Analysis of the direction-based location update schemes for wireless cellular networks

In this paper, we first compare the performance of the direction-based location update (DBLU) schemes with that of the distance-based location update scheme under various mobility behaviors of the mobile hosts (MTs). The comparison results show that under the random walk model, the base DBLU scheme outperforms the distance-based location update scheme when the mobility to call ratios (MCRs) of the MTs are low. However, it has been shown that the MTs are likely to possess forward-prone movement characteristics in micro-cellular architectures. If the MTs are indeed prone to make forward movements, the base DBLU scheme will be better than the distance-based location update scheme in all the MCRs according to our analysis. Therefore we further propose two enhanced DBLU schemes, namely the forward direction-based location update (FDBLU) and the restricted forward direction-based location update (RFDBLU) schemes, for the location tracking of the MTs in micro-cellular architectures. Analytical results also show that both FDBLU and RFDBLU schemes outperform the base DBLU scheme, and RFDBLU scheme is the best among the direction-based location update schemes.