17 research outputs found
A new approach to the, design of MAC Protocols for wireless LANs: Combining QoS guarantee with power saving
An alternative WLAN protocol which could be
adapted in the HCF access scheme defined by IEEE 802.11e, in
place of the HCCA mechanism, is introduced. LEPOAC-QG (Low
Energy Priority Oriented Adaptive Control with QoS Guarantee)
is a centralized access mechanism that supports low energy
consumption, guarantees QoS for all types of multimedia network
applications, enhances the parameterized traffic with priorities,
and supports time division access. It instantly negotiates the
quality levels of the traffic streams trying to support multiple
streams with best possible quality. LEPOAC-QG, compared with
HCCA, exhibits generally superior performance
A Novel Method of Serving Multimedia and Background Traffic in Wireless LANs.
Wireless local area networks (LANs) require the efficient integration of multimedia and traditional data traffic. This paper proposes the priority-oriented adaptive polling (POAP) protocol that could be used in place of the enhanced distributed channel access (EDCA) part of the IEEE 802.11e access scheme. EDCA seems capable of differentiating traffic; however, it exhibits great overhead that limits the available bandwidth and degrades performance. POAP is collision free, prioritizes the different kinds of traffic, and is able to provide quality of service (QoS) for all types of multimedia network applications while efficiently supporting background data traffic. POAP, compared to EDCA, provides higher channel utilization, distributes resources to the stations adapting to their real needs, and generally exhibits superior performance
RLAM: A Dynamic and Efficient Reinforcement Learning-Based Adaptive Mapping Scheme in Mobile WiMAX Networks
WiMAX (Worldwide Interoperability for Microwave Access) constitutes a candidate networking technology towards the 4G vision realization. By adopting the Orthogonal Frequency Division Multiple Access (OFDMA) technique, the latest IEEE 802.16x amendments manage to provide QoS-aware access services with full mobility support. A number of interesting scheduling and mapping schemes have been proposed in research literature. However, they neglect a considerable asset of the OFDMA-based wireless systems: the dynamic adjustment of the downlink-to-uplink width ratio. In order to fully exploit the supported mobile WiMAX features, we design, develop, and evaluate a rigorous adaptive model, which inherits its main aspects from the reinforcement learning field. The model proposed endeavours to efficiently determine the downlink-to-uplinkwidth ratio, on a frame-by-frame basis, taking into account both the downlink and uplink traffic in the Base Station (BS). Extensive evaluation results indicate that the model proposed succeeds in providing quite accurate estimations, keeping the average error rate below 15% with respect to the optimal sub-frame configurations. Additionally, it presents improved performance compared to other learning methods (e.g., learning automata) and notable improvements compared to static schemes that maintain a fixed predefined ratio in terms of service ratio and resource utilization
Performance Evaluation of Acoustic Underwater Data Broadcasting Exploiting the Bandwidth-Distance Relationship
Despite being a fundamental networking primitive, data broadcasting has so far received little attention in the context of underwater networks. This paper proposes an adaptive push system for data broadcasting in underwater acoustic wireless networks with locality of client demands. The proposed system exploits the characteristic relationship between the bandwidth of an underwater acoustic link and the transmitter-receiver distance in order to improve performance in environments with locality of client demands. Simulation results show superior performance of the proposed approach in the underwater environment compared to existing systems
A metaheuristic bandwidth allocation scheme for FiWi networks using Ant Colony Optimization
Optical-wireless access networks constitute a quite attractive solution to meet the ever-increasing bandwidth requirements of end-users, offering significant benefits such as ubiquitous coverage in the wireless domain and huge bandwidth in the optical domain. However, converging optical and wireless networking technologies, with Passive Optical Networks (PONs) and 4G wireless standards, such as the Worldwide Interoperability for Microwave Access (WiMAX) and the Long Term Evolution (LTE), entails major challenges that need to be addressed. In this context, designing an efficient and fair bandwidth distribution with Quality of Service (QoS) support is a difficult task due to the interdependence of resource allocation process to both optical and wireless domains. Specifically, the bandwidth distribution in the optical domain has to be aware of the mobile user heterogeneity in the wireless domain, while in the wireless domain the allocation process depends on the optical transmission grant opportunities. In this work a metaheuristic approach to govern the bandwidth allocation in modern Fiber Wireless (FiWi) networks is proposed. The Ant Colony Optimization (ACO) method is effectively employed in order to optimize the bandwidth report process of Mobile Subscribers (MSs). Simulation results reveal the effectiveness of the proposed approach in terms of latency and network throughput