Maintaining quality of service (QoS) during handoff in cellular system with movement prediction schemes
Liangchi Hsu, R. Purnadi, Suixing Wang · 1999
The advanced capabilities of third-generation (3G) wireless communications open the path for new multimedia services. The multimedia services require advanced resource management, especially the radio resources. The resource management is required to fulfil the target quality of service (QoS) especially during handoff. An early resource reservation (ERES) in the candidate cells for handoff will give a higher probability of satisfying the target QoS. It is important to optimize the tradeoff between the early reserved resources and the target QoS. The ERES involves the amount of the radio resources reserved from the adjacent cells and their associated time-duration of the reservation. The fulfilment of the target QoS is measured based on the confidence level of successful handoff without service degradation, as reflected by the certainty factor (CF). With a mobile station positioning technology implemented, it permits better movement tracking, which leads to a reduction of resource reservations with a higher certainty of successful handoff. This paper presents a method to optimize the resource reservation to fulfil the target QoS with the help of mobile movement prediction. Two cases of ERES based on different radio conditions are compared. Each case has several scenarios: without movement prediction; with the movement prediction derived from FCC E911 (Federal Communication Committee Emergency 911) requirement for RMS error of 125 meters; and with a super-accurate prediction for RMS error of 30 meters.