Scheduling Techniques for Improving Call Capacity for VoIP Traffic in MIMO-OFDMA Networks

Abstract

Abstract-Fourth Generation Networks will almost invariably adopt OFDMA (Orthogonal Frequency Division Multiple Access) and MIMO (Multiple Input-Multiple Output technologies, in order to meet high data rate and Quality of Service (QoS) requirements. The Worldwide Interoperability for Microwave Access (WiMAX) MAC Layer, which is based on the IEEE 802.16 standard, is designed to support a variety of applications, including voice and multimedia services. The problem of providing QoS in broadband wireless systems is one of managing radio resources effectively. Efficient scheduling algorithms that balance the QoS requirements of each application and user with the available radio resources need to be developed. This paper considers a number of scheduling policies concentrating on real-time Voice over IP (VoIP) traffic. Via numerical results we show that the conventional notion of fairness fails to guarantee service for low latency applications such as VoIP for an increasing traffic load. We show better QoS is achieved via a greedy scheduling approach that manages to serve packets faster.

Performance evaluation of MIMO downlink WiMAX for different schedulers

“…However, for 50 users, it is observed that WFQ and PF, t c = 500, experience longer delay of 2s at the cost of facilitating fairness among users. On the contrary, the PF with t c =50K achieves lower delay of approximately 1s, whilst the Greedy scheduler achieves the lowest delay as agrees in [14] for a greedy type of scheduler serving VOIP. The trade-off of a greedy scheduler is that it sacrifices the fairness among users though it has the lowest delay from all the simulated schedulers in our scenario.…”

Dynamic admission control and bandwidth reservation for IEEE 802.16e mobile WiMAX networks

“…The maximum rate scheduling is effective to advance the overall system throughput as it allocates resources to users with relatively good channel qualities among them [27]. On the other hand, the PF scheduling can improve the fairness of channel utilization among users as it distributes resources among them with consideration of their previous records of utilization [28][29][30].…”

Computational Complexity and Energy Consumption Analysis of Dynamic Resource Scheduling Algorithms for LTE

“…The relative strength scheduling algorithm (RSSA) proposed in [15], gives enhanced scheduling priority of weak users on their strong PRBs, resulting in a more equally distributed resource allocation process across an OFDM symbol via variation of tuning parameter.…”