The importance of location prediction is rapidly increasing with the current trend of database applications in mobile computing environment. However, current personal communication services network could only provide currently maintained location information of non-idle mobile terminals. Pertinent researches predict the future location based on tangent velocity approaches, which require mobile terminals to spend lots of precious electronic power to sense and then measure a sequence of positions for predicting the future tangent velocity, and the prediction is effective only within a short range of time. In this study, we propose an approach to predict future locations of mobile terminals based on the moving behaviors mined from their long-term moving history. Location prediction based on moving behavior requires no power consumption for position measurement, and the prediction results are effective for a long time without requiring the queried clients to be non-idle. With the help of moving behavior, we propose several location prediction operators for location query. Finally, we demonstrate the accuracy of the location query operators through simulation statistics. The experimental results show that the predictions are accurate enough for regular moving mobile terminals.
"To obtain this, we have used a new optimized search scheme known as UPB scheme for mobility prediction. In previous studies various algorithms or techniques have been used to predict the user mobility patterns  . However, the proposed scheme is based on the analysis of the user movement from one cell to another in different timestamp and representing it through a transition probability matrix (TPM). "
[Show abstract][Hide abstract] ABSTRACT: The objective of 4G network is to provide best services to the users which in turn made the performance of existing network more critical. Further, the large traffic generated in such networks creates congestion resulting in overloading of the system. Frequent delays, loss of packets, and in addition the number of retransmission/paging also increases the computational cost of the system. This paper proposes a novel way to reduce overloading and retrieval mechanism for VLR through optimized search, based on the information of users mobility pattern (User profiles based (UPB)) to track the user. This not only improves the overall performance of the system, especially in the events when the visitor loca-tion register (VLR) is overloaded due to heavy traffic and congestion of the network. It was also established through simulation studies that the proposed UPB scheme optimizes the search and reduces the average waiting time in a queue. In addition, the provision of VLR w (waiting visitor location register) avoids the overloading of main VLR and provides a recovery/retrieval mechanism for VLR failure.
Communications and Network 04/2012; 04(03). DOI:10.4236/cn.2012.43026
"According to GPB scheme, the probability of users to stay in a particular cell is equally probable. Hence location search is in a random order of cell no, we have taken cell in a random order as: cell no =                Here index of this row vector represents no to search a location while the value of this row vector is represented as a cell number. A graph is plotted in Figure 2 between cell no. "
[Show abstract][Hide abstract] ABSTRACT: In Cellular networks, number of users increase in an exponential manner. As a result of this exponential growth of users, overloading of the system takes place. Besides this, unacceptable delays and high computational cost create a strong prerequisite for efficient location management techniques. Motivated by this fact, a novel user profile based (UPB) scheme is proposed in this paper to track the location of the mobile users. There are a number of user mobility prediction algorithms in the literature and the proposed scheme is also one of them but unique in its own way. This scheme deals with the overloading of Visitor location register (VLR) which results in the congestion of mobile network. First of all, the proposed UPB scheme makes use of historical information of user's movement to generate a probability transition matrix (PTM) which corresponds to user transition from one cell to another cell. After this, a steady state value of each cell is obtained from PTM. Now the PTM is added with other required information of each user in a separate database known as wVLR (weightage factor based VLR). This separate database will play a vital role in the event of congestion of network or main VLR failure. The above proposed scheme is compared with a widely implemented general profile based (GPB) scheme in which user has equal probability of staying in each cell. It was found that the proposed UPB scheme reduces the number of searches as compared to GPB scheme. Also a significant improvement is obtained in terms of average waiting time of user, average time spent by the user in a system and reduction in call dropping when the system is overloaded.
[Show abstract][Hide abstract] ABSTRACT: La mobilité des unités a connu un fort essor depuis quelques années. Une des conséquences directes dans le domaine des bases de données est l'apparition de nouveaux types de requêtes tels que les Requêtes Dépendant de la Localisation (RDL) (e.g. un ambulancier demande l'hôpital le plus proche de sa position). Ces requêtes soulèvent des problèmes qui font depuis quelques années l'objet de plusieurs recherches. En dépit de l'abondance des travaux liés à ce domaine, les différents types de requêtes étudiés jusqu'ici ne répondent pas à tous les besoins applicatifs. En effet, des nouveaux besoins donnent naissance à des requêtes mobiles avec des contraintes de temps réel. La prise en compte à la fois des contraintes de temps réel et de mobilité lors du traitement des requêtes est un problème important à résoudre. Ainsi, notre principal objectif est de proposer une solution pour le traitement des requêtes RDL avec des contraintes de temps réel. D'abord, nous proposons un langage permettant d'exprimer différents types de requêtes RDL. Ensuite, nous concevons une architecture permettant de traiter des requêtes RDL avec des contraintes de temps réel. Les modules conçus sont destinés à être implantés au-dessus de SGBD existants (e.g. Oracle). Dans le cadre de cette architecture, nous proposons des méthodes permettant de tenir compte de la localisation du client et de son déplacement après l'envoi de la requête. Nous proposons aussi des méthodes permettant de maximiser le taux de requêtes respectant leurs échéances. Enfin, nous validons nos propositions par une mise en œuvre et des évaluations des performances des méthodes proposées.
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