Abstract: A radio communication system comprises a communication channel between a transmitter (108) having a plurality of antennas (110) and a receiver (114) having at least one antenna (110). In such a system the communication channel comprises a plurality of paths (112) having a range of characteristics. Data for transmission is generated by one or more applications (102) and has one or more categories assigned to it, for example by the addition of tags by a tagging block (204) indicating its importance or other requirements. Depending on the assigned categories and the characteristics of the paths (112), the data is mapped to one or more of the transmitter's antennas (110) to select a suitable transmission path (112).

Abstract: An internal powerline network is provided with a routing device for routing a signal on only a part of the network. In this way the data capacity of the network is increased. The routing device is advantageously attached to the fuse box of the powerline network.

Abstract: A radio communication system has a random access channel for the transmission of data (214) from a secondary station to a primary station. Such a channel is intended for use by secondary stations having data (214) to transmit to a primary station while not actually engaged in a call. By enabling access requests (202) to be transmitted with a greater range of possible signatures, a much greater number of degrees of freedom is available to a secondary station requesting access to a random access channel. This enables significantly improved efficiency of resource allocation by increasing the amount of information transmitted to the primary station by the access request (202).

Abstract: In a radio communication system having a primary station and a plurality of secondary stations, the power of uplink and downlink channels between the primary station and a secondary station is controlled in a closed loop manner by each station transmitting power control commands to the other station. In response to these commands the receiving station adjusts its output power in steps. By combining a plurality of received power control commands before adjusting its output power the receiving station may emulate the ability to use a smaller power control step size than its minimum, thereby improving performance under certain channel conditions. In one embodiment when the required power control step size is less than the minimum step size of a particular station, that station processes a group of power control commands to determine whether to adjust its output power by its minimum step size. In an alternative embodiment the power control step size is fixed when the combining algorithm is used.

Abstract: A radio communication system has means for ensuring that power control of a communication channel has been established before the transmission of data. This is done by delaying initial transmission of a data channel (either at the start of a transmission or after a pause) until after the initial transmission of control channels. In one embodiment the transmission of a data channel can be delayed until adequate power control has been established. These techniques overcome the problem that data transmissions at the start of a data channel are likely to be corrupted if their power level is too low, or to generate extra interference if their power level is too high.

Abstract: A radio communication system a primary station and a secondary station operating according to two (or more) two-way communication modes. An uplink and/or a downlink communication channel is present for the first mode, but only one of an uplink and a downlink channel is present for the second mode. Modifications to the protocols of the first and second modes enable the traffic for an absent communication channel of one mode to be carried by the corresponding channel of the other mode.

Abstract: A radio communication system has a random access channel for the transmission of data (214) from a secondary station to a primary station. Such a channel is intended for use by the secondary stations having data (214) to transmit to a primary station while not actually engaged in a call. By enabling access requests (202) to be transmitted with a range of time offsets relative to the boundary (302) of their time slot, a much greater number of degrees of freedom is available to a secondary station requesting access to a random access channel. This enables significantly improved efficiency of resource allocation by increasing the amount of information transmitted to the primary station by the access request (202).

Abstract: A radio communication system has a random access channel for the transmission of data from a secondary station to a primary station while the secondary station is not engaged in a call. A secondary station wishing to use a random access channel resource transmits a preamble encoded with a signature corresponding to the required resource. In response the primary station can transmit a positive acknowledgement (ACK) corresponding to the received preamble, indicating that a channel is available, or a negative acknowledgement (NACK), indicating that the resource is not available. A first set of signatures are used to encode ACKs and a second set of signatures are used to encode NACKs. The two sets of signatures have the property that no signature in one set is the inverse of a signature in the other set, thereby avoiding the possibility of simultaneously transmitting an ACK and a NACK with signatures that are the inverse of one another.

Abstract: An electrically releasable form of hook and loop fastener (10) allows one half of the fastener to release from the other half without applying direct physical force to either half. The hook elements (21) of the fastener are formed of a shape-memory alloy material (27) such as commercially available Ninitol. Release of the hook half (14) of the fastener from the loop half (12) is accomplished by passing an electrical current through the shape-memory alloy material to straighten the hooks (21) so that they release their engagement with the loops (18). The flow of electricity through the hook half energizes the Ninitol material (27) to change its shape, either expanding or contracting in length; the change in shape is made to act against another length of material (28) that remains fixed in length or changes shape in an opposite direction so as to cause the hook shape to straighten toward a rod shape.

Abstract: A device with a display is operable in at least two modes, a first mode in which display data is provided to the screen for viewing in a first orientation and a second mode in which display data is provided to the screen for viewing in a second, orthogonal, orientation. In the first mode, the display data fills the screen, and in the second mode the display data comprises two images for filling the screen. The aspect ratio for at least one of the two images in the second mode can then be the same as for the image in the first mode.

