An efficient packet scheduling algorithm for downlink queue to provide lossless handoff and QoS in 4G mobile networks

Next generation mobile networks are expected to provide seamless personal mobile communication and quality of service (QoS). Lossless handoff is a key issue for providing the QoS. This paper presents a two-layer downlink queuing model and proposes a scheduling mechanism for providing lossless handoff and QoS in mobile networks, which exploit IP as a transport technology for transferring datagram between base stations and the high-speed downlink packet access (HSDPA) at the radio layer. In order to reduce handoff packet dropping rate at the radio layer and packet forwarding rate at the IP layer and to provide high system performance, new scheduling algorithms are performed at both IP and radio layer, which exploit handoff priority scheduling principles and take into account buffer occupancy and channel conditions. Performance results obtained by computer simulation show that, by exploiting the downlink queuing model and scheduling algorithms, the system is able to provide low handoff packet dropping rate, low packet forwarding rate, and high downlink throughput.