Abstract: A time division multiplexed communication bus is disclosed that provides a low latency, low pin count solution for communications among information handling systems. The time division multiplexed serial bus is advantageous in providing communications among modular computing systems, passthrough modules and chassis management controllers, as part of a modular computing system chassis.

Abstract: A radio-over-fiber (RoF) system and method for controlling a transmission time is provided. In a Time Division Duplex (TDD) wireless communication system comprising a Base Station (BS) having a donor and a remote connected thereto via am optical fiber, upstream and downstream Radio Frequency (RF) signals are transmitted and received, and by reliably transmitting a switch control signal to the remote and simultaneously compensating for a transmission time delay occurring in the optical cable, time synchronization of the upstream and downstream RF signals transmitted and received via antennas of the BS and the remote is controlled, thereby efficiently increasing the performance of a TDD wireless service system.

Abstract: A method and system for using half-duplex base stations and half-duplex nodes in a Frequency Division Duplexing region to provide wireless connectivity between the half-duplex base stations and customers in multiple sectors of a cell. The method and system can use two physical channels to form two logical channels. Each logical channel shares both physical channels during alternating frames of time. The half-duplex nodes can include a millimeter-wave band frequency synthesizer configured to transmit and receive on different channels to and from the half-duplex base station. Re-use patterns of the physical channels are used for deployment of half-duplex base stations and half-duplex nodes in the FDD region to minimize co-channel interference and interference due to uncorrelated rain fade. Additional methods and systems utilize full-duplex base stations and smart antenna to communicate with the half-duplex nodes.

Abstract: A digital subscriber line transmission (xDSL) system includes a transmitting side which transmits training symbols by adding some data that is contained in a training symbol sequence onto at least one of the beginning and the end of this symbol sequence and then transmits the training symbol sequence. A receiving side removes the data that has been added onto the training symbol sequence and executes training processing. The length of the training symbol sequence and of a transmit symbol sequence at time of normal communication is set in such a manner that the symbol sequence will not fall within an interval in which effects of near-end crosstalk from a neighboring line are received. The data added to the training symbol sequence specifies an interval in which effects of the crosstalk are received.

Abstract: Some embodiments of the present invention are directed to a method and system for monitoring and recording voice from circuit-switched switches via a packet-switched network. A circuit-switched or VoIP recording system may record and/or live-monitor telephone calls by trunk and/or extension tapping over a packet-switched network Alternatively, a circuit-switched or VoIP recording system may record and/or live-monitor telephone calls over a packet-switched network by activating the service observation feature of the circuit-switched switch either by feature code dialing or a computer telephony integration (CTI) link command.

Abstract: A mobile communication system for wireless communications includes a power adapter configured to receive input power from a power source and to adapt the input power to an output power, the output power being within Universal Serial Bus (USB) standards, a USB cable coupled to the power adapter to transmit the output power from the power adapter, the USB cable including at least one USB connector, and a router configured to be coupled to the USB cable and configured to receive the output power transmitted by the USB cable to power components of the router such that the router can operate using the output power transmitted by the USB cable, the router including at least one antenna and being configured to communicate wirelessly through the at least one antenna with a wireless-enabled communication device.

Abstract: A method for transmitting data between a read/write unit (SLG) and one or more mobile data stores (D, HD) in an identification system. The method includes dividing the data transmission occurring between the read/write unit (SLG) and the data stores (D, HD) into a plurality of timeslots (SLOT), subframes (SUBFRAME) and frames. An identification timeslot (S-CH) from the respective data store (D, HD) is received and evaluated in at least one evaluation timeslot (SOa) and the data store is identified as a mobile high-speed data store (HD) if the identification timeslot (S-CH) is a high-speed identification timeslot (S31,0, S0,31), and an associated data-store identifier block (MB2) is evaluated at least beginning during the subsequent timeslot after the identification timeslot (S-CH) onward. The method provides for very rapid detection of high-speed data stores (HD).

