Clientless Mobile Subscribers with Seamless Roaming Over Scalable Wide Area Wireless Networks

Abstract

System and method for seamless roaming over scalable wide area Wireless LAN networks (WAWLAN) with clientless mobile subscribers. A preferred embodiment comprises a wireless gateway (WG) coupled to one or more access points in a wireless network to form a wireless cluster (WC), a network access gateway (NAG) coupled to a wired network, and a switch coupled to the WG and the NAG. Each wireless cluster is a Wireless LAN Network (WLAN) with homogenous or heterogeneous network architecture. The WG detects mobile nodes in a wireless cluster and tracks mobile node location in the wireless cluster. The NAG is an anchor point for mobile nodes in the WAWLAN and maintains a fixed source of information about each mobile node regardless of their mobility. The switch provides connectivity between the NAG and the WG. Seamless roaming across Wireless LAN network boundary by mobile subscribers without requiring special mobility enabling client software.

1 . A wireless gateway comprising:
 a first wireless gateway circuit for coupling to a first network access point set to form a first wireless cluster, the first network access point set employing a first networking technology for communicating with at least a first mobile node and comprising at least one network access point;   a second wireless gateway circuit for coupling to a second network access point set to form a second wireless cluster, the second network access point set employing a second networking technology for communicating with at least a second mobile node and comprising at least one network access point;   a network access gateway interface for coupling to at least one network access gateway coupled to at least one communication network; and   a communication controller coupled between the network access gateway interface and the first and second wireless gateway circuits, the communication controller being operable:
 to track locations of the first and second mobile nodes in the first and second wireless clusters respectively; and 
 to direct message traffic between the network access gateway interface and the first and second mobile nodes via the first and second wireless gateway circuits respectively. 
   
     
     
         2 . The wireless gateway of  claim 1 , wherein the second networking technology is different from the first networking technology. 
     
     
         3 . The wireless gateway of  claim 1 , wherein the communication controller is operable to detect presence of the first mobile node in the first cluster. 
     
     
         4 . The wireless gateway of  claim 3 , wherein the communication controller is operable, responsive to detecting presence of the first mobile node in the first cluster:
 to obtain an address of the first mobile node; and   to transmit the obtained address of the first mobile node on the network access gateway interface.   
     
     
         5 . The wireless gateway of  claim 1 , wherein the communication controller is operable to translate addresses between a first addressing technique employed at the network access gateway interface and a second addressing technique employed at the first gateway circuit. 
     
     
         6 . A method of operating a wireless gateway, the wireless gateway comprising a first wireless gateway circuit for coupling to a first network access point set to form a first wireless cluster, the first network access point set employing a first networking technology for communicating with at least a first mobile node and comprising at least one network access point, a second wireless gateway circuit for coupling to a second network access point set to form a second wireless cluster, the second network access point set employing a second networking technology for communicating with at least a second mobile node and comprising at least one network access point, a network access gateway interface for coupling to at least one network access gateway coupled to at least one communication network, and a communication controller coupled between the network access gateway interface and the first and second wireless gateway circuits, the method comprising operating the communication controller:
 to track locations of the first and second mobile nodes in the first and second wireless clusters respectively; and   to direct message traffic between the network access gateway interface and the first and second mobile nodes via the first and second wireless gateway circuits respectively.   
     
     
         7 . The method of  claim 6 , wherein the second networking technology is different from the first networking technology. 
     
     
         8 . The method of  claim 6 , further comprising operating the communication controller to detect presence of the first mobile node in the first cluster. 
     
     
         9 . The method of  claim 8 , further comprising operating the communication controller, responsive to detecting presence of the first mobile node in the first cluster:
 to obtain an address of the first mobile node; and   to transmit the obtained address of the first mobile node on the network access gateway interface.   
     
     
         10 . The method of  claim 6 , further comprising operating the communication controller to translate addresses between a first addressing technique employed at the network access gateway interface and a second addressing technique employed at the first gateway circuit. 
     
     
         11 . A network access gateway comprising:
 a first network access gateway circuit supporting a first networking technology;   a second network access gateway circuit supporting a second networking technology;   a first wireless gateway interface for coupling to a first wireless gateway supporting the first networking technology;   a second wireless gateway interface for coupling to a second wireless gateway supporting the second networking technology; and   a communication controller coupled between the network access gateway circuits and the wireless gateway interfaces, the communication controller being operable:
 to act as an anchor point for mobile nodes served by the network access gateway; 
 to maintain information about each mobile node served by the network access gateway; and 
 to direct incoming and outgoing traffic to and from wireless gateway interfaces serving the mobile nodes served by the network access gateway. 
   
     
     
         12 . The network access gateway of  claim 11 , wherein the second networking technology is different from the first networking technology. 
     
     
         13 . The network access gateway of  claim 11 , wherein the communication controller is operable:
 to receive an address associated with a first mobile node served by the first wireless gateway interface at the first wireless gateway interface; and   to store the received address in association with the first mobile node and in association with a first wireless gateway coupled to the first wireless gateway interface.   
     
     
         14 . The network access gateway of  claim 13 , wherein the communication controller is operable:
 to receive notification that the first mobile node is being served by a second wireless gateway coupled to the second wireless gateway interface; and   to store the address associated with the first mobile node in association with the first mobile node and in association with the second wireless gateway in response to the received notification that the first mobile node is being served by the second wireless gateway.   
     
     
         15 . A method of operating a network access gateway, the network access gateway comprising a first network access gateway circuit supporting a first networking technology, a second network access gateway circuit supporting a second networking technology, a first wireless gateway interface for coupling to a first wireless gateway supporting the first networking technology, a second wireless gateway interface for coupling to a second wireless gateway supporting the second networking technology, and a communication controller coupled between the network access gateway circuits and the wireless gateway interfaces, the method comprising operating the communication controller:
 to act as an anchor point for mobile nodes served by the network access gateway;   to maintain information about each mobile node served by the network access gateway; and   to direct incoming and outgoing traffic to and from wireless gateway interfaces serving the mobile nodes served by the network access gateway.   
     
     
         16 . The method of  claim 15 , wherein the second networking technology is different from the first networking technology. 
     
     
         17 . The method of  claim 15 , further comprising operating the communication controller:
 to receive an address associated with a first mobile node served by the first wireless gateway interface at the first wireless gateway interface; and   to store the received address in association with the first mobile node and in association with a first wireless gateway coupled to the first wireless gateway interface.   
     
     
         18 . The method of  claim 17 , further comprising operating the communication controller:
 to receive notification that the first mobile node is being served by a second wireless gateway coupled to the second wireless gateway interface; and   to store the address associated with the first mobile node in association with the first mobile node and in association with the second wireless gateway in response to the received notification that the first mobile node is being served by the second wireless gateway.