TY - JOUR

T1 - On channel-discontinuity-constraint routing in wireless networks

AU - Sankararaman, Swaminathan

AU - Efrat, Alon

AU - Ramasubramanian, Srinivasan

AU - Agarwal, Pankaj K.

N1 - Funding Information:
A. Efrat and S. Sankararaman are supported by NSF CAREER Grant 0348000 . P.K. Agarwal is supported by NSF under Grants CNS-05-40347 , CCF-06-35000 , IIS-07-13498 , and CCF-09-40671 , by ARO grants W911NF-07-1-0376 and W911NF-08-1-0452 , by an NIH grant 1P50-GM-081883-01 , by a DOE Grant OEG-P200A070505 , and by a grant from the US–Israel Binational Science Foundation.

PY - 2014/2

Y1 - 2014/2

N2 - Multi-channel wireless networks are increasingly deployed as infrastructure networks, e.g. in metro areas. Network nodes frequently employ directional antennas to improve spatial throughput. In such networks, between two nodes, it is of interest to compute a path with a channel assignment for the links such that the path and link bandwidths are the same. This is achieved when any two consecutive links are assigned different channels, termed as "Channel-Discontinuity-Constraint" (CDC). CDC-paths are also useful in TDMA systems, where, preferably, consecutive links are assigned different time-slots. In the first part of this paper, we develop a t-spanner for CDC-paths using spatial properties; a sub-network containing O(n/θ) links, for any θ > 0, such that CDC-paths increase in cost by at most a factor t = (1 - 2 sin(θ/2))-2. We propose a novel distributed algorithm to compute the spanner using an expected number of O(n log n) fixed-size messages. In the second part, we present a distributed algorithm to find minimum-cost CDC-paths between two nodes using O(n2) fixed-size messages, by developing an extension of Edmonds' algorithm for minimum-cost perfect matching. In a centralized implementation, our algorithm runs in O(n2) time improving the previous best algorithm which requires O(n3) running time. Moreover, this running time improves to O(n/θ) when used in conjunction with the spanner developed.

AB - Multi-channel wireless networks are increasingly deployed as infrastructure networks, e.g. in metro areas. Network nodes frequently employ directional antennas to improve spatial throughput. In such networks, between two nodes, it is of interest to compute a path with a channel assignment for the links such that the path and link bandwidths are the same. This is achieved when any two consecutive links are assigned different channels, termed as "Channel-Discontinuity-Constraint" (CDC). CDC-paths are also useful in TDMA systems, where, preferably, consecutive links are assigned different time-slots. In the first part of this paper, we develop a t-spanner for CDC-paths using spatial properties; a sub-network containing O(n/θ) links, for any θ > 0, such that CDC-paths increase in cost by at most a factor t = (1 - 2 sin(θ/2))-2. We propose a novel distributed algorithm to compute the spanner using an expected number of O(n log n) fixed-size messages. In the second part, we present a distributed algorithm to find minimum-cost CDC-paths between two nodes using O(n2) fixed-size messages, by developing an extension of Edmonds' algorithm for minimum-cost perfect matching. In a centralized implementation, our algorithm runs in O(n2) time improving the previous best algorithm which requires O(n3) running time. Moreover, this running time improves to O(n/θ) when used in conjunction with the spanner developed.

KW - Algorithms

KW - Directional antennas

KW - Routing

KW - Spanners

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U2 - 10.1016/j.adhoc.2011.04.011

DO - 10.1016/j.adhoc.2011.04.011

M3 - Article

AN - SCOPUS:84888869687

VL - 13

SP - 153

EP - 169

JO - Ad Hoc Networks

JF - Ad Hoc Networks

SN - 1570-8705

IS - PART A

ER -