Broadcast Scheduling Of Multiple Channels And Data Items Request In Mobile Computing Environment

Mobile computing is a new technology, which makes the data can be transmitted by computers or other computing devices without fixed physical equipments. Data broadcast is one of the effective data access methods. And the current thesis covers the following parts:Firstly, based on the analysis of multi-channel data broadcast scheduling and multi-data items requested broadcast scheduling, a new strategy is proposed, which employs multi channels to broadcast multi data items request. And another algorithm aiming at multi-data items request through multi channels (MCISR algorithm) is designed.Secondly, this study focuses on two main problems, namely data access collision and channel jump, specific to which preventive strategies are proposed respectively. Thus, the total average access time can be reduced when these strategies are adopted in MCISR.Thirdly, another broadcast mode is put forward which employs multi channels to broadcast multi data items request. In such a mode, upstream channel is used to send data information from mobile clients'dynamic requests. And data items are periodically broadcasted through downstream channel. The period in this mode is dynamic and the broadcasting contents changes with the varying of data information from mobile clients'requests.At last, this thesis firstly analyzes the best experimental result almost equals to the minimum obtained through square root rules of multi channels, which indicates that this algorithm is of relatively outstanding performance.; then the performance of MCISR with different parameters deflections factor (θ) and the number of channel (C); and lastly the effectiveness of preventive strategies aiming at data access collision and channel jump is tested through experiment.and lastly the performance of MCISR is analyzed through square root rules of multi channels. According to the experimental results, MCISR works better with no uniform-distributed data than uniform-distributed data; with certain broadcast data items, the total access time reduces with the increase of channels, that is to say, MCISR acts better when there are more channels. The total access time reduces when the preventive strategies are put into use, which just shows that the strategies are effective.