Joint Realtime and Nonrealtime Flows Packet Scheduling and Resource Block Allocation in Wireless OFDMA Networks

摘要

In this paper, we consider joint realtime (RT) and nonrealtime (NRT) flows packet scheduling and resource block (RB) allocation in orthogonal frequency division multiple access (OFDMA) wireless networks. Radio RBs in the OFDMA plane are to be distributed among RT and NRT flows. In the conventional approach, RT and NRT flows are served sequentially. This sequential approach is inefficient because an RT flow may presumably have enough time until its delay deadline while its channel is in deep fade. In this situation, the transmission of NRT flows with higher level of efficiency can be performed. Intuitively speaking, the conventional sequential approach is too conservative, which can be reengineered. We propose a novel joint RT and NRT flows disutility-based packet scheduling and RB allocation in a common pool of RBs. The proposed joint approach enlarges the effective capacity of the associated wireless system when compared with the separated pool of RBs. The joint approach is particularly relevant for improving voice over LTE (VoLTE). We use mean bit-rate, mean queue-length, and instantaneous queuing delay information, in addition to channel information, to match the demand and supply. Furthermore, we develop a novel model for input–output bit-rate behavior of the mixture of RT and NRT flows. This model sheds light on the identification of different load regions and understanding of the system in an intuitive manner. Our approach and methodology can be extended for broader quality-of-service (QoS) requirements and for the utility of future applications. Simulation results show that the proposed framework is able to unify the serving mechanism of the RT and NRT flows and is able to achieve higher admissible bit-rate when handling mixed RT and NRT flows, compared with various baselines.