Linear ad hoc networks: Information propagation, reliability, and delay

We consider wireless ad hoc networks with a linear topology, which may arise, for example, in a vehicular network. We begin with the design and implementation of an example vehicular ad hoc network, which requires rapid information exchange among mobile nodes. A class of location-based medium access control (MAC) protocols are designed for MAC layer broadcasts to improve the performance of this network. We analyze the multi-hop information propagation of these location-based protocols and compare this with that of a simple slotted Aloha protocol with spatial reuse under a disk interference model. We then analyze the performance of these two protocols, when multi-user interference is explicitly modeled via the received signal-to-interference plus noise ratio (SINR). We measure performance in terms of the average number of nodes that receive each message in one hop.;We also consider optimizing the packet-sizes and the re-use factor to minimize the delay required to send a message between two nodes in a linear multi-hop wireless network subject to a reliability constraint. We consider both systems with a finite and an infinite number of hops. We analyze the rate of growth of the delay as a function of the message size. Two cases are considered: one in which packets are decoded/re-encoded on each hop and one in which this is concatenated with an end-to-end outer code.;We then extend the discussion to the case with redundant message receptions. This results in a better delay performance than the schemes without redundant reception. The optimal spatial re-use factors under different SNR settings are characterized.