Browsing by Subject "Telecommunication services"

Now showing 1 - 6 of 6

Open Access
An approach to manage connectionless services in connection-oriented networks
(IEEE, 1996) Abdelatı, Muhammed; Arıkan, Erdal
In this work we propose a pricing scheme which serves as an instrument for managing connectionless services in connection-oriented communication networks. The scheme is able to allocate network bandwidth in a Pareto-optimal way that maximizes the total surplus. The key idea is to decompose the service provision procedure among three separate parties whose interactions are governed by a set of competitive pricing mechanisms.
Open Access
Client-server synchronization and buffering for variable rate multimedia retrievals
(1996) Hui J.Y.; Karasan, E.; Li J.; Zhang, J.
We consider the use of large buffers and feedback as a mechanism to maintain loosely coupled synchronization between a multimedia server and a client. The multimedia stream is modeled as a fluid flow through rate controlled valves and buffers with multiple thresholds. These thresholds are used to control the rates upstream. The quality of service for the multimedia connection is characterized in terms of the jitter in the received media stream due to buffer underflow and overflow. This quality of service is used to exercise rate and admission control in the presence of congestion. The feedback mechanism is, implemented in GRAMS, an adaptive multimedia client-server system. Experimental statistics are gathered for the purpose of traffic engineering. We employ a fluid flow and first passage time analysis to understand the traffic process through the pipelines and the buffers and to estimate the amount of signaling required by the feedback mechanism.
Open Access
The robust spanning tree problem with interval data
(Elsevier, 2001) Yaman, H.; Karaşan, O. E.; Pınar, M. Ç.
Motivated by telecommunications applications we investigate the minimum spanning tree problem where edge costs are interval numbers. Since minimum spanning trees depend on the realization of the edge costs, we de5ne the robust spanning tree problem to hedge against the worst case contingency, and present a mixed integer programming formulation of the problem. We also de5ne some useful optimality concepts, and present characterizations for these entities leading to polynomial time recognition algorithms. These entities are then used to preprocess a given graph with interval data prior to the solution of the robust spanning tree problem. Computational results show that these preprocessing procedures are quite e9ective in reducing the time to compute a robust spanning tree.
Open Access
A scheme for handling connectionless services in connection-oriented networks
(The Institute of Electronics, Information and Communication Engineers, 1997-10-25) Abdelati, M.; Arikan, E.
In this work we propose a pricing scheme which serves as an instrument for managing connectionless services in connection-oriented communication networks. The scheme is able to allocate network bandwidth in a Pareto-optimal way that maximizes the total surplus. The key idea is to decompose the service provision procedure among three separate parties whose interactions are governed by a set of competitive pricing mechanisms.
Open Access
A simulation model for military deployment
(IEEE, 2007) Yıldırım, Uğur Z.; Sabuncuoğlu, İhsan; Tansel, Barbaros
The Deployment Planning Problem (DPP) for military units may in general be defined as the problem of planning the movement of geographically dispersed military units from their home bases to their final destinations using different transportation assets and a multimodal transportation network while obeying the constraints of a time-phased force deployment data describing the movement requirements for troops and equipment. Our main contribution is to develop a GISbased, object-oriented, loosely-coupled, modular, platformindependent, multi-modal and medium-resolution discrete event simulation model to test the feasibility of deployment scenarios. While our simulation model is not a panacea for all, it allows creation and testing the feasibility of a given scenario under stochastic conditions and can provide insights into potential outcomes in a matter of a few hours.
Open Access
Transmit beamforming with cooperative base stations
(IEEE, 2005-09) Ng, B. L.; Evans, J. S.; Hanly, S. V.; Aktaş, Defne
We consider a cellular network where base stations can cooperate to determine the signals to be transmitted on the downlink. In such a scenario, it would be possible to use "macroscopic" transmit beamforming to improve system performance. The downlink beamformer of interest is generalised from some transmit beamformers that have been shown to meet various optimality criteria in the literature. The particular down-link beamformer structure enables us to recast our downlink beamforming problem as a virtual LMMSE estimation problem. Based on this virtual set up, we exploit the structure of the channel and develop distributed beamforming algorithms using local message passing between neighbouring base stations. Two algorithms are outlined, both of which are based on the Kalman smoothing framework. The first algorithm is a forward-backward algorithm that produces optimal performance, but it has the disadvantage of a delay that grows linearly with array size. The second algorithm, which is a limited extent algorithm, solves the delay problem by using only local information.