Technical Overview

Overview

Canary™Talk can be used to provide communications links from either the surface to below ground or between two below ground locations. The radio equipment is provided with standard audio and data interfaces, allowing it to be connected to a wide variety of communications devices, including sensors, computers, and mobile wireless devices. An uninterruptible power supply maintains communications in the event of a power outage. The Canary™Talk system includes the following components:

Canary™Talk AGU                   Above Ground TTE Unit

Canary™Talk BGU                   Below Ground TTE Unit

Canary™PageBGR                   Below Ground ULF Receiver 

A robust TTE wireless link can be set up between a Canary™Talk AGU and BGU shown below, allowing two-way voice communication from deep in the earth or through other solid media. Once installed, the system set up is fully automatic and adapts to the characteristics of the intervening rock strata to maximize data throughput.  A one-way link can also be set up between the Canary™Talk AGU and one or many Canary™Page BGR receivers to support paging applications.

CanaryTalk Through-The-Earth Communications System Block Diagram

Technical Description

The Canary™Talk system can provide TTE communications through up to 600 feet of rock strata over a ULF wireless communications link operating in the 2 to 8 kHz frequency band. At this extremely low frequency, the long wavelength of the signal minimizes the signal losses that severely attenuate higher frequency radio waves. The heart of the system is a radio that uses advanced adaptive digital signal processing and noise filtering techniques to maximize the range and throughput of the communications link.

Unlike systems that rely on a Push to Talk (PTT) protocol, Canary™Talk uses time-division multiplexing of the data to enable true two-way communications, while minimizing transmission delays.  Voice communications are supported over this interface through the use of a voice compression algorithm, which allows analog voice to be compressed to data rates below 2400 bps.   A diagram of the Canary™Talk transceiver is shown below.  A number of programmable interfaces are provided on the AGU and BGU that enable inter-operability with a wide range of external communications devices.  These include RS-232 and RS-485 serial data ports, USB Ethernet and analog audio and a general purpose digital interface. The AGU and BGU can be monitored and set up using a standard PC running WindowsXP™ and connected locally or remotely via an Ethernet connection. The AGU and BGU are powered via an un-interruptible power supply and use separate receive and transmit antennas to further optimize performance.

CanaryTalk Through-The-Earth Radio Component Block Diagram

Technical Specifications