3010results about "Error detection/prevention using signal quality detector" patented technology

A packet-centric wireless point to multi-point telecommunications system includes: a wireless base station communicating via a packet-centric protocol to a first data network; one or more host workstations communicating via the packet-centric protocol to the first data network; one or more subscriber customer premise equipment (CPE) stations coupled with the wireless base station over a shared bandwidth via the packet-centric protocol over a wireless medium; and one or more subscriber workstations coupled via the packet-centric protocol to each of the subscriber CPE stations over a second network. The packet-centric protocol can be transmission control protocol/internet protocol (TCP/IP). The packet-centric protocol can be a user datagram protocol/internet protocol (UDP/IP). The system can include a resource allocation means for allocating shared bandwidth among the subscriber CPE stations. The resource allocation is performed to optimize end-user quality of service (QoS). The wireless communication medium can include at least one of: a radio frequency (RF) communications medium; a cable communications medium; and a satellite communications medium. The wireless communication medium can further include a telecommunications access method including at least one of: a time division multiple access (TDMA) access method; a time division multiple access/time division duplex (TDMA/TDD) access method; a code division multiple access (CDMA) access method; and a frequency division multiple access (FDMA) access method.

The first data network includes at least one of: a wireline network; a wireless network; a local area network (LAN); and a wide area network (WAN). The second network includes at least one of: a wireline network; a wireless network; a local area network (LAN); and a wide area network (WAN).

A wireless communication network includes a plurality of mobile nodes each including a transceiver, a phased array antenna connected to the transceiver, and a controller connected to the transceiver. The controller schedules a respective semi-permanent time slot for each time frame to establish a communication link with each neighboring mobile node and leaves at least one available time slot in each time frame. The controller also schedules the at least one available time slot to also serve the communication link with a neighboring mobile node based upon link communications demand. The phased array antenna is aimed by the controller towards each neighboring mobile node during communication therewith. The controller also detects interference in time slots for communication with neighboring mobile nodes and coordinates the scheduling of time slots based upon detected interference.

A system and method for identifying ideal channels for communications based on an analysis of communication channel reliability, communicating party preferences, and communicating party contexts is provided. The system attempts to optimize the utility of a communication based on inferred or directly accessed channel reliability data, communicating party preferences and communicating party contexts. Such optimization can be achieved using reliabilities, preferences and policies concerning handling the attempted contact based on a deterministic specification or through inferring reliability, context, content and task under uncertainty by employing decision-theoretic inferences. The methods may consider channels currently available as well as channels available at later times. Thus, the service can include automated rescheduling of communications based on a consideration of forecasts of reliability and availability. The approach may include the use of forecasts about the time required for a communication and the likelihood that a connection will be dropped or will lose fidelity over this period of time. The methods may also include a consideration of metadata within a standard schema that is transmitted along with a communication attempt, the metadata representing information about attributes like the potential communication channels, the identity of the contactor, the task at hand, and the context of the communicating parties. The invocation of the communication service may be performed in a variety of ways, including single button invocations, and via a communication service that is more deeply integrated with other applications and functionalities.

The present invention provides systems and methods for improved data communication between communication terminals such as a base station and an unmanned aerial vehicle. In some instances, the systems and methods described herein provide robust transmission uplink data such as control data and wideband transmission of downlink data such as image data or other sensor data, while avoiding interference between the uplink data transmission and the downlink transmission.

Techniques to support independent power control of multiple channels in CDMA systems (e.g., a W-CDMA system) that define a single power control feedback stream on the uplink, which is to be used for downlink power control. In one aspect, the single feedback stream is "time shared" among multiple channels requiring individual power control. Various time-sharing schemes may be used to implement multiple (substantially parallel) feedback substreams based on the single feedback stream, and different combination of feedback rates may also be achieved for the substreams. Each feedback substream may be assigned to, and used for power control of, a respective channel. In another aspect, multiple feedback substreams are implemented based on multiple fields in newly defined slot formats.

A method for selecting an operating mode for a frame-based communications network consisting of a plurality of stations attached to a transmission medium. The plurality of stations include both a first type station and a second type station. The first type station is capable of transmitting and receiving first protocol frames in accordance with a first protocol. The second type station is capable of transmitting and receiving both first protocol frames and second protocol frames in accordance with a second protocol. The first protocol and the second protocol each use different signals on the transmission medium. The first type station is not capable of reliably detecting second protocol frames. The first protocol has a first protocol frame format containing at least two reserved bits in a first protocol frame header which are ignored in received frames by first type stations and always sent with a same fixed value by first type stations. The first protocol frame format is redefined to provide an updated first protocol frame header wherein two reserved bits in the first protocol frame header are allocated as a mode selection indicator field in the updated first protocol frame header. The mode selection indicator field has meaning for second type stations.

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.

