Combining layer 2-layer 3 paging for wireless LANs

The paper addresses location tracking and paging IEEE 802.11 wireless LAN hosts that are in power save mode. We design a protocol for paging (tracking agent based paging or TAP) IEEE 802.11 wireless LAN hosts. Mobile nodes in each IEEE 802.11 basic service set constitute a layer-2 paging area, which coexists within layer-3 paging areas. The tracking agent is in charge of the L2 paging state, and it continuously updates the paging state after each L2 handoff. Paging on the wireless link is done by extended beacons, and does not involve periodic L3 messages. Signaling in TAP is based on IEEE´s inter-access point protocol with minor extensions. We show that TAP can be integrated with various IP paging algorithms such as mobile IPv6 hierarchical paging, home agent and foreign agent paging. We evaluate the performance of the combined L3-L2 paging protocols analytically and by simulation and show that TAP combined with mobile IPv6 hierarchical paging achieves superior power savings compared individually to mobile IPv6 hierarchical paging without TAP or home agent paging algorithms.