Wide Area Wi-Fi Sam Bhoot Wide Area Wi-Fi Definition: Wi-Fi (Wireless Fidelity) n. – popular term for high frequency wireless local area networks operating on the 802.11 standard. Problem: Local Area Network Question: How to extend this to Wide Area Network? Wide Area Wi-Fi Solution 1 - Mesh Networks: Multi-hop systems in which devices assist each other in transmitting packets through the network. Created using a series of special 802.11b access points (Mesh AP’s) that create a single, scalable wireless network. Wide Area Wi-Fi Mesh Networks: A Mesh AP can send and receive messages and also functions as a router that can relay messages for its neighbors. Through the relaying process, data will find its way to its destination, passing through intermediate Mesh AP’s. Wide Area Wi-Fi Mesh Networks: A mesh network offers multiple redundant communications paths throughout the network. If one link fails for any reason, the network automatically routes messages through alternate paths. Wide Area Wi-Fi Mesh Networks: Advantages Low power transmissions to reach nearby nodes so less interference with radio signals from other nodes. The network is able to benefit from channel reuse, resulting in improved spatial capacity. Traffic balancing by dynamically routing traffic around a congested node. Less broadband connections required. Wide Area Wi-Fi Mesh Networks: Disadvantages Deriving an optimum routing protocol to minimize the number of hops. Dynamic networks eat up bandwidth updating the nodes of the topology. Ensuring security of packets transmitted from an outside agent stealing bandwidth. Significantly lowers the capacity of the Wi-Fi network. Wide Area Wi-Fi Mesh Networks: Main Problem: How to assign IP addresses to mesh nodes? Solution is to use IPv6 but still impractical. Use 10.x.x.x numbers and go through and use NAT. Home Clients will have to go through two NATs. Leads to complicated issues with proper routing. Wide Area Wi-Fi Solution 2 - Repeater / Router: Software that creates meshes instead of a hierarchical wireless LAN. The software loads on the wireless adapter card and turns every adapter into a repeater-router, instead of an endpoint looking for an access point. Wide Area Wi-Fi Repeater / Router: End results Wireless LAN can extend wherever mesh clients exist. Since users connect to nearest WLAN device instead of distant AP, throughput will be maximum. Software being developed by MeshNetworks, SkyPilot, Ember, and CoWave Networks. Wide Area Wi-Fi Future of Wide Area Networking: 802.16 Wireless MAN Feasible backhaul for connecting Wi-Fi Hotspots together. Base-stations similar to cellular costing about $20k each serving 60 customers with T1 speed connections. Operates in the 10-66 GHz range with data rates of up to 120 Mbps.