An Algorithmic Approach to Identify the Optimum Network Architecture and WLAN Protocol for VoIP Application

To determine the optimal network architecture between the Basic Service Set, the Extended Service Set and the Independent Basic Service Set, this study established a new algorithm to assess Voice over Internet Protocol (VoIP) metrics of different IEEE 802.11 technologies. An important coefficient for each VoIP metric parameter has been invented to rank the different IEEE 802.11 standards and to identify the most efficient one for the VoIP application. The best overall network performance that offers good voice quality is ensured by determining the optimum network architecture and technology. Moreover, for the VoIP efficiency parameters, it meets the acceptance threshold values. This algorithm was implemented in different sizes of rooms ranging from 1 × 1 m to 10 × 10 m, and the number of nodes varied from 1 to 65. End to end delay, jitter, throughput and packet loss were the quality of service parameters used

AP-STA association control for throughput maximization in virtualized WiFi networks

To manage and enable service customization among multiple internet service providers (ISPs) sharing the common physical infrastructure and network capacity in virtualized Wi-Fi networks, this paper models and optimizes access point-station (STA) association via airtime usage control. More specifically, an optimization problem is formulated on the STAs’ transmission probabilities to maximize the overall network throughput, while providing airtime usage guarantees for the ISPs. As the proposed optimization problem is inherently non-convex, an algorithm to reach the optimal solution is developed by applying monomial approximation and geometric programming iteratively. Based on the proposed 3-D Markov-chain model of the enhanced distributed channel access protocol, the detailed implementation of the optimal transmission probability of each STA is also discussed by manipulating medium access control parameters. The performance of the developed association and airtime control scheme is evaluated through numerical results. For both homogeneous and non-homogeneous STA distributions, numerical results reveal performance gains of the proposed algorithm in improving the throughput and keeping airtime usage guarantees

Boosting VoIP Capacity via Service Differentiation in IEEE 802.11e EDCA Networks

This paper considers the performance problem of VoIP over 802.11e WLANs caused by the unfairness between uplink and downlink as well as the inefficient EDCA. A novel medium access control scheme named BEDCA (Balanced EDCA) is presented, which provides service differentiation between the access point (AP) and the mobile stations (STAs) to enhance VoIP capacity. In BEDCA, the expression of AP's contention window is obtained which is a relative constant value independent of the participating STAs. The minimum contention window of the STAs is traffic-aware based on the proposed algorithm. The performance improvement of BEDCA is verified through intensive simulations and the results show the capacity improvement of 82.1% compared to EDCA