| Summary: | 碩士 === 高雄師範大學 === 光電與通訊工程學系 === 98 === Mobile stations access network services through base stations in wireless local area networks. A base station periodically broadcasts a message which contains information about its own radio channel; this message is called beacon. A mobile station uses the information contained in a beacon to establish a connection with a base station. A mobile station may move from one base station into another neighbor base station while the mobile station is transmitting data packets. Before the mobile station establishes a new connection with the neighbor base station, the mobile station will pause on data packet transmission, which causes packet delay. If a data packet suffers a certain long delay, the data packet is dropped. From the viewpoint of reduction in packet delay and packet dropping probability, a base station should frequently broadcast beacons in order to establish a connection with a mobile station as soon as possible. However, a mobile users frequently receives beacons will occupy its time to send data packets, which reduces the amount of data packets, i.e., throughput. Therefore, it is a critical issue to select an appropriate time interval to send beacons. In this thesis, we establish a simulation environment, in which we study the impacts of different beacon intervals on throughput, packet delay and packet dropping probability. Finally, we also select a beacon interval which increases throughput as much as possible in the constraint of a certain packet delay and packet dropping probability.
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