Variable Bit Rate Video Workload Modeling for Mobile Broadband Wireless Networks

Achieving high throughput, low packet delay, and fair bandwidth sharing are significant issues in resource allocation schemes for mobile broadband wireless networks. With the advent of the fourth generation (4G) wireless systems such as Long Term Evolution (LTE) and WiMAX, resource allocation schemes must be tailored for orthogonal frequency division multiple accesses (OFDMA). Downlink OFDMA can be modeled as a multi-channel, multi-queue system. In order to be able to evaluate resource allocation algorithms over such systems, efficient network traffic models are necessary. The majority of the studies on scheduling are based only on simulations preventing wireless equipment vendors from obtaining quick insights into the behavior of schedulers. Only a subset of the existing work employs analytical queuing models. This thesis aims to use both model-based and simulation-based scheduling studies for 4G wireless systems. Variable bit rate (VBR) video traffic is used for generating workload for the downlink of a 4G-like system. Four scheduling algorithms, round robin (RR), opportunistic (OP), maximum weight (MW) and server-side greedy (SSG), are then investigated and their performances are compared for video over 4G. The results of the analysis show that RR is highly unstable compared to OP, MW, and SSG. In terms of the length of the user queues, the best performance belongs to SSG having small user queue lengths. Keywords: 4G, OFDMA, scheduling, video traffic models