Abstract: Data packets having different assigned priorities are multiplexed by operating a queue for each different priority of data packet and assembling groups (80) of the data packets for transmission. Each group has two portions. A first portion (90) of the group is populated with data packets selected from one or more of the queues according to a first rule and a second portion (95) of the group is populated with data packets selected from one or more of the queues according to a second rule. Preferably the first portion contains data packets having the highest priority, and the second portion contains a selection of the data packets having a lower a priority. Selection of data packets for the second portion may depend on criteria such as delay experienced and queue length. The size of the first and second portions may be adapted according to delay experienced and queue length.

Abstract: A method of operating a communication system in which transmissions in a first direction, say from a base station, comprise frames formed by data packets and transmissions in a second direction, say from a user equipment (U E), comprise substantially continuous transmissions having acknowledgement fields (ARQ-A, ARQ-B) for data packets and transmission gaps (GP) to allow the UE to make other measurements. The acknowledgement fields are mapped to the data packets to enable the base station to determine which data packets are being acknowledged. In order to avoid ambiguity in mapping acknowledgement fields to data packets when a transmission gap occurs, a single data packet is transmitted in either the frame whose acknowledgement field would occur in the transmission gap or the frame whose acknowledgement field would occur immediately following the transmission gap.

Abstract: A method of, and receiver for, cancelling an unwanted first signal having a bandwidth at least a part of which overlies the bandwidth of a wanted second signal, the bandwidth of one of the first and second signals being greater than that of the other The method comprises receiving the first and second signals (10, 12) and respectively frequency down converting (18,22,26 and 20,24,28) the first and second signals to provide first and second low frequency signals. The first and second low frequency signals are digitised using synchronised ADCs (30,32) to provide respective first and second digitised signals, the wider bandwidth signal being digitised at a higher sampling rate and the lower bandwidth signal being digitised at a lower sampling rate. The sampling rate of one of the first and second digitised signals is adjusted (44) to be the same as the other of the first and second digitised signals.

Abstract: In a multicast transmission system, the transmission of data is acknowledged by each receiving station to indicate whether or not a retransmission is required. For the retransmission, a transmitting station can select between a broadcast mode in which the retransmission is not addressed to a specific recipient, or a dedicated mode in which the retransmission is addressed to a specific recipient. The selection may be based on the number of receiving stations requiring a retransmission.

Abstract: A radio communication system has means for enabling the control channels associated with a data channel transmitting packet data with a low duty cycle to be switched to a dormant state or interrupted entirely. This reduces the excessive overhead that such control channels represent on a data channel only using a small proportion of the available channel capacity.

Abstract: A telecommunications system, such as a cellular telephone system, comprises at least one primary station (12) and a plurality of secondary stations (14) which are able to communicate with each other in accordance with any suitable protocol embedded as software in the respective stations. Software configuration or reconfiguration in the secondary stations is effected over the air using a transmitter other than the primary station(s). Such a transmitter may comprise a broadcast transmitter (16) having spare capacity which can be used for purposes other than broadcasting.

Abstract: A communication system includes first and second terminals which are able to communicate control messages to each other. One of the terminals can reconfigure itself by a process of service negotiations with the other terminal where the capabilities of the reconfigurable terminal are provided to the other terminal. Each of the terminals has a transceiver, a memory for storing software functions, and a processor for controlling the operation of the terminal in accordance with stored software functions. At least one of the software functions is alterable in response to the receipt of a control message containing the new software function plus interface software required by the processor in building a new function into an actual implementation on the terminal. The communication system may be a cordless and/or cellular telephone system where messages are sent over-the-air, or a corded system where messages are relayed by landline.

Abstract: A method of reconfiguring the software interface in software defined radios in which when a transmitting station (PS) sends a reconfiguration software message to a receiving station (SS), the receiving station responds with a message giving an estimated time duration for carrying-out the reconfiguration of its software. The transmitting station listens for the estimated time duration for a message which confirms that the receiving station has been successfully reconfigured and commences normal communications using the new configuration. The estimated time duration may be computed using indicia present in the reconfiguration software message.

Abstract: A radio communication system has means for enabling the control channels associated with a data channel transmitting packet data with a low duty cycle to be switched to a dormant state or interrupted entirely. This reduces the excessive overhead that such control channels represent on a data channel only using a small proportion of the available channel capacity.

Abstract: A radio communication system has means for enabling the control channels associated with a data channel transmitting packet data with a low duty cycle to be switched to a dormant state or interrupted entirely. This reduces the excessive overhead that such control channels represent on a data channel only using a small proportion of the available channel capacity.

Abstract: A method of reconfiguring the software interface in software defined radios in which when a transmitting station (PS) sends a reconfiguration software message to a receiving station (SS), the receiving station responds with a message giving an estimated time duration for carrying-out the reconfiguration of its software. The transmitting station listens for the estimated time duration for a message which confirms that the receiving station has been successfully reconfigured and commences normal communications using the new configuration. The estimated time duration may be computed using indicia present in the reconfiguration software message.

Abstract: The translucency of a material is determined by illuminating the material and detecting the intensity of radiation leaving the material as a function of distance from the radiation source. The resulting measurements may be used to determine a "translucency gradient" for the material. In the case of materials in sheet form or having a defined thickness, the translucency can be measured in transmission mode or back scattering mode to measure "through translucency" or "surface translucency".