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In the literature, many design parameters have been utilized in network optimization but till now little attention has been paid on the buffer management in the base station. In this paper, we propose a new power allocation algorithm suited for Dynamic Time Division Multiple Access (TDMA) scheme, that is based on the minimization of the total transmitted power under the constraint of ensuring the...
The Mesh Coordinated Channel Access (MCCA) defined by the IEEE 802.11s draft standard implements a TDMA-based Medium Access Control (MAC) protocol by allowing mesh routers to negotiate collision-free transmission opportunities, called MCCAOPs, in a hop-by-hop manner. The procedure to determine the duration, in time slots, and the periodic schedule of MCCAOPs is however left unspecified by the standard...
We discuss the dynamic bandwidth allocation schemes in TDMA uplink channel of satellite networks. And a scheme based on max-min fairness is discussed and implemented in Tdma-bod simulator of ns-2. Simulation results show that this scheme can improve the throughput and delay performance and provide better QoS for satellite system. And in future network scenario that including more burst traffic and...
IEEE 802.15.3 efficiently uses time division multiple accesses (TDMA) to support the quality of service (QoS) for multimedia traffic or the transfer of multi-megabyte data for music and image files. In the TDMA mechanism for an allocated channel time (channel time allocation, CTA) and known bit error rate of the channel, the throughput can be maximized by dynamically adjusting the frame size. In this...
The next generation cellular wireless network is expected to provide a broad range of multimedia services, where the traffic asymmetry between uplink and downlink is significant. The code division multiple access system with time division duplex mode (TDD-CDMA), adopting unbalanced slot allocation between uplink and downlink, is a good solution for this traffic asymmetry. Here a QoS adaptive multimedia...
The traffic in the high-speed wireless multimedia network will be a mixture of voice, video and data messages having a large variety of characteristic and inherent requirement. The present work is a medium access control protocol for time division-code division multiple access system to distribute the available bandwidth among the mixture of different traffic classes depending upon their quality of...
Nowadays there is an increasing need of broadband communications anytime, anywhere for users requiring multimedia services with quality of service support. This paper deals with the integration of GEO satellite networks and terrestrial wireless networks. Our interest is for a DVB-RCS GEO system integrated with a WiFi terrestrial segment based on the IEEE 802.11b and e standards. Such a scenario is...
Wireless mesh networking is a promising technology for building broadband wireless access networks. However, wireless mesh networks based on CSMA/CA MAC protocols suffer from unfairness and poor QoS support. Using TCP as a rate control mechanism in such networks further exacerbates the problem. Efficient rate allocation and scheduling algorithms that handle both multicast and unicast traffic in wireless...
In this paper we evaluate an algorithm to distributing resources provided by the access point at the MAC layer in wireless networks. We consider a TDMA/FDD-based mechanism. System model is designed and tested for a wireless ATM networks architecture. In fact, the QoS characterising ATM technology provides the ability to well transmit multiple traffic types and treat every one according to some generic...
Recent research indicates that multi-hop wireless networks can suffer from extreme imbalances in the throughput achieved by simultaneous competing flows. We address this problem by designing a practical distributed algorithm to compute a time-slot based schedule that provides end-to-end max-min fairness. Our system uses randomized priorities based on local weights to arbitrate access between nodes...
Multi-hop wireless networks (MWNs) are a promising technology for releasing the vision of pervasive communications, e.g., providing communications in remote areas without telecommunication infrastructure. In MWNs, the channel resource is efficiently managed by proper spatial reuse. One of the Medium Access Control (MAC) protocols with such characteristic is Spatial TDMA (STDMA). In addition, STDMA...
Major design issues in Wireless Ad Hoc Networks is the design of the routing algorithms and the Medium Access Control (MAC) protocols. Spatial TDMA (STDMA) is a ldquoconflict-freerdquo MAC protocol for these networks, thus enabling high spectral utilization. In link-oriented STDMA, the schedule specifies when particular radio links will be activated. Moreover, the use of power control and heuristic...
Multihop relay networks (MR) use relay stations (RS) to extend or enhance the coverage of a base station (BS) in a cellular network. The base station is attached to a wired backhaul. Relay stations use wireless transmission to connect to the base station and to the mobile stations (MS), while direct BS-MS connection is also possible. Low cost relay technologies are recently proposed for OFDM based...
In this paper, we address the issue of transmission power control (TPC) in wireless ad hoc networks. Power control plays an important role in energy saving and network performance enhancement. However, the existing TPC schemes either face the problem of hidden and exposed terminal or have additional hardware requirements. We propose a novel distributed power control protocol, called Receiver Initiated...
The idea of mobile computing service is to provide a ubiquitous information environment. However, the present mobile ad hoc networks still can't support real-time transmission very effectively. In other words, the capability of supporting QoS guarantee has become a very important issue. IEEE 802.11 PCF adopts the polling scheme to provide time-bounded traffic services, which is not suitable in multihop...
Future military networks will make significant use of transponding satellites to carry converged Internet protocol (IP) traffic to on-the-move communication nodes, which suffer frequent, short signal blockage events. Multi-frequency time-division multiple access (MF-TDMA) with dynamic resource allocation is a leading approach to efficiently use satellite resources under these conditions. The dynamic...
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