This paper proposes a new scheduling scheme which is based on Channel-and QoS-Aware for real-time traffics in LTE downlink direction. The real-time services (VoIP, Video, etc.) are very sensitive to network impairments such as delay, packet loss, jitter, etc. The proposed scheduling scheme considers Maximum Queue Size (MQS) as an essential factor for the priority metric and the combination of well-known M-LWDF-based algorithms such as M-LWDF, VT-MLWDF and Queue-HOL-MLWDF. The simulation results show that the proposed scheme has the performance which not only satisfies QoS requirements of realtime services but also outperforms the M-LWDF, VT-MLWDF and Queue-HOL-MLWDF schedulers in terms of Packet Loss Rate (PLR), cell throughput, Fairness Index (FI) and Spectral Efficiency (SE), especially for Video flow. The proposed scheduler also significantly improves the delay in comparison with the VT-MLWDF and Queue-HOL-MLWDF schedulers ones for both VoIP and Video flows. The performance evaluation is compared in terms of Delay, PLR, Throughput, FI and SE for M-LWDF, VT-MLWDF, Queue-HOL-MLWDF and the proposed schedulers.

This paper proposes a new scheduling scheme which based on the extended E-model, Channel-and QoS-Aware (known as E-MQS scheduler) for real-time traffics in LTE downlink direction. The real-time services (VoIP, Video, etc.) are very sensitive to network impairments such as delay, packet loss, jitter, etc. The proposed scheduling scheme is based on the extension of the E-model and the consideration of Maximum Queue Size (MQS) as a factor for the metric. Since this scheduling scheme considers Mean Opinion Score (MOS) values, thus, it gets higher user perception. The simulation results show that the proposed scheme has the performance which not only satisfies QoS requirements of real-time services but also outperforms the Frame Level Scheduler (FLS), Modified Largest Weighted Delay First (M-LWDF) and Exponential/Proportional Fair (EXP/PF) schedulers in terms of delay, cell throughput, Fairness Index (FI) and Spectral Efficiency (SE), especially for Video flow. Our proposed scheduler also significantly improves the Packet Loss Rate (PLR) in comparison with the M-LWDF and EXP/PF schedulers for both VoIP and Video flows. The performance evaluation is compared in terms of Delay, PLR, Throughput, FI and SE for FLS, M-LWDF, EXP/PF schedulers and our proposed one.

This paper presents a dynamic adaptation algorithm of joint source-channel code rate for enhancing voice transmission over LTE network. In order to assess the speech quality, we use the Wideband (WB) E-model. In this model, both end-to-end delay and packet loss are taken into account. The goal of this paper is to find out the best suboptimal solution for improving voice traffic over LTE network with some constraints on allowed maximum end-to-end delay, allowed maximum packet loss and minimum required bandwidth. The best suboptimal choice is channel code rate corresponding to each mode of the AMR-WB codec that minimizes redundant bits generated by channel coding with an acceptable MOS reduction. Besides, this algorithm can be integrated with rate control in AMR-WB codec to offer the required mode of LTE network. Our results show that the MOS degradation is not significant, but the percent of reduced redundant bits to be very considerable. This will requires less bandwidth, thus, more mobile users can be served. The algorithm has simple computational operations, it can be applied to realtime voice communications.