Enabling large-scale wireless broadband: The case for TAPs

The vision is tantalizing: a high-performance, scalable, and widely deployed wireless Internet that facilitates services ranging from radically new and unforeseen applications to true wireless "broadband" to residences and public spaces at rates of 10s of Mb/sec. However, while high-speed wireless access is easy to achieve in an enterprise network via low-cost IEEE 802.11 (WiFi) access points, wireless technology in public spaces is in its infancy. "Hot spots" provide high-speed wireless access, but do so in very few isolated "islands" at immense costs. Likewise, while fixed wireless (e.g. LMDS) and 3G can provide ubiquitous coverage and 3G can support mobility, throughputs can often be two orders of magnitude slower than WiFi. In this paper, we formulate the challenges of building a high-performance, scalable and widely deployed wireless Internet along 10 premises. We make the case for the requirement of a fundamental new architecture based on beamforming antennas deployed on fixed, wire-powered Transit Access Points (TAPs) that form a multi-hopping wireless backbone with a limited number of wired ingress/egress points. To address scalability, deployability, and performance challenges we present distributed, opportunistic and coordinated resource management problems and a novel "network is the channel" framework that searches for fundamental information-theoretic tradeoffs between protocol overhead and capacity.