Abstract: For an example embodiment, a method for a communication device operating in a synchronous communication system is described. The method includes performing a listen-before-talk (LBT) procedure prior to the start of a downlink subframe of a synchronous frame and determining if a transmission from another communication device of another communication system is detected during the LBT procedure. In the case that a transmission is detected during the LBT procedure, the communication device refrains from transmitting during the downlink subframe. In the case that a transmission is not detected during the LBT procedure, the communication device transmits during the downlink subframe.

Abstract: An error management system and process can be used to identify an erroneous data packet in a data stream. In response to identifying the erroneous data packet, a subsequent valid data packet is located in the data stream. In one embodiment, a plurality of candidate locations of header checksum windows are searched and checked for a valid checksum. Multiple integrity checks of multiple header checksums can be used to reduce the probability of a false positive integrity check. In another embodiment, one or more information data fields can used for determining packet integrity by determining if the fields contain valid information bits.

Abstract: Apparatus, system and method for synchronizing one or more clocks across a communication link. A slave clock may be synchronized to a master clock by means of a synchronization signal sent from the master to the slave clock side of the link. The synchronization signal may be an expected signal pattern sent at intervals expected by the slave side. The slave clock may correlate received signals with a representation of the expected synchronization signal to produce a correlation sample sequence at a first sample rate which is related as n times the slave clock rate. The synchronization signal receipt time indicated by the correlation sample sequence may be refined by interpolating the correlation sample sequence around a best correlation sample to locate a best interpolation at an interpolation resolution smaller than the sample resolution. The best interpolation may in turn be further refined by estimating between interpolator outputs adjacent to the best interpolation output.

Abstract: A base station can communicate resource allocation to a wireless mobile station in an uplink map information element. The base station can identify destination mobile stations using a shorthand connection identifier. The base station parses the connection identifier field into a shorthand connection identifier field and an embedded subfield data field. The shorthand connection identifier field can be sized to support a predetermined number of mobile stations. The base station can further parse the embedded subfield field into a number of sub-fields, each communicating a different set of control information. In one embodiment, the base station utilizes the embedded subfield to communicate power, timing, and frequency information to the destination mobile station.

Abstract: An apparatus, system and method for converting data in a first packet format, having overhead data in the form of headers and/or trailer padding, into a second, variable-length packet format, in which some of the header and/or trailer overhead is removed during conversion in order to more efficiently utilize the limited bit rate capacity of a link which will convey the data in the second format. Embodiments include a communication subnetwork for interconnecting a plurality of users to a wide area network through a wireless link, an Asynchronous Transfer Mode (ATM) switch for converting ATM cells into a variable-length packet format, and a convergence system for converting ATM cells into data packets in Media Access Control (MAC) format.

Abstract: An error management system and process can be used to identify an erroneous data packet in a data stream. In response to identifying the erroneous data packet, a subsequent valid data packet is located in the data stream. In one embodiment, a plurality of candidate locations of header checksum windows are searched and checked for a valid checksum. Multiple integrity checks of multiple header checksums can be used to reduce the probability of a false positive integrity check. In another embodiment, one or more information data fields can used for determining packet integrity by determining if the fields contain valid information bits.

Abstract: A slave clock may be synchronized to a master clock by means of a synchronization signal sent from the master to the slave clock side of the link. The synchronization signal may be an expected signal pattern sent at intervals expected by the slave side. The slave clock may correlate received signals with a representation of the expected synchronization signal to produce a correlation sample sequence at a first sample rate which is related as n times the slave clock rate. A best interpolation may in turn be further refined by estimating between interpolator outputs adjacent to the best interpolation output. The synchronization signal receipt time thus determined is compared to the expected time based upon the slave clock, which is adjusted until the times match. The best interpolation may in turn be further refined by estimating between interpolator outputs adjacent to the best interpolation output.

