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The Wireless Multimedia Sensor Networks (WMSN) are confronted with two basic constraints that are the strong constraint of the energy consumption, and the strong constraint of the traffic performance (Delay, Throughput, etc.). To try to satisfy these two constraints, the IEEE 802.11e Enhanced Distributed Channel Access (EDCA) has been used at the MAC layer in the WMSN. The EDCA access method maintains...
Advanced regulation machine (ARM) is determined to make the perfect parameters (AIFS, CWmin and CWmax) selections in the wireless networks platform. The simple but effective adjustment strategies of three parameters combinations are proposed with the priority theory to obtain the acquired high quality of service (QoS). The internal competitions models of various traffic analysis machines are delivered...
We propose the Most-Emergent-First (MEF) scheduler which regard the emergency score obtained from the delay status and traffic specification (TSPEC) to determine transmit sequence of flows. Via cross-layer signaling, transmission opportunities (TXOPs) of flows are dynamically adjusted to meet the TSPEC while the bandwidth utilization in a IEEE 802.11e environment is maintained. The proposed prioritized...
In recent years, IEEE 802.11 Wireless Local Area Networks (WLANs) have emerged as one of the prevailing technologies for the broadband wireless access. Although IEEE802.16 wireless network has become a newer generation of wireless network, it will be used as wireless metropolitan area network in the beginning because of its price. IEEE 802.11 network will continue to be the most important wireless...
Energy consumption in wireless sensor networks (WSN) was always a basic constraint to respect. But, with the appearance of Wireless Multimedia Sensor Networks (WMSN), another basic constraint comes from added, which is the traffic performance in terms of delay, throughput, and Packet Delivery Rate (PDR). The choice of channel access method can help us to better respond the two constraints in WMSN...
Experimental evaluation of QoS mechanism defined in IEEE 802.11e standard is presented in this paper. Measurements were carried out in controlled laboratory conditions, with and without configured QoS. Mean and maximum delay, jitter and packet loss are measured in voice communications between two clients, competing with other voice clients. The results show that QoS mechanism brings significant improvements...
In recent studies, an equal-spacing-based (equal-SP) design was developed to generalize and enhance the reference design in IEEE 802.11e standard. Different from the reference design in which all streams will be scheduled in a common minimum spacing, the equal-SP design may schedule different streams with different spacings and it might improve bandwidth utilization of the reference design, up to...
IEEE 802.11e constitutes the “state of the art” standard for providing QoS to multimedia traffic in Wireless Local Area Networks (WLANs). However, it has been proven inadequate in certain network conditions (high load). Several mechanisms improving its performance have been proposed in the past years. Most of them focused on altering the static nature of resource allocation specified in IEEE 802.11e...
A new subfunction for the IEEE 802.11e EDCF allowing efficient transport of real-time traffic is proposed. The delay induced by the freezout of the backoff counter is to be considered. Intentional dropping is used if a certain threshold delay is exceeded. A system enabled with this suggested feature is analyzed and the impact of backoff parameters on the transmission probability, the dropping probability,...
We propose a malicious detection algorithm that permits identification of misbehaving wireless stations, and then meeting out punishment by not supplying an ACK packet permitting transmission by the malicious stations. The proposed algorithm is designed for IEEE 802.11e network and based upon detecting a change in QoS moving a station up in terms of a measure of permission to a level which is not...
The advancement of 3D video technologies enables us to experience 3D video at home, office and public places. In this paper, a prioritization scheme for backward compatible 3D video distribution over Wireless Local Area Networks (WLANs) is proposed for home/office environments. The scheme is designed to work with the colour plus depth representation format. Colour and depth map sequences have different...
Due to the advance of WLAN technology, the use of the multimedia service such as the video streaming service has been increased in the home network or CCTV monitoring for cars or construction materials. However, we need to study the method which decreases the transmission delay and the frame loss rate to provide QoS of the video streaming service. Therefore, this paper proposes an active buffer management...
In this paper, we carry-out a study of the Quality of Service (QoS) mechanism in IEEE802.11e Enhanced Distribution Coordination Function (EDCF) and how it is achieved by providing traffics with different priorities. It can perform the access to the radio channel or just simply it can considerably be declined subsequently to a variation of network dynamicity. The results of the proposed analysis show...
TCP, the facto standard used in today's Internet, has been found to perform poorly in Mobile Ad Hoc Networks (MANETs). This is exacerbated by contention with increasing UDP-based high priority multimedia traffic and the class differentiation introduced in current QoS protocols, which results into TCP starvation and increased spurious timeouts. In this paper, we propose a cross-layer TCP enhancement...
IEEE 802.11 Wireless Local Area Network (WLAN) is one of the most widely deployed wireless network technologies in the world today. However, 802.11 MAC algorithm is unable to support modern multimedia applications which require certain level of quality of service (QoS) guarantees in terms of consistent, timely and reliable data transfer. The 802.11e MAC protocol provides extension for adjustment of...
The IEEE 802.11e technology is receiving much interest due to the enhancements offered to wireless local area networks in terms of QoS. Other application fields for this technology are wireless ad-hoc networks, wireless mesh networks and vehicular ad-hoc networks. In the literature, most of the research works available focusing on the IEEE 802.11e technology offer simulation results alone, being hard...
The IEEE 802.11 legacy standard could not offer QoS support for time-critical applications. Considerable research efforts on medium access control (MAC) layer have been carried out important enhancements on improving QoS for IEEE 802.11 device implemented standard. Among them, IEEE 802.11e standard is the QoS enhanced proposed by the IEEE. The contention based channel access method called enhanced...
The IEEE 802.11 protocol has achieved worldwide acceptance with WLANs with minimum management and maintenance costs. However, IEEE 802.11 can only provide a best effort service and does not support the quality of services (QoS). Furthermore, the performance of the distributed coordination function (DCF) degrades significantly under heavy load due to the increasing time wasted during collision. In...
In recent years, voice over Internet Protocol (VoIP) has gained much attention in wireless local area networks (WLANs). Although IEEE 802.11e has been standardized to provide voice traffic with quality of service (QoS) support, the voice quality will still be severely degraded with a large amount of best-effort traffic generated by distributed coordination function (DCF) or enhanced distributed channel...
IEEE 802.11e (EDCA) standard is concerned to support QoS in wireless ad-hoc networks. However, EDCA cannot control traffic when there is a congestion to guarantee QoS required by real-time and multimedia applications. Therefore, the ill-behaved sources consume the most of bandwidth allowed. That leads to some of source nodes (i.e. out-ranged nodes) suffer from the lack of bandwidth and unfairness...
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