Summary: | 碩士 === 國立臺灣科技大學 === 資訊工程系 === 94 === In personal communication service (PCS) networks, location management composed of location update and paging is used to keep track of mobile terminals (MTs) to enable people with MTs to communicate with each other at any time and any place. However, how to efficiently manage locations and reduce related costs under the limited bandwidth is a fundamental and challenging issue as the number of subscribers increasingly grows. In this thesis, we propose an enhanced velocity-based location update scheme with two velocity-related parameters, i.e., time ratio when velocity goes up and distance ratio when velocity goes down. Adopting the strategy of strictly increasing velocity and not easily decreasing velocity, it can avoid oscillations caused by the original velocity-based location update scheme. Additionally, ring-structured paging has been extensively used in many various location management studies in the literature but it wastes much processing resources. Hence, we design a three-step angular paging strategy which adapts the paging angle according to the velocity to reduce the paging cost. Compared with the distance-based and velocity-based location management schemes, it turns out that our proposed location management schemes perform better for both higher and lower velocities through extensive simulations of the cellular network.
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