Meteorcomm LLC

Physio-control, Inc.

Sr Telecom, Inc.

Arun Naidu

Jonathan A Morarity

Eamonn Gormley

Chaz Immendorf

Reza Sharif

Todd Klump

Shiva Sarrafan

Jim M Elder

Mark Davies

In method for facilitating the more efficient opportunistic use of one or more frequency division multiplexed (FDM) channels by a two or more secondary users (SU) in a point-to-multipoint, centralized ad hoc network, one SU acts as a central node and the remaining SU acting as remote nodes. Each SU adheres to a predetermined protocol utilizing synchronized time slots in each of the channels, each time slot having at least one data transmission period and at least one primary user detection period during which no SU transmits. The central SU node determines channel availability.

Opportunistic radio frequency transmissions in a centralized network of secondary users

A radio for determining the occupancy of a variable width channel for secondary use, the variable width channel with a bandwidth equal to an integer multiple of the bandwidth of a plurality of narrowband channels in an RF frequency band. The radio decides whether the variable width channel in the RF band is occupied by whether classifying each of the narrowband channels corresponding to the variable width channel and each of a plurality of sub-bands with bandwidths of narrowband channels but center frequencies shifted by one-half of the bandwidth of the narrowband channel and overlap with the bandwidth of the variable width channel as containing signal or noise based on measured energy levels.

Wide band sensing of transmissions in FDM signals containing multi-width channels

A railroad communication system includes a radio transmitter for generating radio communications signals and a length of railroad rail coupled to the radio transmitter. The length of rail is disposed on a set of nonconductive railroad ties to form a transmission line for radiating the radio communications signals to a radio receiver in a vicinity of the length of railroad rail.

Systems and methods for using a railroad rail as radiating element for transmitting wireless communications signals

A cabinet capable of attenuating or blocking wireless signals contains, a medical device, such as an AED, an internal directional antenna mounted to an internal surface of the cabinet, an external omnidirectional antenna mounted to an external surface of the cabinet, and an electrical connection between the internal directional antenna and the external omnidirectional antenna. The internal and external antennas are configured to transmit wireless signals at particular frequencies and to receive wireless signals at the particular frequencies. The internal antenna is a high gain directional antenna, and the external antenna is a lower gain omnidirectional antenna.

High gain passive repeater antenna for medical device cabinets

A method of linearizing a relationship between a signal to an amplifier and an output signal from the amplifier includes applying an inverse of a transfer function of the amplifier to the signal prior to presenting the signal as the amplifier input. The inverse transfer function is represented by a polynomial defined by a set of coefficients. The transmitter output signal is measured by the idle receiver in a time division duplex system. The output signal is filtered to isolate intermodulation products of a selected order and the peak power of the isolated intermodulation products is then estimated. An adaptive algorithm is applied in response to the estimate of the peak power to update the set of coefficients of the polynomial representing the inverse of the transfer function of the amplifier.

Systems and methods using digital predistortion to linearize radio transmitter operation

A method of supporting voice-band modem-to-modem calls in a wireless communication system is disclosed. In some embodiments, once a modem call is detected, the modem call is terminated. Data in the terminated modem call is then demodulated and relayed from one end of a wireless broadband channel to the other end of the wireless broadband channel. Transfer of the data to the second modem is completed when the other end of the wireless broadband channel places a modem call to the second modem. By sending data in high-rate modem calls via a wireless broadband channel rather than over multiple, dedicated wireless voice channels, resources of the wireless communication system are utilized more efficiently that can result in significant gains in system capacity.

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Woodinville, WA, United States of America

Arun Naidu