Abstract: The present invention relates to a method for requesting access to a resource, said method comprising a secondary station transmitting an access preamble to a primary station, upon failure of correct transmission of the access preamble, the secondary station starting a first power ramping scheme for transmitting the access preamble, upon failure of correct transmission of the access preamble with the first power ramping scheme, the secondary station transmitting a second access preamble with a second power ramping scheme being different from the first power ramping scheme.

Abstract: A communication system includes a downlink indicator channel for the transmission of an indicator signal indicating that a data packet is scheduled to be transmitted on a downlink data channel from a primary station to a secondary station. In response to detection of the indicator signal, the secondary station transmits a status signal, for example a negative acknowledgement signal, on an uplink channel to the primary station immediately before transmission of a positive or negative acknowledgement signal to indicate the status of the received data packet. By providing the primary station with two chances to detect the case where the secondary station fails to detect the indicator signal, peak power requirements of the uplink channel can be reduced, thereby reducing system interference levels.

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 packets of 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 channels it wishes to access. If that channel is busy access is denied, even if other suitable channels are available. In the present system the primary station transmits a random access channel availability (AV) message (302) once per frame to inform secondary stations about the resources currently available. Hence a secondary station can select a channel known to be free. If no channels are available the secondary station can avoid a wasted access attempt.

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 packets of 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 channels it wishes to access. If that channel is busy access is denied, even if other suitable channels are available. In the present system the primary station transmits a random access channel availability (AV) message (302) once per frame to inform secondary stations about the resources currently available. Hence a secondary station can select a channel known to be free. If no channels are available the secondary station can avoid a wasted access attempt.

Abstract: A receiver (13) of user equipment, UE, (10) of a Universal Mobile Telecommunications System, UMTS, network receives a digitally encoded radio signal over a downlink (11) from a base station (12). A Digital Signal Processor, DSP, (14) of the UE (10) estimates BER of data bits of power control commands received in the signal during an out of synchronisation procedure. More specifically, the DSP (14) samples the amplitude with which the data bits are received and determines a ratio of functions of one or more moments of the sampled amplitudes. The DSP (14) then compares the determined ratio to one or more values of BER for different ratios in a look-up table to estimate BER.

Abstract: A communication system employs discontinuous transmission to create gaps in transmission during which a transmitting device (200) can receive. When the transmission of a data block coincides with a transmission gap such that a portion of the data block is not transmitted, the block is retransmitted later. Prior to the retransmission, the data in the data block is reordered. The reordering may be predetermined, or may be selected to ensure that the same portion of data does not coincide with a transmission gap in the retransmission.

Abstract: A system and method of operating a radio communication system uses a random access channel to enable a secondary station to transmit a message to a primary station. The secondary station transmits a preamble to the primary station. After successful receipt of the preamble the primary station transmits a control channel including power control information to instruct the secondary station to adjust the output power of its transmitter. This ensures that the secondary station transmits at a sufficient power for the message to be received successfully by the primary station, while minimizing interference generated by the transmission.

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 packets of data (214) to transmit to a primary station while not actually engaged in a call. The primary station transmits a random access channel availability (AV) message (302) once per frame to inform secondary stations about the resources currently available. Hence a secondary station can select a channel known to be free. If no channels are available the secondary station can avoid a wasted access attempt.

Abstract: A radio station (100), transmits a continuous control signal and a discontinuous data signal simultaneously. It receives UP and DOWN power control commands and adjusts its transmit power by ? in response to the UP power control commands, increasing its transmit power by a power step, ? in response to the DOWN power control commands, decreasing its transmit power by a power step, ? in response to initiating transmission of the data signal, increasing the transmit power of the control signal, and ? in response to terminating transmission of the data signal, decreasing the transmit power of the control signal; In response to initiating or terminating transmission of the data signal, the radio station (100) temporarily modifies its response to the power control commands.

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 method of operating a packet data multicast communication system which comprises a network or NodeB (BS) and a plurality of mobile stations (MS1, MS2, MS3). The network and the mobile stations have transceiving equipment (14, 34) for the transmission of data packets on a downlink between the network and mobile stations, and feedback signalling (ACK/NACK) on an uplink. The mobile stations have means for receiving a data packet transmitted by the first station, means (46) for measuring the quality of reception, means (30, 48) for determining into which one of at least three predetermined quality ranges the measured quality falls. Each of the at least three predetermined quality ranges represents a respective transmitter behavior of the first station and the transmitter behavior corresponding to at least two non-contiguous ones of the quality ranges is identical.

