NETWORK-BASED MICRO MOBILITY IN CELLULAR NETWORKS USING EXTENDED VIRTUAL PRIVATE LAN SERVICE

• US 20100177752A1
• Filed: 04/10/2009
• Published: 07/15/2010
• Est. Priority Date: 01/12/2009
• Status: Abandoned Application

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: Juniper Networks Incorporated
• Inventors: Murphy, James, Aggarwal, Rahul
• Application Number:
  US12/421,693
• Publication Number:
  US 20100177752A1
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]
• CPC Class Codes: H04W 8/082 for traffic bypassing of mobility servers, e.g. location registers, home PLMNs or home agents
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

A new architecture provides network-based mobility in cellular networks that is built on Internet Protocol (IP)/Multiprotocol Label Switching (MPLS) technologies, such as Virtual Private Local Area Network (LAN) Service (VPLS), the Border Gateway Protocol (BGP) and BGP MPLS Layer 3 Virtual Private Networks (VPNs). The architecture consists of several building blocks that provide functionality for different aspects of cellular network mobility. One building block is network-based macro mobility in IP/MPLS networks. The macro mobility techniques described herein are built on extensions to a routing protocol such as BGP. Another building block relates to transferring subscriber context between network devices while preserving the IP address of the subscriber. The techniques described herein provide a subscriber context transfer mechanism for mobile subscriber management that is built on extensions to a routing protocol such as BGP. Another building block of the mobility architecture is network-based micro mobility based on VPLS.

Claims

1. A method comprising:

deploying a virtual private local area network service (VPLS) instance within a layer two (L2) backhaul network of a cellular network, wherein the L2 backhaul network is positioned between a mobile device and a gateway device connected to a packet-based wide area network (WAN), wherein the gateway device is configured as a member of the VPLS instance, and wherein the mobile device is in wireless communication with a base station associated with a backhaul element of the cellular network;

receiving, with the gateway device, an address resolution request from the mobile device, wherein the address resolution request is flooded by the VPLS instance;

responding to the address resolution request, with the gateway device, with a media access control (MAC) address of the gateway device;

identifying a first backhaul element of the cellular network through which a MAC address of the mobile device is reachable based on the received request;

receiving Internet Protocol (IP) packets destined for the IP address of the mobile device;

forwarding the received IP packets to the identified backhaul element using the VPLS instance for communication to the mobile device;

wherein the gateway device of the cellular network is connected to a second base station reachable via a second backhaul element associated with the L2 backhaul network,

upon movement of the mobile device from wireless communication with the first base station to wireless communication with the second base station, performing MAC address learning with the VPLS instance to detect that the MAC address for the mobile device is no longer reachable by the first backhaul element and is reachable by the second backhaul element;

in response to the MAC address learning, dynamically updating a stored location of the mobile device within the cellular network;

subsequently receiving IP packets destined for the IP address of the mobile device; and

forwarding the subsequently received IP packets to the second backhaul element using the VPLS instance for communication to the mobile device.

2. The method of claim 1, further comprising:

upon detecting movement of the mobile device from wireless communication with the first base station to wireless communication with the second base station, the second base station generating a packet on behalf of the mobile device;

with the second base station, flooding the generated packet to network devices configured as members of the VPLS instance.

3. The method of claim 2,

wherein performing MAC address learning with the VPLS instance comprises receiving, with the gateway device, the flooded packet generated by the second base station, and dynamically updating the location of the mobile device within the cellular network based on re-learning reachability for the MAC address for the mobile device from the flooded packet.

4. The method of claim 1, wherein forwarding the received IP packets using the VPLS instance to the mobile device comprises forwarding the received IP packets on a pseudowire associated with the identified backhaul element.

5. The method of claim 1, wherein the backhaul element is configured as a member of the VPLS instance.

6. The method of claim 1, wherein the mobile device generates packets that identify the gateway device as the next hop for the mobile device.

7. A gateway device of a cellular network comprising:

a control unit configured to execute a virtual private local area network service (VPLS) instance;

an interface configured to receive an address resolution request from the mobile device, wherein the address resolution request is flooded by a member of the VPLS instance of which the gateway device is configured as a member,

wherein the control unit is configured to respond to the address resolution request with a media access control (MAC) address of the gateway device, and identify a first backhaul element of a layer two (L2) backhaul network of the cellular network through which a MAC address of the mobile device is reachable based on the received request, wherein the L2 backhaul network is positioned between a mobile device and a gateway device connected to a packet-based wide area network (WAN), and wherein the mobile device is in wireless communication with a base station associated with a backhaul element of the cellular network, and

wherein the interface is configured to receive IP packets destined for the IP address of the mobile device, and forward the received IP packets to the identified backhaul element using the VPLS instance for communication to the mobile device,

wherein the gateway device is connected to a second base station reachable via a second backhaul element associated with the L2 backhaul network,

wherein the control unit is configured to perform MAC address learning with the VPLS instance to detect when the MAC address for the mobile device is no longer reachable by the first backhaul element and is reachable by the second backhaul element, and, in response to the MAC address learning, dynamically update a location of the mobile device within the cellular network, and

wherein the interface is configured to receive subsequent IP packets destined for the IP address of the mobile device, and forward the subsequently received IP packets to the second backhaul element using the VPLS instance for communication to the mobile device.

