A.2 Functional requirement

05.083GPPRadio subsystem link controlTS

The present algorithm is based on the following assumptions:

‑ single cell BSS;

‑ the necessity to make a handover according to radio criteria is recognized in the BSS. It can lead to either an (internal) intracell handover or an intercell handover;

‑ evaluation of a preferred list of target cells is performed in the BSS;

‑ cell allocation is done in the MSC;

‑ intracell handover for radio criteria (interference problems) may be performed directly by the BSS;

‑ the necessity to make a handover because of traffic reason (network directed handover) is recognized by the MSC and it is performed by sending a "handover candidate enquiry message" to BSS;

‑ the RF power control algorithm shall be implemented in order to optimize the RF power output from the MS (and BSS if power control is implemented) ensuring at the same time that the signal level received at the BSS (MS) is sufficient to keep adequate speech/data quality;

‑ all parameters controlling the handover and power control processes shall be administered on a cell by cell basis by means of O&M. The overall handover and power control process is split into the following stages:

i) BSS pre‑processing and threshold comparisons;

ii) BSS decision algorithm;

iii) MSC cell allocation algorithm.

A BSS decision algorithm is specified such that the BSS can fulfil the mandatory requirement of being able to produce a preferred list of target cells for handover.

It should be noted that since measurement results can also be sent to the MSC in the "handover required" message, the handover decision algorithm may be implemented in either the MSC or the BSS.