At+t Corp.

At&t Bell Laboratories

Avaya Technology LLC

Richard D Miller

Richard Alan Windhausen

Jacob Aaron Myers

Charles Y Farwell

Todd J Frascone

Michael A Smith

Philip Wittmer

Gaurav Mehra

Yangguang Li

Douglas A Spencer

John S Thompson

Alan S Mulberg

Paul E Miller

Richard M Heidebrecht

David M Kissel

Michael J English

Kenneth Wayne Strom

Kenneth Frank Smolik

Kenneth Yiu-Kwong Ho

Kelvin K Ho

Michel L Hearn

Brian D Bolliger

Billy G Fuller

Talmage P Bursh, Jr

Donald G Koch

LaJeana N Roberts

Victor Medrano

Michael L Hearn

Marc K Dennison

Christopher Scott Basham

Michael Sluterbeck

Sanjay Sharma

Disclosed is a way of enhancing capabilities of an interface, such as a communications bus ( ), while retaining backwards compatibility of the interface. The bus has a plurality of signal lines ( ) including critical control signal lines. Legacy devices ( ) present a legacy interface to each other over the bus by communicating with each other via a legacy protocol ( ) over the bus. Critical control signals of the legacy protocol are conveyed by the critical control signal lines. New devices ( ) present an enhanced interface to each other over the same bus by communicating with each other via an enhanced protocol ( ) over the bus. Control signals of the enhanced protocol are conveyed by signal lines other than the critical control signal lines for the legacy protocol, so that the critical control signal lines remain idle or invalid for the legacy protocol. The new devices signal to each other an intent to use the enhanced protocol by sending a signal on a signal line ( ) that is not used by the legacy protocol. The new devices preferably can communicate on the bus via either protocol, and thus can communicate not only with each other but also with the legacy devices.

Arrangement for redefining an interface while maintaining backwards compatibility

Base stations responding on a shared channel to a registration request message received on another shared channel from a wireless mobile unit with the base station to which the mobile unit is assigned transmitting in a first time slot and the other base stations transmitting in a time slot determined by the strength of the received signal from the mobile unit. If two base stations respond to the registration request message in the same time slot and the assigned base station does not respond, the mobile unit determines whether there is a response in a time slot which is earlier in time to the first time slot than the collided time slot. If the collided time slot is earlier in time than any other time slot in which a response is received, the mobile unit transmits a second registration request message specifying the collided time slot. Each of the base stations that had responded in the collided time slot responds by sending a base reply message in a random time slot, and the other base stations do not respond to this second registration request message. The mobile unit selects one of the base reply messages in a random time slot.

Prioritizing a multiple access channel in a wireless telephone system

An arrangement for effecting call handoffs in a wireless communications system (FIG. 1 ) in a substantially glitchless manner. The arrangement relies on the mobile terminal (4) that is involved in a handoff to trigger the handoff by transmitting a handoff coordination signal simultaneously to the base stations (1, 2) that are involved in the handoff. The base stations receive the signal substantially simultaneously, and in response the base station that has been serving the mobile terminal's call ceases to do so while the base station that is henceforth to serve the mobile terminal's call commences to do so at the same instant in time.

Mobile-synchronized handoff in a wireless communications system

Signaling a mobile unit to transmit a synchronization pattern with voice information upon detecting from the signal strength of the wireless mobile unit by a base station that the mobile unit is approaching a minimum threshold. Where the voice information is initially being transmitted in a set of frequency hopping channels using spread spectrum transmission, the synchronization pattern is transmitted in one or more of the set of frequency hopping channels. In addition, the base station alerts a system controller to this fact, and the system controller requests that neighboring base stations monitor the set of frequency hopping channels being transmitted by the mobile unit. In order to synchronize to the mobile unit, the base stations utilize the synchronization pattern to come into synchronization with the mobile unit. The system controller transfers the wireless mobile unit to the base station which is receiving the strongest signal strength.

Call handoff in a wireless telephone system

A wireless-access communications system, such as a CDMA cellular radio-telephone system (FIG. 2), comprises a packet-switched communications network (202, 207, 201) that interconnects cells (base stations; 202) with each other and with the public telephone network (100). Traffic of individual calls is packetized, and packet-bearing frames (300 in FIG. 7) of a plurality of calls are then statistically multiplexed and frame-relayed through the network to yield the high capacity, efficiency, and speed of traffic transport and handoff required for a CDMA cellular system. At each call processing unit (264 in FIG. 5), individual calls are handled by individual service circuits (602 & 612) which perform speech-processing functions such as coding and decoding, tone insertion, and echo cancellation, and packet-to-circuit-switched-PCM traffic conversion. Processors (602) adapt call processing unit timing to compensate for asynchrony between cells and call processing units and variations in call path transmission delays. Cell-to-cell communications, fixed call path addressing, and packetized control message transfers ensure that the same service circuit handles a call through even multiple soft handoffs (FIGS. 27-29) and efficiently communicates simultaneously with all cells involved in the handoff without involvement of system control entities and negative effect on system call-handling capacity. Both coded (packet-switched) and uncoded (circuit-switched) radio-telephone traffic are accommodated side-by-side. Wherever possible, existing and proven technology and component units are used to achieve low cost and high reliability.

Wireless access telephone-to-telephone network interface architecture

A wireless-access communications system, such as a CDMA cellular radio-telephone system (FIG. 2), comprises a packet-switched communications network (202, 207, 201) that interconnects cells (base stations; 202) with each other and with the public telephone network (100). Traffic of individual calls is packetized, and packet-bearing frames (300 in FIG. 7) of a plurality of calls are then statistically multiplexed and frame-relayed through the network to yield the high capacity, efficiency, and speed of traffic transport and handoff required for a CDMA cellular system. At each call processing unit (264 in FIG. 5), individual calls are handled by individual service circuits (602 and 612) which perform speech-processing functions such as coding and decoding, tone insertion, and echo cancellation, and packet-to-circuit-switched-PCM traffic conversion. Processors (602) adapt call processing unit timing to compensate for asynchrony between cells and call processing units and variations in call path transmission delays. Cell-to-cell communications, fixed call path addressing, and packetized control message transfers ensure that the same service circuit handles a call through even multiple soft handoffs (FIGS. 27-29) and efficiently communicates simultaneously with all cells involved in the handoff without involvement of system control entities and negative effect on system call-handling capacity. Both coded (packet-switched) and uncoded (circuit-switched) radio-telephone traffic are accommodated side-by-side. Wherever possible, existing and proven technology and component units are used to achieve low cost and high reliability.

Growing community of inventors

Northglenn, CO, United States of America

Richard D Miller