Abstract: A digital subscriber line transmission (xDSL)-, system includes a transmitting side which transmits training symbols by adding some data that is contained in a training symbol sequence onto at least one of the beginning and the end of this symbol sequence and then transmits the training symbol sequence. A receiving side removes the data that has been added onto the training symbol sequence and executes training processing. The length of the training symbol sequence and of a transmit symbol sequence at time of normal communication is set in such a manner that the symbol sequence will not fall within an interval in which effects of near-end crosstalk from a neighboring line are received. The data added to the training symbol sequence specifies an interval in which effects of the crosstalk are received.

Abstract: A communication system for controlling remote devices within a vehicle is provided. The communication system includes a master module for generating a command message, and a remote module for executing the command message and generating a response message. A data bus provides bidirectional communication between the master module and the remote module. The communication system also includes a message frame for communicating data between the master module and the remote module, the message frame includes the command message generated by the master module for execution by the remote module, and the message frame includes the response message generated by the remote module for providing feedback to the master module.

Abstract: Multimode, multi-function, multiple modulator-demodulator (modem) system containing a fingerprint sensor, detection, identification, authentication, and processing device for one or multiple fingerprint information to activate one or multiple modulators for signal transmission and generation of authentication information signals. A location information receiver and a processor device for processing and combining the location information and fingerprint information activated signals with one or more additional user generated signals. Processed, combined signals are provided for filtering and/or spread spectrum encoding and/or cross-correlating and connection to one or more modulators and transmitters.

Abstract: Systems and methods for enabling a mobile user to notify an automated monitoring system of an emergency situation are provided. The automated monitoring system may be configured for monitoring and controlling a plurality of remote devices and may comprise a site controller in communication with the plurality of remote devices via a plurality of transceivers defining a wireless communication network and in communication with a host computer via a wide area network. Briefly described, one such method comprises the steps of: receiving notification that the mobile user desires to initiate transmission of an emergency message to the site controller; determining the identity of the mobile user; and providing an emergency message over the wireless communication network for delivery to the site controller, the emergency message indicating the identity of the mobile user.

Abstract: Performing communications between numerical control apparatus 1a and peripheral devices (composed of at least one of a servo amplifier 2a, a spindle amplifier 3a and a remote I/O unit 4a) by connecting a numerical control apparatus 1a and peripheral devices using a communication cable composed of a pair of data transmission cables 7 for transmission and a pair of data transmission cables 8, in a numerical control system having numerical control apparatus 1a and peripheral devices composed of at least one of a servo amplifier 2a, a spindle amplifier 3a and a remote I/O unit 4a.

Abstract: A system and method for generating a flexible time slot in an internal voice mail system, the system includes: a first counter/time slot playback device operating as a counter in response to a system synchronization signal and outputting at least one time slot (TS) signal; a second counter/time slot playback device operating as a counter in response to the system synchronization signal and outputting at least one time slot (TS_n) signal; a transmit start of transfer (TSX) channel synchronization generator generating a proper TSX channel synchronization signal in response to channel information data transmitted from the voice mail system; and a flexible TSX generator outputting a TSX signal corresponding to a channel synchronization data value selected and transmitted by the TSX channel synchronization generator after synthesizing the signals output from the first counter/time slot playback device and the second counter/time slot playback device and generating at least one synchronized TSX signal.

Abstract: A transceiver for use in a wireless access network comprising a plurality of base stations, each of the plurality of base stations capable of bidirectional time division duplex (TDD) communication with wireless access devices disposed at a plurality of subscriber premises in a corresponding cell site of the wireless access network. The transceiver is associated with a first base station and comprises transmit path circuitry associated with a beam forming network for transmitting directed scanning beam signals in a sector of a cell site of the first base station. The transmit path circuitry transmits at a start of a TDD frame a broadcast beam signal comprising a start of frame field and subsequently transmits downlink data traffic in a downlink portion of the TDD frame to at least one of the wireless access devices using at least one directed scanning beam.

