Airbiquity Inc.

Kiley Birmingham

Leon Hong

Michael Hirano

David Quimby

Lee Zhao

Leon L Hong

An inband signaling modem receives digital user data for transmission to a remote location, via wireless and land line telecommunication networks. The modem converts the user data into audio tones for transmission, and encodes the audio tones into digital form suitable for transmission through a voice channel call session of a digital wireless network. After establishing a voice channel call session on a digital wireless network, the modem disables any echo cancellation or echo suppression means that may be encountered in the voice channel call session; and then transmits the user data audio tones. Preferably, disabling the echo cancellation or echo suppression means comprises transmitting a predetermined tone in the voice channel call session. Further, the modem preferably repeats the tone, to again disable echo cancellation or echo suppression means, at the beginning of each data burst during the call session.

Echo cancellation in wireless inband signaling modem

In one example, a mobile device segments a payload for transmission to a remote server and provides redundant data for each payload segment. The remote server examines the received payload on a per segment basis using the redundant data to identify segments associated with errors. The server then requests error correction bits for the identified segments using one or more exchanges with the mobile device. Thereafter, the server can perform error correction using the received error correction bits and then request re-transmission of the payload, if needed.

Efficient error correction scheme for data transmission in a wireless in-band signaling system

This invention pertains to methods and apparatus for data communications from vehicles, to obtain emergency, concierge and other services, using a voice channel of a digital wireless telecommunications network. Signaling is described for commencing data sessions after establishing a voice channel call. The call may be initiated from the vehicle automatically, and the call taker location may be unattended. Signaling methods are selected for traversing both newer and legacy vocoders for ubiquitous operation.

Wireless in-band signaling with in-vehicle systems

In one example, a mobile device encodes a digital bitstream using a particular set of modulation parameters to generate an audio signal that has different audio tones selected to pass through a vocoder of the mobile device. The particular set of modulation parameters is optimized for a subset of a plurality of vocoding modes without a priori knowledge of which one of the vocoding modes is currently operated by the vocoder. The mobile device conducts transmissions over the wireless telecommunications network through the vocoder using the particular set of modulation parameters, and monitors these transmissions for errors. If the errors reach a threshold, then the vocoder may be using one of the vocoding modes that are not included in the subset for which the particular set of modulation parameters is optimized, and accordingly, the modulation device switches from the particular set of modulation parameters to a different set of modulation parameters.

Adaptive data transmission for a digital in-band modem operating over a voice channel

Improvements are disclosed for in-band signaling, i.e., transmission of data in a voice channel of a digital wireless network during a voice call session. A family of narrow-band signaling methods is disclosed to successfully pass data-carrying signals through the low-bit rate modes of the EVRC-B vocoder commonly used in CDMA wireless channels. Some embodiments generate a tapered signaling waveform in tandem with another waveform using FSK-modulation. These features can be used in cell phones or other wireless communication devices, including automotive applications.

Methods for in-band signaling through enhanced variable-rate codecs

A receiver with a time diversity combining component recovers a digital data signal transmitted over a voice channel of a digital wireless telecommunications network. A feature extraction module receives an audio frequency waveform encoding the digital data signal and generates a feature vector representing the digital data signal. A bit sequence estimation module analyzes the feature vector and generates an estimated bit sequence corresponding to the digital data signal. A memory stores the feature vector if the estimated bit sequence contains errors. A time diversity combining component generates a second estimated bit sequence by analyzing the first feature vector in combination with one or more feature vectors stored in the memory.

Growing community of inventors

Seattle, WA, United States of America

Kiley Birmingham