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Long Tone Zero Protocols

Mutual Assistance Procedures for VHF/UHF FM


One of the great features of Multi-Use & General Mobile Radio Services is it gives the ability to provide mutual assistance to one another. There are two common procedures adopted by Northeast Wisconsin Communications Network currently in place for mutual assistance on VHF/UHF FM frequencies. The first is "LiTZ", a DTMF (Touch-Tone) based all-call priority alerting system. The second is the "Wilderness Protocol".

LiTZ (i-added to make it easier to pronounce).

LiTZ is a simple method to indicate to others on an MURS-FRS-GMRS VHF/UHF FM radio channel that you have an immediate need to communicate with someone, anyone, regarding a priority situation or condition.

LiTZ stands for LONG TONE ZERO. The LiTZ signal consists of transmitting DTMF (Touch-Tone) ZERO for at least 3 seconds. After sending the LiTZ signal the operator announces by voice the kind of assistance that is needed. For example: (5-seconds-DTMF-zero) "This is WABC999. I'm on Interstate 5 between mile posts 154 and 155. There's a 3 car auto accident in the southbound lane. Traffic has been completely blocked. It looks like paramedics will be needed for victims. Please respond if you can contact authorities for help. This is WABC999.

If your situation does not involve safety of life or property, try giving a general voice call before using LiTZ. Use LiTZ only when your voice calls go unanswered or the people who respond can't help you.

When you see the notation "LiTZ" for a repeater in this directory that means that it's highly likely that someone will receive and respond to LiTZ signals transmitted on the input frequency of the repeater. Please note, however, that if a CTCSS tone is needed to access that repeater you should transmit that CTCSS tone along with your LiTZ signal.

The type and nature of calls that justify the use of LiTZ may vary from repeater to repeater, just as other

uses vary. Here are some general guidelines that may be suitable for most repeaters and simplex calling channels.


 Event/Situation Waking Hours Sleeping Hours
Calling CQ No No
Calling a buddy No No
Weekly Test of LiTZ Yes No
Club Message Yes No
Need Driving Directions Yes No
Report Drunk Driver * Yes Yes
Car Break Down * Yes Yes
Safety of Life or Property * Yes Yes