Abstract: Briefly, in accordance with one embodiment of the invention, an apparatus comprises a plurality of RF antennas, the plurality of RF antennas have a calibrated radiation pattern. The apparatus may further comprise a directional finding program that receives RF signal information from said plurality of RF antennas and RF antenna calibrated radiation pattern information and then calculates the direction from which said RF signals emanate relative to said apparatus.

Abstract: A civil moderate (CM) code and a civil long (CL) code are time division multiplex (TDM) as a combined code having alternating code chips that spectrum spread a transmitted signal received by a receiver tracking the spectrum spreading code using a two-level correlator operating with +1 and ?1 values to alternately correlate the received CM and CL code chips using a gating signal to gate by time the correlation of the two codes. The time gated two-level TDM correlation can be used in communication receivers, such as GPS receivers, receiving the TDM spectrum spreading codes.

Abstract: A method and system for the synchronization of the transmission of digitally converted analog modem signals between two or more modems using either RF over-the-air or A/C power line communication channels. This invention provides for modem speed optimization my minimizing or eliminating clock variance between the modems in a digital communication system. A fixed delay is created and maintained during modem operation. This invention is also adapted to function in a full-duplex communication system maintaining a fixed delay in both directions.

Abstract: Providing an audio broadcast for a TDMA system. During a single time slot, an audio message is broadcast from a base art and received at a number of portable arts. An audio broadcast command is generated by designating the single time slot and then transmitted to the plurality of portable parts. An additional portable part transmits a broadcast origination signal and the audio message to the base part which transmits the audio broadcast command to the portable parts. by assigning a time slot other than the designated time slot to a portable part, the portable part does not broadcast audio messages during the designated time slot. More than three receiving time slots and more than three sending time slots are divided out for the base art that includes the designated time slot. The audio broadcast command is transmitted during at least two of the more than three sending time slots.

Abstract: Various gain factors for pilot information are used to determine a corresponding plurality of likely channel performance values for a plurality of data channels (and/or services). The resultant information is used to select a specific gain factor to apply when transmitting the pilot information. In one embodiment, the gain factor that correlates to the highest signal to interference plus noise ratio is used.

Abstract: In hyperframe synchronization processing of a hyperframe including FEXT frames and NEXT frames, each difference between the number of consecutive FEXT frames and the number of consecutive NEXT frames is calculated, and a unique sequence of these differences is detected. When the unique sequence of differences can be detected from a received hyperframe, the position of a frame which is being received now in the hyperframe can be specified at that point in time. Hence, hyperframe synchronization can be established in a short time after frame synchronization is established.

Abstract: There is disclosed a TDD frame transmission synchronization apparatus for use in a fixed wireless access network comprising a plurality of base stations capable of bidirectional time division duplex (TDD) communication with wireless access devices disposed at a plurality of subscriber premises. The TDD frame transmission synchronization apparatus comprises a frame allocation controller for receiving from a first radio frequency (RF) modem shelf associated with a first base station access requests generated by a first group of wireless access devices communicating with the first base station and determining from traffic requirements associated with the access requests a time duration of a longest downlink portion of TDD frames used by a first one of a plurality of RF modems in the RF modem shelf to communicate with a first wireless access device.

Abstract: The present invention relates to a radio inter-face for a cordless small system using the 2.4 GHz ISM band. According to the present invention, a transmission system having a fixed station (1) and at least one mobile station (2, 3) is provided for this purpose, the fixed station (1) and the mobile station (2) each having devices (RF modules 4, 5) in order to transmit the data in time slots using a frequency-division multiplex method (FDMA) and a time-division multiplex method (TDMA), and with time division duplexing (TDD). As is known from DECT Standard, the data are modulated onto a carrier frequency (fx) using a GMSK modulation method. The RF modules (4, 5) in the fixed station (1) and, respectively, the mobile station (2) are in this case designed such that the carrier frequency (fx) is changed after a predetermined time period, which may correspond, for example, to the time duration of a time slot or of a transmission frame. A transmission frame in this case contains 16 time slots.

