Nortel Networks Corporation

Apple Inc.

Blackberry Corporation

Research in Motion Corporation

Avaya Inc.

Northern Telecom Limited

Rockstar Bidco, LP

Andrew William Jeffries

David Damian Bevan

Steven Raymond Hall

Steven John Baines

Christopher Robert Ward

Martin Stevens Smith

James Mark Naden

Chris Ward

Keith S Wilson

Simon John Gale

John Edward Hudson

Julius Robson

Mathieu Boue-Lahorgue

Simon Avis

Keith Stewart Wilson

The invention is directed to a mobile communications system having improved spectral efficiency. The invention is further directed to methods and apparatus to achieve this improved spectral efficiency. In the mobile communications system communication with a plurality of mobile terminals is provided by a base station. Within the system terminals are adapted to communicate with one or more adjacent similar terminals to establish groups of terminals, called micro-cells. Each terminal within a micro-cell receives signals from the base station and then performs a first processing step on these signals. These processed signals are shared with all the other terminals within the micro-cell. Each terminal then performs a second processing step on the information it has received from all the other terminals within the micro-cell which enables it to derive a signal intended for reception by that terminal. The technique is applicable to both the uplink (user to base station) and the down link (base station to user) and also to peer to peer (user to user) communication.

Wireless communications system and method

A method of estimating user location involving collecting data from the access points in the network. The data can then be used to define a relationship, for example the loss of power experienced by a transmitted signal, between the access points. The relationship can be stored within a matrix, database or any other suitable storage method that can be referenced to determine the position of a user device within the network and correlated with corresponding measurements from a user device to determine the location of the user device within the network.

Estimating user device location in a wireless network

A mobile communications system having improved spectral efficiency, and methods and apparatus to achieve this improved spectral efficiency. In the mobile communications system communication with a plurality of mobile terminals is provided by a base station. Within the system terminals are adapted to communicate with one or more adjacent similar terminals to establish groups of terminals, called micro-cells. Each terminal within a micro-cell receives signals from the base station and then performs a first processing step on these signals. These processed signals are shared with all the other terminals within the micro-cell. Each terminal then performs a second processing step on the information it has received from all the other terminals within the micro-cell which enables it to derive a signal intended for reception by that terminal. The technique is applicable to both the uplink and the down link and also to peer to peer communication.

In a cellular wireless system, power thresholds used for determining whether to add or drop servers held in a set of servers, such as an active set, for serving a user equipment (UE) are determined based on the motion of the respective UE. A lower threshold may be used with respect to the adding or dropping of a given server to or from a set of servers for serving a fast moving UE than would be used for the same server with respect to adding or dropping to or from a set of servers for serving a slow moving UE, while maintaining a given quality of service. As a result, the average number of servers held in sets is reduced in a typical network that comprises a plurality of UEs moving at different speeds, compared to a situation in which the threshold is set irrespective of the motion of a UE.

Handover for cellular radio systems

Embodiments of the invention relate to cellular wireless networks and are particularly suited to networks including different types of base stations. So-called femtocell base stations are typically deployed within a subscriber's premises and operate at low transmit power, providing a very limited area of wireless coverage. A femtocell is typically deployed within the area of wireless coverage of a conventional macrocell type of base station, and if handover from a macrocell is performed on the basis of the best signal to noise plus interference ratio, a connection is likely to be transferred to another macrocell rather than to a femtocell. However, in view of the low density of user equipments capable of transceiving with a femtocell, the femtocell could potentially provide a greater data rate to the user equipment terminal than is possible with a macrocell. A cellular wireless network according to an embodiment of the invention employs a method of handover algorithm that has dependence on both a measure of signal quality such as signal to noise plus interference ratio and on a measure of loading of the base station. The handover algorithm is thereby able to weight selection of a base station on the basis of data rate, and intelligently engineer handover to a femtocell.

