La Coexistence De Femtocell Avec Le Wifi ( En Cas De Fractionnement Et Le Partage Du Spectre sans Licence ) Mémoire Présenté Comme

Femtocells and WiFi are often presented as opposing technologies. The reality is that both have a vital role to play in supporting future mobile traffic growth. In many cases both technologies will eventually be employed in a single box with access via an intelligent mobile deviee that will automatically select the best option. Deploying Femtocells in WiFi hotspots would let access providers add 3G capacity for users who do not have WiFi on their deviee and improve their quality of experience during mobility. Partitioning of the spectrum resources and fine-tuning the performance in case of co-existence carry critical importance for maximizing the total capacity and quality of service (QoS) satisfaction of end users. In this thesis, we have investigated two studies in case of co-existence of Femtocell and WiFi: (i) We propose fair and QoS-based unlicensed spectrum splitting strategy between WiFi and Femtocell networks. Numerical results show that spectrum splitting under total capacity maximization constraint allows for unfair spectrum allocation, while a more equitable spectrum splitting can be accomplished by taking into account the fairness and QoS constraints. (ii) We propose and develop a framework to increases the total sum of throughput for Femtocells while they simultaneously access both licensed and unlicensed bands. The channel access of both Femtocell and WiFi networks are analytically modeled and numerically verified . Moreover, the effects of WiFi channel access parameters on the performance of WiFi and Femtocell networks are investigated. Keywords-Femtocell, WiFi, spectrum allocation, QoS, fairness, capacity, unlicensed spectrum, back-off madel.