A cell range extension technique for GSM/DCS1800 - using half-rate codec over full-rate channel

To provide cellular coverage in rural areas where user density is low, the operators tend to build large cells in order to reduce the number of base station (BS) sites. This reduces the total cost of BS equipment, network installation, and maintenance. The cell range extension technique described in this paper is specifically targeted to the GSM/DCS1800 for providing cost-effective countryside coverage. It is based on the use of the GSM half-rate speech codec over-the full-rate traffic channel cross the extended cell range, so that additional channel coding can be utilized to improve the error rate performance. The paper presents the computer simulation results to show the improved bit error rate performances of the proposed new channel coding scheme. The results of relevant speech tests are reported and call setup probability at the extended cell edge is considered. It also describes how this technique can be effectively realized in the network design in order to increase the cell radius of the current GSM/DCS1800 and how it is related to the use of frequency hopping.