8. The gateway device of claim 7, wherein the control unit is configured to forward the received IP packets on a pseudowire associated with the identified backhaul element.

9. A computer-readable storage medium comprising instructions for causing a programmable processor of a gateway device of a cellular network to:

execute a virtual private local area network service (VPLS) instance within a control unit of the gateway device;

receive an address resolution request from the mobile device, wherein the address resolution request is flooded by a member of the VPLS instance of which the gateway device is configured as a member;

respond to the address resolution request with a media access control (MAC) address of the gateway device;

identify a first backhaul element of a layer two (L2) backhaul network of the cellular network through which a MAC address of the mobile device is reachable based on the received request, wherein the L2 backhaul network is positioned between a mobile device and a gateway device connected to a packet-based wide area network (WAN), and wherein the mobile device is in wireless communication with a base station associated with a backhaul element of the cellular network, wherein the gateway device of the cellular network is connected to a second base station reachable via a second backhaul element associated with the L2 backhaul network;

receive IP packets destined for the IP address of the mobile device;

forward the received IP packets to the identified backhaul element using the VPLS instance for communication to the mobile device;

upon movement of the mobile device from wireless communication with the first base station to wireless communication with the second base station, perform MAC address learning with the VPLS instance to detect that the MAC address for the mobile device is no longer reachable by the first backhaul element and is reachable by the second backhaul element;

in response to the MAC address learning, dynamically update a stored location of the mobile device within the cellular network;

subsequently receive IP packets destined for the IP address of the mobile device; and

forward the subsequently received IP packets to the second backhaul element using the VPLS instance for communication to the mobile device.

10. The computer-readable storage medium of claim 10, further comprising instructions for causing the programmable processor to forward the received IP packets on a pseudowire associated with the identified backhaul element.

11. A system comprising:

a layer two (L2) backhaul network within a cellular network in which a virtual private local area network service (VPLS) instance is deployed;

a mobile device connected to the cellular network, in wireless communication with a first base station;

a first backhaul element of the L2 backhaul network associated with the first base station, through which a media access control (MAC) address of the mobile device is reachable; and

a first gateway device connected to a packet-based wide area network (WAN), wherein the L2 backhaul network is positioned between the mobile device and the first gateway device,

wherein the first gateway device comprises;

a control unit configured to execute a VPLS protocol associated with the VPLS instance; and

an interface configured to receive an address resolution request from the mobile device, wherein the address resolution request is flooded by a member of the VPLS instance of which the first gateway device is configured as a member,

wherein the control unit is configured to respond to the address resolution request with a MAC address of the first gateway device, and identify the first backhaul element through which the MAC address of the mobile device is reachable based on the received request,

wherein the interface is configured to receive IP packets destined for the IP address of the mobile device, and forward the received IP packets to the identified backhaul element using the VPLS instance for communication to the mobile device,

wherein the gateway device is connected to a second base station reachable via a second backhaul element associated with the L2 backhaul network,

wherein the control unit is configured to perform MAC address learning with the VPLS instance to detect when the MAC address for the mobile device is no longer reachable by the first backhaul element and is reachable by the second backhaul element, and, in response to the MAC address learning, dynamically update a location of the mobile device within the cellular network, and

wherein the interface is configured to receive subsequently IP packets destined for the IP address of the mobile device, and forward the subsequently received IP packets to the second backhaul element using the VPLS instance for communication to the mobile device.

12. The system of claim 11, further comprising:

a second gateway device connected to the packet-based WAN;

a second L2 backhaul network, wherein the second L2 backhaul network is positioned between the mobile device and the second gateway device,

wherein when the mobile device moves from being in wireless communication with the base station to a second base station associated with the second gateway device, the first gateway device is configured to advertise a mobile subscriber (MS) virtual private network (VPN) route advertisement to the second gateway device using an extended routing protocol, wherein the MS VPN route advertisement encodes reachability information associated with the mobile device.

13. The system of claim 12, wherein the MS VPN route encodes subscriber context for the mobile device in accordance with the extended routing protocol to enable the second gateway device to process data communications associated with a data session in accordance with the subscriber context.

14. The system of claim 12, wherein the second base station is configured to execute the VPLS instance, and wherein the VPLS instance executing on the second base station is configured to cause the second base station to, upon detecting movement of the mobile device from wireless communication with the first base station to wireless communication with the second base station, generate a packet on behalf of the mobile device, and wherein the second base station is configured to flood the generated packet to network devices configured as members of the VPLS instance.

15. A method comprising:

providing network-based micro mobility for a mobile device in a cellular network using an extended virtual private local area network service (VPLS);

providing network-based macro mobility for the mobile device using an extended routing protocol to send virtual private network (VPN) routes that encode reachability information associated with the mobile device; and

transferring subscriber context to other network devices in the cellular network using the extended routing protocol to encode the subscriber context.