Ensemble Communications, Inc.

Harington Valve, LLC

Wi-lan Inc.

Other

Ensemble Communication, Inc.

Jacques Behar

Kenneth L Stanwood

Gary Lee Samad

Yair Bourlas

David Gazelle

Stephen C Pollmann

Israel Jay Klein

Frederick Wales Price

Timothy L Gallagher

Sheldon I Gilbert

James F Mollenauer

Eli Arviv

Steve Pollmann

Moti Kabelly

Gary Lee Samad, Jr

Shelden L Gilbert

Yossi Keren

Frederick W Price

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. If an undetectable error exists in the second TDU, no discard action is taken. The error is noted, and both TDUs are passed through to the higher MAC communication layers. The inventive method protects against errors occurring in the ATM header because the ATM header is always carried in the first TDU. Consequently, misinsertion of ATM cells is also prevented.

Method and apparatus for synchronization between MAC and physical layers in a wireless communication system

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.

Compression of overhead in layered data communication links

A system that provides a wireless broadband connection between base stations and customer sites is described. The system includes indoor units within the base stations and customer sites and communicate across cables to outdoor units. The indoor units link to routers, switches and other devices and services. The outdoor units transmit and receive wireless data and send it to the indoor units. The indoor units control the timing of detector measurements in the outdoor unit by transmitting a regular, repeating control message at a predetermined time. Once the outdoor unit receives the control message, it samples its detectors and reports measurements back to the indoor unit.

System and method for timing detector measurements in a wireless communication system

A method reduces channel interference in a communication system that includes base stations and terminal stations with each base station having a plurality of sectors, each sector having a channel, and with each terminal station associated with a sector of a base station. A first set of terminal stations associated with a first sector that may potentially interfere with a second set of terminal stations associated with a second sector is determined. A first frequency sub-channel for use by the first set of terminal stations is selected and a second frequency sub-channel for use by the second set of terminal stations is selected. Transmissions by the first set of terminal stations are coordinated with transmissions by the second set of terminal stations, thereby reducing channel interference between the terminal stations of the first set and the terminal stations of the second set, as seen by a base station in the first or second sector.

Method and system for reducing channel interference in a frame-synchronized wireless communication system

A system and method for enhancing the performance of an equalizer in a modem. Multiple techniques are disclosed which improve the modem performance. A first technique uses stored parameters for each burst from each remote site to demodulate a received data stream. A second technique compensates for the gain droop caused by storing parameters across each burst. A third technique minimizes errors caused by adapting the equalizer coefficients for each data burst by analyzing the SN ratio and error rate of the received burst. A fourth technique improves the convergence of the equalizer by using a two-part preamble, whereby both parts are transmitted using different modulation techniques. A fifth technique is provided which performs a soft reset of the modem without performing a complete reset of the modem. A sixth technique determines a modem adaptation factor based on the expected modulation type of an incoming burst transmission. A seventh technique calculates a phase correction value for the stored tap values and applies the value to the incoming signal.

Equalizer performance enhancements for broadband wireless applications

Base stations having potentially interfering terminal stations that are geographically located on the same or similar diagonal or Line of Sight (relative to the base station) operate on a first set of time frames (e.g., 'even' time frames). Similarly, base stations having potentially interfering terminal stations that are not geographically located on the same or similar diagonals operate on a second set of time frames (e.g., 'odd' time frames). By alternating in their use of the even and odd frames, the potential for co-channel interference between terminal stations is minimized. Systems and methods are disclosed which reduce co-channel and adjacent channel interference between terminal stations of different cells as well as adjacent channel interference between terminal stations of adjacent cells. The methods and systems so described can be used during the deployment or expansion of a communication system in a region.

Method and apparatus for synchronization between MAC and physical layers in a wireless communication system when transporting ATM cells

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. Depending on the length of the MAC packet to be transported, the present invention either fragments or concatenates the MAC packet when mapping to the physical layer. When a MAC packet is too long to fit in one TC/PHY packet, the MAC packet is fragmented and the resultant multiple TC/PHY packets are preferably transmitted back-to-back within the same TDD frame. When a MAC packet is shorter than a TC/PHY packet, the next MAC packet is concatenated with the current MAC packet into a single TC/PHY packet unless an exception applies (e.g., a change in CPE on the uplink or a change in modulation on the downlink). When an exception applies, the next MAC packet is started on a new TC/PHY packet following either a CTG or MTG.

Method and apparatus for data transportation and synchronization between MAC and physical layers in a wireless communication system

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San Diego, CA, United States of America

Jacques Behar