LBS中理想的移动台位置更新策略

位置服务（LBS）的许多应用需要记录用户的历史轨迹，现有的LBS系统开销比较大，降低了系统的容量。 针对这些缺点，提出了一种理想的移动台位置更新策略，通过把用户分成2类，并依据该分类生成了2个动态改变 用户定位频率的算法，结合用户的运动状态和用户指定的触发定位距离以及最大定位间隔时间来改变用户定位频 率，使得记录下来的用户历史轨迹更加准确，同时提高了移动台位置更新的灵活性。

Optimal geo-location updating strategy in location based service

Many Location Based Service (LBS) Applications need record user''s trace, most existing LBS system positioning the user after a fixed interval then record its location. Such fixed positioning frequency mechanism is irrational, the recorded trace will have great defect, the location points are dense when the user moving in a high speed or sparse in a low speed; on the other hand, such positioning mechanism record many unnecessary points so that the system have to endure a great burden which decrease system performance greatly. In order to avoid these defects, this paper introduce optimal geo-location updating strategy, in the strategy, the user are divided into two kinds. We present two dynamically alter user''s positioning frequency algorithms based on this classify. The algorithms combine user''s moving state with triggered positioning distance and maximal positioning interval that specified by user to alter the user''s positioning frequency which makes the user''s recorded trace more accurate and greatly increase the flexibility of user''s geo-location updating.