@conference {3017, title = {Fractional Frequency Reuse in Integrated Femtocell/Macrocell Environments}, booktitle = {11th International Conference on Wired/Wireless Internet Communications (WWIC 2013), Saint - Petersbourg, Russia}, year = {2013}, month = {June 5-7}, pages = { 229 - 240}, abstract = {

Femtocells have a strong potential for increasing the efficiency, cell coverage and network capacity of next-generation mobile networks. In Long Term Evolution technology, the adaptation of Fractional Frequency Reuse techniques has been proposed in order to overcome the co-channel interference and augment the total throughput of the network. In this work, we propose a Fractional Frequency Reuse method that on the one hand calculates the optimal inner region radius and frequency allocation of a macrocell and on the other hand assigns frequency resources to the femtocells in order to mitigate the co-channel interference. We apply this method in an integrated femtocell/macrocell environment and evaluate it based on the optimization of three metrics, depending on the network operator?s needs.

}, keywords = {FFR}, author = {Christos Bouras and Andreas Papazois and Vasileios Kokkinos and Georgia Tseliou} } @article {3121, title = {Selecting the Optimal Fractional Frequency Reuse Scheme in Long Term Evolution Networks}, journal = {Wireless Personal Communications, Springer Verlang}, volume = {71}, year = {2013}, pages = {2693-2712}, abstract = {

Long Term Evolution (LTE) networks offer high capacity and are specified and designed to accommodate small, high performance, power-efficient end-user devices. One limiting factor that influences LTE performance is the interference from neighbouring cells, the so called Inter-Cell Interference (ICI). The investigation of ICI mitigation techniques has become a key focus area in achieving dense spectrum reuse in next generation cellular systems. Fractional Frequency Reuse (FFR) has been proposed as a technique to overcome this problem, since it can efficiently utilize the available frequency spectrum. This manuscript proposes a dynamic mechanism that selects the optimal FFR scheme based on a custom metric, which is called user satisfaction. In detail, the proposed mechanism divides the cell into two regions, the inner and outer region, and selects the optimal size as well as the optimal frequency allocation between these regions with main target to maximize the user satisfaction metric. The proposed mechanism is evaluated through several simulation scenarios that incorporate users? mobility and its selected FFR scheme is compared with other frequency reuse schemes in order to highlight its performance.

}, keywords = {FFR}, author = {Christos Bouras and Andreas Papazois and Vasileios Kokkinos and Georgia Tseliou and Dimitrios Bilios} } @conference {2997, title = {Interference Management in LTE Femtocell Systems Using an Adaptive Frequency Reuse Scheme}, booktitle = {Wireless Telecommunications Symposium (WTS 2012), London, UK}, year = {2012}, month = {18-20 April}, abstract = {Long Term Evolution (LTE) has developed a new technology in order to enhance indoor coverage. This new technology is called femtocells and is achieved with the use of access points installed by home users. However, interference problem between the femtocell and the macrocell decreases the system{\textquoteright}s capacity and as a result users{\textquoteright} throughput. In this paper we study the interference mitigation techniques in femtocell/macrocell networks and we propose a frequency reuse mechanism that leads to increased overall system performance. In particular, the mechanism aims to maximize throughput via a variety of combinations between inner cell radius and frequency allocation to the macrocell. Additionally, a position minded frequency allocation to the femtocells targets to further optimize the total throughput of the cell.}, keywords = {Femtocell, FFR, LTE}, author = {Christos Bouras and Andreas Papazois and Vasileios Kokkinos and Georgios Kavourgias} } @conference {2995, title = {Optimization of Fractional Frequency Reuse in Long Term Evolution Networks}, booktitle = {2012 IEEE Wireless Communications and Networking Conference (WCNC 2012), Paris, France}, year = {2012}, month = {1-4 April}, pages = {1875-1879}, abstract = {In cellular systems, Fractional Frequency Reuse (FFR) partitions each cell into two regions; inner region and outer region and allocates different frequency band to each region. Since the users at the inner region are less exposed to inter-cell interference, the frequency resources in each inner region can be universally used. Based on this frequency band allocation, FFR may reduce channel interference and offer large system capacity. This paper proposes a mechanism that selects the optimal FFR scheme based on the user throughput and user satisfaction. In detail, the mechanism selects the optimal size of the inner and outer region for each cell as well as the optimal frequency allocation between these regions that either maximizes the mean user throughput or the user satisfaction. The mechanism is evaluated through several simulation scenarios.}, keywords = {FFR, LTE}, author = {Christos Bouras and Andreas Papazois and Vasileios Kokkinos and Georgia Tseliou and Dimitrios Bilios} } @conference {3008, title = {A Performance Study of Fractional Frequency Reuse in OFDMA Networks}, booktitle = {Fifth IFIP Wireless and Mobile Networking Conference, Bratislava, Slovakia}, year = {2012}, month = {19-21 September}, pages = {38 - 43}, abstract = {

Long Term Evolution (LTE) technology is considered as the most possible candidate for next generation mobile communications. LTE networks offer high capacity and are specified and designed to accommodate small, high performance, power-efficient end-user devices. One limiting factor that influences LTE performance is the interference from neighbor cells, the so called Inter-Cell Interference (ICI). Fractional Frequency Reuse (FFR) has been proposed as a technique to overcome this problem, since it can efficiently utilize the available frequency spectrum. This paper analyzes the FFR scheme and proposes a dynamic FFR mechanism that selects the optimal frequency allocation based on the cell total throughput and user satisfaction. In detail, the mechanism divides the cell into two regions (inner and outer) and selects the optimal size as well as the optimal frequency allocation between these regions with main target to maximize the overall throughput and user satisfaction. The mechanism is evaluated through several simulation scenariosthat incorporate users? mobility.

}, keywords = {FFR, LTE}, author = {Christos Bouras and Andreas Papazois and Vasileios Kokkinos and Georgia Tseliou and Dimitrios Bilios} }