Abstract: The present invention relates generally to the problem of determining the identity of a cell for e.g. cell handoff or automatic frequency planning, and more particularly to the problem of determining the true identity of a cell when only the transmission frequency and a non-unique identity code is known. A candidate list is created for each cell. This candidate list is created based on a function of various elements e.g. distance, transmission power, cell type, and antenna placement. The cells are then ranked on the candidate list based on this function. When a particular frequency/code combination is detected, the candidate list is then consulted, and the highest ranking cell with the same frequency/code combination is chosen as being the signal source. In an alternative embodiment the neighbor cell list is used to create the candidate list.

Abstract: A method is disclosed whereby a cellular network's Broadcast Control Channel Allocation BA lists are modified so that the mobile terminals in the network can measure downlink interference on predetermined Broadcast Control Channel Frequencies BCCH frequencies. These measurements can be made in all cells where the mobile terminals are located and then reported back to the base station. The base station maps the reported measurements to corresponding cells, and uses the mapping to produce a cell-to-cell interdependency matrix. For the preferred embodiment, the matrix describes the difference in path loss between cells. This path loss information can be used to derive downlink Carrier to Interference Ratio C/I Carrier to Adjacent Ratio or C/A ratios between cells (or combinations of those ratios) and thus an estimate of the downlink interference in the frequencies assigned to the same cells.