Hughes Aircraft Company

Hughes Electronics Corporation

Ashok D Mehta

Stanley Edward Kay

Michael I Parr

Daniel R Wendling

John E Corrigan, Iii

Charles A Barnett

Lou King

Graham M Avis

Pradeep Kaul

Hans Bhatia

George D Farmer

Christopher J Kain

Lin-Nan Lee

Youngky Kim

Jim Hobza

Nicholas P Sampson

Nick Sampson

John E Corrigan Iii

A multisubscriber unit is disclosed for use of in a digital cellular communication system to communicate with a base transceiver station and eventually to switched telephone network. The multisubscriber unit connects to a plurality of individual subscriber telephones. It includes a plurality of upconverters, modulators, downconverters, demodulators speech compressors, speech decompressors, and voice activity detectors that are assigned to a subscriber telephone upon detection of an off hook signal from the telephone. Preferably, upon the detection of data to be transmitted, to channel allocation is requested from a pool of time division multiple access channels in a digital speech interpolation pool.

Multi-subscriber unit for radio communication system and method

A dispatch system and a cellular interconnect system are combined to form a single system in which dispatch and interconnect communications are made with use of common system equipment. Different system configurations are employed according to the number of cells in the system to minimize loss of cellular interconnect capacity arising from dispatch communication operations.

Communication system and method providing dispatch and cellular

A digital cellular communication system in which fixed subscribers and mobile subscribers share base transceiver stations, base station controllers and mobile switching centers to communicate with the switched telephone network. Mobile subscribers communicate using any cellular radio protocol, while the fixed subscribers communicate via a multi-subscriber unit (MSU) using the inventive air interface. The MSU system uses digital speech interpolation to transmit speech spurts between subscribers and the switched telephone network. Preferably, time division multiple access channels in a digital speech interpolation pool are allocated and deallocated on a speech spurt basis.

Combined fixed and mobile radio communication system and method

A mobile telephone system multiplexes plural voice traffic channels on a single carrier using a TDMA protocol. The capacity of the mobile telephone system is increased by assigning voice traffic capacity, not on a conversation basis, but on an information burst basis. In order to avoid compromising the voice transmission capacity, control signals (for the allocation and deallocation of both forward and reverse traffic channels) are sent using multiple diversity, i.e. both time and frequency. In addition, to increase the number of available control channels, a control channel comprises a sub-divided portion of an otherwise equivalent voice traffic slot. For reverse allocation requests, which are transmitted over a contention access channel, power diversity is used in addition to time and frequency diversity.

Method for exploitation of voice inactivity to increase the capacity of

Each cell has an assigned classification that determines its inclusion in a measurement list for handing off. The candidate cells, which are selected from the measurement list are given priority level assignments. The priority levels are implemented by the candidate neighboring cells measured RF signal strength; and the order of handing off is arranged in accordance with the adjusted RF signal strength.

Prioritization of neighboring cells

A method and system for handing off an on-going communication from a serving cell to a neighboring cell of a cellular communication system having mobile units with a scanning capability. A dynamic threshold is calculated for effecting the handoff under certain operating criteria. The minimum attenuation level of the mobile unit and the minimum level permitted by a neighboring cell is used in selecting the dynamic threshold.

Dynamic thresholding for mobile assisted handoff in a digital cellular

A cellular system supports dispatch and datagram operations. The architecture of a conventional cellular system, such as the GSM system, is modified by adding a local area network (TIL) where nodes on the network include various base switching controllers (BSC). The BSC has a Switching Interface Module (SIM) which provides an interface to the TIL. The TIL may also include one or more gateways (40) to landline based networks. The datagram operation uses an appropriate gateway to complete a data path which includes an RF segment to or from the BSC. Dispatch operations provide for switching by the BSC so that switching is at a level below the Mobile Switching Center (MSC). For example, compressed voice traffic received by the BSC may be transmitted over the TIL to another BSC from where it is sent over an RF segment to a mobile receiver (MS).

