Location-based services (LBS) depend on data gathered from mobile and ubiquitous devices and provide services like getting the appropriate location of a mobile user presented in physical and logical maps. The main operations of location management in LBS are update and search methods. Some studies to improve these were presented by using optimal sequential paging, location area scheme and hiera...

A Mobile Ad-hoc Network (MANET) is a network topology of choice where autonomous nodes form a collaborative community. Position based routing protocols have been studied extensively over the past years, But how to efficiently provide the location information for nodes and how to control location update frequency is still a challenge. In this paper, we address the problem of maintaining location...

This paper studies the location management problem in cellular wireless networks. We propose a HandoffVelocity Prediction (HVP) scheme to minimize the paging cost in searching a mobile terminal. HVP is based on the assumptions that the movement behavior of mobile terminals has temporal and spatial properties. Based on handoff statistics, the system maintains a handoff graph to describe the move...

Location-aware application s need not only rapid location-related query, but also proactive spatial event service, both of which the traditional database system does not excel at. Aiming at the deficiencies of database system, we present a light-weighted proactive spatial service model for Smart Classroom: ASMod. This model adopts such new technologies as combined spatial index, refreshing-up &...

We propose a performance benchmark for dynamic spatial indexing that is directly geared towards Location-Based Services (LBS). A set of standard, realistic location trace les is used to measure the update and query performance of a spatial data management system. We de ne several query types relevant for LBS: proximity queries (range queries), k-nearest neighbor queries, and sorted-distance que...

Since mobile user mobility behaviors can vary according to time periods, e.g. office-going/closing and office hours, the location management traffic load for tracking user positions is also a function of time. The transient characteristics of location management traffic vary according to users' initial starting positions. In this paper, we propose a mobile user mobility model considering office...

Ef®cient resource utilisation in future cellular systems is related to the control of the signalling load imposed by the location update and paging operations. Important means for controlling this load is the apropero planning of location areas. In this paper we de®ne and solve a version of the location area planning problem. Starting from a formal de®nition and an optimal formulation of the pr...

This paper is on the homotopy classification of maps of (n+1)-dimensional manifolds into the n-dimensional sphere. For a continuous map f : M → S define the degree deg f ∈ H1(M;Z) to be the class dual to f[S], where [S] ∈ H(S;Z) is the fundamental class. We present a short and direct proof of the following specific case of the Pontryagin-Steenrod-Wu theorem: Theorem. Let M be a connected orient...

Read-copy update (RCU) is a light-weight synchronization mechanism that has been used in production for well over a decade, most recently, as part of the Linux kernel. Although RCU is well-understood in the sense that practitioners are able to make good use of it without special training, there are a number of intriguing open questions related to RCU. This paper introduces a number of such ques...