Implementation and Evaluation of a QoS-aware Downlink Scheduling Algorithm for LTE Networks

Long Term Evolution (LTE) is becoming the mainstream of the fourth generation standard for high-speed wireless communications for mobile devices. Its radio access for downlink involves allocation of Physical Resource Blocks (PRB). In order to achieve optimal download performance for different applications to satisfy different QoS requirements, the downlink scheduling algorithm in use plays an important role in determining which PRBs and how are they allocated to each flow of bits. Several researches have exploited different scheduling strategies for flows; however, both the frequency and time domain allocations for PRBs should be taken into account. In this project, we implement and evaluate a QoS-aware downlink packet scheduling algorithm for LTE networks known as the Packet Prediction Mechanism (PPM) using the LTE Simulator (LTE-Sim). The PPM consists of three phases. It first utilizes the PRBs effectively in the frequency domain. It then manages queues and predicts the behaviour of future incoming packets based on the current ones in the queue by the concept of virtual queuing. Finally, it incorporates a cut-in process to rearrange the transmission order and discard overdue packets based on the predicted information from the previous phase. The simulation results demonstrate the effectiveness of the PPM scheme in achieving better downlink transmission performance in terms of Throughput, Delay, Fairness Index, Packet Loss Ratio (PLR), and Spectral Efficiency than other downlink schedulers such as Priority First (PF), Modified Largest Weighted Delay First (MLWDF), and Exponential Proportional Fair (EXPPF).