The capacity of wireless networks

Abstract

When identical randomly located nodes, each capable of transmitting at bits per second and using a fixed range, form a wireless network, the throughput () obtainable by each node for a randomly chosen destination is 2 log bits per second under a noninterference protocol. If the nodes are optimally placed in a disk of unit area, traffic patterns are optimally assigned, and each transmission's range is optimally chosen, the bit-distance product that can be transported by the network per second is 2() bit-meters per second. Thus even under optimal circumstances, the throughput is only 2 bits per second for each node for a destination nonvanishingly far away. Similar results also hold under an alternate physical model where a required signal-to-interference ratio is specified for successful receptions. Fundamentally, it is the need for every node all over the domain to share whatever portion of the channel it is utilizing with nodes in its local neighborhood that is the reason for the constriction in capacity. Splitting the channel into several subchannels does not change any of the results. Some implications may be worth considering by designers. Since the throughput furnished to each user diminishes to zero as the number of users is increased, perhaps networks connecting smaller numbers of users, or featuring connections mostly with nearby neighbors, may be more likely to be find acceptance. Index Terms-Ad hoc networks, capacity, multihop radio networks, throughput, wireless networks. I. INTRODUCTION W IRELESS networks consist of a number of nodes which communicate with each other over a wireless channel. Some wireless networks have a wired backbone with only the last hop being wireless. Examples are cellular voice and data networks and mobile IP. In others, all links are wireless.

Engineering wireless mesh networks

“…Whereas the two previous interference models are only concerned with pairwise (binary) link conflict, this model [6] captures a more realistic situation: the interference to a certain link is the cumulative interference from multiple links that are active at the same time. Hence, under this interference model, a set s ⊆ L is an ISet iff:…”

Throughput Capacity of Multi-Channel Hybrid Wireless Network with Antenna Support

“…Lemma 1.The capacity of MC-HDAS networks is nλ = O nW θ 2 logn bits/sec, and that of MC-HDAH networks is nλ = O nW (θ 2 +(4π 2 −θ 2 )s 2 )logn bits/sec. Proof.for MC-HDAS networks, the condition interference zone is θ 2 (2π) 2 portion of that when ominidirectional antennas are used at both ends [4,14]. Since for ominidirectional antennas, Therefore, the interference zone is θ 2 (2π) 2 π r 2 i 4 ( r i is the transmission radius)for each transmission on channel i (1 ≤ i ≤ c ).…”

“…The protocol model proposed by Gupta and Kumar [4] is extended to include directional antennas in the paper. It is the receiver-based interference model proposed in [14].…”

“…In the landmark paper [4], Gupta and Kumar showed that the throughput capacity obtainable by each node for a randomly chosen destination is bits/s assuming that number of mobile nodes are placed randomly, a somewhat disappointing results. Inspired by this work, many researchers have investigated the capacity issue for wireless networks under various constraints and tried to find out the method to improve the throughput capacity [5].…”

Optimized Clustering for Maximal Lifetime of Wireless Sensor Networks

“…Because the sensor nodes carry limited and generally irreplaceable power sources, the protocols designed for WSN must seriously take the issue of energy efficiency into consideration. The clustering-based routing protocols proposed for the WSN try to evenly distribute the consumption of the energy of the sensors [3][4][5]9]. The main idea of the protocol is based on dynamical selection of the cluster-heads among the eligible active nodes.…”