移动计算环境下路网上移动对象的位置更新

针对移动网络环境下移动对象的位置更新、断连检测和处理的问题，提出了现有位置更新策略的改进算法。采用固定时限策略进行断连检测，虽然能够获取快速而准确的断连检测，但是直接增加了位置更新的次数，降低了原有位置更新策略的性能。为了改正该缺点，提出了自适应策略，即根据移动对象的位置估计一个最晚的更新时限，实现强制更新。此外，还提出了群组更新策略中断连的处理算法。实验仿真结果表明，新算法既能减少位置更新次数，又能实现有效合理的网络处理。

Research on Location Updates of Network-constrainted Moving Objects in Mobile Computing Environment

New algorithms were proposed in this paper based on the segment-based policy, in order to detect disconnection in mobile computing environment and update location efficiently. First algorithm uses fix-time policy, can detect disconnection quickly and efficiently, but cause more numbers of location updates. Second algorithm uses adaptive time limit policy and finds a good balance. At last group-based policy will be modified to detect and deal with disconnection. Our experiments show that these algorithms not only decrease numbers of location updates,but also can detect network disconnection efficiently.