Design of a flat wireless Internet Service Provider network

The drawbacks of a hierarchical, tunnel-based architecture for wireless networks have recently become apparent. These include higher than necessary latency, wasted bandwidth, scalability bottlenecks, single points of failure, and increased complexity. The realization that handoff need not be the centerpiece of a network architecture when a large number of users are stationary and/or do not need to be reachable on externally initiated connections at a fixed IP address has led to recent proposals for flatter architectures where traffic is offloaded to a generic (not wireless specific) Internet Service Provider (ISP) at the closest possible opportunity to the wireless link. While these proposals do support mobility for flows ongoing at the time of handoff, tunneling traffic to and from the previous access router may lead to sub-optimal performance, efficiency, and reliability. In this paper, we outline a possible approach to the design of a wireless ISP that handles local mobility in a way that does not suffer from these drawbacks. Our solution is based on existing protocols commonly deployed in wireline ISPs, such as BGP, DHCP, and dynamic DNS update. Unlike existing approaches that use wireless-specific core network nodes such as SGSNs and GGSNs, our solution requires only modified mobile nodes and first-hop access routers, leaving the core network running unmodified, wireline-standard protocols.