Inter-system mobility in integrated wireless networks

Abstract

A system is disclosed for providing inter-system mobility in integrated LTE and WiFi systems. A control plane interface referred to as the S1a-C interface, is defined between a trusted WLAN access network (TWAN) and a mobility management entity (MME) comprised in an LTE wireless access network. A user plane interface, referred to as the S1a-U interface, is defined between the TWAN and a server gateway (SGW) in the LTE wireless access network. The MME operates as a common control plane entity for both LTE and TWAN access, while the SGW operates as a user plane gateway for both LTE and TWAN. The integrated MME and SGW allow for user equipment (UE) to access the capabilities of a packet data network (PDN) through either the LTE access network or TWAN.

What is claimed: 
     
         1 . A system, comprising:
 a mobility management entity server programmed to communicate with a 3GPP access network, the mobility management entity server communicatively coupled with a trusted wireless access network via a first communication interface, the first communication interface adapted to communicate control plane data between the mobility management entity server and the trusted wireless access network; and   a serving gateway communicatively coupled with the 3GPP access network and a packet data network, the serving gateway communicatively coupled with the trusted wireless access network via a second communication interface, the second communication interface adapted to communicate user plane data between the serving gateway and the trusted wireless access network.   
     
     
         2 . The system of  claim 1 , further comprising a trusted wireless access network adapted to provide a user device with access to a radio wireless network. 
     
     
         3 . The system of  claim 2 , wherein the trusted wireless access network comprises a trusted wireless access gateway, the trusted wireless access gateway programmed to communicate with the mobility management entity server via the first communication interface. 
     
     
         4 . The system of  claim 3 , wherein the trusted wireless access gateway is programmed to communicate with the serving gateway via the second communication interface. 
     
     
         5 . The system of  claim 2 , wherein the trusted wireless access network comprises a wireless local area network access node, the wireless local area network access node programmed to communicate with the mobility management entity server via the first communication interface. 
     
     
         6 . The system of  claim 5 , wherein the wireless local area network access node is programmed to communicate with the serving gateway via the second communication interface. 
     
     
         7 . The system of  claim 1 , wherein the first communication interface is an S1a-C interface. 
     
     
         8 . The system of  claim 1 , wherein the second communication interface is an S1a-U interface. 
     
     
         9 . The system of  claim 2 , wherein the trusted wireless access network is programmed to communicate data between the serving gateway and a user device communicatively coupled with the trusted wireless access network via the second communication interface. 
     
     
         10 . The system of  claim 9 , wherein the serving gateway is programmed to communicate data between the data packet network and the trusted wireless access network via the second communication interface. 
     
     
         11 . A method, comprising:
 at a mobility management entity server communicating control plane data via a first communication interface with a trusted wireless access network, the mobility management entity server communicatively coupled with a 3GPP access network;   at a serving gateway communicating user plane data via a second communication interface with the trusted wireless access network, the serving gateway communicatively coupled with the 3GPP access network and a packet data network.   
     
     
         12 . The method of  claim 11 ,
 wherein communicating control plane data via a first communication interface with a trusted wireless access network comprises communicating control plane data via an S1a-C interface.   
     
     
         13 . The method of  claim 11 ,
 wherein communicating user plane data via a second communication interface with the trusted wireless access network comprises communicating user plane data via an S1a-U interface.   
     
     
         14 . The method of  claim 11 , further comprising:
 at the serving gateway communicating the user plane data with the packet data network.   
     
     
         15 . The method of  claim 11 , further comprising:
 at the trusted wireless access network, communicating user plane data with a user device communicatively coupled with the trusted wireless access network.   
     
     
         16 . A method, comprising:
 at a trusted wireless access network generating and transmitting a request to create a session to a mobility management entity over a first communication interface, the mobility management entity adapted to communicate with both the trusted wireless access network and a small cell network;   at the mobility management entity generating and transmitting a request to create a session to a serving gateway;   at the serving gateway generating and transmitting a request to create a session to a packet data network gateway;   at the serving gateway receiving responsive information for establishing a session from the packet data network gateway;   at the serving gateway transmitting the responsive information for establishing a session to the mobility management entity; and   at the mobility management entity transmitting the responsive information for establishing a session to the trusted wireless access network over the first interface.   
     
     
         17 . The method of  claim 16 , further comprising:
 at the trusted wireless access network receiving a request from a user device to establish a communication session;   at the trusted wireless access network generating and transmitting an authentication request to a 3GPP server; and   at the trusted wireless access network receiving information indicating communication between the trusted wireless access network and the mobility management entity via the first interface is authorized, the mobility management entity enabled to perform integrated small-cell and WIFI communications.   
     
