Ad hoc networks with heterogeneous smart antennas: performance analysis and protocols
Karthikeyan Sundaresan, Raghupathy Sivakumar · Wireless Communications and Mobile Computing · 2006
Abstract The use of smart antennas in wireless ad hoc networks has garnered attention over the last few years. Given the unique capabilities of smart antennas, and how they can improve performance in a typically constrained ad hoc network environment, the attention is with merit. However, not much light has been shed on wireless ad hoc networks that have nodes with varying antenna capabilities. While homogeneous ad hoc networks with all nodes having the same antenna capabilities will have certain applications, we argue that ad hoc networks with nodes having heterogeneous antenna capabilities are more likely to be the norm due to a variety of motivating factors. In this context, we answer two fundamental questions in this paper: (i)what is the theoretical capacity of an ad hoc network when its nodes have varying antenna capabilities? We consider nodes equipped with only omnidirectional antennas to those that are equipped with more sophisticated adaptive‐array and MIMO capable antennas. Perhaps more interestingly, we provide insights into what percentage of nodes in an ad hoc network have to be ‘smart’ to get a certain overall network capacity. (ii)What medium access control (MAC) and routing protocols should nodes use in such a heterogeneous network? We present MAC and routing protocols for ad hoc networks with heterogeneous antenna capabilities that allow nodes to interact with each othereffectivelydespite their heterogeneity, and in the process deliver considerably improved performance over simplistic strategies. We substantiate our theoretical results, and evaluate the proposed protocols using ns2‐based network simulations. Copyright © 2006 John Wiley & Sons, Ltd.