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Wireless Sensor Networks (WSNs) is a key area of new investments and investigations. Quality of Service (QoS) is an important requirement for this networks. In this survey, we firstly introduce WSNs briefly. Then, We propose the existence of Qos issue on both network layer and MAC layer, as well as the existence of solutions, especially to MAC layer. Finally, we propose a network topology and a MAC...
The sensor network consist of multi-purpose of node in a scarred networks area. The modern motes that have multiple sensor board on a single radio board, which have different type of transmission rate, required bandwidth, packet loss, delay demands etc. In this paper we proposed Heterogeneous Congestion Control Protocol(HCCP), which controls the efficient rate for heterogeneous traffic. This protocol...
Nowadays, Wireless Local Loop (WLL) systems due to its advantages in comparison with Wire Systems has become one of the first choices in technologies. In this paper a WLL network is presented. The scenarios were created in OPNET modeler as simulation tool to obtain the results. The proposal is based on the OFDM and CDMA technique. Providing QoS requirements like good throughput and minimum access...
Wireless Sensor Network (WSN) is a novel information acquiring and processing technology. To increase the life of WSN, each sensor node has to transmit the queuing data efficiently and conserve its energy, how to share the query of transmission for the collected information of sensor nodes becomes a new problem. Based on polling scheme with the unique characteristics of contention-free of access,...
IEEE 802.11n is a next-generation indoor wireless network technology supporting high definition (HD) video streaming with enhanced bandwidth, coverage, and quality of service (QoS). Unfortunately, such benefits vanish while supporting coexistence with the legacy 802.11a/b/e/g stations. Proposed wireless virtualization method contributes to guarantee the medium access control (MAC) throughput to nearly...
A prioritized medium access control (PMAC) protocol is proposed for wireless sensor networks, based on a binary count down approach. PMAC effectively eliminates data collision and optimizes channel allocation. Moreover, as many networks nowadays compose traffic with several priorities, the simple yet effective design of PMAC offers strict service differentiation for prioritized packets. In this paper,...
WiMAX and WiFi have emerged as promising broadband access solutions for the latest generation of wireless MANs and LANs, respectively. Their complementary features enable the use of WiMAX as a backhaul service to connect multiple dispersed WiFi hotspots to the Internet. This study proposes an integrated architecture utilizing a novel WiMAX/WiFi Access Point (W2-AP) device to effectively combine the...
Mobile IPTV is a technology that enables users to transmit and receive multimedia traffic anywhere and anytime, using any device. However, in a wireless environment, the network capacity often does not reliably support high-quality high-bandwidth IPTV service traffic. In this paper, a novel resource allocation scheme for Qos-guaranteed mobile IPTV that considers the TV viewing behavior of the user...
Wireless networks and multimedia applications are two rapidly emerging technological trends. The IEEE 802.11e protocol has been developed to support QoS for such delay-sensitive applications in wireless networks. This protocol has also been extensively studied in the literature over the past few years, and several mechanisms to improve its performance have been proposed concentrating on ways to reinforce...
Multimedia communication over wireless networks has become the driving technology for many important applications, experiencing dramatic market growth and promising revolutionary experiences in personal communication, gaming, entertainment, military, security, environment monitoring, and more. The advances in wireless communications and growth of real-time applications have necessitated the development...
Abundant hidden node collisions and correlated channel access due to multi-hop flows degrade QoS in wireless mesh networks. QoS in nearby WLANs operating on a single channel is also affected. We propose using wider contention windows for backoff to lower the risk of repeated hidden-node collisions, a spatial extension of the TXOP concept called 'express forwarding' to clear multi-hop flows sooner,...
Ubiquitous processing is impacting several applications affecting our lives. In this paper we propose a remote health care monitoring system that uses sensor networks to extend the coverage of medical application to underserved area. We delineate the challenges that face researchers in this area. In addition, the paper describes the general architecture and proposes a MAC scheme for healthcare sensor...
Most of QoS-capable IEEE 802.11 MAC protocols are unable to deliver sustained quality of service while maintaining high network utilization, particularly under congested network conditions. The problem often resides in the fact that flows belonging to the same service class are assigned the same MAC parameters regardless theirs respective bitrate, which leads to throughput fairness rather than perceived...
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