Echo360 RF devices are commercial off-the-shelf (COTS) and operate at frequencies in the 2.4GHz (2.4 gigahertz) ISM band. They are fixed frequency devices and operate at a single relatively narrow-band frequency or “channel”. Each of the 82 available channels is 1MHz in width.
Transmit power levels for the Echo360 devices are very low – less than +4dBm (2.5mW). This signal is estimated to travel only 400 feet. Receive sensitivity is -85dBm max. Bit transfer rate for the Echo360 devices is 1Mbps. Packets of information are sent from each ResponseCard® keypad to the receiver. These packets include only a device ID and response selection. The ResponseCard NXT device also includes a user ID if that field is populated on the device. With overhead, the total packet duration is less than 265μs.
Communication is only between the ResponseCards and the RF receivers. The USB based receiver then communicates the response data directly to the Echo360 software products. The USB receiver is designed to only communicate to Turning Technology software products through a proprietary licensing system. No network transmission will occur from the USB device.
Flow Diagram of Communication
* RRRF-03 is the only receiver with built in storage capacity.