Telefonaktiebolaget Lm Ericsson (Publ)

Peter Butovitsch

Niklas Jaldén

Paul Stjernholm

Lars B Johansson

Petter Blomberg

Ulrich Jetzek

Magnus Persson

Walter M&uuml;ller

Tomas Sandin

Peter Andersson

Sture Jonsson

A method and apparatus for minimizing interference in a wireless communication system. A base transceiver station transmits and receives over a first frequency band and a second frequency band. The maximum range of the first frequency band can be smaller than the maximum range of the second frequency band. Alternatively, the maximum range of the first frequency band can be larger than the maximum range of the second frequency band. Further, the maximum range of the second frequency band can vary based upon factors such as the capacity of the first frequency band and the amount of interference on the first frequency band. A control channel for the second frequency band which is measured for determining whether to handoff from the first frequency band to the second frequency band can be transmitted within the first frequency band.

Hot spot with tailored range for extra frequency to minimize interference

A power control method in accordance with the present invention synchronizes the transmit power levels at the base stations currently serving a mobile station and an initial transmit power level of a new target base station being added in a diversity handover situation. At the beginning of the handover, a radio network controller orders the serving base stations to measure their respective transmit powers to the mobile station. Each serving base station then measures its transmit power to the mobile station and reports the power level measurements to the radio network controller. An initial transmit power setting is determined for the target base station, and new transmit power settings are determined for the serving base stations synchronized for example to a particular time (t ). At or about synchronizing time t , the target base station transmits to the mobile station at the initial power setting, and at or about the same time, the serving base stations preferably also adjust their transmit powers toward the new values. Alternatively, the serving base stations transmit at their respective new values at or about time t . In a preferred embodiment of the present invention, the serving base station power adjustment is performed gradually.

Base station transmit power control in a CDMA cellular telephone system

Systems and methods for estimating inter-frequency measurements used for radio network functions are disclosed. The systems and methods described allow systems to evaluate the quality of a second frequency by using offset adjusted measurements on a first frequency. By using the described methods, system capacity is increased by providing a &ldquo;low cost&rdquo; measurement mechanism for support of handover that substantially balance the load between two or more frequency bands. By using the proposed method, handover can be performed more frequently and the interference within each frequency band can therefore be kept at a more optimal level.

System and method for estimating interfrequency measurements used for radio network function

A method and system for controlling handoffs in radiocommunication systems using a softzone concept are described. Soft handoff is permitted between members of a particular softzone, but not between members of different softzones. Hard handoff is permitted between members of different softzones, but not between members of the same softzone.

Methods and systems for controlling hard and soft handoffs in radio communications systems

Methods of controlling the power levels of transmitted signals in telecommunication systems are described. For example, a remote terminal measures the quality of a received signal, either by determining the frame error rate or the bit error rate, and reports its quality measurement to a network by sending a quality message. The network causes the signal transmitters to adjust their transmit power levels appropriately. Faster power control methods may be combined with slower power control methods for downlink (network to remote terminal) transmissions in various communications scenarios, such as soft hand-overs.

Growing community of inventors

Bromma, Sweden

Peter Butovitsch