2835results about "Adaptation strategy characterisation" patented technology

A telerobotic surgery system for remote surgeon training includes a robotic surgery station at a first location in a first structure at a first geographic point. Harvested animal tissue is at the robotic surgery station. A remote surgeon station at a second location in a second structure is at a second geographic point remote from the first geographic point. A remote party conferencing station at a third location in a third structure is at a third geographic point remote from the first and second geographic points. A communications network couples the robotic surgery station, the remote surgeon station, and the remote party conferencing station so that a surgeon at the remote surgeon station is able to remotely train using the harvested animal tissue at the robotic surgery station and while conferencing with a party at the remote party conferencing station.

In embodiments of the present invention improved capabilities are described for a mobile broadband routable internet (MBRI) providing for carrier-grade, networked, broadband, IP-routable communication among a plurality of mobile devices, where the mobile devices may represent a plurality of nodes that are linked together through a mobile ad-hoc network (MANET). Mobile devices may operate as peers in a peer-to-peer network, with full IP routing capabilities enabled within each mobile device, thereby allowing routing of IP-based traffic, including deployment of applications, to the mobile device without need for infrastructure conventionally required for mobile ad hoc networks, such as cellular telephony infrastructure. Full IP-routing to mobile devices may allow seamless integration to the fixed Internet, such as through fixed or mobile access points, such as for backhaul purposes. Thus, the MBRI may function as a standalone mobile Internet, without connection to the fixed Internet, or as an IP-routable extension of another network, whether it be the Internet, a local area network, a wide area network, a cellular network, a personal area network, or some other type of network that is capable of integration with an IP-based network.

The present invention relates to wireless networks using relaying. In the method according to the present invention of performing communication in a two-hop wireless communication network, a transmitter 210, a receiver 220 and at least one relay station 215 are engaged in a communication session. The relay station 215 forwards signals from a first link between the transmitter 210 and the relay station 215 to a second link between the relay stations 215 and the receiver 220. The forwarding performed by the at least one relay station 215 is adapted as a response to estimated radio channel characteristics of at least the first link. Preferably the forwarding is adapted as a response to estimated radio channel characteristics of both the first and second link.

In a wireless communication system, a base station assigns resources to mobile stations using indices. Each index is associated with an assignment schedule for assigning resources. Once the base station determines an assignment schedule to assign particular resources, it encodes the schedule into an index and transmits it. A mobile station receives the index and decodes it to recover the assignment schedule. Both the base station and the mobile station may use look-up tables and/or algorithms for storing or generating indices associated with assignment schedules. To assign resources so as to indicate transmission characteristics over the resources, the base station transmits assignment blocks. Each assignment block indicates original transmission, retransmission, persistent assignment, non-persistent assignment, HARQ signaling, RAS-HARQ signaling, DRCH assignment, and/or LRCH assignment.

Estimates of a communication system configuration, such as a DSL system, are based on operational data collected from a network element management system, protocol, users and/or the like. The operational data collected from the system can include performance-characterizing operational data that typically is available in an ADSL system via element-management-system protocols. Generated estimates and/or approximations can be used in evaluating system performance and directly or indirectly dictating/requiring changes or recommending improvements in operation by transmitters and/or other parts of the communication system. Data and/or other information may be collected using “internal” means or may be obtained from system elements and components via email and/or other “external” means. The likelihood of a model's accuracy can be based on various data, information and/or indicators of system performance, such as observed normal operational data, test data and/or prompted operational data that shows operating performance based on stimulation signals. One example of such prompted data uses frequency carrier masks to approximate the Hlog of a given channel, including information regarding bridged taps, attenuation, etc.

A method and system for optimizing performance in a data-over-cable system. The method includes determining parameters for data transmission on an upstream channel of the data-over-cable system, and negotiating use of the parameters. A measurement is made of a signal-to-noise ratio (“SNR”) on the upstream channel. Associated with the SNR and a target packet-error-ratio (“PER”) are parameters that provide optimal data throughput. The parameters, such as symbol rate, type of modulation, or amount of error correction, are used to construct a message that is sent to the cable modems. The message instructs the cable modems to reconfigure themselves to transmit according to the parameters. The reconfiguration helps ensure optimal performance.