Cellular telephone with datagram and dispatch operation

A cellular system uses dynamic repartitioning and channel packing to improve capacity without impacting quality. Dynamic repartitioning is employed to convert a carrier which operates, at one time, as an analog carrier to operate, at a later time, as a digital carrier in response to changes in offered traffic. Alternatively, a carrier which, at one time, operates as a digital carrier is converted to operate, at a later time, as an analog carrier in response to changes in offered traffic. The system also supports multiple digital protocols so that a carrier can also be converted to operate in any one of several different digital modes. Channel packing is used to allocate as many digital channels as possible to as few digital carriers as possible. In a preferred embodiment, both repartitioning and channel packing are implemented in response to a request for a channel allocation or deallocation.

Channel compression and dynamic repartitioning for dual mode cellular

A method and system for handing off an on-going communication from a serving cell to a neighboring cell of a cellular communication system having scanning receivers associated with each base transceiver station. A dynamic threshold is calculated for effecting the handoff in accordance with various operating conditions. The current mobile minimum attentuation level, (MT) the minimum permissible attenuation level of a serving (MS) cell and a neighboring cell (MN), together with the RF signal strength of the mobile unit at the neighboring cell (RSSI-NBR) and the serving cell (RSSI-SRV) are used in calculating a dynamic threshold (RSSI-THP).

Method and system for effecting handoff in a cellular communication

Cellular handoff is improved by tailing or adapting the measurement time based on the characteristics of the received signal intensity or power. More particularly, base stations typically measure mobile signal power in order to determine the necessity for handoff and the identity of a new cell. The measurement time must be of a duration which is sufficient to characterize the environment of the mobile. In accordance with the invention, the duration of the measurement time is determined from the received signal itself. Once the duration of the measurement time is determined, that data may be passed to a target cell along with other handoff data.

Sequential power estimation for cellular system handoff

A mobile telephone system multiplexes plural voice traffic channels on a single carrier using a TDMA protocol. The capacity of the mobile telephone system is increased by assigning voice traffic capacity, not on a conversation basis, but on a speech spurt basis. Accordingly, delays of undetermined duration may occur between subsequent information bursts which correspond to the transmission of speech spurts. An adjustment request regarding the power with which the information bursts are transmitted from a transmitting station to a receiving station is generated by detecting an information burst transmission at the receiving station, measuring the time which elapses following the transmission, and comparing the elapsed time with a predetermined threshold value. If the elapsed time exceeds the threshold, a further transmission is requested from the transmitting station notwithstanding the availability of any information to transmit. The power of the transmission received in response to the request is measured and a control message for requesting an adjustment to the transmission power level in response to the measurement is transmitted to the transmitting station.

Transmission power level adjustment in radio telephony

A cellular system uses dynamic repartitioning and channel packing to improve capacity without impacting quality. Dynamic repartitioning is employed to convert a carrier which operates, at one time, as an analog carrier to operate, at a later time, as a digital carrier in response to changes in offered traffic. Alternatively, a carrier which, at one time, operates as a digital carrier is converted to operate, at a later time, as an analog carrier in response to changes in offered traffic. Channel packing is used to allocate as many digital channels as possible to as few digital carriers as possible. In a preferred embodiment, both repartitioning and channel packing are implemented in response to call origination or call termination.

A mobile telephone system multiplexes plural voice traffic channels on a single carrier using a TDMA protocol. The capacity of the mobile telephone system is increased by assigning voice traffic capacity, not on a conversation basis, but on a speech spurt basis. In order to avoid compromising the voice transmission capacity, control signals (for the allocation and deallocation of both forward and reverse traffic channels) are sent using multiple diversity, i.e. both time and frequency. In addition, to increase the number of available control channels, a control channel comprises a sub-divided portion of an otherwise equivalent voice traffic slot. For reverse allocation requests, which are transmitted over a contention access channel, power diversity is used in addition to time and frequency diversity.

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North Potomac, MD, United States of America

Ashok D Mehta