QOS-Based Performance Evaluation of Channel-Aware/QOS-Aware Scheduling Algorithms for Video Applications Over LTE/LTE-A

Abstract

Long Term Evolution (LTE) is defined by the Third Generation Partnership Project (3GPP) standards as Release 8/9. The LTE supports at max 20 MHz channel bandwidth for a carrier. The number of LTE users and their applications are increasing, which increases the demand on the system BW. A new feature of the LTE-Advanced (LTE-A) which is defined in the 3GPP standards as Release 10/11 is called Carrier Aggregation (CA), this feature allows the network to aggregate more carriers in-order to provide a higher bandwidth. Carrier Aggregation has three main cases: Intra-band contiguous, Intra-band non-contiguous, Inter-band contiguous. The main contribution of this paper was in implementing the Intra-band contiguous case by modifying the LTE-Sim-5, then evaluating the Quality of Service (QoS) performance of the Modified Largest Weighted Delay First (MLWDF), the Exponential Rule (Exp-Rule), and the Logarithmic Rule (Log-Rule) scheduling algorithms over LTE/LTE-A in the Down-Link direction. The QoS performance evaluation is based on the system's average throughput, Packet Loss Rate (PLR), average packet delay, and fairness among users. Simulation results show that the use of CA improved the system's average throughput, and almost doubled the system's maximum throughput. It reduced the PLR values almost by a half. It also reduced the average packet delay by 20-40\% that varied according to the video bit-rate and the number of users. The fairness indicator was improved with the use of CA by a factor of 10-20%.

Traffic Offloading Impact on the Performance of Channel-Aware/Qos-Aware Scheduling Algorithms for Video-Applications Over Lte-A Hetnets Using Carrier Aggregation

“…This approach of operating various formats of cells, radio access technologies, and combining them in a seamless way raised the concept of Heterogeneous Networks (HetNet) [4]. This motivated the work of this paper, which is an extension to a previous work in [5], in-which the Intra-band contiguous case of the CA was implemented by modifying the LTE-Sim-5, then the QoS performance of a three Channel-aware/QoS-aware scheduling algorithms was evaluated for video-applications over LTE/LTE-A in the Down-Link (DL) direction. The extension in this work relies in evaluating the performance of the same three scheduling algorithms, the Modified Largest Weighted Delay First (MLWDF), the Exponential Rule (Exp-Rule), and the Logarithmic Rule (Log-Rule) in an LTE-A HetNets layout using CA in the DL direction while different serving scenarios of traffic offloading are applied.…”

LTE Cellular Networks Packet Scheduling Algorithms in Downlink and Uplink Transmission: A Survey

“…It aims to obtain satisfying throughput and at the same time, guarantee fairness among traffic flows. The selection is based on the following formula [18]:…”

Enhanced exponential rule scheduling algorithm for real-time traffic in LTE network

“…The transmission metric in some degree is identical to the EXPRULE scheduler, the variance is that this scheduler impalement the logarithm function approach which is the inverse of exponential function [20]. The scheduler for NRT transmission uses the PF scheduler and for the RT the transmission metric is calculated based on (9). The proposed eEXPRULE try to reduce the head-of-line delay by computing the transmission metric for each traffic separately, which leads to an increment in the UE's throughput.…”

“…In general, a resource block is composed of 12 subcarriers whose bandwidth is equal to 15 kHz. Each RB is equal to a slot duration as illustrated in Figure 1 [8][9][10][11][12][13][14]. Figure 1.…”

“…Figure 1. LTE frame structure [9] When it comes to the resource allocation using QoS scheduling, there are several factors that affecting the distribution mechanism such as the number of RBs available, the number of active users, the size of flow buffer, the average past throughput, the maximum flow delay, the Packet Lose Rate (PLR), and the Channel Quality Indicator (CQI) which periodically reported by User Equipment (UEs) [9] to the base station. The base station of LTE, Evolved NodeB (eNodeB) is responsible for resource allocation determination at its Medium Access Control (MAC) layer [14].…”