Vertical handoffs in wireless overlay networks

摘要: No single wireless network technology simultaneously provides a low latency, high bandwidth, wide area data service to large number of mobile users. Wireless Overlay Networks – hierarchical structure room-size, building-size, and networks solve the problem providing connectivity users in an efficient scalable way. The specific topology cells variety technologies that comprise overlay present new problems have not been encountered previous cellular handoff systems. We implemented vertical system allows roam between networks. Our goal is provide user with best possible for as long minimum disruption during handoff. Results our initial implementation show latency bounded by discovery time, amount time before host discovers it has moved into or out overlay. This measured seconds: enough disrupt reliable transport protocols such TCP introduce significant disruptions continuous multimedia transmission. To efficiently support applications cannot tolerate these disruptions, we enhancements basic scheme significantly reduce without assuming any knowledge about channel characteristics. For handoffs room-size building-size overlays, lead best-case approximately 170 ms 1.5% overhead terms resources. wide-area networks, 800 similarly overhead.