Motorola Corporation

Google Inc.

Robert J O'Dea

Vernon Anthony Allen

Matthew R Perkins

Qicai Shi

Priscilla L Chen

Neal K Patwari

Jian C Huang

Jimmy W Cadd

Monique J Bourgeois

Juan Carlos Palacios

William Paul Alberth, Jr

Gary W Grube

Frederick W Vook

Robert E Stengel

Mark J Johnson

David L Muri

William L Olson

Michael A Newell

Lance Eric Hester

Steve Bunch

Ralph L D'Souza

Chung-Chieh Lee

Scott Loren Miller

Stephen Raphael Korfhage

Tzer-Hso Lin

Described are methods and devices for identifying a group that include various methods to determine a group. Also described are devices and methods for attempting communication with a missing member of the group include different manners in which to determine information related to an entry of a group. The described devices and methods may be particularly beneficial at the particular time the certain group members plan to be or are in communication with one another. In this way, in the event that two or more entries of a group planned to be in communication or are in communication in-real time, in accordance with the disclosed devices and methods, the parties may be able to bring one or more other entries of the group into the communication as needed or desired.

Devices and methods for determining a group and for determining information related to group entries

An adaptive channel access scheme allows for statistics that are collected to be used to group radio users into subgroups according to the desired statistic. The subgroups then utilize channels, separated by time or frequency, to access the communication system (). The sub-grouping of the radio users is designed to help minimize the chances of channel-access collisions from occurring.

Adaptive channel access scheme

A communication device () operates in a training mode to develop parameters based on estimates related to at least two different instances of channel conditions, such as indicated by bit error rates for channel transmissions (). The parameters are used to define a function that characterizes an optimized throughput or energy consumption per bit through varying channel conditions. The function is preferably of the form a0+a1*Log(1+L), where a0 and a1 are fitted parameters, and Lthe frame size. The device responds to changes in channel conditions by transmitting messages on the communication channel using a frame size adapted for channel conditions based on the particular function and the developed parameters ().

Method and apparatus incorporating adaptive datalink framing for message communication

A communication system provides for data collection and route discovery for a network of distributed nodes. A base code having a data collection function occasionally sends agent packets to selected nodes of the network (), and these nodes in turn route the agent packets to other nodes. A route suitability level is maintained for each node that reflects the suitability of that node for routing packets to the base node (). At least some data packets contain reporting criteria for particular nodes (). When a condition exists at a node that meets the reporting criteria, a selected packet is updated with reporting data, and routed toward the based node via a neighbor node based on the route suitability level of the neighbor node ().

Method and system for data in a collection and route discovery communication network

A system and method for inferring an electronic rendering () of an environment () comprises a plurality of devices (and), and a processing device. Each wireless device is capable of determining a distance between a neighboring wireless device. Moreover, each device is capable of performing at least one of the following: determining an environmental attribute of the environment, and determining a location of an object in the environment. The processing device gathers information determined from the plurality of devices and infers the electronic rendering of the environment based on the information gathered.

System and method for inferring an electronic rendering of an environment

A method and apparatus for direct sequence spread spectrum communication having low complexity. In the transmitter, the data bit is spreaded by a code sequence, a reference code is interleaved with the code sequence, and together they are transmitted by the transmitter. The corresponding receiver recovers the data signal from the received signal by transforming the received signal to a complex base band signal and differentially decoding the base band signal at the chip level. The spreaded signal is despreaded by the chip-level differential operation, thus eliminating the decorrelation operation, and so significantly reducing the cost of the overall system. Furthermore, this system is very robust to any carrier frequency drift since the chip-level differential operation is used, thus releasing the reference clock or crystal requirements, and so further reducing the cost of the system.

