Title :
Capacity and delay of hybrid wireless broadband access networks
Author :
Li, Pan ; Zhang, Chi ; Fang, Yuguang
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Florida, Gainesville, FL
fDate :
2/1/2009 12:00:00 AM
Abstract :
An optical network is too costly to act as a broadband access network. On the other hand, a pure wireless ad hoc network with n nodes and total bandwidth of W bits per second cannot provide satisfactory broadband services since the pernode throughput diminishes as the number of users goes large. In this paper, we propose a hybrid wireless network, which is an integrated wireless and optical network, as the broadband access network. Specifically, we assume a hybrid wireless network consisting of n randomly distributed normal nodes, and m regularly placed base stations connected via an optical network. A source node transmits to its destination only with the help of normal nodes, i.e., in the ad hoc mode, if the destination can be reached within L (L /spl geq/ 1) hops from the source. Otherwise, the transmission will be carried out in the infrastructure mode, i.e., with the help of base stations. Two transmission modes share the same bandwidth of W bits/sec. We first study the throughput capacity of such a hybrid wireless network, and observe that the throughput capacity greatly depends on the maximum hop count L and the number of base stations m. We show that the throughput capacity of a hybrid wireless network can scale linearly with n only if m = Omega(n), and when we assign all the bandwidth to the infrastructure mode traffics. We then investigate the delay in hybrid wireless networks. We find that the average packet delay can be maintained as low as Theta(1) even when the per-node throughput capacity is Theta(W).
Keywords :
ad hoc networks; bandwidth allocation; broadband networks; optical fibre networks; radio access networks; telecommunication traffic; average packet delay; bandwidth assignment; bandwidth sharing; hybrid wireless broadband access network; infrastructure mode traffic; optical network; throughput capacity; transmission mode; wireless ad hoc network; Bandwidth; Base stations; Bit rate; Delay; Mobile ad hoc networks; Optical fiber networks; Telecommunication traffic; Throughput; Web and internet services; Wireless networks; Hybrid wireless networks; capacity; delay; broadband access networks;
Journal_Title :
Selected Areas in Communications, IEEE Journal on
DOI :
10.1109/JSAC.2009.090203