Summary: | 碩士 === 淡江大學 === 電機工程學系碩士班 === 100 === Abstract:
With the rapid development of wireless mobile networks, Vehicular Ad hoc Networks (VANET) that uses transportation tools as the mobile platforms has received great attention and how to integrate VANETs with wireless infrastructure to provide high-quality transmission services also has currently become one of the important research topics. The terminal equipment in the VANET has a higher mobile speed, so the mobile node in the network are often face handover frequently. If the handoff AP each selected have long service delay will affect the quality of network service,the voice service,and video service which has real-time request will be influence by the service delay. Previous researches in VANET handoff problem are focus on reduce the latency in scan period, and didn''t consider the service delay cause by the load in the AP and just choose the AP by its RSSI. And not distinguish between different types of services in the VANET, their have different levels of load in each access point will cause different service delay. Currently approach unable choose the appropriate AP for mobile node by the load of each different service.
For this reason, this paper uses a packet scheduler for APs'' classified services to present a handover scheme based on service delay prediction. Every wireless service area is pre-established by several APs and the service is monitored and collected by the AP Controller (APC). According to the scheduling mechanism, we can estimate the load and service delay of different service types to the APs in the area. Our mechanism allows the mobile node of real time service needs can be assigned to the smaller access point waiting service delay. Our method can selected access point not only reduce the waiting delay of the network service and make the front area load balancing.
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