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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)...
In IEEE 802.11 DCF, performance unfairness inevitably occurs between downlink (AP-to-station) and uplink (station-to-AP) directions. The asymmetry of the DCF operation degrades downlink traffic severely. Therefore, it is important to enhance downlink QoS by alleviating link congestion. In this paper, we propose a novel medium access control scheme, BDCF (Burst DCF), to enhance the legacy DCF. It is...
This paper presents a VoIP packet loss model applicable to wireless access transmission media and usable for determination of admissible call number threshold value. The main contribution is a more realistic approach for VoIP packet loss evaluation. The known bufferless fluid-flow method is applied but a new simple exact formula for ACT voice packets loss is developed. The suggested method is evaluated...
IEEE 802.16 standard or WiMax network is one of the new alternatives for broadband wireless access. Among its promising applications is the creation of a wireless backhaul support for WiFi traffic. In this context, it is mandatory to design a Call Admission Control in the WiMax Base Station for resource allocation for the integration of both network technologies. In this paper, we investigate this...
In the original study based on the EDCA, the paper puts forward a concept of priority threshold to control traffics in a node. It makes EDCA mechanisms not only have the characteristics of priority, but also have good fairness. Among the nodes, optimized EDCA mechanism uses slot utilization to reflect the current network status, and changes the maximum and minimum contention window in order to improve...
IEEE 802.11 lacks of the capability to support quality of services such as multimedia and real-time traffic properly. This paper presents a simple approach to enhance the multimedia real-time performance over the 802.11 WLAN by implementing a Quality Of Service Manager (QoSM) for differentiating services with two queues on top of the 802.11 medium access controller. With slow decrease of contention...
QoS support entails fair arbitration, efficient assignment, and firm admission schemes guaranteeing specified parameters for transfer of QoS-sensitive traffic. Even if deployed in ad hoc WLANs, such schemes need not be adhered to by noncooperative stations. Using a game-theoretic approach we outline QoS support for lower-bounded elastic traffic in an anonymous and noncooperative ad hoc WLAN setting,...
Widespread use of wireless networks nowadays raises many problems for service providers in managing their resources. These problems are caused mainly by restricted bandwidth and variable radio condition in this type of network. Moreover, with the emergence of multimedia traffic and its requirements in terms of quality, admission control is hence an inevitable choice to optimize network resources while...
In current trends, the central target of interest for multimedia applications is to meet the stringent quality of service (QoS) requirements for traffic flow over contention based MAC protocol of IEEE 802.11 WLAN. To achieve this objective, our paper proposes a connection admission control (CAC) policy, which attempts to maintain the flow of incoming traffic in the wireless network so as to effectively...
Deployment of Wireless Mesh Networks (WMNs) is becoming increasingly popular due to the low-impact and low- cost features of wireless devices. This is especially true for WMNs based on IEEE 802.11 which, however, does not include native support for multi-hop relaying. This gap is being filled by the Task Group 's' of the IEEE 802.11 which has recently published an amendment in order to add mesh functions...
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