Low-energy wireless communication network design

Energy-efficient wireless communication network design is an important and challenging problem. Its difficulty lies in the fact that the overall performance depends, in a coupled way, on the following subsystems: antenna, power amplifier, modulation, error control coding, and network protocols. In addition, given an energy constraint, improved operation of one of the aforementioned subsystems may not yield better overall performance. Thus, to optimize performance one must account for the coupling among the above subsystems and simultaneously optimize their operation under an energy constraint. In this article we present a generic integrated design methodology that is suitable for many kinds of mobile systems and achieves global optimization under an energy constraint. By pointing out some important connections among different layers in the design procedure, we explain why our integrated design methodology is better than traditional design methodologies. We present numerical results of the application of our design methodology to a situational awareness scenario in a mobile wireless network with different mobility models. These results illustrate the improvement in performance that our integrated design methodology achieves over traditional design methodologies, and the tradeoff between energy consumption and performance.

Introduction

Energy-efficient wireless communication network design is an important and challenging problem. It is important because mobile units operate on batteries with limited energy supply. It is challenging because there are many different issues that must be dealt with when designing a low-energy wireless communication system (e.g., amplifier design, coding, modulation design, resource allocation, and routing strategies), and these issues are coupled with one another. Furthermore, the design and operation of each component of a wireless communication system present trade-offs between performance and energy consumption. The key observation is that constraining the energy of the nodes in a wireless network imposes a coupling among the design components that cannot be ignored in performing system optimization. Therefore, the challenge is to exploit the coupling among the various components of a wireless communication system and understand the trade-off between performance and energy consumption in each individual component/subsystem in order to come up with an overall integrated system design that satisfies an energy constraint and has optimal performance with respect to some performance metric. Traditional design methodologies that optimize each layer separately may not be appropriate in terms of overall system optimality. The purpose of this article is to present a methodology for the design, simulation, and optimization of wireless communication networks that achieves maximum performance under an energy constraint. The presentation of our methodology also gives some insight as to why traditional design methodologies may not achieve overall system optimality. The integrated design methodology is applied to two scenarios of mobile ad hoc networks. The results show that significant gains are possible with an integrated design approach over traditional designs.