Capacity bounds for three classes of wireless networks

Abstract

We present capacity results for three classes of wireless ad hoc networks, using a general framework that allows their unified treatment. The results hold with probability going to 1 as the number of nodes in the network approaches infinity, and under a general model for channel fading.We first study asymmetric networks that consist of n source nodes and around n d destination nodes, communicating over a wireless channel. Each source node creates data traffic that is directed to a destination node chosen at random. When 1 2 < d < 1, an aggregate throughput that increases with n as n 1 2 is achievable. If, however, 0 < d < 1 2 , bottlenecks are formed and the aggregate throughput can not increase faster than n d .We also consider cluster networks, that consist of n client nodes and around n d cluster heads, communicating over a wireless channel. Each of the clients wants to communicate with one of the cluster heads, but the particular choice of cluster head is not important. In this setting, the maximum aggregate throughput is on the order of n d , and it can be achieved with no transmissions taking place between client nodes.We conclude with the study of hybrid networks. These consist of n wireless nodes and around n d access points. The access points are equipped with wireless transceivers, but are also connected with each other through an independent network of infinite capacity. Their only task is to support the operation of the wireless nodes. When 1 2 < d < 1, an aggregate throughput on the order of n d is achievable, through the use of the infrastructure. If, however, 0 < d < 1 2 , using the infrastructure offers no significant gain, and the wireless nodes can achieve an aggregate throughput on the order of n 1 2 by using the wireless medium only.

Capacity of Hybrid Cellular-Ad Hoc Data Networks

“…It is shown that with n ad-hoc nodes and m base stations, the benefits provided due to the base stations are insignificant when m grows asymptotically slower than √ n. In [8], in a similar network setting, it is shown that Θ(1) per node throughput can be achieved when the nodes can optimally control their transmission powers. In [9], it is shown that a hybrid network with n wireless nodes and n d access points, inter-connected by wires, can achieve throughput gains only when 1 2 < d < 1. Unlike our work, the above efforts assume that the traffic flows are established between randomly chosen ad-hoc nodes and the base stations or access points are for relaying purposes only.…”

“…While there has been a surge in interest in modelling various kinds of hybrid networks (to be elaborated in section II) [3], [4], [5], [2], [6], [1], [7], [8], [9], [10], [11], the above question has not been answered to date. While the use of shorter range and hence, higher rate wireless ad-hoc links may improve spatial reuse (more simultaneous transmissions can occur) [12], the use of multi-hop relaying increases the number of wireless hops traversed and this reduces the achievable throughput.…”

Capacity of Inhomogeneous Hybrid Wireless Networks in Three-Dimensional Space

“…Following this work, extensive studies have been conducted to achieve a tighter capacity bound [2][3][4][5][6][7][8]. Franceschetti et al [2] apply percolation theory to obtain a per-node transmission rate higher than 1 ( ) n !…”

Per User Throughput in Large Wireless Networks

“…A capacity of 1 √ n per node is verified through extensive simulations. The effect of channel fading is considered in [2], [3] and [4]. Another branch of work focuses on different traffic patterns in wireless networks.…”

“…Following the work, researchers have studied capacity scaling laws under different assumptions or applications, e.g. in [2] [3][4] [6][8] [15] [16].…”