Methods and systems are provided for efficient handover of a media session between heterogeneous Internet Protocol (IP) networks. A mobile device with Internet access can operate a software program to communicate with a corresponding node. The corresponding node may access the Internet through a firewall which may include Network Address Translation (NAT)-routing functionality. The mobile device establishes a media session with a corresponding node via the transmission of a first media stream and receipt of a second media stream, and a media-control channel can optionally be implemented. The mobile device can acquire Internet access through a second IP address, and packets routed between the second IP address and the Internet may traverse a firewall. The mobile device can evaluate a set of network parameters at the second IP address from a stored Local Area Network (LAN) profile. A software routine can (i) evaluate that handover of the media session from the first IP address to the second IP address is preferred and (ii) select an efficient handover procedure according to handover procedure rules.

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.

Systems, devices and methods for updating link adaptations in multi-carrier modulated signals between an access point (AP) and a wireless local area network (WLAN) station (STA) include (are configured for) periodically transmitting a channel sounding signal from the AP. The STA receives each unsolicited channel sounding signal and evaluates the current channel conditions between the AP and STA. The AP adjusts a rate of transmission of the channel sounding signals in accordance with the channel coherence time so that the channel estimates performed by the STA will be valid within the time varying characteristics of the channel. Depending on the length of the coherence time for network environment, the channel sounding signals may be AP beacons, low overhead signal fragments with no payload, or a combination of both.

A method and apparatus for optimizing the data transfer rate over a transport layer (i.e., communication link) such as the Internet is provided. Initially the data is prepared for transmission by a transfer rate controller, then the data is encoded by a Forward Error Correction (FEC) encoder. After the data has been transferred over the transport layer, the quality of the data transfer link is assessed by an FEC decoder that determines if any errors occurred during data transfer and if errors are detected, the magnitude of the errors (i.e., FEC-correctable packets, FEC-uncorrectable packets). This information is used to generate a feedback message which is used by the transfer rate controller to adjust and optimize the data transfer rate for the link quality as determined at that point in time. By continually monitoring and assessing link quality and providing feedback to the transfer rate controller, the transfer rate can be continually adapted to the varying link quality. In addition to generating feedback used by the transfer rate controller to optimize data transfer rate, the FEC decoder can generate feedback that is used by the FEC encoder to optimize the FEC algorithm. If desired, feedback from the FEC decoders within the link layer demodulator and/or feedback from the receiver can be used to augment the feedback generated by the FEC decoder.

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.

A device for identifying interference source in wireless communications is provided, including a correlation compound module, a matching and screening module, a statistical analysis module, and a match identification module. The correlation compound module uses the time of arrival (TOA) of the burst as the synchronization basis to compound the correlated frequency word, time difference of arrival (TDOA) word, amplitude word and angle of arrival (AOA) word to form a burst descriptor word (BDW). The matching and screening module uses the BWD to match the burst library to screen out the non-interference sources. The statistic analysis module uses the screened outcome for statistical analysis, and obtains a source discriminator file (SDF). The matching and identification module uses the SDF to search the interference source library for matching and obtains an identification result.

The present invention provides an improved channel quality indicator indicia for OFDM communication environments. In addition to taking into consideration carrier-to-interference ratios, the present invention also takes into consideration the degree to which the channel response varies among the sub-carriers throughout the OFDM frequency band. The carrier-to-interference ratio and the degree of channel response variation are directly or indirectly used by a base station to select coding and modulation schemes for transmissions from the base station to the mobile terminal reporting these factors. Further, scheduling of data sent to the mobile terminal and other mobile terminals competing for the same channel resources may also be based in part on the carrier-to-interference ratio and the degree to which the channel response varies.

A wireless communication network may include a plurality of mobile nodes each including a wireless transceiver and a controller for controlling the wireless transceiver. The controller may also be for scheduling a plurality of time slots for establishing a communication link with a neighboring mobile node for transmitting data therebetween, where the data has a plurality of priority levels. The controller may also determine respective link quality values associated with the communication link during the time slots, and prioritize data to be transmitted during the time slots based upon the priority level of the data and the link quality values.

A measurement apparatus for measuring traffic of packets with high time resolution is provided. The measurement apparatus includes an accumulation part for accumulating packet lengths of packets having predetermined header information in successively received packets, and storing an accumulated value of the packet lengths in a storage; and a periodic reading part for reading the accumulated value from the storage at predetermined time intervals, and outputting the accumulated value.

An apparatus for adjusting the transmission bit rate and fragmentation threshold of a wireless station in response to transmission errors is disclosed. In particular, the illustrative embodiment of the present invention is based on a wireless station that employs both an IEEE 802.11 radio and a Bluetooth radio, and determines whether transmission errors of the IEEE 802.11 radio are due to fading, or interference from the Bluetooth radio. It will be clear to those skilled in the art how to make and use alternative embodiments of the present invention for protocols other than IEEE 802.11 and Bluetooth, as well as stations that employ wireline or non-RF-wireless transceivers.