Motorola Corporation

Motorola Mobility LLC

Kenneth A Felix

Joseph Rinchiuso

Mark Conrad Cudak

Jeffrey D Bonta

Amitava Ghosh

Dennis R Schaeffer

Thomas B Hart

Thomas G Hulsebosch

Charles L Whittington

John R Haug

Alton P Werronen

Philip J Smanski

John P Lodwig

James A Pautler

Scott A Hardman

Richard A Kaman

Remote units (,) having large amounts of data to transmit will be dynamically assigned Orthogonal Variable Spreading Factor (OVSF) codes corresponding to higher data rates and remote units (,) with lower amounts of data to be transmitted will be assigned OVSF codes corresponding to lower data rates. Additionally, in an alternate embodiment of the present invention, once system interference becomes greater than a predetermined threshold, the data rate between the base station (,) and remote units (,) in communication with the base station (,) is reduced. The reduction of the data rate between the base station (,) and remote units (,) occurs by changing the current OVSF codes utilized by both the remote units (,) and the base station (,).

Data transmission within a spread-spectrum communication system

In order to reduce messaging within a wireless communication system an emulator (137) is provided that receives multicast packet data from a router (138). The multicast packet data is transmitted from a server (120) and destined to at least one remote unit (113-117). The emulator (137) additionally receives control data for the current multicast session from the router (138). The first set of data is transmitted to the remote unit (113-117) and the emulator (137) responds to the control data (via a response message (134)) without transmitting the control messages to the remote unit (113-117).

Data transmission within a wireless communication system

Remote units (113-117) that wish to receive a multicast session, monitor a multicast advertisement message on a system broadcast channel to determine a session to receive. Once a remote unit (113-117) requests participation in the multicast event, a common supplemental channel (205) is assigned to the remote unit (113-117), and the multicast session is broadcast to all remote units (113-117) currently participating in the multicast event. The common supplemental channel (205) utilizes two unique spreading codes for channel assignment, with one of the spreading codes being a function of the multicast session address (501) that is broadcast by the server (120).

Channel assignment within a broad-band communication system

During data transmission to a remote unit (113) utilizing a supplemental, high-speed data channel (105), data transmission stops due to all data being communicated to the remote unit (113) or because of an interruption in transmission. In the situation where all data has been transmitted to the remote unit (113) the remote unit (113) will drop the supplemental channel (105) prior to acknowledging reception of the last frames transmitted, and acknowledgment will take place utilizing the low-speed fundamental channel (103). In the situation where an interruption occurs, data transmission will continue utilizing a fundamental channel (103) if less than a predetermined amount of data remains to be transmitted.

Method and apparatus for data transmission within a broad-band

Data transmission within a broad-band communication system occurs as follows: During time periods where a remote unit (113) is not actively communicating to a base station (100) utilizing either a fundamental or a supplemental channel, the remote unit (113) is actively or periodically monitoring a forward control channel (IS-95A paging channel) for notification of any pending transmission by the base station (100). The base station (100) determines that a high data rate transmission to the remote unit (113) needs to take place and determines if supplemental channel circuitry (105) is available for utilization. Shortly prior to supplemental channel availability, the base station (100) notifies the remote unit (113) of a pending data transmission and assigns the remote unit (113) a fundamental channel to establish an appropriate transmit power level. Finally, data transmission to the remote unit (113) takes place utilizing the supplemental channel.

A method of transferring a user message-conveying radiotelephone call by a subscriber unit from a first radio coverage area, served by a first fixed control unit which is coupled to a wireline telephone switch, to a second radio coverage area served by a second fixed control unit, includes transmitting a directory number, associated with the first fixed control unit and the wireline telephone switch, the directory number identifying a wireline telephone number of the first fixed control unit, from the first fixed control unit to the subscriber unit; storing the transmitted directory number at the subscriber unit; transmitting the stored directory number from the subscriber unit to the second fixed control unit when a need for transfer of the radiotelephone call to the second fixed control unit from the first fixed control unit is determined; calling the transmitted directory number from the second fixed control unit; in response to the calling of the directory number, connecting the second fixed control unit to the first fixed control unit via the wireline telephone switch; and transferring control of the radiotelephone call from the first fixed control unit to the second fixed control unit by dialing the transmitted directory number from the second fixed control unit.

Method and system for transferring a radiotelephone call from one

A method is provided of allocating channels in a trunked radio frequency communication system having a plurality of channels, each with a channel rate. The method includes the steps of transmitting channel characteristics on idle channels of the plurality of channels by a base site. Idle channels are then scanned for channel characteristics by a communication unit. The method also includes the step of seizing an idle channel, by the communication unit, based, at least in part, upon the channel characteristics.

Method of allocating channels in multi-rate channel environment

A digital radiotelephone system requiring a transfer of communication from a source base-site (200) in a source cell (100) to a selected one target base-site in a target cell. A source base-site (200) in the source cell (100) provides a first and a second threshold and measures the received signal strength of a mobile unit (225) communicating to the source base-site (200). When the measured signal strength at the source base-site (200) falls below the first threshold, the source base-site (200) initiates a handoff to target base-sites located by the mobile unit (225). The target base-sites measure the received signal strength of the mobile unit (225) and a target base-site is selected. The source base-site (200) is notified of the selected target base-site and hands off communication of the mobile unit (225) to the selected target base-site when the previously measured signal strength at the source base-site (200) falls below the second threshold.