Abstract: A radio communication system includes a primary station which is arranged to transmit a series of data packets to a secondary station which operates according to an ARQ scheme for acknowledging correct reception of each packet. The primary station transmits error correction information relating to any packets that are not received correctly, thereby enabling the secondary station to extract correctly the data. The data packets are transmitted via a plurality of logical channels, so that an error in transmission of one packet does not hold up transmission of packets in other channels. Transfer of data transmission from one primary station to another is done by transferring each channel when correct reception of a data packet on that channel has been acknowledged, thereby avoiding the extra signaling required in transferring logical channels in which a data packet has been received in error and the error correction transmissions have not been completed.

Abstract: A radio communication system has a random access channel for the transmission of data (214) from a secondary station to a primary station. Such a channel is intended for use by secondary stations having data (214) to transmit to a primary station while not actually engaged in a call. A problem with known systems of this type is that a secondary station requesting access also specifies which of a plurality of resources it wishes to access. If that resource is busy access is denied, even if other suitable channels are available. In the present system allocation of a channel is performed by the primary station when acknowledging (206,210) a secondary station's access attempt (202,208), thereby eliminating wasted attempts. In one embodiment the primary station also periodically broadcasts a short message indicating the availability of channels for access attempts.

Abstract: A method of operating a radio communication system in which secondary stations use dedicated time slots to request services from a primary station. A secondary station wishing to request a service sends a request in every time slot allocated to it until it receives an acknowledgement from the primary station. The primary station can use combining techniques on multiple time slots to identify the presence or absence of a request from a secondary station with improved accuracy.

Abstract: A radio communication system has improved power control of transmissions between a first station and a second station. The second station adjusts the power of its transmissions to the first station in response to power control commands received from the first station. The first station determines when it has synchronised to transmissions from the second station and informs the second station of synchronisation. After synchronisation has been signalled, the rate of adjustment of transmission power by the second station is increased (508). The changed rate of power control can be achieved by adjustments to the power control step size, or by other modifications to the response of the second station to received power control commands or to its rate of reception of power control commands. These techniques overcome the problem that, because synchronisation can take a significant time to be established, there is a danger that transmission power may be increased too much and cause unacceptable interference.

Abstract: A radio communication system has means for improving power control of a communication channel for the transmission of data after an interruption in the transmission. This is done by adjusting the transmission power immediately after the interruption by an offset from the power used before the interruption. The offset may be fixed or may be determined from the transmission power in the period before the interruption. This technique reduces, on average, the time taken for power control to be re-established, thereby addressing the problem that data transmissions immediately after the interruption are likely to be corrupted if the power level is too low, or to generate extra interference if the power level is too high.

Abstract: A radio communication system has a random access channel for the transmission of data (214) from a secondary station to a primary station. Such a channel is intended for use by secondary stations having data (214) to transmit to a primary station while not actually engaged in a call. By enabling access requests (202) to be transmitted with a greater range of possible signatures, a much greater number of degrees of freedom is available to a secondary station requesting access to a random access channel. This enables significantly improved efficiency of resource allocation by increasing the amount of information transmitted to the primary station by the access request (202).

Abstract: In a radio communication system having a primary station and plurality of secondary stations, power of uplink and downlink channels between the primary station and a secondary station is controlled in a closed loop manner by each station transmitting power control commands to the other station. Responsive to these commands receiving station adjusts its output power in steps. By considering a plurality of received power control commands receiving station may emulate the ability to use power control step sizes other than those it directly implements, for example step sizes smaller than its minimum or intermediate between implemented step sizes. Performance can thereby be improved under certain channel conditions. In one embodiment when required power control step size is less than the minimum step size of the receiving station, that station processes a group of power control commands to determine whether to adjust its output power by its minimum step size.

Abstract: A radio communication system has a random access channel for the transmission of data (214) from a secondary station to a primary station. Such a channel is intended for use by secondary stations having data (214) to transmit to a primary station while not actually engaged in a call. Before the transmission of its data (214), a secondary station transmits a message (302) that provides information on the length of the data transmission (214), and may include format information relating to the data (214). This scheme is particularly effective when combined with a scheme signaling availability of random access channel resources, for example by use of an availability (AV) message (402). In this case, a primary station can signal future availability of resources that are currently in use.

Abstract: A radio communication system has a random access channel for the transmission of data (214) from a secondary station to a primary station. Such a channel is intended for use by secondary stations having data (214) to transmit to a primary station while not actually engaged in a call. By enabling access requests (202) to be transmitted with a greater range of possible signatures, a much greater number of degrees of freedom is available to a secondary station requesting access to a random access channel. This enables significantly improved efficiency of resource allocation by increasing the amount of information transmitted to the primary station by the access request (202).

Abstract: A radio communication system has means for improving power control of a communication channel for the transmission of data after an interruption in the transmission. This is done by adjusting the transmission power immediately after the interruption by an offset from the power used before the interruption. The offset may be fixed or may be determined from the transmission power in the period before the interruption. This technique reduces, on average, the time taken for power control to be re-established, thereby addressing the problem that data transmissions immediately after the interruption are likely to be corrupted if the power level is too low, or to generate extra interference if the power level is too high.