A METHOD AND APPARATUS FOR FACILITATING HANDOVER FROM A WCDMA PUBLIC LAND MOBILE ACCESS NETWORK TO A GENERIC ACCESS NETWORK

摘要

A method and arrangement are proposed for facilitating handover from a 3 G WCDMA UTRAN to a generic access network (GAN) cell. In preparation for handover, mobile stations measure the signal level transmitted from neighbouring cells as instructed by the RNC. When in a WCDMA UTRAN, the measurement of inter-frequency cells, i.e. cells having a frequency number that is different from the serving cell, requires the network to generate time gaps during which the mobile station can perform measurements on different frequencies (compressed mode). GAN cells do not transmit on their allotted frequency number, but this number together with an identifier is used to identify the GAN cell between the MS and RNC. In order to permit GAN cells to always have the same frequency number as neighbouring UTRAN cells, a modified registration procedure is proposed, wherein the MS communicates the frequency number used in the current UTRAN cell to the GAN controller, which adopts this frequency, and if necessary uses it to determine the corresponding identifier. The identifier may be the same for all GAN cells, or can be obtained from a small mapping table, which maps an identifier to each frequency or to a group of frequencies.