Initial ranging is the primary and important process in wireless networks for the customer premise equipments (CPEs) to access the network and establish their connections with the base station. Contention may occur during the initial ranging process. To avoid contention, the mandatory solution defined in the standards is based on a truncated binary exponential random backoff (TBERB) algorithm w...

In current wireless LANs multiple kinds of losses occur (i.e., channel errors, collisions, interference). In this paper we examine the extent to which loss differentiation based physical layer transmission bit–rate and contention window adaptation aids in improving network performance. We show that loss differentiation can have a positive impact on performance, especially in low contention scen...

In this paper, we are interested to enhance the QoS in sensor networks. First, we study the MMSPEED routing protocol (Multi path Multi SPEED) [1] conceived to ensure the quality of real-time services in sensor networks. We present, then, a second approach which takes advantage of the standard 802.11e EDCA protocol [16] that ensures effective end to end delay and good quality of traffic. Finally...

In this paper, a new bakeoff algorithm is proposed to enhance the performance of the IEEE 802.11 Distributed Coordination Function (DCF) which employs Binary Exponential Backoff (BEB) algorithm. We present simulation results showing that the new algorithm outperforms the BEB algorithm and compared with the previously proposed enhancement algorithms, a salient feature of our algorithm is that it...

Network designs with multichannel and multi-interface capabilities are fast emerging as the new solution to the high interference and low throughput problems faced by wireless mesh networks today. Multichannel capability, ideally, isolates transmissions over different channels and hence interference is expected to be minimized. Multi-interface capabilities aim to solve network partitioning prob...

Trace-level reuse is based on the observation that some traces (dynamic sequences of instructions) are frequently repeated during the execution of a program, and in many cases, the instructions that make up such traces have the same source operand values. The execution of such traces will obviously produce the same outcome and thus, their execution can be skipped if the processor records the ou...

In this article we introduce a new contention resolution algorithm called Look-ahead Window Contention Resolution (LCR). This unique contention resolution approach can be used in conjunction with a scheduling technique to reduce the packet loss in an optical burst switched network. We analyze the performance of LCR by means of simulations and compare it with other major existing contention reso...

In this paper, a comprehensive overview of the new features of an upcoming new standard IEEE 802.11e to support Quality of Service (QoS) in Wireless Local Area Networks (WLANs) is presented. We address Medium Access Control (MAC) enhancements found in the current 802.11e draft specification by emphasizing the differences from the legacy 802.11 standard. New mechanisms for QoS support, namely En...