Abstract: Methods and apparatuses are presented for communicating using a shared communication medium. A request is sent in a request signal space where the request represents a code sequence that is a member of a set of code sequences. Each member is characterized by an autocorrelation function that has a peak centered at zero time offset. Each member is further characterized by a cross correlation function. The cross correlation function has a low correlation window having a width and surrounding a zero time offset. An assignment is received that assigns the request to a transmission opportunity in a scheduled transmission signal space. The assignment is made in response to detecting the code sequence from receiving multiple requests having relative timing offsets less than the width of the low correlation window. A data transmission is sent using the assigned transmission opportunity in the scheduled transmission signal space.

Abstract: Methods and apparatuses are presented for conducting communications over a shared communication medium, involving (a) sending a request from a first node, the shared communication medium organized to include (i) a request signal space including a plurality of request segments each having a different location within the request signal space and (ii) a scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request segment, (b) obtaining an assignment associating the request with a scheduled transmission segment, the assignment taking into account location of the request within the request signal space, (c) from the first node, sending a current data transmission in the scheduled transmission segment associated with the request, and (d) wherein a portion of the current data transmission includes a piggyback request from the first node for a subsequent data transmission.

Abstract: Methods and apparatuses are presented for conducting communications over a shared communication medium, involving (a) sending an initial request from a first node, the shared communication medium organized to include (i) a request signal space including a plurality of request segments each having a different location within the request signal space and (ii) a scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the initial request sent in an initial request segment, (b) obtaining a request assignment associating the initial request with at least one follow-up request segment, (c) from the first node, sending a follow-up request in the at least one follow-up request segment, (d) obtaining a scheduled transmission assignment specifying a scheduled transmission segment, and (e) from the first node, sending a data transmission in the scheduled transmission segment.

Abstract: Methods and apparatuses are presented for conducting communications over a shared communication medium involving (a) sending a request from a first node, the shared communication medium organized to include a request signal space and a scheduled transmission signal space, the request signal space including a plurality of request segments each having a different location within the request signal space, the scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request segment, (b) obtaining an assignment associating the request with a scheduled transmission segment, and (c) from the first node, sending a data transmission in the scheduled transmission segment associated with the request in accordance with the assignment.

Abstract: Methods and apparatuses are presented for conducting communications over a shared communication medium, involving (a) sending a request from a first node, the shared communication medium organized to include (i) a request signal space including a plurality of request segments each having a different location within the request signal space and (ii) a scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request segment, (b) if no assignment is received from a second node in response to the request, retransmitting the request from the first node, and (c) if an assignment is received from the second node in response to the request, associating the request with a scheduled transmission segment selected from the plurality of scheduled transmission segments, sending a data transmission from the first node in the scheduled transmission segment associated with the request.

Abstract: Methods and apparatuses are presented for conducting communications over a shared communication medium involving (a) sending a request from a first node, the shared communication medium organized to include (i) a request signal space including a plurality of request segments each having a different location within the request signal space and (ii) a scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request segment, (b) obtaining an assignment associating the request with a scheduled transmission segment, (c) from the first node, sending a data transmission in the scheduled transmission segment associated with the request, and (d) wherein a collection of request segments in the plurality of request segments is separated by a guard zone from an adjacent collection of scheduled transmission segments in the plurality of scheduled transmission segments.

Abstract: Methods and apparatuses are presented for conducting communications over a shared communication medium, involving (a) sending a request from a first node, the shared communication medium organized to include (i) a request signal space including a plurality of request segments each having a different location within the request signal space and (ii) a scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request segment, (b) obtaining an assignment associating the request with a scheduled transmission segment, the assignment taking into account location of the request, (c) from the first node, sending a data transmission in the scheduled transmission segment associated with the request, and (d) wherein the assignment is made remotely at a second node in response to the request as received at the second node, and a corresponding assignment message is communicated to the f

Abstract: Methods and apparatuses are presented for conducting communications over a shared communication medium involving a plurality of nodes, involving (a) sending a request from a first node, the shared communication medium organized to include a request signal space and a scheduled transmission signal space, the request signal space utilizing a plurality of request code words each corresponding to a different location within the request signal space, the scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent using a request code word that is one of the plurality of request code words, (b) obtaining an assignment associating the request with a scheduled transmission segment, the assignment taking into account location of the request within the request signal space, and (c) from the first node, sending a data transmission in the scheduled transmission segment associated with the req

Abstract: Methods and apparatuses are presented for conducting communications over a shared communication medium involving a plurality of nodes, involving (a) sending a request from a first node, the shared communication medium organized to include a request signal space and a scheduled transmission signal space, the request signal space including a plurality of request time slots each having a different location within the request signal space, the scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request time slot that is one of the plurality of request time slots, (b) obtaining an assignment associating the request with a scheduled transmission segment, the assignment taking into account location of the request within the request signal space, and (c) from the first node, sending a data transmission in the scheduled transmission segment associated with the request.

