New handover algorithm

Hi, Jean-Samuel and me developed an advanced handover algorithm for OpenBSC. Before implementing it, we would like to get any feedback, so I decided to post it in this mailing list. The document that describes the algorithm can be downloaded at: http://home.eversberg.eu/handover-algorithm-v2.3.pdf Regards, Andreas Handover shall ensure that the mobile station is always on the best cell during a call. This results in best speech quality and allows a lower TX level (up-link) to save battery and reduce interference. Sometimes this is not desirable, especially if a cell with large coverage becomes congested after handover. In this situation it makes sense to balance the usage between cells to prevent congestion. If a cell is congested, one or several mobile stations need to be handovered to a different cell, even if that cell is not the best cell for these mobile station. In case that a mobile station needs to handover to prevent a loss of radio link, it makes sense to handover it to a cell that is congested afterwards. In this situation, a different mobile station on the congested target cell must be handovered to a non-congested neighbor cell, to solve or balance the congestion. In order to negotiate used codec and TCH rate during call setup, Immediate Assignment shall assign an SDCCH channel, if available. After negotiation is complete, assignment to the available TCH slot is made.