Abstract: A time division duplex communication system using code division multiple access transmits a plurality of data signals over a shared spectrum in a time slot. A combined signal is received over the shared spectrum in the time slot. The plurality of data signals are grouped into a plurality of groups. The combined signal is matched filtered based on in part symbol responses associated with the data signals of one of the groups. Data from each data signal in the one group is jointly detected. An interference signal is constructed based on in part the one group detected data. The constructed interference signal is subtracted from the combined signal. Data from the other groups is detected by processing the subtracted signal.

Abstract: An arrangement including a terminal for outputting at least a pair of video and acoustic signals, and a display for receiving the signals from the terminal and displaying a corresponding image, utilizes (1) a terminal modem including a multiplexer for time division multiplexing video and acoustic signals, and an input/output driver circuit for outputting the multiplexed signal, and (2) a display modem including an input/output driver circuit for inputting the multiplexed signal output from the terminal, and a demultiplexer for demultiplexing the input multiplexed signal into corresponding video and acoustic signals. The display can be connected to an optional device, and the optional device is also controlled by the terminal.

Abstract: A system and method of data communication uses variable transmit antenna delays based on uplink measurements for the time division duplex (TDD) mode of WCDMA communication. The signals for each channel are delayed at baseband, so different delays can be used for each channel. The delay between each antenna is chosen so that the strongest paths do not overlap in order to implement full transmit antenna diversity. The transmitted signals are detected at a mobile terminal via a joint detector to eliminate noise from other mobile terminals within the cell.

Abstract: The invention concerns a digital radio (2) for pseudo-duplex radio communication, and a method of transmission time mediation for pseudo-duplex radio communication. A digital radio (2) is in time division duplex communication with a second digital radio (4). The digital radio (2) derives a source signal activity parameter (VAD) indicating the likelihood of there being a source signal for transmission by the digital radio (2) to the second digital radio (4) over a single radio channel. The digital radio (2) also derives a first value (VADDir1) of a signal direction parameter (VADDir) in dependence on both the value of the signal activity parameter (VAD) for the digital radio (2) and a second value (VADDir2) of the signal direction parameter (VADDir) received from the second digital radio (4); The digital radio (2) selects the proportions of time for transmission and reception over the single radio channel in dependence on the first value (VADDir1) of the signal direction parameter (VADDir).

Abstract: There is disclosed a radio frequency (RF) modem shelf for use in a fixed wireless access network comprising a plurality of base stations capable of bidirectional time division duplex (TDD) communication with wireless access devices disposed at a plurality of subscriber premises.

Abstract: The connection device connects a telecommunications system to a data processing device which provides telecommunications applications. The telecommunications system and the data processing device in each case have a switching network for through-connecting the relevant telecommunications application. The connection device is a switching device directly connected between the respective switching networks.

Abstract: The present invention integrates resource allocation between time division duplex (TDD) and frequency division duplex (FDD) in wireless communication systems. A radio network controller (RNC) receives a radio access bearer (RAB) request from a core network or a wireless receive/transmit unit. The RNC utilizes a TDD-FDD selector to assign radio resources in response to the request. The TDD-FDD selector evaluates various parameters regarding the received RAB request and determines whether it is preferable to assign TDD resources or FDD resources and whether such resources are currently available. Once resources are assigned, system conditions are evaluated to determine whether optimizations may be made to a current resource allocation.

