Motorola Corporation

Motorola Mobility LLC

William K Doss

Dale Robert Buchholz

Frederick W Vook

Hungkun J Chang

Karen E Robbins

R Lee Hamilton, Jr

Mark G Demange

Michael P Nolan

Thomas A Freeburg

Richard E White

Brian J Wesselman

Paul Odlyzko

Alan P Rottinghaus

Alan D Muehlfeld

John E Shaver

John W McKown

James D McGrath

Farzad Farhangnia

Mark Taylor

Jeffrey W Manning

Mai T Nguyen

Mark A Yednak

R Lee Hamilton

A wireless communication system (), method, and site controller () schedule at least one of transmission and reception of wireless data by at least one wireless communication device. A distance is determined between at least one wireless communication device () and a base station () in a wireless communication cell (). At least one of a downlink subframe () and an uplink subframe () of a time division duplexing frame () is segmented into a plurality of segments. The at least one wireless communication device () is scheduled into at least one of the plurality of segments of the downlink subframe () and the uplink subframe () based on the distance determined between the at least one wireless communication device () and the base station ().

Intelligent scheduling in a time division duplexing system to mitigate near/far interference scenarios

A packet delivery method for assuring the delivery of packets in an wireless local area network (LAN) having a service access point (AP) and a plurality mobile user devices, said user devices in communication with each other and with the access point. The access point determines when a destination device is in the sleep mode of operation and stores data packets intended for that device in memory. Thereafter the access point determines when the destination device enters the active mode of operation, delivers the data packets to the destination device and informs the source device of delivery of the data packets to the destination device.

Packet delivery method for use in a wireless local area network (LAN)

A power management technique for use in an wireless communication system having a service access point and a plurality mobile battery powered user devices, user devices in communication with each other and with the access point, power management technique for determining when a user device may transition from an active mode of operation to a sleep mode of operation and further for determining when a user device in the sleep mode of operation should transition to the active mode of operation.

Power management technique for determining a device mode of operation

A method used in a communication system (10) having central controllers (14) in communication with a plurality of user devices (12) where synchronizing data (34) and user data (35) are transmitted for a predetermined period of time defining a dwell (30). The method for delivering data to more than one user device (12) simultaneously includes the steps of providing an indicator (34) associated with at least a portion of a dwell indicating that the transmission of user data (35) is directed towards more than one user device (12), and informing the user devices of the repetition rate at which the indicator is transmitted. The user device schedules periods of time during which it is enabled and disabled respectively, based upon the repetition rate of the indicator received such that the user device is enabled and receives the data directed towards more than one user device.

Method for delivering broadcast packets in a frequency hopping local

A packet transmission system (100) with reduced transmission delays includes a communications controller (110) and a plurality of remote requesting units (112) requesting packet transmission services. Each remote unit (112) sequentially stores transmitted access requests (302) in a memory queue (500) and awaits a resource grant (306) from the communications controller (110). Upon receipt of a granted resource the remote unit (112) will apply the granted resource to the oldest request (502) stored in the queue (500) in order to transmit data (310) to the communications controller (110). A separate and distinct aspect of the transmission system (100) resides within the communications controller (110). In response to the receipt of a data packet (310) from a remote unit (112), the communications controller (110) identifies missing data within the data packet transmission, determines whether communication resources are available to support retransmission of the missing data, and if so, transmits a response to the requesting remote unit identifying the missing data and simultaneously granting sufficient resources for retransmission of the missing data.

Method for reducing transmission delays in a packet transmission system

In a wireless TDMA network a control module (CM) sends a time stamp relative to the beginning of its frame in a synchronization packet allowing each of a plurality of user modules (UM) to maintain synchronization relative to the CM. The CM uses a plurality of directional antennas and transmits the synchronization packets over each antenna over a predetermined number of frames. The UMs use a receive time stamp to identify the beginning of a received synchronization packet. The difference between the time stamps combined with a delay constant is used by the UMs to adjust time synchronization to the CM frame.

Synchronization method and apparatus for a wireless packet network

A method for prioritizing data transmissions in a frequency hopping communication system (10) includes defining a predetermined number of time slots at the beginning of a dwell or end of a transmission, each time slot having a duration and a data type, the communication device attempting to transmit data if the data type of the data corresponds to the data type of the slot, the attempt being based on at least one of the first and second assigned probability of transmission values, assigning the second probability of transmission value to the communication device if the attempt succeeds, reassigning the first probability of transmission value to the communication device if the transmission of data is complete.