A method for proposing at least one transmission rate change including calculating a plurality of latency values, computing at least one derivative-based proposed change from the plurality of latency values, and proposing a rate change selected from the at least one derivative-based proposed change. Also provided is a system including a rate controller controlling the transmission rate of data between two stations over a network and a rate reporter in communication with the rate controller.

A WCDMA system includes a Base Station (BS) transmitter, or forward transmitter and a pilot channel that transmits control signals between the BS and a Mobile Station (MS) to reconfigure their transmitter/receiver. Reconfiguration is performed according to the prediction of the channel attenuation and the threshold set at the BS or MS based on its channel power probability density function separated into three distinct equal probable regions. In one embodiment, Seamless Rate Change (SRC)/Transmitter Power Control (TPC) logic uses the predicted channel attenuation to signal both the transmitter and the receiver in a channel to reconfigure their transmit power level according to the power density function (pdf) of the channel power and threshold level. A transmission rate is reduced when the power level is below the threshold and increased when the channel power is above threshold. The pilot channel is used to signal the mobile station and the base station.

A system for providing an accurate prediction of a signal-to-interference noise ratio is described. The system includes a first circuit for receiving a signal transmitted across a channel via an external transmitter. A second circuit generates a sequence of estimates of signal-to-interference noise ratio based on the received signal. A third circuit determines a relationship between elements of the sequence of estimates. A fourth circuit employs the relationship to provide a signal-to-interference noise ratio prediction for a subsequently received signal. In the illustrative embodiment, the inventive system further includes a circuit for generating a data rate request message based on the signal-to-noise ratio prediction. A special transmitter transmits the data rate request message to the external transmitter. In the specific embodiment, the relationship between elements of the sequence of estimates is based on an average of the elements of the sequence of estimates. The third circuit includes a bank of filters for computing the average. The bank of filters includes finite impulse response filters. Coefficients of the transfer functions associated with each filter in the bank of filters are tailored for different fading environments. The different fading environments include different Rayleigh fading environments, one environment associated with a rapidly moving system, a second environment associated with a slow moving system, and a third system associated with a system moving at a medium velocity. A selection circuit is connected to each of the filter banks and selects an output from one of the filters in the filter bank. The selected output is associated with a filter having a transfer function most suitable to a current fading environment.

From an electric pole outside to a cordless handset inside a building/facility, a communication line is established via an electric power line. At this point, it is judged whether or not electric power line communication is possible, and if electric power line communication is possible, the communication line between the cordless handset and a base unit is switched to an electric power line communication system, and a communication line is formed via an optical fiber cable from the electric power line. By measuring the communication quality levels of all lines of the wireless and electric power lines, the communication line having the highest communication quality level may be selected.

In an adaptive modulation and coding method one or more adjustable values are created (S1), each corresponding to at least one of a plurality of available modulation and coding levels applicable to a signal transmitted from a transmitter to a receiver, and each representing a change to the level(s) to which it corresponds. One or more of said adjustable values is/are adjusted in dependence upon whether or not the signal is received successfully by the receiver (S2-S5). One of said available modulation and coding levels is selected (S6-S8) to apply to the signal based on such an adjustable value. Such a method can enable the appropriate modulation and coding level to be selected even when the path and channel conditions vary. The method is applicable to selecting modulation and coding levels in a high-speed downlink packet access system of a wireless communication network.

A medium streaming distribution system reduces effects of packet loss in a network before the packet reaches radio base station. A medium distribution device for packet-transmits via the base station, a medium stream to the network by a real time transmission protocol. A packet analyzer monitors the packet arriving at the radio base station and transmits feedback Information associated with loss of a packet to the medium distribution device. Based on the feedback from a relay device and a terminal device of the medium stream, the transmission rates from the medium distribution device to the relay device and from the relay device to the terminal device are obtained to provide a greater transmission rate in a surplus band for re-transmission or a forward error correction.