Abstract: When a radio station terminates a first service on a first radio frequency channel and selects a second radio frequency channel for engaging in a second service, a time delay is inserted after the termination of the first service and before selecting the second radio frequency channel or before engaging in the second service. The time delay is dependent on the state of the radio station and/or a characteristic of the second service.

Abstract: A method of operating a radio network, such as UMTS or cdma2000, which comprises at least one primary station (PS), i.e. and access point or bare station, and a plurality of secondary stations (SSI, SS2, SS3), i.e. mobile stations. The primary station determines the level of interest of the users of the secondary stations in a particular service, such as Multimedia Broadcasting and Multicast Services (MBMS), by allocating a respective plurality of access slots in which the secondary stations can transmit an indication of its interest. The primary station receives the indications of interest to and estimates the level of interest from the number of transmitted indications, for example whether or not they exceed a threshold value. Depending on the result of the estimation process the primary station selects a particular one of at least two transmission modes for transmitting the service.

Abstract: In a communication system subject to variations in channel quality, transmit power control is used to reduce the variations in received signal quality. If the channel quality degrades to such an extent that a high transmit power would be required to ensure good received signal quality, the transmit power is decreased and is not increased until the channel quality recovers sufficiently to enable an acceptable transmit power level to be used. While the power is at the decreased level, transmission of a data block may continue, or may be suspended, with the data block being truncated if the whole block has not been transmitted by the end of the time period available for transmission of the data block.

Abstract: A first radio station (100) monitors, either continuously or intermittently, a channel for an indication of a transmitted data packet and measures the quality of the channel. The first radio station (100) transmits indications of the measured quality and when the measured quality falls below a quality threshold, it reduces the proportion of time spent monitoring the channel by introducing or increasing time periods when no monitoring takes place, and subsequently increases the time spent monitoring when the quality recovers. A second radio station (200) transmits data packets to the first radio station (100) and receives the indications of measured channel quality. When the measured quality falls below the quality threshold, the second station reduces the proportion of time spent transmitting the data packets to the first radio station (100) by introducing or increasing time periods between transmitted the data packets.

Abstract: A secondary station has a receiver capable of resolving signals received as a plurality of multipath signals from a plurality of base stations during a soft handover process. This capability may, for example, be provided by a Rake receiver. In order to decode and act upon the received signals in a very short period of time, signals arriving after a predetermined time are not processed by the receiver which is able instead to process weaker signals which arrived before the time. Such a secondary station is particularly suitable for decoding and acting upon power control commands included in received signals in a UMTS system, for which a very limited period of time is provided by the UMTS specification. The predetermined time may be the time after which signals are received too late for use in determining the next power control change.

Abstract: When a radio station terminates a first service on a first radio frequency channel and selects a second radio frequency channel for engaging in a second service, a time delay is inserted after the termination of the first service and before selecting the second radio frequency channel or before engaging in the second service. The time delay is dependent on the state of the radio station and/or a characteristic of the second service.

Abstract: A radio communication system has a plurality of transmission formats available for the transmission of data signals by a sending station, and a pilot signal is transmitted to enable channel estimation by the receiving station. A receiving station transmits a control signal indicating the transmission formats that the sending station may use for transmitting the data signals. The sending station selects one of the indicated transmission formats for transmitting a data signal and derives a transmission power level for the pilot signal from the control signal. The transmission power level of the pilot signal may be independent of the selected transmission format, or may depend on selected transmission format.

Abstract: A system (50) for communicating data packets from a first station (100) to a destination (400) via at least one of a plurality of second stations (200) which are coupled to the destination (400), in which the second stations (200) acknowledge receipt of the data packets. The first station (100) decides whether to retransmit a data packet or to proceed with transmitting the next data packet, the decision being dependent on receiving a plurality of positive acknowledgements or a plurality of negative acknowledgements.

Abstract: A method of operating a communication station including queuing data units, estimating the transmission delay of at least one of the data units in the queue, and if the estimated transmission delay exceeds a threshold, requesting permission to transmit at least one data unit.