     
         18 . The method of  claim 17 , further comprising:
 at the trusted wireless access network identifying a second interface between the selected serving gateway and the wireless access network has been created; and   at the trusted wireless access network generating and transmitting to the user device information indicating a connection has been established.   
     
     
         19 . The method of  claim 18 , further comprising the trusted wireless access network transmitting an internet protocol address to the user device. 
     
     
         20 . The method of  claim 18 , further comprising the trusted wireless access network routing data between the selected serving gateway and the user device via the second interface. 
     
     
         21 . The method of  claim 17 , wherein receiving a request from a user device to establish a connection comprises receiving a request by the user device to associate with a WiFi access point. 
     
     
         22 . The method of  claim 17 , wherein generating and transmitting an authentication request to a 3GPP server comprises generating and transmitting an authentication request comprising information specifying a type of connection between the user device and a packet data network gateway. 
     
     
         23 . The method of  claim 22 , wherein generating and transmitting an authentication request comprising information specifying a type of connection comprises generating and transmitting an authentication request comprising information specifying an integrated small-cell network and a WIFI network. 
     
     
         24 . The method of  claim 23 , wherein generating and transmitting an authentication request further comprises generating and transmitting an authentication request comprising information specifying support for a local trusted wireless access gateway or a remote combined trusted wireless access gateway and serving gateway. 
     
     
         25 . The method of  claim 23 , wherein the trusted wireless access network receiving information communication between the trusted wireless access network and a mobility management entity via a first interface is authorized comprises receiving information indicating communication between the trusted wireless access network and a mobility management entity may take place over a S1a-C interface. 
     
     
         26 . The method of  claim 16 , wherein generating and transmitting a request to create a session to a serving gateway comprises generating and transmitting a create request to a combined serving gateway and trusted wireless access gateway. 
     
     
         27 . A method, comprising:
 at a trusted wireless access network receiving a request from a user device to establish a connection to a wireless local area network, the user device having an existing connection to a packet data network via a cellular network;   at the trusted wireless access network generating and transmitting an authentication request to a 3GPP server;   at the trusted wireless access network receiving an answer indicating communication between the trusted wireless access network and a mobility management entity via a first interface is authorized, the mobility management entity being enabled to perform integrated cellular and wireless local area network communications;   at a trusted wireless access network generating and transmitting a request to create a session to the mobility management entity over the first interface, the request specifying to handover the existing connection to the packet data network via a cellular network to communication via the trusted wireless access network;   at the mobility management entity generating and transmitting a request to a serving gateway, the request specifying to handover the existing connection to the packet data network via a cellular network to communication via the trusted wireless access network;   at the serving gateway generating and transmitting a request to a packet data network gateway, the request specifying to handover the existing connection to the packet data network via a cellular network to communication via the trusted wireless access network;   at the serving gateway receiving a response from the packet data network gateway, the response comprising a network address previously allocated to the user device in connection with the existing connection to the packet data network via a cellular network;   at the serving gateway transmitting the response to the mobility management entity;   at the mobility management entity transmitting the response to the trusted wireless access network over the first interface; and   at the trusted wireless access network generating and transmitting to the user device information indicating a connection been established with the user device.   
     
     
         28 . The method of  claim 27 , further comprising at the user device initiating release of the existing connection to a packet data network via a cellular network. 
     
     
         29 . The method of  claim 27 , further comprising at the wireless access network routing data between the user device and the serving gateway using a second interface connection between the wireless access network and the serving gateway. 
     
     
         30 . A method, comprising:
 at a trusted wireless access network receiving a request from a user device to establish a connection to a packet data network, the user device having an existing connection to the packet data network via a cellular communication network and a serving gateway, the request indicating to maintain the existing connection;   at the trusted wireless access network transmitting a request to create a session to a mobility management entity over a first communication interface, the request indicating to maintain the existing connection;   at the mobility management entity transmitting a create request to the serving gateway, the request indicating to maintain the existing connection;   at the serving gateway transmitting a request to create a session to a selected packet data network gateway, the request indicating to maintain the existing connection;   at the selected serving gateway receiving a create session response from the selected packet data network gateway, the create session response comprising a network address previously allocated to the user device in connection with the existing connection;   at the selected serving gateway transmitting the create session response to the mobility management entity;   at the mobility management entity transmitting the create session response to the trusted wireless access network over the first interface; and   at the wireless access network transmitting to the user device information indicating a connection has been established to the packet data network via the wireless access network.   
     
     
         31 . The method of  claim 30 , further comprising:
 the serving gateway communicating data to and from the user device via a second communication interface with the wireless access network; and   the serving gateway communicating data to and from the user device via the via a cellular communication network.