230 research outputs found
A survey of self organisation in future cellular networks
This article surveys the literature over the period of the last decade on the emerging field of self organisation as applied to wireless cellular communication networks. Self organisation has been extensively studied and applied in adhoc networks, wireless sensor networks and autonomic computer networks; however in the context of wireless cellular networks, this is the first attempt to put in perspective the various efforts in form of a tutorial/survey. We provide a comprehensive survey of the existing literature, projects and standards in self organising cellular networks. Additionally, we also aim to present a clear understanding of this active research area, identifying a clear taxonomy and guidelines for design of self organising mechanisms. We compare strength and weakness of existing solutions and highlight the key research areas for further development. This paper serves as a guide and a starting point for anyone willing to delve into research on self organisation in wireless cellular communication networks
Resource allocation in cellular CDMA systems with cross- layer Optimization
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A Connection Admission Control Framework for UMTS based Satellite Systems.An Adaptive Admission Control algorithm with pre-emption control mechanism for unicast and multicast communications in satellite UMTS.
In recent years, there has been an exponential growth in the use of
multimedia applications. A satellite system offers great potential for
multimedia applications with its ability to broadcast and multicast a large
amount of data over a very large area as compared to a terrestrial system.
However, the limited transmission capacity along with the dynamically
varying channel conditions impedes the delivery of good quality multimedia
service in a satellite system which has resulted in research efforts for deriving
efficient radio resource management techniques. This issue is addressed in
this thesis, where the main emphasis is to design a CAC framework which
maximizes the utilization of the scarce radio resources available in the
satellite and at the same time increases the performance of the system for a
UMTS based satellite system supporting unicast and multicast traffic.
The design of the system architecture for a UMTS based satellite system is
presented. Based on this architecture, a CAC framework is designed
consisting of three different functionalities: the admission control procedure,
the retune procedure and the pre-emption procedure. The joint use of these
functionalities is proposed to allow the performance of the system to be
maintained under congestion. Different algorithms are proposed for different
functionalities; an adaptive admission control algorithm, a greedy retune
algorithm and three pre-emption algorithms (Greedy, SubSetSum, and
Fuzzy).
A MATLAB simulation model is developed to study the performance of the
proposed CAC framework. A GUI is created to provide the user with the
flexibility to configure the system settings before starting a simulation. The
configuration settings allow the system to be analysed under different
conditions.
The performance of the system is measured under different simulation
settings such as enabling and disabling of the two functionalities of the CAC
framework; retune procedure and the pre-emption procedure. The simulation
results indicate the CAC framework as a whole with all the functionalities
performs better than the other simulation settings
A Fairness Load Balancing Algorithm in HWN Using a Multihoming Strategy
Due to the growth of the number of intelligent devices and thebroadband requirements, between others technical requirements, of the newapplications, suppose a new challenge in planning, maintenance and resourceallocation in mobile networks for the telecommunication operators. Serviceproviders must ensure a quality of service for users in a new environmentbased in Heterogeneous Wireless Networks (HWN). A good way to achievethis goal is to prevent the quantity of services of each mobile users beingconnected to the same access networks and therefore reducing the possibilityof overloading it. This paper presents a load balancing optimization schemethat enables operators to make decisions about re-allocation of each of theservices in different access networks, keeping the required Quality of Service(QoS). In this paper, we propose 1) a mathematical model addressed as afairness resource allocation in order to obtain a global load balancing, and 2) atwo-step algorithm based on the anchor-adjustment heuristic to solve it. Ouralgorithm contribute to unload the network with maximum load while at thesame time, the other networks are balanced. As a result, we show that ouralgorithm finds (near)-optimal solutions while keeps low complexity
A pre-emption framework for UMTS compatible satellite system supporting multimedia traffic
The pre-emption procedure is an important part of the radio resource management when dealing with the emergency traffic. It allows resources to be allocated to higher priority connections by pre-empting lower priority connections. The provision of the pre-emption mechanism becomes much more important in the case of satellite systems such as the Inmarsat Broadband Global Area Network system, which aids in providing the communication during a catastrophe. This paper focuses on the pre-emption framework for a Universal Mobile Telecommunications System-based satellite systems. Three algorithms have been proposed, Greedy, SubSetSum and Fuzzy pre-emption algorithm. Extensive simulations are carried out for the three algorithms, and their performances are compared against each other. Simulation results show that the Fuzzy pre-emption algorithm performs better than the other two algorithms
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