the preceding system claims, wherein the response indicates call characteristics, preferably accepted QoS values, and/or accepted information on the second network element, and/or an indication indicating whether the connection is a normal call or an emergency call. 
     
     
         34 . System according to any one of the preceding system claims, wherein the first network element is adapted to address a fifth network element when trying to establish a call, the fifth network element being adapted to send an authorization message to the fourth network element characterizing at least one call parameter, the fourth network element being adapted to form its response to the third network element based on the contents of the authorization message. 
     
     
         35 . System according to any one of the preceding system claims, wherein subscription information stored for the first network element includes a parameter defining the necessity of sending a request from the third to the fourth network element when establishing a connection between the first and second network element, this parameter being sent to the third network element when establishing a connection between the first and second network element, the third network element being adapted to decide on the necessity of sending the request to the fourth network element depending on the contents of this parameter. 
     
     
         36 . System according to  claim 35 , wherein, when the parameter indicates no necessity for sending a request from the third to the fourth network element, the third network element does not send such a request and proceeds with the establishing of the connection between the first and second network elements. 
     
     
         37 . System according to any one of the preceding system claims, wherein a common identifier is provided for identifying a network element requesting the establishment to another network element, or for identifying a call, both in an IP-based network and an GPRS- or UMTS-based network. 
     
     
         38 . System according to  claim 37 , wherein the common identifier is used for mapping connection parameter, in particular PDP Context information, to a call, and is transmitted to both the third and the fourth network element when establishing a connection between the first and second network element. 
     
     
         39 . System according to  claim 37  or  38 , wherein the common identifier is NSAPI, or a Call Identifier provided in a connection initiating protocol, preferably SIP (Session Intitiation Protocol). 
     
     
         40 . System according to any one of the preceding system claims, wherein an address of the fourth network element is contained in subscription information stored for the first network element, the address being transmittable to the third network element when establishing a connection being the first and second network element. 
     
     
         41 . System according to any one of the preceding system claims, wherein a charging record for charging for the connection is provided taking account of the result of a check of the connection parameter. 
     
     
         42 . System according to any one of the preceding system claims, wherein the connection parameter indicates requested or accepted QoS, and the QoS information provided in both the signalling and user traffic is checked, a charging record being provided taking account of the check result. 
     
     
         43 . System according to  claim 42 , wherein the QoS check is effected in response to a check request. 
     
     
         44 . System according to any one of the preceding system claims, wherein the connection parameter indicates call characteristics, preferably accepted QoS values, and/or information about the second network element, and/or an indication indicating whether the connection is a normal call or an emergency call. 
     
     
         45 . System according to any one of the preceding system claims, wherein the connection involves at least two networks of different types, preferably a GPRS/UMTS-based network and an IP-based network, and QoS values provided provided in both networks for the connection are checked and compared for gaining charging-related information. 
     
     
         46 . System according to any one of the preceding system claims, wherein a check request for checking a charging-related parameter is sent from the first network element to the fourth or another network element when sending a call establishment request. 
     
     
         47 . A method for establishing a connection in a two-layer communication network comprising a first communication network layer adapted to establish a communication channel to a terminal and a second communication network layer adapted to establish a session carried on said communication channel, said method comprising the steps of:
 establishing a session with an identifier, establishing a communication channel with said identifier,   authorizing said communication channel by said session using said identifier.   
     
     
         48 . Method according to  claim 47 , wherein said authorizing comprises the steps of:
 a network element in said first communication network layer (e.g. GGSN) initiating a request for said authorization at communication channel establishment   a network element in said second communication network layer (e.g. CSCF) performing said authorization.   
     
     
         49 . Method according to  claim 47  or  48 , wherein said first communication network layer is a GPRS/UMTS layer, and said second communication network layer is an IP Multimedia Subsystem. 
     
     
         50 . Method according to  claim 47 ,  48 , or  49 , wherein said terminal is a User equipment or Mobile Station. 
     
     
         51 . A system for establishing a connection in a two-layer communication network comprising a first communication network layer adapted to establish a communication channel to a terminal and a second communication network layer adapted to establish a session carried on said communication channel, said system being adapted:
 to establish a session with an identifier,   to establish a communication channel with said identifier,   to authorize said communication channel by said session using said identifier.   
     
     
         52 . System according to  claim 51 , wherein for performing said authorizing:
 a network element in said first communication network layer is adapted to initiate a request for said authorization at communication channel establishment   a network element in said second communication network layer is adapted to perform said authorization.   
     
     
         53 . System according to  claim 51  or  52 , wherein said first communication network layer is a GPRS/UMTS layer, and said second communication network layer is an IP Multimedia Subsystem. 
     
     
         54 . System according to  claim 51 ,  52 , or  53 , wherein said terminal is a User equipment or Mobile Station.