Patent ID: 8200230

Claim:
A method of reducing the number of uplink interference peaks during soft handover of a mobile station (MS) from a radio base station (RBS) A of a source cell to a radio base station (RBS) B of a target cell in a cellular mobile communication system, the method comprising the steps of: a radio network controller (RNC) ordering RBS B in the target cell to set up a link to the MS involved in the soft handover procedure; the RNC ordering the MS to start listening for RBS B in the target cell and to synchronize to RBS B in the target cell; and RBS B in the target cell synchronizing with the MS in a downlink; wherein the method is characterized by the RNC ordering RBS A in the source cell: to set a transmission power floor below which transmission power of RBS A must not fall; and to set said floor active for a predefined period of time; wherein the floor is set equal to the current transmission power of RBS A in the source cell or is set to a predefined value relative to the current transmission power of RBS A in the source cell; and wherein the floor is set to the current transmission value of RBS A in the source cell by the RNC signaling to RBS A in the source cell, an order to set as the minimum transmission power in RBS A′s downlink, a value that exceeds the maximum transmission power allowed in RBS A's downlink, thereby causing RBS A to set its minimum transmission power in the downlink to the power with which RBS A is currently transmitting.