2011/11/21 by Sreeram Kannan, Pramod Viswanath, Kannan, Sreeram +1
Computer Science · Engineering · #Advanced Wireless Network Optimization #Cooperative Communication and Network Coding #FOS: Computer and information sciences #Information Theory (cs.IT) #Mobile Ad Hoc Networks #Networking and Internet Architecture (cs.NI)
paper · pdf · doi:10.48550/arxiv.1111.4768
openalex publication_date 2011/11/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A classical result in undirected wireline networks is the near optimality of routing (flow) for multiple-unicast traffic (multiple sources communicating independent messages to multiple destinations): the min cut upper bound is within a logarithmic factor of the number of sources of the max flow. In this paper we "extend" the wireline result to the wireless context. Our main result is the approximate optimality of a simple layering principle: \em local physical-layer schemes combined with global routing. We use the \em reciprocity of the wireless channel critically in this result. Our formal result is in the context of channel models for which "good" local schemes, that achieve the cut-set bound, exist (such as Gaussian MAC and broadcast channels, broadcast erasure networks, fast fading Gaussian networks). Layered architectures, common in the engineering-design of wireless networks, can have near-optimal performance if the \em locality over which physical-layer schemes should operate is carefully designed. Feedback is shown to play a critical role in enabling the separation between the physical and the network layers. The key technical idea is the modeling of a wireless network by an undirected "polymatroidal" network, for which we establish a max-flow min-cut approximation theorem.