METHOD AND ARRANGEMENT FOR SWITCHING CELLS

摘要

The invention pertains to a method and arrangement for switching the serving base station. The invention is especially applicable to digital TDMA (Time Division Multiple Access) cellular systems in which the operating ranges of the cells are wide. An idea of the invention is that data transmission proper utilizes extended timing advance, and the mobile station sends to the new base station a HANDOVER ACCESS message on a logical channel established for such a message in order to start the handover. A second idea of the invention is to use call re-establishment procedure in a handover. This feature can be used even in cells/systems without an extended range operation. A third idea of the invention is that in a synchronous handover the mobile station sends the handover request to the base station on a DCCH channel using a timing advance. A fourth idea of the invention is that the mobile station sends the handover request to the base station on a DCCH channel, and the base station barres the consecutive slot from traffic during the handover, but allows a time slot for traffic, if a handover access burst is not expected to extend on the time slot. By means of the invention it is possible to create cells with wide operating ranges using only one GSM carrier, whereby it is possible to carry out a handover to the appropriate cell. Furthermore, the solution according to the invention makes it possible to realize extended cells with no significant reduction in the cell's data transmission capacity.