Abstract: A self-correcting bandwidth request/grant protocol in a broadband wireless communication system. The protocol uses a combination of incremental and aggregate bandwidth requests. Stations primarily transmit incremental bandwidth requests to their associated base stations, followed by periodic transmissions of aggregate bandwidth requests. Risks are reduced that a base station erroneously issues duplicate bandwidth allocations to the same station for the same connection. Race conditions that may have occurred using only aggregate bandwidth requests are eliminated. Use of periodic aggregate bandwidth requests that express the current state of respective connection queues provides a “self-correcting” property.

Abstract: The subject matter disclosed herein provides methods and apparatus for closed loop operation of a wireless system implementing multiple input multiple output (MIMO). In one aspect, there is provided a method. The method may include receiving a payload including channel estimation information. Moreover, one or more bits of the payload may be inserted into a subset of the tiles of a slot. The slot including the subset of the tiles carrying the one or more bits of the payload may be provided as part of a closed loop MIMO-based system. Related systems, apparatus, methods, and/or articles are also described.

Abstract: In a system utilizing double wide communication channels, if a particular CPE requires a sustained rate that is greater than the bandwidth of a single channel, data to and from the CPE may be split across Channels A and B. Also, when the bandwidth requirements of a particular CPE peaks at a data rate greater than the capacity of a single channel, the CPE's data may be split across the two channels. In one embodiment, a single-wide CPE may communicate with the base station without knowing that it is communicating with a base station configured to communicate using a double wide channel.

Abstract: In a system in which both the media access layer and the physical layer use error control, information from the physical layer error control process is used to provide surrogate media access layer error control messaging. In one aspect, the physical layer error control state machine in the transmitting station sends the surrogate message internally to the media access layer error control state machine based on physical layer error control results, thereby eliminating a need to transmit the error control messaging from the media access layer error control state machine of the receiving station over the wireless link.

Abstract: Apparatus, system and method for synchronizing one or more clocks across a communication link. A slave clock may be synchronized to a master clock by means of a synchronization signal sent from the master to the slave clock side of the link. The synchronization signal may be an expected signal pattern sent at intervals expected by the slave side. The slave clock may correlate received signals with a representation of the expected synchronization signal to produce a correlation sample sequence at a first sample rate which is related as n times the slave clock rate. The synchronization signal receipt time indicated by the correlation sample sequence may be refined by interpolating the correlation sample sequence around a best correlation sample to locate a best interpolation at an interpolation resolution smaller than the sample resolution. The best interpolation may in turn be further refined by estimating between interpolator outputs adjacent to the best interpolation output.

Abstract: A method and system for prioritizing connection data that is associated with different classes of service for transmission in a frame based communication system. These classes of service can include CBR, nrt-VBR, MGR, and UBR traffic. One embodiment of the scheduling method and system uses hierarchical round-robin (HRR) with deficit round-robin (DRR). In this embodiment, the scheduling method and system guarantees minimum rates of nrt-VBR and MGR traffic to the connections. The excess bandwidth is then fairly allocated between the existing connections and their classes of service. For example, the excess is allocated for UBR traffic and for the excess demands of the nrt-VBR and MGR connections. In one embodiment, the scheduling method and system allocates the excess bandwidth in a frame to the existing connections using weighted round robin to differentiate between different classes of service.

Abstract: The subject matter disclosed herein provides methods and apparatus, including computer program products, for selecting a modulation and coding scheme. In one aspect, there is provided a method. The method may receive information representative of a first normalized channel characteristic power associated with a downlink and receiving information representative of a second normalized channel characteristic power associated with an uplink. A predicted normalized channel characteristic power of the uplink may be determined based on the first normalized channel characteristic power and the second normalized channel characteristic power. Related systems, apparatus, methods, and/or articles are also described.

Abstract: A self-correcting bandwidth request/grant protocol in a broadband wireless communication system. The protocol uses a combination of incremental and aggregate bandwidth requests. stations primarily transmit incremental bandwidth requests to their associated base stations, followed by periodic transmissions of aggregate bandwidth requests. Risks are reduced that a base station erroneously issues duplicate bandwidth allocations to the same station for the same connection are re. Race conditions that may have occurred using only aggregate bandwidth requests are eliminated. Use of periodic aggregate bandwidth requests that express the current state of respective connection queues provides a “self-correcting.” property.

