Finding the route with maximum end-to-end spectral efficiency in multihop wireless networks has been subject to interest in the recent literature. All previous studies, however, focused on finding one route from a given source to a given destination under the constraint of equal bandwidth sharing. To the best of our knowledge, for the first time, this paper provides extensions to the multicommodity flow case, i.e., the case of multiple simultaneous source-destination (s-d) pairs. In particular, given an arbitrary number of s-d pairs, we address the problem of finding a route for every s-d pair such that the minimum spectral efficiency across all routes is maximized. We provide two alternative approaches, where one is based on fixed-sized time slots and the other is based on variable-sized time slots. For each approach, we derive the provably optimal routing algorithm. We also shed the light on the arising tradeoff between the complexity of network-layer route computation and the complexity of medium access control (MAC) layer scheduling of time slots, as well as the amenability to distributed implementation of our proposed algorithms. Our numerical results further illustrate the efficiency of the proposed approaches and their tradeoffs.
Optimal Multicommodity Spectrum-Efficient Routing in Multihop Wireless Networks