Low cost DSSS communication system

A network protocol for low-cost, low-power devices coupled to a self-organizing wireless network using a spanning tree backbone architecture is described. In this protocol, physical and logical network construction and maintenance operations, which supports efficient data routing in the network, are performed. The construction phase in conjunction with the maintenance phase insures the self-organizing capability of the network. At the same time, the maintenance operations provide a self-healing mechanism so that the network can recover from node failures and a self-updating mechanism so that the network can expand as more nodes enter the system. Also, the logical backbone hierarchy will facilitate multi-hop communication. The construction of a logical layered spanning tree backbone architecture from an underlying physical topology allows seamless data communication routing between all nodes in the network.

Protocol for self-organizing network using a logical spanning tree backbone

According to the present invention a received Direct Sequence Code Division Multi-Access (DS-CDMA) signal is differentially decoded at the chip level. A number of signaling schemes can be used in the invention including (1) an ON/OFF signaling scheme in which a pseudo noise number (PN) code is sent only in response to one data bit value, and no signal is sent in response to the other bit value; (2) a Two Code signaling scheme in which bit values of 1 triggers a first PN code to transmitted, and a bit value of 0 triggers a second PN code to be transmitted; and (3) an M-ary signaling method in which a plurality of data bit patterns respectively, trigger a plurality of PN codes to be transmitted. After differential decoding the received signal is despread using one or more PN codes, that can be vector sums of two or more PN codes.

System for code division multi-access communication

An optically based location system and method of determining a location at a structure include a lighting infrastructure having lights at a structure. Each light is configured to illuminate and to transmit a respective relative or absolute terrestrial position through modulation of emitted light. An optical receiver is configured to detect the lights, to demodulate the position of detected lights, and to determine from the detection a position of the receiver. The receiver can have a conventional optical detector for determining a two-dimensional position of the receiver relative to a detected light, or can have a three-dimensional spot collimating lens and charged couple device optical detector for determining a three-dimensional position of the receiver relative to a detected light. The receiver and lights can be synchronized for converting a delay time into a distance measurement to calculate a distance between a light and the receiver.

Optically-based location system and method for determining a location at a structure

A beacon assisted asynchronous method of wireless communication according to the present invention enables initiating and target devices ( ) to remain in sleep mode most of the time and to periodically wake up to asynchronously, and directly, communicate with one another. Specifically, each of the initiating and target devices ( ) transmits a beacon while operating in a default transmit/receive mode ( ) and subsequently listens for a response. Alternatively, the initiating device ( ) may enter a data packet message mode to receive a beacon from the target device ( ) and to subsequently transmit a data packet message to the target device ( ) after receiving the first beacon. The initiating device ( ) minimizes the length of time in which it must wait to receive the target device beacon by timing a corresponding target beacon receive period based on stored data such as information based on previous communication with the target device ( ).

Beacon assisted hybrid asynchronous wireless communications protocol

A contention resolution method includes the steps of determining a contention has occurred and requesting contention resolution from radios in the system ( ). Radios in the system receive the request and do not transmit in the next control frame ( ). Group leader radios ( and ) transmit the identification code they were able to demodulate in the previous frame to the master radio ( ). The master radio ( ) receives the information from the group leaders and transmits a control-channel access message to one of the contending radios ( ).

Neighbor-assisted contention resolution for multi-user communication

DS-CDMA system with high resolution timing

A system for locating a number of devices ( ) by measuring signals transmitted between known location devices ( ) and unknown location devices ( ), and signals transmitted between pairs of unknown location devices ( ), entering signal measurements into a graph function that includes a number of first sub-expressions, a number of which include signal measurement prediction sub-expressions, and have extrema when a predicted signal measurement is equal to an actual signal measurement, and optimizing the graph function.

Method and apparatus for location estimation

A modulated signal, having a varying magnitude signal envelope, is conditioned, such as to facilitate amplification ( ). Minimum values are determined values for portions of the signal envelope ( ), and a window expansion function applied to scale each portion of the signal envelope having a minimum value below a particular threshold, such that each scaled portion has a new minimum value of at least the particular threshold ( ).

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Fort Lauderdale, FL, United States of America

Robert J O'Dea