Method for controlling channel access priorities in a frequency hopping

A method for a synchronizing user devices (12) performing handoffs includes providing a set of location synchronizing frequencies and data frequencies selected from a hopping set used by network access points (14). Each AP transmits synchronizing data (36) at the synchronizing frequencies during a portion of a short dwell (32), the short dwells (32) being interleaved between long dwells (30). When a user device (12) attempt a handoff, it tunes to at least one of the synchronizing frequencies and receives synchronizing information (36). The user device (12) then selects one AP (14) for link transfer and synchronizes its operation to the hopping set used by the selected AP (14).

Synchronization method in a frequency hopping local area network having

A packet transmission system (100) for reducing request traffic contention and the likelihood of resource misallocation includes a communications controller (110) and a plurality of remote requesting units (112) requesting packet transmission services. In response to receipt of a request (302), the controller (110) transmits a grant (306) to a requesting unit (112) when packet transmission resources (304 & 310) are available or a request acknowledgment (306) when packet transmission resources (304 & 310) are unavailable. Each remote unit (112) comprise apparatus structure and method steps for transmitting requests (302) to the controller (110) and starting a first timer having an interval (T) determined as a function of a number (Q) of outstanding requests (302). Upon receipt of an acknowledgement (306), the remote unit (112) starts a second timer having an interval (T.sub.1) longer than the interval (T). Upon expiration of either the first timer or the second timer, the remote unit (112) will then and only then transmit a duplicate request (302). By limiting the number of duplicate requests transmitted by a remote unit (112), the present invention operates to reduce request traffic contention and the likelihood of resource misallocation.

Method and apparatus for reducing the likelihood of contention and

A packet switching system (100) having a packet switch (140) employs an acknowledgement scheme in order assure the delivery of all fragments (310) comprising a fragmented data packet (300) to improve overall system throughput during the handling of packets (310) that require reassembly. When packet fragments (310) are lost, corrupted or otherwise unintelligible to a receiving device (92, 94), the acknowledgement scheme permits retransmission of the missing data. In addition, a second acknowledgment signal is scheduled by system processing resources (110) in order to verify the successful delivery of all retransmitted data.

Packet delivery system

Transmission of broadcast packets (46) in a radio frequency (RF) communication system between a control module (22) and user modules (20), wherein the control module (22) and the user modules (20) each have a plurality of antennae (A1-A6) includes generating a list (1100) of control module antennae (A1-A6) in radio communication with at least one of said plurality of user modules; and selecting the listed control module antennae for transmission of broadcast packets (46).

Transmission of broadcast packets in an RF system

A method and apparatus for preserving the sequential relationship of a plurality of data packets 310 generated by separate source devices 14 and ordered as a data stream 300, despite transmission over radio channels which introduce ordering errors comprises method steps and apparatus structure for identifying at a first terminal, data packets from within the data stream as a function of source, generating data packet sequence information for identified data packets, storing values corresponding to data packet sequence numbers as a function of source and transmitting data packets, source device identity and packet sequence information to a second terminal having first terminal source device and data packet sequence information. Upon receipt of a first terminal transmission, the second terminal retrieves from second terminal memory, first terminal data packet sequence information and compares the stored data packet sequence information with received data packet sequence information. As a function of the comparison, received data packets are forwarded to an appropriate application for further processing when sequence information sequence numbers compare and stored in an order determined by the sequence information when the sequence numbers do not compare.

Method and apparatus for preserving packet squencing in a packet

An RF communication system contains a control module which communicates with a plurality of user modules that are each connected to at least one user device. The system provides a method for packet communications in which traditional destination addressed packets are communicated to the specified destination point or user module while also permitting information intended for a plurality of user modules to be broadcast simultaneously to all user modules using a broadcast protocol. The probability of each UM receiving the broadcast packet is enhanced by the transmission by the control module of each broadcast packet over at least several of its directional antennas and preferably repeated over each antenna a number of times. Packets of data which are longer than a predetermined number of bytes are broken into packet fragments.

Broadcasting of packets in an RF system

An antenna selection technique is used in an RF communincation system in which user modules (UM) communicate with at least one node. The UM's and nodes each have multiple antennae. The combination of each UM and node antenna is evaluated at the UM. Based on at least signal quality, the UM selects its antenna and the best node antenna for use. An alternate antenna is selected if a person is determined to be present in a predetermined area adjacent a UM corresponding to a predetermined RF power level.

Antenna pattern selection for optimized communications and avoidance of

An antenna selection technique is used in an RF communication system in which user modules (UM) communicate with at least one node. The UM's and nodes each have multiple antennae. The combination of each UM and node antenna is evaluated at the UM. Based on both signal quality and strength, the UM selects its antenna and the best node antenna for use.

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Lake in the Hills, IL, United States of America

William K Doss