Analysis of Neighbourhood Relations for Femtocell Networks

Nowadays mobile operators are trying to find an economic solution to improve coverage, mainly indoor, and to meet exponentially growing data traffic demands. A cost-effective means to manage these challenges represent small cells, such as metrocells or femtocells. However, in highly populated areas, a large number of these cells can be deployed and can operate in a network. Thus, to enable smooth and simple deployment of small cells, self-organizing concept has to be employed, including an automatic cell identifier assignment mechanism.Due to limited number of available cell identifiers, Physical Cell Identities (PCI), a de-sign of the PCI assignment algorithm is a challenging task, especially in dense small cell environment. In our work, we focus on neighbour relations of densely deployed femtocells because number of neighbouring cells and their relations have direct impact on the PCI assignment algorithm design. Since femtocells are not conventionally deployed by operator but by users, the cells tend to form cell clusters. We investigate these clusters of cells and their structures under different scenarios such as number of cells or radius of cell. Based on our study, the PCI assignment algorithms can be adapted and can be optimised to actual state of a network.