Power-aware virtual base stations for wireless mobile ad hoc communications Ahmed Safwat a, * , Hossam Hassanein a , Hussein Mouftah b a Telecommunications Research Laboratory, School of Computing, QueenÕs University, Kingston, ON, Canada K7L 3N6 b School of Information Technology and Engineering, University of Ottawa, Ottawa, ON, Canada K1N 6N5 Abstract In this paper, we propose a novel infrastructure formation scheme for wireless mobile ad hoc networks. The proposed architecture, namely, power-aware virtual base stations (PA-VBS), mimics and maintains the operation of the con- ventional fixed infrastructure in cellular networks. In the PA-VBS protocol, a mobile node is elected from a set of nominees to act as a temporary base station within its zone based on its residual battery capacity. We study the characteristics and performance of PA-VBS by means of simulation. It is shown that PA-VBS scales well to large networks of mobile stations, and that it outperforms other infrastructure-formation protocols in terms of load bal- ancing. The PA-VBS architecture facilitates the development of a comprehensive and promising framework for quality of service (QoS) management in wireless mobile ad hoc networks once the proper integration of the MAC protocol with the routing and call admission control mechanisms is established. Moreover, it lays the groundwork for assigning bandwidth, and/or implementing priorities, and hence for QoS-based routing by conveying the quality of a path prior to call setup. To the authorsÕ best knowledge, this is the first time that energy is used as a basis for developing a wireless mobile infrastructure, and achieving load balancing. Ó 2002 Published by Elsevier Science B.V. Keywords: Wireless mobile ad hoc communications; Wireless mobile infrastructure; Energy conservation; Routing; Medium access control; Quality of service 1. Introduction Ad hoc wireless networks eradicate the costs of infrastructure deployment, setup, and adminis- tration. Ad hoc wireless networks allow anywhere, anytime network connectivity with complete lack of control, ownership, and regulatory influence. The interest in wireless ad hoc networks stems from their suitability for different types of appli- cation scenarios ranging from home and road to office and school. Since there is no fixed infra- structure, a wireless mobile ad hoc network can be deployed quickly. Thus, such networks can be used in situations where either there is no other wireless communication infrastructure present or where such an infrastructure cannot be used be- cause of military tactics, an emergency (as a result of a natural disaster or an enemy attack), cost reasons, etc. The limited energy capacity of the mobile devices making up the network draws our attention to the importance of power awareness in * Corresponding author. E-mail addresses: safwat@cs.queensu.ca (A. Safwat), hos- sam@cs.queensu.ca (H. Hassanein), mouftah@site.uottawa.ca (H. Mouftah). 1389-1286/03/$ - see front matter Ó 2002 Published by Elsevier Science B.V. PII:S1389-1286(02)00419-X Computer Networks 41 (2003) 331–346 www.elsevier.com/locate/comnet