Radiotelephone system incorporating two thresholds for handoff

A cellular radiotelephone system transfers a call from a source base-site (200) to one target base-site (205,210). A source base-site (200) in the first RF coverage area (100) measures the signal strength (RSSI.sub.S) of a mobile (225), provides a forecasted signal strength (RSSI.sub.F) representing a would-be power increase of the mobile (225) and sets up two time windows. The source base-site (200) sends the measured and forecasted signal strengths to candidate target base-sites (205,210) found by the mobile (225) which measure the mobile (225) signal strength (RSSI.sub.T) and compare it once to RSSI.sub.S plus a hysteresis value. If RSSI.sub.T is greater than RSSI.sub.S, the call is transferred to the best responding cell. If RSSI.sub.T is below RSSI.sub.S, RSSI.sub.T is compared to RSSI.sub.F. During this time, the mobile 225 will increase power at the end of the first time window. If RSSI.sub.T is ever greater than RSSI.sub.F at any of the candidate target base-sites (205,210), the call is transferred to the responding target base-site (205,210). If the source base-site (200) receives no responses during the second time window, the process ends.

Radio telephone system incorporating multiple time periods for

A unique packet-switched cellular telephone system includes a cellular switch (140) and base sites (110) for providing packet-switched data services to cellular data telephones (102). Cellular switch (140) includes packet access points (152, 153) coupled to a packet network and T1 span lines (160, 161) coupled to the landline telephone network. Base sites (110) are coupled to cellular switch (140) by T1 span lines (164, 165) in which all time slots are clear channels and one time slot is dedicated for common channel signalling. Multiple data calls are assigned to each packet-mode radi channel thereby conserving valuable radio channel spectrum. Data calls are handed off from one packet-mode radio channel to another on the basis of cellular data telephone movement, signal strength, and/or bit-error rate, or on the basis of radio channel data packet capacity, data packet traffic, and/or data packet throughout.

Packet-switched cellular telephone system

A cellular radiotelephone system (101) includes a control terminal (420) coupled by in trunks and out trunks to the telephone central office (110) and by data and voice lines to base sites (411-416) in corresponding cells (401-406) for providing telephone coverage to mobiles located throughout a geographical area. In order accommodate additional voice channels in each cell (401-405), base sites (441-446) are colocated with corresponding existing base sites (401-405). Paging/access channels are assigned to existing base sites (411-416) for paging mobiles for all outgoing originations and processing all incoming mobile originations and page responses. Access-only channels are assigned to colocated base sites (441-446) for processing mobile originations and page responses transferred thereto by a directed retry message from corresponding existing base sites (401-405). The additional voice channels assigned to colocated base sites (441-446) may be voice channels in new radio frequency bands allocated to cellular radiotelephone systems. If both existing and additional voice channels are assigned to existing base sites (411-416) and/or colocated base sites (441-446), new voice channels are assigned to requesting mobiles before assigning existing voice channels, provided that the requesting mobile operates on both existing and new voice channels.

Cellular radiotelephone system having colocated base sites

Apparatus is disclosed for enabling a mobile radiotelephone to automatically attempt to seize a radio channel in a multichannel radio communication system. The mobile radiotelephone scans the radio channels for a non-busy radio channel and provides an indication signal when detecting a non-busy radio channel. A counter which is continuously clocked by a clock signal is incremented for each clock cycle interval of the clock signal in response to the presence of the indication signal and is decremented for each clock cycle interval of the clock signal in response to the absence of the indication signal. Thus, the totalized count of the counter is proportional to the degree of radio channel blocking of the radiotelephone system. After an unsuccessful channel seizure attempt by the mobile radiotelephone user, time interval generating circuitry provides a random time interval that has a maximum magnitude that is inversely proportional to the totallized count of the counter. Thus, the maximum random time interval is shortest when the totallized count of the counter is greatest. At the end of the random time interval, circuitry automatically attempts to seize a radio channel and if unsuccessful, additional automatic channel seizure attempts are provided after corresponding random time intervals. Thus, overall radiotelephone system efficiency is enhanced by dynamically optimizing the average random time interval between automatic channel seizure attempts according to the degree of radio channel blocking.

Method and apparatus for automatically attempting to seize a radio

A method and detector are described for detecting a data signal including at least three repeated data words each preceded by a Barker word. The detector includes a microcomputer that is responsive to interrupt and correlation programs for receiving and timewise correlating the repeated data words in the data signal. Upon detection of each Barker word, the microcomputer stores the following data word and measures the elapsed time interval between data words by measuring the time between detection of Barker words. The elapsed time interval between the previously and presently received data words is added to the stored time interval of all previously received data words. If at least three of the received data words have corresponding stored time intervals that are correlated with predetermined time interval ranges, a correlation indication signal is provided to indicate that valid data words have been received. The inventive method and detector may be advantageously utilized in mobile and portable stations of a radio communication system for receiving high speed data on a noisy voice channel.

Method and apparatus for detecting a data signal including repeated data

An improved multiprocessor bus arbiter which provides dynamically prioritized access for a plurality of processors to shared peripheral devices on a common bus through bus access switches. The arbiter includes logic circuitry to which incoming bus access request signals are coupled and a memory means which stores bus access status. The logic circuit determines bus access based on the input request signal and the stored information. The arbiter is adapted to provide a cycle shared mode of access or a lock out mode of access, as may be required.

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Crystal Lake, IL, United States of America

Kenneth A Felix