Abstract: A method and apparatus for allocating bandwidth in a broadband wireless communication system is disclosed. One embodiment uses a self-correcting bandwidth request/grant protocol. The self-correcting bandwidth request/grant protocol utilizes a combination of incremental and aggregate bandwidth requests. CPEs primarily transmit incremental bandwidth requests to their associated base stations, followed by periodic transmissions of aggregate bandwidth requests. The use of periodic aggregate bandwidth requests (that express the current state of their respective connection queues) allows the bandwidth allocation method and apparatus to be “self-correcting”. Another embodiment utilizes an abridged bandwidth request/grant protocol to allocate bandwidth. The abridged bandwidth request/grant protocol system utilizes padding packets to request a reduction in bandwidth allocation to a CPE. A base station modem alerts a base station CPU when the BS modem receives a padding packet from a CPE.

Abstract: One or more clocks are synchronized across a communication link using a synchronization signal sent from a master to a slave clock. The synchronization signal may be an expected signal pattern sent at intervals expected by the slave. The slave clock may correlate received signals with a representation of the expected synchronization signal to produce a correlation sample sequence at a first sample rate. The synchronization signal receipt time is compared to the expected time and the slave clock is adjusted until the times match. Master and slave clocks synchronized across the communication link constitute a noncommon clock which may be compared on each side of the link to secondary independent clocks. The secondary independent clocks may be separately synchronized by adjusting one to have the same difference from its local noncommon clock as the secondary clock on the other side of the link has from its local noncommon clock.

Abstract: The invention relates to communication systems and to systems and methods for implementing adaptive call admission control (CAC) in such systems. Adaptive call admission control can determine what CPE to base station calls (connections) are allowed at any given time. CAC, coupled with precedence, can further determine what connections are suspended if less bandwidth is available than is currently committed. Multiple techniques are disclosed to select connections for suspension. These techniques include suspending enough connections through the affected CPE until there is enough bandwidth to meet the remaining commitment, randomly (or in a round robin fashion) choosing connection to suspend from the entire set of connection, and using precedence priority levels.

Abstract: A method and apparatus for a self-correcting bandwidth request/grant protocol in a broadband wireless communication system is disclosed. The self-correcting bandwidth request/grant protocol utilizes a combination of incremental and aggregate bandwidth requests. In accordance with the present inventive protocol, CPEs primarily transmit incremental bandwidth requests to their associated base stations, followed by periodic transmissions of aggregate bandwidth requests. The use of incremental bandwidth requests reduces risks that a base station erroneously issues duplicate bandwidth allocations to the same CPE for the same connection. Race conditions that may have occurred using only aggregate bandwidth requests are eliminated by requiring the CPEs to request bandwidth in an incremental manner. However, use of periodic aggregate bandwidth requests (that express the current state of their respective connection queues) allows the present bandwidth allocation method and apparatus to be “self-correcting.

Abstract: The present invention is a novel method and apparatus for efficiently transporting and synchronizing data between the Media Access Control (MAC) and physical communication protocol layers in a wireless communication system. An inventive method and apparatus for transporting and synchronizing to fixed-length ATM cell boundaries and for protecting against the potential misinsertion of ATM cells has been described. An inventive ATM packet format is described. The ATM packet format is used by the present invention for the transportation and synchronization of ATM cells. The ATM packets include fields that are used to detect errors occurring within each ATM cell. ATM cells are transported in exactly two TC/PHY packets, or TDUs. ATM header information is contained in the first TDU only. No ATM header information is carried by the second TDU. An entire ATM cell is discarded if an uncorrectable error is detected in the first TDU. If no uncorrectable error occurs in the first TDU, the second TDU is checked for errors.