Efficient Location-Based Hard Handoff Algorithms for Cellular Systems

Abstract

Abstract. Mobile world's rapid growth hasspurred development of new protocols and new algorithms to meet changing operation requirements-such as mobile networking, and quality-of-service support. Handoff is one of the most critical procedures in cellular systems. Network operators give emphasis to optimize handover, since it is strongly related to dropped calls, network overload and subsequently users' criticism. Handoff can be seen as a blind procedure, if it is only based on the comparison of measurements, without the information of location. Since signal propagation and pathloss are complex in nature, we can expect unnecessary and wrong handoff executions. Both UMTS and those of the second generation (GSM) systems will require redefined handoff algorithms of active connections as the smooth mobility support and continuous connection are essential issues for obtaining high performance and increasing user satisfaction. In this paper we present a set of intelligent algorithms using the mobile terminal (MT) location information and area awareness to assist safe handoff decisions. The implemented algorithms are validated by means of cellular network simulators that clearly show the impact of these techniques to major system performance metrics.

Data Retrieval for Location‐Dependent Queries in a Multi‐Cell Wireless Environment

“…On the other hand, Sykas et al [11] propose another four handover approaches, namely Ping-Pong avoidance (PPA), Towards the Border (TTB), MGIS Data Resolution (MDR) and Transmission Power and Interference Optimization (TPIO). In the PPA approach, undesirable handoffs can be minimized by taking advantage the area information and mobility model to predict users movement.…”

“…Location, either for users or targets, can be defined in two-dimensional coordinates (2D) or threedimensional coordinates (3D) [11]. The 2D coordinates is a coordinate formed by x-axes and y-axes.…”

“…When more than one BS is involved, delays might occur during this period, which results in handovers or others delays (such as transmission or processing). Handover is a process to transfer an ongoing call from one cell to another as a user changes the coverage area of a cellular system [1,11]. Some approaches have been proposed in handling handover in [1,11,16].…”

Ping-Pong Reduction Using Sub Cell Movement Detection

“…For this, the paper involves a new type of information, which is the terminal mobility on the sub-cell level. There are solutions [5][6] [7] which use different types of location info to assist in the reduction of unnecessary handovers but the resolution of these solutions is not precise enough to be sufficiently effective. Also mobility models are used to predict if the UE has a moving or stationary state but these solutions can have significant error ratio [5] [8] and operate on a macro scale rather than on a subcell level.…”