Abstract: Techniques for transmitting voice/data and packet data services such that packet data transmissions have less impact on voice/data transmissions. In one aspect, voice/data and packet data can be multiplexed within a transmission interval such that the available resources are efficiently utilized. In another aspect, the amount of variation in the total transmit power from a base station is controlled to reduce degradation to transmissions from this and other base stations. In a specific method for concurrently transmitting a number of types of data, a first data type (e.g., voice, overhead, and some data) and a second data type are respectively processed in accordance with first and second signal processing schemes to generate first and second payloads, respectively. First and second partitions are then defined in a transmission interval. The first and second payloads are time multiplexed into the first and second partitions, respectively, and the multiplexed payloads are transmitted.

Abstract: A multi-path transceiver apparatus, method and system for implementation in a bidirectional antenna path by which a transceiver output signal is provided with a path independent from a separate signal path provided for incoming signals. The invention facilitates the amplification of transmitted signals without damaging the received signals and avoids modification to transceiver and bidirectional antenna hardware.

Abstract: The invention provides a method and system for dynamically controlling link parameters during communication between one or more receiver/transmitters. Transmissions are sent as frames from a Base Station Controller to one or more Customer Premises Equipment. Together with a payload, each frame contains a special control message that pre-announces to both the transmitter and receiver the link parameters to be used until changed. The receiving Customer Premises Equipment processes the link parameters and returns a payload of its own within the same frame. With this dynamic approach, link parameters may be changed as often as every frame.

Abstract: Method and apparatus for interference signal code power noise variance estimation employing a reduced number of samples utilizing the equation σ ^ n 2 = T · ∑ i = 1 N sample ⁢ &LeftBracketingBar; h n ⁢ ( i ) &RightBracketingBar; 2 , where T = G · γ ⁢ ( r

Abstract: A time division multiplexed communications method and system in which time is divided into a number of frames and each frame is divided into N data bursts. The method and system further has a first multiplexer by which a half rate channel is formed as a series of bursts that occur periodically every N bursts once per frame, a second multiplexer in which a full rate channel is formed as two half rate channels on consecutive timeslots, and a transmitter transmitting the full rate channel from a first wireless station to a second wireless station. The full rate channel provided by two half rate channels on consecutive timeslots yields a significantly larger resource pool available for assignment of communication traffic. For full rate channels, the interleaving 0246/1357 method that is used by the system is just as good as the known 0123/4567 method when ideal frequency hopping is used, and the 0246/1357 method performs better when non-ideal frequency hopping or no frequency hopping is used.

Abstract: A method for determining uplink power requirements for a transceiver in a wireless communication system includes obtaining measurements from a beacon signal occupying a first timeslot in a frame; obtaining measurements from at least one additional channel having a known transmitted signal strength and occupying a second timeslot in the frame; and utilizing the measurements to determine a path loss estimate.

Abstract: The eavesdropping prevention system and method of the present invention provides a controllable line selection unit which couples a receiver and a transmitter to a selected one of a plurality of subscriber loops according to the current channel of a time-multiplexed communication signal. The controllable line selection unit prevents meaningful detection and amplification of the leakage signal by physically isolating communication connections from each other. In the preferred embodiment, the controllable line selection unit actuates a plurality of switches coupled to a plurality of communication connections. Alternative embodiments of a controllable line selection unit are described.

Abstract: The present invention relates generally to a cellular telecommunications network. Each cell has at least one base station for sending messages on a downlink of a Frequency Division Duplex (FDD) to end user equipments within the cell and for receiving messages on an uplink from end user equipments within the cell. Other end user equipment located within the cell which have no or only poor communication directly with the base station over the FDD communicate with the base station indirectly via an intermediate end user equipment, such as a mobile telephone. The intermediate end user equipment includes an FDD transceiver and a Time Division Duplex (TDD) transceiver and an FDD/TDD interface.

