Recently, Nenadić et al. (2004) proposed the RSA-CEGD protocol for certified delivery of e-goods. This is a relatively complex scheme based on verifiable and recoverable encrypted signatures (VRES) to guarantee properties such as strong fairness and non-repudiation, among others. In this paper, we demonstrate how this protocol cannot achieve fairness by presenting a severe attack and also point...

This paper proposes a contention-based fair coexistence mechanism among heterogeneous networks that have different transmission power and/or coverage. First, we show that the existing carrier sensing multiple access (CSMA) mechanism, that is a prevailing contention-based protocol, results in significant unfairness in channel access when heterogeneous networks coexist; a system with lower transm...

This paper addresses an unfairness problem that exists among vehicles of distinct velocities in IEEE 802.11p based vehicle-to-infrastructure (V2I) networks used for drive-thru Internet applications. The standard IEEE 802.11p does not take into account, the residence time of vehicles within the coverage of each road side unit (RSU), for granting channel access. Due to this, a vehicle moving with...

IEEE 802.11p is an approved amendment to the IEEE 802.11 standard to facilitate wireless access in vehicular environments (WAVE). In this article, we present an analytical model to evaluate the impact of vehicle mobility on the saturation throughput of IEEE 802.11p-based vehicle-to-infrastructure (V2I) networks. The throughput model is then used to investigate an unfairness problem that exists ...

Over the past few years, Wireless Local Area Networks (WLANs) have gained an increased attention and a large number of WLANs are being deployed in universities, companies, airports etc. Majority of the IEEE 802.11 based WLANs employ Distributed Coordination Function (DCF) in Wireless Access Points (AP) to arbitrate the wireless channel among Wireless Stations (STAs). However, DCF poses serious ...

We consider an appointment system where heterogeneous participants are sequenced and scheduled for service. As service times are uncertain, the aim is to mitigate the unpleasantness experienced by the participants in the system when their waiting times or delays exceed acceptable thresholds, and address fairness concerning balance of service levels among participants. In evaluating uncertain de...