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In multi-interface multi-channel (MIMC) based tactical ad hoc networks, QoS support is one of the main challenging issues for multi-hop transmissions. To support QoS in such a harsh environment, we propose a novel MAC scheme to minimize multi-hop as well as per-hop delay. The current IEEE 802.11 MAC protocols should contend to reserve the channel resource at every hop by each sender. The every-hop...
There are real challenges in both the IEEE 802.11 wireless local area network (WLAN) protocol and the medium access control (MAC)-functions providing the required quality-of-service, high throughput and minimum latencies. The IEEE 802.11 layer supports both the distributed coordination function (DCF) and the enhanced DCF (EDCF). The different access categories (AC) within the EDCF can enhance the...
The MAC protocol is important, especially for wireless LAN because of limited bandwidth. A great deal of research has been carried out and some of proposed schemes are effective. Specifically, considerable effort has been devoted to improving the IEEE 802.11 standard which is utilized widely. Previous theoretical analysis gave the upper bound of IEEE 802.11 DCF throughput which is far below the channel...
This paper addresses the problem of MAC performance evaluation of a contemporary IEEE 802.11 WLAN. The network is observed under saturation conditions and the packet transmission probability analysis is conducted with the novel regenerative approach. The proposed model accounts for collision resolution protocol parameters, packet retry limit, coexistence of unicast and broadcast traffic, and heterogeneous...
UWB technology has offered a huge application bandwidth and its bandwidth has been reached up to Gbps recently. One of the various UWB specifications, WiMedia Alliance's MAC and PHY can also be used for high-speed multimedia applications to establish wireless video area network (WVAN). In this paper, we propose a gigabit UWB video transmission system for WVAN. To guarantee Gbps operation, we implemented...
The increasing use of wireless networks and the constant minituarization of electrical devices has empowered the development of body area networks (BAN). The BAN for medical applications cover continuous waveform sampling of biomedical signals, monitoring of vital signal information. In order to fulfill the diverse medical applications, these networks have to follow stringent technical requirements...
This paper proposes a multi-channel MAC protocol that provides QoS for ad-hoc networks based on the IEEE 802.11 DCF mode. The IEEE 802.11 standard gives methodologies and examples for contention-based distributed coordination systems for only a single channel. To overcome this limited channel usage, many studies on how it works in multi-channel environment have been performed. The IEEE 802.11e has...
The technology of flow-based QoS control on wireless LANs is receiving a lot of attention. There are several QoS technologies that can provide bandwidth guarantees by using TCP congestion control (QoS-TCP) and MAC control (QoS-MAC). Unfortunately, since QoS-TCP runs on the end terminal, it is possible that QoS-TCP will attempt to guarantee bandwidth without the permission of the network administrator...
This article presents a new MAC layer protocol for IEEE 802.11 EDCA-based ad-hoc networks with hidden nodes. The key idea of the proposed solution is based on an intelligent two-step reservation procedure which is combined with the advantages of EDCA service differentiation. The new protocol achieves significant performance improvement for high priority traffic (e.g., Voice) in terms of fairness,...
The Web Services Challenge (WSC) is a forum where academic and industry researchers can share experiences of developing tools that automate the integration of web services. In the sixth year (i.e. WSC-10) of the Web Services Challenge, software platforms will extend their solutions to the several composition challenges. Again this year, requests and results will be transmitted within SOAP messages...
The primary responsibility of a medium access control (MAC) protocol in Ad hoc Network is the distributed arbitration for the shared channel for transmission of packets. The performance of Ad hoc Network depends upon the sincerity of the MAC protocol. The MAC protocol of this type of network should be distributed, faired & free from hidden and exposed terminal problem. It should also support real-time...
A goal for next generation mobile networks is to provide seamless personal mobile communication and improved quality of service (QoS). Fair, class based service and lossless handoff are a focus for improving QoS. The research presented in this paper proposes a scheduling mechanism for providing improved QoS in mobile broadband Internet Protocol (IP) high-speed downlink packet access (HSDPA) networks...
The spread use of wireless sensor networks (WSNs) in a variety of fields, ranging from the military to environmental protection, has drawn the attention of researchers to this type of networks. Despite their use in interesting applications, such as healthcare and surveillance, many shortcomings derived from their small size and constrained batteries limit their use, calling for solutions to enhance...
Polling schemes in the IEEE 802 MAC layer provide some QoS support for multimedia applications above what can be provided with the contention scheme. However, in highly loaded environments, reliability and efficiency remain the main challenges for current detailed polling schemes. In this paper, we present a detailed analysis of polling medium access, and propose a novel mechanism, the Registered...
We propose a simple unified analytical model to analyze the IEEE 802.11 DCF infrastructure BSS performance in terms of MAC delay, PLR, and throughput efficiency under non-homogeneous and non-saturation conditions. Our model accounts for: (i) asymmetric traffic load between an AP and its associated STAs of an infrastructure BSS; (ii) transition from the non-saturation to saturation mode (and vice-versa)...
Resource reservation is one of the effective solutions in guaranteeing the quality-of-service (QoS) in communication networks. In this paper, we propose a novel resource reservation scheme for dynamically managing the bandwidth resources in IEEE 802.11e-based wireless local area networks (WLANs). The proposed solution consists of two components namely (i) dynamic medium access control (MAC) scheduler...
In this paper, we propose a new 802.16 Qos scheduling architecture based on GPSS, integrating some kinds of existing scheduling algorithms. Then we design a simulation experiment to validate the effectiveness of the Qos scheduling architecture using Anylogic. The simulation results prove the new QoS architecture is effective, which can not only meet the delay requirement of real time applications,...
The primary concern of broadband wireless technologies is to provide the end-to-end Quality of Service (QoS) for integrated real-time and non real-time applications. The main focus of the IEEE 802.16d/e MAC layer is to manage the radio recourse in an efficient way. The basic functional blocks of the QoS model are addressed by the standards to support five different types of service classes. However,...
It is difficult to provide QoS guarantees for streams in wireless network based on IEEE802.11 DCF because of limited bandwidth. Taking CBR traffic as example, we studied the traffic performance with different parameters in this paper. The results show that for an overloaded network, the traffic with longer packet size has greater throughput. Since the MAC layer performs the same competitive algorithm,...
This paper presents a Model of Quality of Service (QoS) for Next Generation Networks (NGN), that consist of a tower of five defined layers such as the Model Layer of QoS, Control of Admission, QoS in the Routing, QoS in the Signaling, and MAC QoS. In addition, the model raises a method based on the concept of segregation of functions defining two functional networks along with the tasks of QoS. Then,...
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