Cooperative mobility management in a mobile data network with data breakout at the edge

Abstract

A TCP context is transferred to a Gi Optimizer to provide cooperative mobility management in a mobile data network with a breakout system. The breakout system includes an Iub Optimizer at the MIOP@NodeB, and the Gi Optimizer at the MIOP@Core. When a MIOP@NodeB detects a mobility event for a broken out user equipment (UE), the Iub optimizer in the MIOP@NodeB coordinates with the Gi optimizer to transfer the TCP/UDP connection established between the UE and the IuB Optimizer to the Gi Optimizer. After the transfer, the UE is served by the Gi Optimizer. The transfer of the TCP/UDP connection to the Gi optimizer may require tunnel stitching at the MIOP@RNC depending on the PDP context state and the RRC state of the UE.

1 . A mobile data network comprising:
 a plurality of basestations, each basestation communicating with a corresponding antenna that transmits and receives radio signals to and from user equipment, wherein the plurality of basestations are part of a radio access network that communicates with a core network in the mobile data network, each basestation comprising:
 a first service mechanism that defines an existing first data path in the radio access network for non-broken out data, defines a second data path for broken out data, identifies first data corresponding to a user equipment (UE) received from a corresponding basestation as data to be broken out, sends the first data on the second data path, and forwards other data that is not broken out on the first data path, wherein the first service mechanism establishes a packet data protocol (PDP) context with the UE for the broken out data, wherein the first service mechanism includes a first optimizer and a transmission control protocol (TCP) context for an application in the UE that is broken out on the second data path; 
 a second service mechanism in the mobile data network that communicates with the first service mechanism on an overlay network, wherein the second service mechanism includes a second optimizer; and 
 wherein the first optimizer and the second optimizer coordinate to transfer the TCP context to the second optimizer in response to detecting a mobility event of the UE to allow the second optimizer to serve the UE after the mobility event. 
   
     
     
         2 . The mobile data network of  claim 1  wherein the first service mechanism places the PDP context that is broken out into a preserved state by:
 placing the UE into a radio resource control (RRC) idle state and the PDP context into a preserved state; 
 releasing resources related to the PDP context at the first service mechanism except a network address translation (NAT) internet protocol (IP) address; 
 maintaining the context and resource information at the first service mechanism; 
 placing the NAT IP address at the first mechanism into a frozen state; 
 the UE moves to an adjacent cell to create a mobility event while in the RRC idle state; and 
 the UE initiating data transfer procedure again for the preserved PDP context through invocation of 3G signaling by establishing a RRC connection and issuing a network access server (NAS) Service Request. 
 
     
     
         3 . The mobile data network of  claim 1  wherein the first optimizer and the second optimizer coordinate to transfer the TCP context to the second optimizer by performing the steps of:
 upon detection of the mobility event, the first service mechanism sending a TCP application context transfer message to the first optimizer; 
 the first optimizer transferring the TCP context for the UE to the second optimizer; 
 the second optimizer starting to receive packets from the UE; 
 the first service mechanism stopping the sending of maintenance data in uplink for the broken out PDP context; 
 the first service mechanism deregistering the UE with a third service mechanism connected to a radio network controller (RNC); 
 the third service mechanism stopping the sending of maintenance data in a down link for the broken out TCP context; 
 the first service mechanism triggering a radio link control (RLC) reset procedure towards both the RNC and the UE to reestablish a ciphering context; 
 the third service mechanism stitching a data tunnel so that data being received from the RNC can be forward to GPRS support node (SGSN) and data received from the SGSN can be forwarded to the RNC; and 
 the second optimizer continuing to serve the broken out TCP context belonging to the UE. 
 
     
     
         4 . The mobile data network of  claim 3  wherein the step of the first optimizer transferring the TCP context for the UE to the second optimizer comprises the steps of:
 blocking all receives to establish a know state at the time of the TCP context transfer; 
 reading in all data received in a socket buffer associated with a connection for the TCP context in the first service mechanism; 
 invoking a kernel software module to determine socket details for a connection prior to the TCP context transfer; 
 sending the socket details to the second optimizer; 
 creating a new socket at the second optimizer with the socket details; and 
 reinstating all data buffers to the new socket with data from the connection prior to the TCP context transfer. 
 
     
     
         5 . The mobile data network of  claim 1  wherein the second service mechanism is located in a core network of the mobile data network. 
     
     
         6 . The mobile data network of  claim 1  wherein transferring the TCP context includes application context data for a state of an application. 
     
     
         7 - 14 . (canceled)