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DMR Etiquette PDF Print E-mail


Networked DMR communications is a shared resource, with
imposed latencies (delays) that require a high level of ETIQUETTE
applied to radio operation. Operators must visualize that their
communications may not only be heard by hundreds, or
thousands of DMR users, but that resources are being tied up by
communications and may deny other users access. Users should
invoke a higher level of operational courtesy, and a stronger
adherence to structured protocols to avoid denying access to
other operators.


Because of latency that is introduced by digitally encoding of
digitized voice communications with Forward Error Correction
codes at the transmitter, the application of Forward Error
Correction to decoded data at the receiver, and the delay
inherent in internet traffic, significant and noticeable latency
(delay) is inherent in DMR communications. DMR requires that
you wait after a transmission stops, and before you start a transmission,
to accommodate breaking traffic. It should be noted that there is no
repeater squelch tail with DMR. Operators should wait for a minimum
of 2 seconds after hearing the end of a transmission before initiating a
transmission, and then wait an additional 1 second after keying the
transmitter before speaking.


Nowhere is the importance of listening first more applicable to
radio operation as it is with DMR, and especially networked
DMR. When you arrive on channel, listen for a minimum of 30
seconds to get a sense as to whether the repeater or the talk
group is in use. If the repeater or talk group is in use, listen for
a while to acquire conversational context, and then intelligently
decide whether you can or should interject in the conversation.
Do not interject to mislead or take over a conversation. Rather,
wait until the conversation is completed before interjecting if you
mean to change topics or focus.


Remember that there's two different timeslots on each
repeater (1 & 2). You may see your radio indicating a receive
light, and hear nothing. This traffic may be the CWID, or on the
other timeslot, or a talk group that you're not listening to.


When you press the Push To Talk (PTT) button, wait to hear
the confirmation tones before you start talking. When you
push the button, your radio contacts the repeater, and makes
sure it's not busy, and that you can hit the repeater. A long
tone, or no tone when you hit the PTT means your
transmission won't go through.  Ensure to program you digital
channel “TX Admit” parameter to ‘color code free’.  This will
prevent you from doubling with someone.


Check your audio level. Since the audio is digitized on your
radio, and there's no leveling happening in transit, it's very
important for you to send a proper audio level. Use the Parrot,
or ask your friends to verify that your audio level is proper, and
remember the mic to mouth distance for your radio.


When you wish to talk with anyone on a given talkgroup, it is
common to give your callsign, your location, and the
talkgroup. For example, "This is K4AC, in Venice, Florida on TAC 311".


If you're in a conversation with another person, and for some
reason you lose contact with them, it may be that either end
has traffic that blocks your conversation. Watching your
receive light will let you know if the blocking is happening at
your end. Simply wait for a clear condition, and try again.


DMR latencies can make it difficult to complete a call if
another station responds to a call that is not directed toward
them. Unlike other operating modes, such as analog FM
simplex or analog FM repeater operations, a station that is not
targeted in a call and that responds, even with a simple query
to ask if they were called, can cause the targeted station to not
be heard. There may be no indication that doubling has
occurred. If you think that your station may have been called
but are not certain because you did not actually hear the call,
it is important that your first response is to wait in order to
allow for the targeted station to respond. It is far better to wait
10 or 15 seconds, and then, if the channel is clear, make a
query to ask if your station was called than to respond when
uncertain and deny the calling station and called station the
opportunity to establish contact.


The DMR-ID of a station appearing on the talk-group may be
displayed momentarily on your radio. This can be a
consequence of the other station moving a dynamic talkgroup
on a repeater, or a hot-spot (such as a SharkRF OpenSpot), to
another talk-group, and occurs when the station momentarily
keys their transmitter to move the repeater or hotspot to the
target talkgroup. Such display of DMR-ID, or additional
identifying information that may be programmed into the
radio contact list, is not an indication that the station wishes to
be called. The station may only wish to monitor the talkgroup.
It is difficult to determine what the station intends.


Use the smallest area talk group to make the communication
work. If you and the person you're talking to are using the
same repeater, be sure to use the Local talkgroup. If you're
both in AL, use the Alabama Statewide channel. AL/TN area,
use Regional, etc