Under heterogeneous radio conditions, Wireless LAN stations may use different modulation schemes, leading to a heterogeneity of bit rates. In such a situation, 802.11 DCF allocates the same throughput to all stations independently of their transmitting bit rate; as a result, the channel is used by low bit rate stations most of the time, and efficiency is… (More)
The upcoming new standard IEEE 802.11e aims at providing Quality of Service (QoS) support in 802.11 Wireless LANs. While the QoS mechanisms in 802.11e, namely the EDCF and the HCF, have already been defined in the standard draft, the challenge lies in the configuration of these mechanisms in order to provide the desired services. In this paper, we deal with… (More)
— In this paper, we propose ARME (Assured Rate MAC Extension), an extension of the IEEE 802.11 MAC protocol to provide throughput guarantees. The proposed extension relies on the Distributed Coordination Function (DCF) with a modified algorithm for the computation of the Contention Window (CW). Best Effort service (with no throughput guarantee) is supported… (More)
Effort is supported by the functionality of the current 802.11 standard in such a way that legacy IEEE 802.11 terminals behave as Best Effort terminals in the DIME architecture. While the performance of the Assured Forwarding extension has been thoroughly evaluated by the authors elsewhere , this paper concentrates on the overall architecture and the… (More)
— With Weighted Fair Queuing, the link's bandwidth is distributed among competing flows proportionally to their weights. In this paper we propose an extension of the DCF function of IEEE 802.11 to provide weighted fair queuing in Wireless LAN. Simulation results show that the proposed scheme is able to provide the desired bandwidth distribution independent… (More)
—The enhanced distributed channel access (EDCA) mechanism of the IEEE 802.11e standard provides quality-of-service (QoS) support through service differentiation by using different medium-access-control (MAC) parameters for different stations. The configuration of these parameters, however, is still an open research challenge, as the standard provides only a… (More)
— In this letter we present a model to analyze the delay behavior of the EDCA mechanism of IEEE 802.11e. Simulation results validate the accuracy of our analysis.
— In recent years, multi-technology enabled terminals are becoming available. Such multi-mode terminals pose new challenges to mobility management. In order to address some of these challenges, the IEEE is currently working on a new specification on Media Independent Handover services (IEEE 802.21 MIH). The main aim of this specification is to improve user… (More)