Methods (300) and corresponding systems (100) for adapting a clear channel assessment (CCA) threshold in a node in a wireless network includes determining a first successful transmission rate of the node and neighboring nodes in the wireless network when the node is set to use a first CCA threshold. Next, a second successful transmission rate of the node and the neighboring nodes is determined when the node is set to use a second CCA threshold. Thereafter, one of the first and the second CCA thresholds is selected based upon the first and second successful transmission rates. The determining a successful transmission rate of the node and neighboring nodes can include counting successful packet indications transmitted by the node and received by the node from the neighboring nodes. Transmitted successful packet indications can include transmitted acknowledgement messages.

A multi-carrier communication system such as an OFDM or DMT system has nodes which are allowed to dynamically change their receive and transmit symbol rates, and the number of carriers within their signals. Changing of the symbol rate is done by changing the clocking frequency of the nodes' iFFT and FFT processors, as well as their serializers and deserializers. The nodes have several ways of dynamically changing the number of carriers used. The selection of symbol rate and number of carriers can be optimized for a given channel based on explicit channel measurements, a priori knowledge of the channel, or past experience. Provision is made for accommodating legacy nodes that may have constraints in symbol rate or the number of carriers they can support. The receiver can determine the correct symbol rate and number of carriers through a priori knowledge, a first exchange of packets in a base mode that all nodes can understand, or an indication in the header of the data packet which is transmitted in a base mode of operation that all nodes can understand.

Controlling margins in a DSL modem pair is based on collected operational data. The operational data is analyzed and at least one of the modems in the modem pair is instructed to use a margin-related parameter value to assist the modem pair in meeting a margin target, such as a margin limit imposed by a DSL standard or the like. A controller, such as a DSM Center, a “smart” modem unit and/or a computer system can collect and analyze the operational data and generate one or more margin-related parameter values. The margin-related parameter value may be a PSD-related value, such as the MAXNOMPSD, MAXNOMATP or PSDMASK parameter used by various ADSL systems, and may be a shaped spectral mask and/or caps or limits on bit loading for use in transmissions between the modems. In some cases, preference bands can be imposed to direct modems to favor and/or avoid certain frequencies in the modem's usable band(s). The operational data may include historical data relating to prior performance of the modem pair and prior margin compliance. A distribution of margins also may be based on operational data and may be estimated as a function of data rate. Using the estimated margin distribution, a distribution of performance parameters also is calculated, including the probabilities of line outages and probabilities of one or more error parameters exceeding minimum levels. Data rates and/or performance-related parameters may be set on the basis of the estimated performance of the system using various margin settings and levels.

Health information communications systems and methods are disclosed. In one embodiment, the system includes one or more medical sensors providing one or more health information data types. The system further includes a patient communications device coupled to at least one medical sensor over a communications network. Particularly, the patient communications device includes a patient quality of service (QoS) manager that dynamically specifies a set of data quality management parameters for transporting at least some of the health information and modifies at least some of the health information into value factored health information. Additionally, the system includes a specialist communications device communicatively coupled to the patient communication device over the communications network. The specialist communications device includes a specialist QoS manager that provides measured channel characteristics to the patient communications device. The patient QoS manager dynamically specifies the set of data quality management parameters based at least in part on the measured channel characteristics of the specialist communications device.

Provided is a method of processing hybrid automatic repeat request (HARQ) and adaptive transmission of a device-to-device (D2D) link. In the method, an operation method of user equipment (UE) includes (a) receiving an initial transmission mode (TM) and transmission power for the D2D link from a base station, and performing data transmission through the D2D link, (b) determining, at the UE, a TM and transmission power of a succeeding subframe, or receiving a TM control value and a transmission power control value from counterpart UE of the D2D link and determining the TM and the transmission power of the succeeding subframe, and (c) performing the data transmission to the counterpart UE using the determined TM and transmission power. Here, (b) and (c) are repeated.

