Abstract: A multiple-access MIMO WLAN system that employs MIMO, OFDM, and TDD. The system (1) uses a channel structure with a number of configurable transport channels, (2) supports multiple rates and transmission modes, which are configurable based on channel conditions and user terminal capabilities, (3) employs a pilot structure with several types of pilot (e.g., beacon, MIMO, steered reference, and carrier pilots) for different functions, (4) implements rate, timing, and power control loops for proper system operation, and (5) employs random access for system access by the user terminals, fast acknowledgment, and quick resource assignments. Calibration may be performed to account for differences in the frequency responses of transmit/receive chains at the access point and user terminals. The spatial processing may then be simplified by taking advantage of the reciprocal nature of the downlink and uplink and the calibration.
Type:
Grant
Filed:
October 23, 2003
Date of Patent:
November 27, 2012
Assignee:
Qualcomm Incorporated
Inventors:
J. Rodney Walton, Mark S. Wallace, John W. Ketchum, Steven J. Howard
Abstract: The invention relates to interpreting the change in the increment of the RTP TS field as occurring either due to silence suppression for a voice flow or a change in sampling/frame rate of a video flow. By interpreting this change correctly, the value of the TS_STRIDE field in robust header compression may be correctly calculated leading to efficient header compression performance. In one aspect, there is disclosed a method of improving ROHC between an Access Network (AN) having a compressor and an Access Terminal (AT) having a decompressor, comprising providing flow information to the compressor relating to a change in the increment of an RTP TS field of a header; determining the change in the increment of an RTP TS field as occurring either due to silence suppression or due to a change in a sampling/frame rate; and taking appropriate action for TS_STRIDE.
Abstract: A method and apparatus for providing a proof of delivery verification for freight transportation systems. A vehicle transmits an indication of arrival at a destination. A remote station receives the indication and validates the arrival of the vehicle. If the arrival is validated, a proof of delivery verification of a delivery associated with the arrival is provided to a shipper, carrier, or other interested party.