A directionally based bandwidth reservation scheme for call admission control

This paper proposes a new advanced Call Admission Control(CAC) strategy involving for the first time, a bandwidth reservation scheme that is influenced by the direction attribute of a mobile terminal (MT). Aside from the Quality-of-Service (QoS) parameters, the direction attribute plays a key role in efficiently reserving resources for MTs supporting multimedia communications for different QoS classes. The framework for a direction-based CAC system is entirely distributed and may be viewed as a message passing system, where MTs inform their neighbouring base stations (BS) not only of their QoS requirements, but also of their mobility parameters. The base stations then predict future demand and reserve resources accordingly, only admitting those terminals that can be adequately supported. The bandwidth reservation scheme proposed in this paper, integrates the direction attribute into the conventional Guard Channel (GC) scheme. Simulation results prove that this new scheme offers significant improvements in both Call Blocking Probability (CBP) and bandwidth utilization, under a variety of differing traffic conditions

Optimal computation of the contour of maximal elements on constrained reconfigurable meshes

The Reconfigurable Mesh (RM) attracted criticism for its key assumption that a message can be broadcast in constant time independent of bus length To account for this limit Beresford-Smith et al. have recently proposed k-constrained RM where buses of length at most k, a constant, are allowed to b formed. Straightforward simulations of optimal RM algorithms on this constrained RM model are found to be non-optimal. This paper presents two optimal algorithms to compute the contour of maximal elements of a set of planar points

Adaptive AT2 Optimal Algorithms on reconfigurable meshes

Recently a few self-simulation algorithms have been developed to execute algorithms on a reconfigurable mesh (RM) of size smaller than recommended in those algorithms. Optimal slowdown, in self-simulation, has been achieved with the compromise that the resultant algorithms fail to remain AT2 optimal. In this paper we have introduced, for the first time, the idea of adaptive algorithm which runs on RM of variable sizes without compromising the AT2 optimality. We have supported our idea by developing adaptive algorithms, for sorting items and computing the contour of maximal elements of a set of planar points on RM. We have also conjectured that to obtain an AT2 algorithm to solve a problem of size n with I(n) information content on an RM of size p x q where pq=kI(n), it is sufficient to form buses of length O (k)

Seek Distances in Two Headed Disk Systems

We make a correction to the calculation of mean seek time in a recent algorithm of intelligently positioned two headed disk systems. We also introduce a new two headed disk system with better mean seek time. 1 Introduction Two headed disk systems, as categorized in [3], may have (a) two arms autonomously controlled [2,4], (b) two arms and a single controller [1] and, (c) a single arm with two fixed heads on it [4,5]. In calculating seek distances for intelligently positioned two headed systems in [4] authors ignore jockeying time of the dummy head. In this paper we recalculate the seek distance considering the penalty for jockeying. A new two headed disk system has been introduced in which the disk surface is partitioned into two equal halves and each dedicated head serves the half it is in while the other tries to occupy the center of its half. 2 Preliminaries Consider that a disk is a linear storage medium consisting of N cylinders, each of which is divided into a number of sectors..

Optimal Computation of the Contour of Maximal Elements on Mesh-Connected Computers

: Dehne presented an optimal algorithm to compute the contour of the maximal elements of n planar points on a p n \Theta p n mesh. We have calculated that Dehne's algorithm requires 23 p n steps and we have been able to reduce the required steps to 19 p n through pre-sorting and using an efficient strategy in dividing the mesh into halves. It has also been established that any implementation of Dehne's algorithm requires at least 15 p n steps. We have further developed a new optimal algorithm which requires at most 10 p n steps. Key Words: Mesh-Connected Computer, Parallel Algorithm, Computational Geometry. 1 Introduction Despite the large communication diameter, the meshconnected computer, defined in Sec. 2.1, has been given considerable attention because of its simplicity, regularity of interconnection pattern, and modularity of the layout which make it an ideal model for VLSI applications. A large number of efficient algorithms have been developed on meshes for a variety..