Downlink Packet Scheduling with Minimum-Bandwidth Provisions in LTE/LTE-A Networks

With the growing number of human and machine devices in IoT (Internet of Things), ubiquitous network connection and traffic classification become more essential. The LTE/LTE-A system, proposed by 3GPP, is a solution. An evolved NodeB (eNB) in LTE/LTE-A system encounters the challenge of allocating the radio resource to meet different QoS (Quality of Service) requirements for multiple traffic classes. QCI (QoS Class Identifier) is defined to specify the QoS characteristics of user data in LTE/LTE-A networks. This paper proposes a packet scheduling algorithm with minimum-bandwidth provisions (PSMP) over LTE/LTE-A downlink. The PSMP scheme can calculate the minimum-bandwidth requirements for GBR (Guaranteed Bit Rate) and NGBR (non-GBR) traffic according to their associated packet delay constraint and packet loss ratio, respectively. Due to beginning with the minimum-bandwidth allocation by referring to QCIs, the proposed PSMP scheme not only can satisfy the delay constraint for real-time traffic, but also can alleviate non-real-time traffic starvation problem. The simulation results show our proposed PSMP scheme outperforms the previous works in the packet delay of GBR traffic and the throughput of NGBR traffic. As to VoIP service, the PSMP scheme can reduce L1/L2 control overhead to improve the network performance by alternatively adopting the semi-persistent scheduling (SPS) scheme.