FAWNA

Abstract

The concept of a fiber aided wireless network architecture (FAWNA) is introduced in [Ray et al., Allerton 2005], which allows high-speed mobile connectivity by leveraging the speed of optical networks. In this paper, we consider a single-input, multiple-output (SIMO) FAWNA, which consists of a SIMO wireless channel interfaced to an optical fiber channel, through wireless-optical interfaces. We propose a scheme where the received wireless signal at each interface is quantized and sent over the fiber. The capacity of our scheme approaches the capacity of the architecture, exponentially with fiber capacity. We show that for a given fiber capacity, there is an optimal operating wireless bandwidth and an optimal number of wireless-optical interfaces. We also address the question of how fiber capacity should be divided between the interfaces. We show that an optimal allocation is one which ensures that each interface gets at least that fraction of the fiber capacity which ensures that its noise is dominated by front end noise rather than by quantizer distortion. After this requirement is met, SIMO-FAWNA capacity is almost invariant to allocation of left over fiber capacity. The wireless-optical interfaces of our scheme have low complexity and do not require knowledge of the transmitter code book. They are also extendable to FAWNAs with large number of transmitters and interfaces and, offer adaptability to variable rates, changing channel conditions and node positions.