Published online by Cambridge University Press: 03 May 2011
The number of endpoints connected wirelessly to the Internet has long overtaken the number of wired endpoints, and the difference between the two is widening. Wireless mesh networks, sensor networks, and vehicular networks represent some of the new growth segments in wireless networking in addition to mobile data networks, which is currently the fastest-growing segment in the wireless industry. Wireless networks with time-varying bandwidth, error rate, and connectivity beg for opportunistic transport, especially when the link bandwidth is high, error rate is low, and the endpoint is connected to the network in contrast to when the link bandwidth is low, error rate is high, and the endpoint is not connected to the network. “Connected” is a binary attribute in TCP/IP, meaning one is either part of the Internet and can talk to everything or is isolated. In addition, connecting requires a globally unique IP address that is topologically stable on routing timescale (minutes to hours). This makes it difficult and inefficient to handle mobility and opportunistic transport in the Internet. Clearly we need a new networking paradigm that avoids a heavyweight operation like end-to-end connection and enables opportunistic transport. In addition to the these scenarios, given that the predominant use of the Internet today is for content distribution and content retrieval, there is a need for handling dissemination of content in an efficient manner. This chapter describes a network architecture that addresses the previously mentioned unique requirements.