A DSL system includes a multiple loop segment where K loops are bonded to provide a multiple loop segment having up to (2K−1) communication channels on which transmissions are vectored. The segment may be a drop to a customer premises, an inter-pedestal link, or any other suitable part of a larger DSL system. Generally the bonded loops are relatively short, being 300 meters or less. Signal vectoring is used to increase the speed and data carrying capability of the channels. In some embodiments, an expanded frequency spectrum also can be used to increase the data carrying capability of one or more of the channels. An impedance matching circuit may be coupled to each end of the segment to provided efficient transmission of data across the segment. A controller may provide control signals used to operate the segment as a vectored system and, if desired, frequency bandwidth control signals. The controller may monitor and/or collect data and information from the DSL system to assist in generating control signals. The controller can be a dynamic spectrum manager or DSM Center that includes a computer system and/or other hardware to assist in performing the required functions.

The invention relates to a method for transmitting signals via a point-to-point microwave radio link from a transmitting unit 1, 2 to a receiving unit 2, 1 of a point-to-point microwave radio system, which signals comprise packets. In order to improve the efficiency on the radio link, it is proposed that in a first step, the packets are classified before transmission based on at least one quality of service parameter assigned to each packet. In a second step, the signals are modulated by the transmitting unit 1, 2 for transmission with a real-time adaptive modulation. This modulation is adapted based on the current traffic amount, on signal quality measurements indicative of the propagation conditions on the radio link, and on the classification of packets comprised in the signals. The invention relates equally to such a point-to-point microwave radio system comprising two units 1, 2 between which signals are to be transmitted, and to transmitting unit 1, 2 for such a system.

In a multi-user frequency domain spreading downlink MC-CDMA system. a group of sub-carriers can be replaced by an equivalent sub-carrier of a conventional OFDM modem for purposes of resource allocation to improve the system performance. The chips for a given user are spread only within the group. Confinement insures synchronization between different users' chips that is essential to the recovering and separation of user symbols at the receiver. There is no limit imposed on the group size, which permits different spreading code lengths to be used for different scenarios or for performance tuning.

An apparatus 300 for a cellular communication system (100) comprises a buffer (303) which receives data for transmission over an air interface (115). The buffer (303) is coupled to a scheduler (305) which schedules the data and allocates the physical resource of the air interface (115). The transmissions are performed using a retransmission scheme such as a Hybrid-Automatic Repeat reQuest scheme. A load processor (309) determines a load characteristic associated with the scheduler (305) and a target controller (311) sets a target parameter for the retransmission scheme in response to the load characteristic. Specifically, a block error rate target may be set in response to a load level of a cell or plurality of cells. A transmission controller (307) sets a transmission parameter for a transmission in response to the target parameter and a transmitter (301) transmits the data using the transmission parameter. Accordingly, an operating point of the retransmission scheme may be dynamically adjusted thereby reducing overall latency.

Operational parameters for transmitting a signal over a communication channel of a network are selected by first determining RF conditions on the communication channel from a received signal transmitted over the communication channel. An initial set of parameter values is selected for transmitting the signal based on RF conditions determined from the received signal. The initial set of parameter values is used to identify other sets of parameter values as other potential candidates for transmitting the signal. The parameter values in the other sets of parameter values differ from parameter values in the initial set of parameter values by less than a predetermined amount. The expected performance of the candidate sets of parameter values is compared to determine which set of parameter values has the best expected performance among the candidate sets of parameter values. The signal is transmitted on the communication channel using the selected set of parameter values.

A novel and useful media access control (MAC) protocol that is intended for use over noisy shared media channels. The MAC protocol provides layer 2 functionality over a network using a shared medium including a backoff mechanism for CSMA/CA channel access, link addressing that reduces the overhead of long MAC addresses, a flooding scheme having controlled exposure for broadcast transmissions, multicast transmissions using selective ACKs, implementation of traffic prioritization using an adaptive backoff scheme, a second layer repeater establishment process and multi-packet transport for short packets and fragmentation for long packet transport.

Methods and apparatuses for improved data transmission control protocols. Acknowledgment streams are used by a sender process to generate various estimates of eligible transmission rates that are fair to other processes competing for bandwidth across a common network. In addition, the acknowledgment streams are used in conjunction with various other standard transmission control protocol metrics to adapt a filter for use on the rate estimates. Additional improvements in throughput may no be had by measuring the overall capacity of the computer network using packet pair dispersion measurements and adaptive network probing. In addition, the methods may be adapted for both packet transmission and video streaming applications.