Abstract: In an array antenna used in a transceiver in a time division communication system such as TDD (Time Division Duplex) system, amplitude and phase of each antenna element are calibrated in a transceiver itself during actual communication without using external information. A first transmitter (1-3-1) has means (1-5-1) to send a transmit signal to an antenna element (1-1-1) as well as to at least one of the receivers (1-4-1 through 1-4-N). Other transmitter (1-3-2 through 1-3-k) except the first transmitter has means (1-5-k) which sends a transmit signal to a related antenna element (1-1-2 through 1-1-k) as well as to a first receiver (1-4-1) which relates to the first transmitter. Amplitude/phase value obtained in the first receiver (1-4-1) and amplitude/phase values obtained in other receivers (1-4-2 through 1-4-k) except the first receiver provide weighted amplitude/phase values of each antenna elements according to desired desired radiation pattern.

Abstract: A multi-logical access for a serial data link designed with a multi-logical serial interface protocol which permits multi-drop applications to communicate in a time division multiplex mode over a singular drop or physical serial link such as an RS-232 link. Data is exchanged over the serial data link between multiple applications on a transmitter side of the serial data link and multiple applications on a receiver side of the serial data link. Both the transmitter and the receiver have a link layer connected to the serial data link for handling the transmission/receiving of packets through the serial data link, for detecting the start/end of each packet, and to ensure the sequence of the packets. Both the transmitter and the receiver also have a relay layer connected between the multiple applications and the link layer, which operates to allow the different access functions to share the serial data link.

Abstract: The invention concerns a digital radio (2) for pseudo-duplex radio communication, and a method of transmission time mediation for pseudo-duplex radio communication. A digital radio (2) is in time division duplex communication with a second digital radio (4) over a single radio channel. Control of the radio channel may reside with either radio. However, authority for a radio to change the frame format in order to increase the proportion of time for which it transmits always resides entirely with the radio currently transmitting the least per frame. This arrangement allows rapid response to a need for a radio to move from listening to speaking mode, thereby reducing speech clipping. When the digital radio (2) and the second digital radio (4) are transmitting for equal proportions of the frame, authority to change the frame format passes to the radio that is transmitting at that instant.

Abstract: A system and method for communication monitoring in a mobile radio network uses a distributed system having one or more processing devices coupled to different links of a serving switching entity of the mobile radio network. The processing devices extract current deciphering parameters from data on the different links, including an additional deciphering parameter set obtained from a subscriber data base entity, from the data flow of the connection, and from each packet data unit as the sequence number of data packets (PDUs) making up the data. The current deciphering parameters are stored in a deciphering parameter providing device so they are available for other processing devices upon request, the deciphering parameter providing device being coupled to the processing device(s) by a communication link such as a LAN or WAN.

Abstract: The present invention relates to air-link protocols which optimally permit wireless communication in a point-to-multipoint communication system. The protocols include establishment of an adaptive time division duplex channel, dynamic allocation of bandwidth, provision of multiple modulation schemes within the TDD operation, and bandwidth allocation.

Abstract: An orthogonal data link is provided by a first digital device, a second digital device, and a bus coupling the first digital device to the second digital device. The first digital device has a first transmitter that encodes data of the first device with a first code (e.g., [1,1]), for transmission on the bus. The second device has a second transmitter that encodes data of the second device with a second code (e.g., [0,1] or [1,0]), for transmission on the bus. The first device has a first receiver that renders the second data by (a) multiplying signals of the bus with the second code and (b) integrating over a periodicity of the codes. The second device has a second receiver that renders the first data by (a) multiplying signals of the bus with the first code and (b) integrating over a periodicity of the codes.

Abstract: A system and method for controlling information transmission and communication handoff between frequency division multiplexing (FDD) and time division multiplexing (TDD) communication systems using any multiple access scheme is provided. The mobile unit transmits information via a current one of the FDD and TDD communication systems while it moves toward the other, or targeted one of the FDD and TDD communication systems. A pilot search signal is generated by the targeted communication system, where the pilot search signal corresponds to a transmission range of the targeted communication system. A communication handoff is initiated from the current communication system to the targeted communication system when the mobile unit recognizes a predetermined threshold level of the pilot search signal. Concurrent communications are synchronized and temporarily maintained between the mobile unit and both the current and targeted communications systems using an increased data rate for each of the communications links.

