Dynamic Bandwidth Scheduling Algorithm for Real-Time VBR Services in IEEE 802.16m Communication Systems: Using Contribution Approach

• Main Authors: Yu Chin Lin, 林鈺欽
• Other Authors: J. H. Chen
• Format: Others
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/62390700965053941975

碩士 === 長庚大學 === 資訊工程學系 === 100 === The most difficult part of dealing with the real-time polling services (rtPS) is to schedule them on time as well as to consider the channel utilization. Usually, for the reason of channel utilization consideration, the call admission control (CAC) may let more number of connections to enter the system to increase the channel utilization degrees. However, due to the characteristics of variable bit rate (VBR) of the rtPS, the scheduler may easily get into the dilemma situation, e.g., the scheduler has to delay some connections when the system hits the saturated condition, and, then, violate the quality of service (QoS) guarantee. In this paper, we investigate an rtPS scheduling algorithm by giving the contribution credits to real-time connections for priority scheduling. The proposed contribution-based scheduling algorithm (CSA) uses the parameters of 1) the amount of obtained bandwidth of each connection, 2) the total amount of required bandwidth of connections, and 3) the reaming time to the end of polling period to evaluate the priority of connections for scheduling per each time frame. Simulation results shows that CSA can achieve a lowest dropping rate as well as maximize the channel utilization. CSA outperforms other schemes especially in the saturated condition.