Wireless Local Area Networks (WLANs) based on the IEEE 802.11 have been widely implemented in most commercial products available in the market. This paper proposes a simple and effective contention window-resetting scheme, named Double Increment Double Decrement (DIDD), to improve the performance of the contention based IEEE 802.11 Distributed Coordination Function (DCF). An alternative mathema...

Quality of Service (QoS) of IEEE 802.11e is currently under research for the upcoming multimedia applications over broadband wireless networks. IEEE 802.11e is a contention based channel access function that uses the enhanced distributed channel access (EDCA) techniques. EDCA statically resets the Contention Window (CW) after each successful transmission. This article discusses a fuzzy logic ap...

This paper introduces a new backoff mechanism for IEEE802.11 which aims to achieve fair channel access without knowledge of the network topology. By adjusting a time interval and the contention window dynamically, the algorithm aims to approach the optimal equilibrium where the time interval is the minimum possible such that every node that faces the same contention successfully sends only one ...

This paper describes a control mechanism for dynamic selection of Quality of Service (QoS) parameters used in a IEEE 802.11e Wireless Local Area Network (WLAN). The 802.11e specification, still under development, provides a new contention-based access method, called Enhanced Distributed Coordination Function (EDCF). This method uses distinct values for interframe space and for contention window...

the standard IEEE 802.11 Medium Access Control protocol uses the Binary Exponential Backoff algorithm. The Binary Exponential Backoff makes exponential increments to contention window sizes. This work has studied the effect of choosing a combination between linear, exponential and logarithmic increments to contention windows. Results have shown that choosing the right increment based on network...

IEEE 802.11 distributed coordination function (DCF) can alleviate the collision and hidden station problem, but it doesn’t differentiate traffic categories (TC). Therefore, it can’t provide sufficient QoS support for different traffic categories. Recently, a new contention-based enhanced distributed channel access (EDCA) scheme was proposed which provides a probabilistic QoS support. In this pa...

The IEEE 802.11 MAC standard for wireless ad hoc networks adopts Binary Exponential Back-off (BEB) mechanism to resolve bandwidth contention between stations. BEB mechanism controls the bandwidth allocation for each station by choosing a back-off value from one to CW according to the uniform random distribution, where CW is the contention window size. However, in asymmetric multi-hop networks, ...

In several ubiquitous sensor networks, sensor nodes often face contention for medium access and service. Unfortunately, traditional carrier sense multiple access with collision avoidance (CSMA/CA) protocols such as the IEEE 802.11 Distributed Coordination Function (DCF) do not handle such constraints adequately, and this weakness finally leads to an increase in the latency and degradation of th...

Current anti-collision protocols for active RFID systems stem from the ISO-18000-7 standard, which selects Frame Slotted Aloha as the underlying medium access control protocol. However, these approaches neglect the possibility of using the listen-before-talk mechanism already available in active RFID tags. In a previous work, a CSMA (Carrier Sense Multiple Access) mechanism CSMA/MS (Multi-Stage...