Abstract: A synchronous digital communications network incorporating a number of nodes arranged in path protected rings and has two or more timing reference sources. The reference sources each allocated an artificial ranking of unique quality level values and these quality level values are transmitted as a section overhead message to provide a unique identifier for each source. Identification of the source to a node enables that node to be aware of a synchronization signal that has in fact originated from that node so as to prevent the setting up of synchronization loops. In a further embodiment the technique is extended to protection path identification for signals coupled between adjacent rings in a network having ring topology.

Abstract: A system (and method) for linking wireless and land line communications media, includes a connector for connecting a communications media, and an indicator for alerting a user of the state of a connection. The connector automatically initiates a continuous reestablishment operation after the indicator announces a state of disconnection and in which the system provides a conferencing capability using the Internet. A handset to be used in voice communications includes a housing including a receiver and transmitter for connecting to a computer network, a plurality of wireless protocols for use with the transmitter, and a universal telephone port coupled to the housing for connecting to a universal telephone jack.

Abstract: Provided is a method of packet transmission capable of efficiently utilizing ACL link resources in transmitting and receiving packets after an ACL link is established in Bluetooth. A Bluetooth device A determines the maximum rate for packet size to be transmitted to a Bluetooth device B established in the link based on the ratio between a token rate A requested by the device A and a token rate B requested by the device B. When the token rate A is greater than the token rate B, the maximum rate N is set from the candidates of current time slot numbers occupiable as an ACL packet. When the token rate A is smaller than the token rate B, a rate is selected from the candidates of current time slot numbers occupiable as the ACL packet based on rate U=N×token rate A/token rate B.

Abstract: A method and arrangement for automatic frequency correction in UTRA TDD mode, having a first stage (500) for frequency lock in idle mode, and a second stage (600) for receiving a channel estimate from beacon function (mx1), receiving a channel estimate from at least one other physical channel (mx2), and receiving output from a primary synchronisation code correlator (mx0, pc1, pc2), and for producing therefrom signals (X,Y,N) for use in frequency correction. By utilising first and second partial correlation values (pc1, pc2) which are balanced, DC offset effects may be substantially removed. This provides the following advantage of significantly improving performance at low levels of SNR, and removal of DC offset effects provides immunity to DC offsets arising from imperfections in hardware.

Abstract: A satellite-based communications system (20) includes a communication satellite (22) using a Time Division Duplex (TDD) frame structure. The communication satellite (22) transmits first data (63) during a first sub-frame (150) and receives second data (65) during a second sub-frame (152) of a time division multiple access (TDMA) frame (144). A terrestrial repeater (30) receives the first data (63) using a first link (36) during the first sub-frame (150), delays the first data (63) by a sub-frame duration, and transmits the first data (63) to a subscriber unit (32) using a second link (42). The terrestrial repeater (30) receives the second data (65) from the subscriber unit (32) using the second link (42), delays the second data (65) by the sub-frame duration, and transmits the second data (65) using the first link (36) to the satellite (22) during the second sub-frame (152).

Abstract: The present invention relates to a header structure for a TDD system which uses preferably an OFDM transmission system. Thereby a header slot according to the present invention fits entirely into one time slot of the GSM TDD structure. The header slot HS comprises a downlink channel DC and an uplink channel UC. The downlink channel DC comprises a synchronization channel SYNCH, a general broadcast channel GBCCH as well as an optional broadcast channel OBCCH. The uplink channel comprises a random access channel RACH. Both the synchronization channel SYNCH and the general broadcast channel GBCCH can comprise two identical repeated symbols S1, S2. The repetition of the identical symbols S1, S2 provides for a very efficient (secure) data transmission and a high-efficient correlation in view of a frequency and time synchronization due to the large number of samples in the symbols of the synchronization channel SYNCH and the general broadcast channel GBCCH.