Capacity optimisation in a cellular wireless network

In a cellular wireless system, power thresholds used for determining whether or not to add or drop servers held in a set of servers, such as an active set, for serving a user equipment are determined on the basis of the motion of the respective user equipment. A lower threshold may be used with respect to the adding or dropping of a given server to or from a set of servers for serving a fast moving user equipment than would be used for the same server with respect to its adding or dropping to or from a set of servers for serving a slow moving user equipment, while maintaining a given quality of service. As a result, the average number of servers held in sets is reduced in a typical network that comprises a plurality of user equipments moving at different speeds, compared to a situation in which the threshold is set irrespective of the motion of a user equipment. A reduction in the average number of servers held in sets of servers for serving the user equipment has the benefit of reducing data traffic loading in a backhaul network, since the need to send duplicated data to each member of sets of servers is reduced and/or increasing network capacity, since the radio resource is used more efficiently because the proportion of servers sending duplicate data is reduced.

In a wireless network comprising access points deployed within a designated zone of coverage, the radio frequency field strength resulting from radiation from the access points is optimised as a function of location by means of control of the transmission power and/or radiation pattern of the access points in response to measurements from sensors at defined locations that measure received signal power, the received power being related to radio frequency field strength. Sensors may be deployed within the designated zone of coverage, at the edge of the zone and/or outside the zone and optimization of the transmission parameters of the access points in terms of transmission power and/or radiation pattern is carried out taking into account the location of the sensors in addition to the received power at the sensors.

Optimisation of transmission parameters of access points in wireless networks

The invention relates particularly to fixed wireless access networks and provides a cellular communication network which serves directional subscribers while reducing co-frequency interference substantially uniformly across the network. The network comprises a plurality of base stations arranged to form sectored cells using a plurality of carrier frequencies, where sectors carrying common frequencies are directionally mis-aligned and arranged such that the polarization of said frequencies are varied with respect to each other across the network in order to reduce co-frequency interference.

Cellular communications system

A base transceiver station operating a sectorized cell of a cellular radio system operates a plurality of narrow uplink main receive beams, and one or a plurality of uplink diversity received beams. A scanning means scans each of the uplink main receive beams to locate a communications channel on the main uplink beams. A diversity receiver receives a diverse beam signal from the diverse beam(s), which is compared with a beam signal received from a main uplink beam, and the main beam signal from the main beam, or a diverse beam signal from the diversity antenna is selected, depending on the comparative signal to noise ratio and signal strength of the main beam signal and diversity beam signal.

Multi-beam antenna system for cellular radio base stations

An antenna beam forming for generating a plurality of broad overlapping radiation beams for a cellular radio application comprises an antenna array having a plurality of individual antenna elements, each individual antenna element connected by a cable to a respective diplexor, each diplexor fed by a multi-channel power amplifier receiving an input from an output port of an eight way Butler matrix. Transmission signals are input to seven input ports of the Butler matrix, and output transmission signals are produced at four of the output ports of the Butler matrix. A remaining four output ports are each terminated with a respective matched load. A 3 dB power loss incurred in the Butler matrix is compensated by provision of a plurality of pre-amplifiers prior to the input ports of the Butler matrix, with the power amplification stage being carried out on the outputs of the Butler matrix. Side lobe suppression is maintained by ensuring phase and amplitude integrity across the output channels. A set of phase and amplitude adjusters operate on the output transmission signals from the Butler matrix output ports. The phase and amplitude adjusters may be electronically controlled.

Down link beam forming architecture for heavily overlapped beam

A frequency allocation method for allocating carrier frequencies to a plurality of fixed beams in a cellular radio based transceiver station comprises maintaining a reserve pool of carrier frequencies, such that any available carrier frequency can be allocated to any fixed beam at any one time in order to deal with capacity demands from mobile stations within an area covered by a fixed beam. A frequency allocation algorithm operates such as to allow a plurality of transceivers to float anywhere across a plurality of fixed directional beams. More carrier frequencies can be added to a beam to deal with increased mobile station capacity demand. The occupancy of channels on the carrier frequencies is continuously monitored, and the number of carrier frequencies per beam is continuously monitored, with the object of releasing unused carrier frequencies to a reserve pool of carrier frequencies, allowing re-deployment of unused carrier frequencies to other beams where necessary. Carrier frequencies are periodically 'groomed' by assessing the number of vacant channels on the carrier, and reallocating any un-utilized vacant channels to other carrier frequencies. The grooming process can be constrained to operate during natural gaps in speech, to avoid channel degradation.

Growing community of inventors

Saffron Walden, United Kingdom

Andrew William Jeffries