Method and System for Implementing Inter-Access Networks Handoff in Active State in HRPD Network

Abstract

A method and system for implementing an inter-Access Network (AN) handoff in an active state in a High Rate Packet Data (HRPD) Network are disclosed. The method includes determining that an inter-AN handoff operation is necessary and initiating a handoff procedure to perform the inter-AN handoff, sending data to be transmitted to an access terminal to the destination AN in advance in the handoff procedure, and then sending the access terminal the data to be transmitted to the access terminal by the source AN or the destination AN according to the result of the handoff procedure.

1 . A method for implementing an inter-Access Network (AN) handoff in an active state in a High Rate Packet Data (HRPD) network, the method comprising:
 during a handoff procedure from a source AN to a destination AN, initiating, by the destination AN, a connection establishment between the destination AN and a Packet Data Service Network (PDSN) before an access terminal establishes a connection with the destination AN;   receiving, by the destination AN or a destination Packet Control Function (PCF), data from the PDSN; and   after the access terminal has established the connection with the destination AN, sending, by the destination AN or the destination PCF, the data received from the PDSN to the access terminal.   
     
     
         2 . The method according to  claim 1 , further comprising receiving, by the destination AN, a handoff request message from the source AN. 
     
     
         3 . The method according to  claim 2 , wherein initiating the connection establishment between the destination AN and the PDSN before the access terminal establishes the connection with the destination AN comprises:
 sending, by the destination AN, a connection establishment request to the destination PCF, and establishing a connection between the destination PCF and the destination AN; and   registering, by the destination PCF, to the PDSN, and establishing a connection between the destination PCF and the PDSN.   
     
     
         4 . The method according to  claim 2 , wherein the data received by the destination PCF or the destination AN from the PDSN are sent to the source AN or a source PCF simultaneously. 
     
     
         5 . The method according to  claim 1 , further comprising:
 sending, by the destination AN, a handoff complete message to the source AN when the access terminal can receive data via the destination AN, to cause the source AN interchange information with the source PCF to release the connection between the source PCF and the source AN.   
     
     
         6 . The method according to  claim 2 , wherein after receiving, by the destination AN, a handoff request message from the source AN, the method further comprises:
 sending, by the destination AN, a handoff reply message to the source AN to make the source AN send a channel assignment message to the access terminal and interchange information with a source PCF to disconnect an air interface connection when receiving a reply from the access terminal, or, interchange information with the source PCF to disconnect the air interface connection directly after sending the channel assignment message without waiting for the reply from the access terminal.   
     
     
         7 . The method according to  claim 6 , wherein after sending, by the destination AN, the handoff reply message to the source AN to make the source AN send the channel assignment message to the access terminal, the method further comprises:
 allocating, by the destination AN, a Uni-cast Access Terminal Identifier (UATI), for the access terminal.   
     
     
         8 . The method according to  claim 7 , wherein the method further comprises:
 interchanging, by the destination AN, information with the destination PCF so as to establish an air interface connection.   
     
     
         9 . A access network (AN), comprising:
 a first unit, configured to initiate a connection establishment between the AN and a Packet Data Service Network (PDSN) before an access terminal establishes a connection with the AN during handoff procedure from a source AN to the AN;   a second unit, configured to receive data from the PDSN; and   a third unit, configured to send the data received from the PDSN to the access terminal after the access terminal has established the connection with the AN.   
     
     
         10 . The AN according to  claim 9 , further comprising:
 a fourth unit, configured to receive a handoff request message from the source AN.   
     
     
         11 . The AN according to  claim 9 , the first unit is configured to send a connection establishment request to a destination PCF and establish a connection between the destination PCF and the AN to make the destination PCF establish a connection between the destination PCF and the PDSN. 
     
     
         12 . The AN according to  claim 10 , further comprising:
 a fifth unit, configured to send a handoff complete message to the source AN when the access terminal can receive data via the AN, to make the source AN interchange information with the source PCF to release the connection between a source PCF and the source AN.   
     
     
         13 . The AN according to  claim 9 , further comprising:
 a sixth unit, configured to allocate a Uni-cast Access Terminal Identifier (UATI) for the access terminal.   
     
     
         14 . The AN according to  claim 9 , further comprising:
 a seventh unit, configured to interchange information with a destination PCF so as to establish an air interface connection.