Optimal number and placement of network infrastructure in wireless networks
- Authors: Kouhbor, Shahnaz
- Date: 2007
- Type: Text , Thesis , PhD
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- Description: Wireless Local Area Networks (WLANs) have become a major success in telecommunications during the last few years, due to advantages such as mobility, flexibility, and easier maintenance. A device called an access point (AP) acts as a base station in WLAN for connecting a group of users to the network via radio signal. During the planning of such a network an important problem is to determine the optimal number of these devices and their placement/distribution so that coverage, capacity, and physical security are maximised at minimum cost. In this thesis we are using continuous optimisation techniques to optimise the number of APs and their distribution while cost of deployment is reduced and physical security of the network is enhanced. To find the number and placement of APs, we developed a multi-objective functions model based on path losses and power for free space environments. The two functions in the models are combined by using a balancing parameter. Since it is recognised that some of the objectives can be handled one at a time, in another approach, we followed a step-by-step procedure. We start with a novel optimisation model based on path losses for indoor environments including obstacles. Cost of deployment is saved by finding the minimum number of APs ensuring that the path loss at each test point/receiver is below the given maximum path loss. Next, the physical security of the network is enhanced by placing the APs far from places accessible to unauthorised users to reduce the risk of intrusion into the network. This is achieved in the framework of the model by introducing potential unauthorised users in unauthorised areas for whom coverage is minimised. Due to the presence of obstacles in indoor buildings, the path loss function is discontinuous. Therefore, the objective functions are very complicated and most of the existing optimisation algorithms cannot be applied to solve the problem. We use a global optimisation algorithm that is not used by other researchers to solve the same problem. To validate the accuracy of the optimisation model and performance of the numerical methods, we run tests on several indoor buildings and use wide range of WLAN parameters. The results demonstrate the quality of our model and algorithm. Based on the proposed model and algorithm, we developed a software to assist the network designers in planning wireless LANs.
- Description: Doctor of Philosophy
A new algorithm for the placement of WLAN access point based on nonsmooth optimization technique
- Authors: Kouhbor, Shahnaz , Ugon, Julien , Kruger, Alexander , Rubinov, Alex , Branch, Philip
- Date: 2005
- Type: Text , Conference paper
- Relation: Paper presented at the 7th International Conference on Advanced Communication Technology, Phoenix Park, Korea : 21st February, 2005
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- Reviewed:
- Description: In wireless local area network (WLAN), signal coverage is obtained by proper placement of access points (APs). The impact of incorrect placement of APs is significant. If they are placed too far apart, they generate a coverage gap but if they are too close to each other, this leads to excessive co-channel interferences. In this paper, we describe a mathematical model we have developed to find the optimal number and location of APs. To solve the problem, we use an optimization algorithm developed at the University of Ballarat called discrete gradient algorithm. Results indicate that our model is able to solve optimal coverage problems for different numbers of users.
- Description: E1
- Description: 2003001376
Optimal placement of access point in WLAN based on a new algorithm
- Authors: Kouhbor, Shahnaz , Ugon, Julien , Kruger, Alexander , Rubinov, Alex
- Date: 2005
- Type: Text , Conference paper
- Relation: Paper presented at ICMB 2005, International Conference on Mobile Business, Sydney, Australia, 11-13 July 2005, Sydney : 11th - 13th July, 2005
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- Reviewed:
- Description: When designing wireless communication systems, it is very important to know the optimum numbers and locations for the access points (APs). The impact of incorrect placement of APs is significant. If they are placed too far apart, they will generate a coverage gap, but if they are too close to each other, this will lead to excessive co-channel interferences. In this paper we describe a mathematical model developed to find the optimal number and location of APs. To solve the problem, we use the Discrete Gradient optimization algorithm developed at the University of Ballarat. Results indicate that our model is able to solve optimal coverage problems for different numbers of users.
- Description: 2003001377
Physical security enhancement in wireless LAN systems
- Authors: Kouhbor, Shahnaz
- Date: 2007
- Type: Text , Conference paper
- Relation: Paper presented at 3rd International Conference on Intelligent Sensors, Sensor Networks and Information, ISSNIP 2007, Melbourne, Victoria : 3rd-6th December 2007 p. 733-738
- Full Text: false
- Description: During the planning of Wireless Local Area Network (WLAN) systems, it is important to determine the optimal number of access points (APs) in order to maximise their coverage with minimum cost. It is also essential to take proactive steps to secure their position in order to enhance the physical security of the network. In this paper we describe a mathematical model that finds the minimum number of APs for indoor buildings and places them in the area in a manner that the physical security of the network is maintained. A Global Optimisation Algorithm (AGOP) developed at the University of Ballarat is used to solve this problem. Results obtained demonstrate that the model and software are able to optimally solve the placement problem in areas that have different obstacles and number of users.
- Description: 2003004952
Coverage in WLAN : Optimization model and algorithm
- Authors: Kouhbor, Shahnaz , Ugon, Julien , Mammadov, Musa , Rubinov, Alex , Kruger, Alexander
- Date: 2006
- Type: Text , Conference paper
- Relation: Paper presented at the First International Conference on Wireless Broadband and Ultra Wideband Communications, AusWireless 2006, Sydney : 13th March, 2006
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- Reviewed:
- Description: When designing wireless communication systems, it is very important to know the optimum numbers of access points (APs) in order to provide a reliable design. In this paper we describe a mathematical model developed for finding the optimal number and location of APs. A new Global Optimization Algorithm (AGOP) is used to solve the problem. Results obtained demonstrate that the model and software are able to solve optimal coverage problems for design areas with different types of obstacles and number of users.
- Description: 2003001757
Facility location via continuous optimization with discontinuous objective functions
- Authors: Ugon, Julien , Kouhbor, Shahnaz , Mammadov, Musa , Rubinov, Alex , Kruger, Alexander
- Date: 2007
- Type: Text , Journal article
- Relation: ANZIAM Journal Vol. 48, no. 3 (2007), p. 315-325
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- Description: Facility location problems are one of the most common applications of optimization methods. Continuous formulations are usually more accurate, but often result in complex problems that cannot be solved using traditional optimization methods. This paper examines the use of a global optimization method - AGOP - for solving location problems where the objective function is discontinuous. This approach is motivated by a real-world application in wireless networks design. © Australian Mathematical Society 2007.
- Description: 2003004859
Optimization in wireless local area network
- Authors: Kouhbor, Shahnaz , Ugon, Julien , Kruger, Alexander , Rubinov, Alex , Branch, Philip
- Date: 2004
- Type: Text , Conference paper
- Relation: Paper presented at ICOTA6: 6th International Conference on Optimization - Techniques and Applications, Ballarat, Victoria : 9th December, 2004
- Full Text: false
- Reviewed:
- Description: 2003000886
Coverage in WLAN with minimum number of access points
- Authors: Kouhbor, Shahnaz , Ugon, Julien , Rubinov, Alex , Kruger, Alexander , Mammadov, Musa
- Date: 2006
- Type: Text , Conference paper
- Relation: Paper presented at VTC 2006 - Spring, 2006 IEEE 63rd Vehicular Technology Conference, Melbourne : 7th May, 2006
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- Description: E1
- Description: 2003001610