Abstract: Methods and apparatuses are presented for conducting communications over a shared communication medium involving a plurality of nodes, involving (a) sending a request from a first node, the shared communication medium organized to include a request signal space and a scheduled transmission signal space, the request signal space including request segments each having a different location within the request signal space, the scheduled transmission signal space including scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request segment, (b) obtaining an assignment associating the request with a scheduled transmission segment, taking into account location of the request within the request signal space, (c) from the first node, sending a data transmission in the scheduled transmission segment associated with the request, and (d) wherein the plurality of scheduled transmission segments include multiple categories of scheduled trans

Abstract: Methods and apparatuses are presented for conducting communications over a shared communication medium involving (a) sending a request from a first node, the shared communication medium organized to include (i) a request signal space including a plurality of request segments each having a different location within the request signal space and (ii) a scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request segment, (b) obtaining an assignment associating the request with a scheduled transmission segment, the assignment taking into account location of the request within the request signal space, and (c) from the first node, sending a data transmission in the scheduled transmission segment associated with the request in accordance with the assignment.

Abstract: Methods and apparatuses are presented for conducting communications over a shared communication medium involving a plurality of nodes, involving (a) sending a request from a first node, the shared communication medium organized to include a request signal space and a scheduled transmission signal space, the request signal space including a plurality of request segments each having a different location within the request signal space, the scheduled transmission signal space including a plurality of scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request segment, (b) wherein the request segment is randomly selected by the first node, (c) obtaining an assignment associating the request with a scheduled transmission segment, the assignment taking into account location of the request within the request signal space, and (d) from the first node, sending a data transmission in the scheduled transmission segment associated with the

Abstract: Methods and apparatuses are presented for conducting communications over a shared communication medium, involving (a) sending a request from a first node, the shared communication medium organized to include (i) a request signal space including request segments each having a different location within the request signal space and (ii) a scheduled transmission signal space including scheduled transmission segments each having a different location within the scheduled transmission signal space, the request sent in a request segment, (b) obtaining an assignment, in a first tier of assignments, associating the request with a scheduled transmission segment, (c) from the first node, sending a data transmission in the scheduled transmission segment associated with the request, and (d) the plurality of scheduled transmission segments including at least one default use segment available for use by a default entity if the at least one default use segment is not assigned in the first tier of assignments.

Abstract: A communication system comprising three communication resources: a contention-type access block, a non-contention access block and a second non-contention access block called a reserved block. Each time that a remote unit has a block of data to transfer to a hub station, it sends the block of data over the contention-type access block. It also sends a corresponding notification message over the reserved block. If the hub station receives the notification message but not the block of data, it sends a response message to the remote unit which designates a resource within the non-contention access block. The remote unit then sends the block of data to the hub station over the designated resource.

Abstract: Self-interference cancellation in two-way relayed communications is improved by creating models of upconverter and downconverter imperfections and then compensating for those imperfections before self interference cancellation processing. The model includes compensation for phase offset, for amplitude imbalance and for leakage in the mixers.

Abstract: A communication system comprising three communication resources: a contention-type access block, a non-contention access block and a second non-contention access block called a reserved block. Each time that a remote unit has a block of data to transfer to a hub station, it sends the block of data over the contention-type access block. It also sends a corresponding notification message over the reserved block. If the hub station receives the notification message but not the block of data, it sends a response message to the remote unit which designates a resource within the non-contention access block. The remote unit then sends the block of data to the hub station over the designated resource.

Abstract: A method and apparatus related to a communication system in which a plurality of remote units encode data bursts using a predetermined codeword set and transmit the encoded data bursts to a hub station over a multiple-access channel. When the hub station receives a data burst from one of the remote units, the hub station demodulates the received data burst and correlates the received data burst with each codeword within the predetermined codeword set to determine which codeword has the maximum correlation. The hub station uses the correlation to derive a timing synchronization signal and/or a carrier frequency adjustment signal to be sent back to the remote unit. The signals provide information to the remote unit to synchronize its timing or adjust its carrier frequency for transmitting subsequent data bursts. The hub station may also use the correlation to estimate a signal-to-noise ratio.

Abstract: When an installed wireless remote unit is operating in the field, routine operation is interrupted to enter a calibration mode. In calibration mode, the compression point of a circuit element is determined by applying a series of different drive levels to the circuit element. Based upon the determination of the compression point, a maximum transmission point is selected for the remote unit. Upon resumption of normal operation, the remote unit uses the maximum transmission point to limit the signal power level transmitted over the wireless link. As time passes or operating conditions change, the calibration process is re-executed.

Abstract: When an installed wireless remote unit is operating in the field, routine operation is interrupted to enter a calibration mode. In calibration mode, the compression point of a circuit element is determined by applying a series of different drive levels to the circuit element. Based upon the determination of the compression point, a maximum transmission point is selected for the remote unit. Upon resumption of normal operation, the remote unit uses the maximum transmission point to limit the signal power level transmitted over the wireless link. As time passes or operating conditions change, the calibration process is re-executed.

Abstract: A method and apparatus for digitally demodulating QPSK signals includes a first portion in which the digitally sampled data burst is resampled with a plurality of predetermined timing hypotheses. The timing offset is determined according to an analysis of the resampled data. The digitally sampled data burst is then resampled according to the timing estimation. Modulation of the resampled data burst is then removed by twice squaring the complex I/Q pairs. The data with the modulation removed is then subjected to a Chirp-Z Transform to move the data into the frequency domain. The highest spectral power is used to determine the frequency offset. The phase offset is determined and the resampled data burst is derotated and dephased according to the phase offset and the frequency offset.