Geometry modeling in cellular network planning

To design a cellular radio network (GSM, UMTS, WiFi …) it is indispensable today to use a radio planning software. In current commercialized tools, radio network planning is based on a numerical evaluation of a set of radio metrics, directly linked to quality of service notion, such as interference, throughput, coverage, capacity … The network configurations produced by such tools are generally faced with the human expert judgment who attaches great importance to the organizational aspects such as cells size and the topology. In other words, all those concepts related to the visual cells shape and geometry. In this article we emphasize the simplicity and the strength by which the geometrical concepts helps to bring out good network properties which are not taken into account by conventional radio criteria. On one hand, well-formed cells lead to reduce the number of handover calls, and to form transition zones between cells allowing proper completion of the handover procedure. On the other hand, cell geometry optimization produce performing network schemes in which the frequencies reuse (frequencies planning in GSM, WiFi) is simplified. We describe in this paper an original and practical modeling of the cellular geometry criteria granting the integration of this concept into the automatic planning process of mobile radio networks. The relevance of this criterion is assessed on three different levels. On a local level, we first establish the correlation between the geometric criteria and the improvement of point-by-point radio quality indicators. We secondly show geometry impact on radio frequency planning and the improving of the handover zones. Finally we analyze the impact of geometric criterion on improving indoor positioning systems.