Online charging for roaming users in a proxy online charging system of a visited network

Abstract

Communication networks and methods are disclosed for performing online charging credit control in a visited network when a user is roaming. The visited network which is providing service to a roaming user includes a proxy online charging system (OCS) that communicates with a home OCS in a home network of the user. The proxy OCS transmits an online charging request message to a home OCS in a home network for the roaming user requesting charging information for the roaming user. The proxy OCS receives an online charging response message from the home OCS that includes the charging information for the roaming user. The proxy OCS then processes the charging information to perform credit control for one or more network elements in the visited network that is serving the session.

1 . A system comprising:
 a proxy online charging system (OCS) implemented in a visited network that provides service to a roaming user for a session;   the proxy OCS is configured to determine a rating for the session, and to grant a quota of service units to at least one network element in the visited network based on the rating.   
     
     
         2 . The system of  claim 1  wherein:
 the proxy OCS is further configured to transmit an online charging request to a home OCS in a home network for the roaming user that requests charging information for the roaming user, to receive an online charging response from the home OCS that includes the charging information for the roaming user, and to determine the rating for the session based on the charging information provided by the home OCS. 
 
     
     
         3 . The system of  claim 2  wherein the charging information includes a service plan for the roaming user. 
     
     
         4 . The system of  claim 2  wherein the charging information includes a subset of a subscriber profile for the roaming user. 
     
     
         5 . The system of  claim 4  wherein:
 the proxy OCS is further configured to store the subset of the subscriber profile during the session, and to erase the subset of the subscriber profile at the end of the session. 
 
     
     
         6 . The system of  claim 2  wherein:
 the charging information includes an allotment of service units granted by the home OCS; and 
 the proxy OCS is further configured to grant the quota of service units to the at least one network element in the visited network based on the rating and the allotment of service units. 
 
     
     
         7 . The system of  claim 6  wherein:
 if the allotment of service units expires, then the proxy OCS is further configured to transmit another online charging request to the home OCS requesting a new allotment of service units, to receive another online charging response from the home OCS, to process the other online charging response to determine if the new allotment of service units was granted by the home OCS, and to grant another quota of service units to the at least one network element in the visited network based on the new allotment of service units. 
 
     
     
         8 . The system of  claim 2  wherein the online charging request and the online charging response comprise enhanced Diameter Rc messages. 
     
     
         9 . A method comprising:
 receiving a credit request in a proxy online charging system (OCS) implemented in a visited network that provides service to a roaming user for a session, wherein the credit request is received from a network element of the visited network;   determining a rating for the session in the proxy OCS; and   granting a quota of service units in the proxy OCS to the network element based on the rating.   
     
     
         10 . The method of  claim 9  further comprising:
 transmitting an online charging request from the proxy OCS to a home OCS in a home network for the roaming user that requests charging information for the roaming user; 
 receiving an online charging response from the home OCS that includes the charging information for the roaming user; and 
 determining the rating for the session based on the charging information provided by the home OCS. 
 
     
     
         11 . The method of  claim 10  wherein the charging information includes a service plan for the roaming user. 
     
     
         12 . The method of  claim 10  wherein the charging information includes a subset of a subscriber profile for the roaming user. 
     
     
         13 . The method of  claim 12  further comprising:
 storing the subset of the subscriber profile in the proxy OCS during the session; and 
 erasing the subset of the subscriber profile form the proxy OCS at the end of the session. 
 
     
     
         14 . The method of  claim 10  wherein:
 the charging information includes an allotment of service units granted by the home OCS; and 
 granting the quota of service units in the proxy OCS comprises granting the quota of service units to the network element based on the rating and the allotment of service units. 
 
     
     
         15 . The method of  claim 14  wherein:
 if the allotment of service units expires, then:
 transmitting another online charging request from the proxy OCS to the home OCS requesting a new allotment of service units; 
 receiving another online charging response from the home OCS; 
 processing the other online charging response to determine if the new allotment of service units was granted by the home OCS; and 
 granting another quota of service units to the network element based on the new allotment of service units. 
 
 
     
     
         16 . The method of  claim 10  wherein the online charging request and the online charging response comprise enhanced Diameter Rc messages. 
     
     
         17 . A system comprising:
 a proxy online charging system (OCS) implemented in a visited network for a roaming user, the proxy OCS comprising:
 an online charging function (OCF) configured to obtain charging information for the roaming user from a home OCS in a home network for the roaming user; and 
 a rating function configured to determine a rating for a session involving the roaming user based on the charging information; 
 the OCF is further configured to provide credit control for the session by granting a quota of service units for the session to at least one network element in the visited network based on the rating. 
   
     
     
         18 . The system of  claim 17  wherein the charging information includes a subset of a subscriber profile for the roaming user. 
     
     
         19 . The system of  claim 17  wherein:
 the charging information includes an allotment of service units granted by the home OCS; and 
 the OCF is further configured to grant the quota of service units to the at least one network element based on the rating and the allotment of service units. 
 
     
     
         20 . The system of  claim 19  wherein:
 the proxy OCS further comprises:
 an Account Balance Management Function (ABMF) configured to store the allotment of service units granted by the home OCS, and to monitor the allotment of service units while the OCF provides credit control.