Title: A better deployment of 802.11 wireless access points

Master RSD

Nowadays, WIFI 802.11 wireless networks [1] are becoming popular way to access the Internet. WIFI access points can be found in many places such as airports, universities, restaurants, etc. Moreover, many people deploy access points to provide wireless connectivity at their own places. A wireless access point can cover an area on the order of hundreds of meters square and provide people within this area with a bandwidth on the order of tens of Mbytes if one uses the new 802.11g standard. More than one access point can be deployed to cover larger areas.

The performance obtained by users of WIFI networks is known to be function of many parameters as the number of hosts connected to the access point, the noise on the air, and the tuning of the MAC layer [2]. In a recent work [3], we found that this performance is also function of the spatial distribution of hosts around the access point (AP). An analytical model has been proposed to this end. Our model [3] shows that hosts close to the access point can get much higher throughput compared to remote hosts. The total throughput of the network also changes with the distribution of hosts. So, one can conclude that for some distribution of hosts in some area, there should be an optimal placement of the access point that provides the maximum total throughput and the best fairness to connected users.

The purpose of this internship is to seek this optimal placement of the one or more access points to deploy. First, the student will make a state of the art of past studies done and techniques elaborated to optimize placement of APs. Then, based on the proposed model in [3], an optimization problem has to be developed and solved with standard tools. The challenge is in the localisation of the search region since many optimal solutions could exist. Another challenge is in the definition of a function that balances throughput and fairness. The solution will be validated with simulations.

If time left, the internship will continue into the development of a heuristic that takes into account the specificities of the problem while finding the solution. The heuristic will be implemented in an application that shows graphically how the optimized placement has to be done.

Chadi Barakat
Chargé de recherche
Planète research group, INRIA
Email: Chadi.Barakat(at)sophia.inria.fr
Web: http://www.inria.fr/planete/chadi

Thierry Turletti
Chargé de recherche
Planète research group, INRIA
Email: Thierry.Turletti(at)sophia.inria.fr
Web: http://www.inria.fr/planete/turletti

Planète research group
INRIA Sophia Antipolis
2004, route des lucioles
06902 Sophia Antipolis

General Knowledge of wireless protocols and optimization tools.


[1] IEEE 802.11 WG, part 11a/11b/11g , “Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications,”, Standard Specification, IEEE, 1999.

[2] Giuseppe Bianchi, “Performance Analysis of the IEEE 802.11 Distributed Coordination Function”, IEEE Journal on Selected Areas in Communications, Vol. 18, Number 3, March 2000.

[3] Hossein Manshaei, Gion Reto Cantieni, Chadi Barakat, Thierry Turletti, "Performance Analysis of the IEEE 802.11 MAC and Physical Layer Protocol", in proceedings of WoWMoM, Taormina, June 2005.