Lucent Technologies Inc.

Stanislav Vitebskiy

Sanjiv Nanda

Sarath Kumar

Harvey Rubin

A back haul architecture effectively reduces the reactivation times for both forward-link and reverse-link data transmissions over CDMA wireless communications systems, by relying on packet-mode transmissions over the back haul between a frame selection/distribution (FSD) function and the appropriate base stations. In particular, for the forward direction, the FSD function transmits forward-link data only to one base station, which is solely responsible for controlling the forward-link air interface with the corresponding mobile unit. For the reverse direction, each base station that receives frames of reverse-link data from the mobile unit, assigns a time tag to the frame, divides the frame into one or more data packets, assigns a different sequence number to each data packet, and transmits the data packets to the FSD function over the back haul, all without first synchronizing time with any other base station that is also operating in reverse-link soft hand-off with that mobile unit.

Low back haul reactivation delay for high-speed packet data services in CDMA systems

A back haul architecture enables efficient primary transfer (i.e., transfer of the designation of primary base station from one base station to another). A frame selection/distribution (FSD) function queues packets of forward-link data&mdash;to which sequence numbers have been assigned&mdash;for packet-mode transmission over the back haul only to one base station&mdash;the current primary base station&mdash;where the packets are again queued for over-the-air transmission to the mobile unit. If and when it becomes appropriate to transfer the designation of primary base station to another base station, there may still be packets of data queued at the old primary base station awaiting transmission to the mobile unit. The old primary base station sends a message to the new primary base station indicating a particular sequence number that identifies the remaining packets of forward-link data queued at the old primary base station. The new primary base station then sends a message to the FSD function requesting transmission of those packets of forward-link data corresponding to the particular sequence number. The FSD function then transmits those requested packets of forward-link data to the new primary base station, which queues the requested packets for over-the-air transmission to the mobile unit. In this way, transmission of all of the forward-link data to the mobile unit is enabled without having to transmit the remaining queued packets of forward-link data from the old primary base station to the new primary base station over the back haul, thereby providing an efficient mechanism for primary transfer in wireless communications systems that support forward-link data transmissions only in simplex mode.

Primary transfer for simplex mode forward-link high-speed packet data services in CDMA systems

Bursts of additional bandwidth (e.g., one or more supplemental channels or a channel having variable bandwidth) is assigned to users (e.g., high-speed data users) in a cellular telecommunication system. A request for assignment of additional bandwidth may be an initial request, a continuation request for an on-going burst, or a retry request after a previously rejected request. In any case it is determined whether to grant or reject the request. If the request is rejected, instructions are given to submit a retry request after a specified backoff time. The present invention may be implemented using either an asynchronous approach or a synchronous approach. According to the asynchronous approach, all requests are handled asynchronously. According to the synchronous approach, initial requests are handled asynchronously, but continuation requests and retry requests are handled synchronously at epoch times that coincide with specific time slots.

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Parsippany, NJ, United States of America

Stanislav Vitebskiy