1. Wide Area Wi-Fi Sam Bhoot

2. 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?

3. 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.

4. 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.

5. 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.

6. 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.

7. 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.

8. 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.

9. 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.

10. 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.

11. 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.