Frequently Asked Questions
Cellular/Wireless: Issues and Solutions
A standard telephone line is the preferred service line for the RFC-1/B when possible. Cellular and wireless link devices emulate a telephone line with varying degrees of accuracy. Some installations work perfectly with factory settings.
Wireless Devices and Networks
Tests with wireless devices have generally been successful. It should be noted that we are working in an environment that is relatively free from RF and electrical noise.
Feedback from the field indicates that, with the RFC-1/B, wireless devices on GSM networks operate more reliably than devices on CDMA networks. We have no proof that this is the case but this is what we are told.
Touch Tones Issues
Digital wireless communication systems transmit voice and digital data reasonably well but they are not good at transmitting the DTMF tones required by the RFC-1, voice mail systems, etc. An artifact of noise reduction and data compression algorithms is distortion. Sometimes the signal quality falls low enough to interfere with RFC-1/B operation.
Weak Signal Level
Most of the wireless devices transmit Touch Tones at levels significantly lower than a standard telephone line. There are no system settings to work around this problem but there are some hardware adjustments that can be made. (See links)
We are told that some systems intercept DTMF tones and regenerate them later in the system. This approach may be effective at transmitting the signal but the DTMF tones are delayed noticeably in the process. Key presses must be made deliberately with a brief pause in between keys.
Such delays can cause a problem when the RFC-1/B is waiting for the main security code. There is a relatively short window in which to enter an eight digit code. The solution is to use fewer digits in the main security code.
Non-standard Touch Tone Dialing
Early RFC-1/B systems cannot generate Touch-Tones. Systems with firmware version 5.07 or higher are capable of tone dialing. The tones are a little unusual to compensate for a system was not designed to generate them from the start. A small number of devices do not respond to the DTMF tones that the RFC-1/B produces.
Non-standard Ring Signal
Many devices produce a ring signal that is not exactly like that of a POTS line. With its default setting the RFC-1 may fail to recognize it as a ringing telephone line and will not answer as a result. There is a ring sensitivity setting in the RFC-1 that will accommodate the non-standard ring signal. (See links)