I've an AnyTone 878uv pluss and I want to know if roaming is only a DMR feature or if it can be used with analog repeaters?

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    $\begingroup$ I might be inexperienced here, but it's not quite sure what you're referring to when you say "roaming with analog repeaters": Since these are analog, how would you know of the existence of a better, neighboring repeater? $\endgroup$ Oct 21 '19 at 11:47
  • $\begingroup$ This handheld radio requires you program in all the repeaters you want to use, so it already knows what is available and could, in theory, check GPS or it could check to see if there's a usable signal on a given channel. ...but it already knows the channels. Auto-discovery would be one Hell of a feature, though, huh? :-) $\endgroup$ Oct 22 '19 at 17:55

This handheld radio requires you program in all the repeaters you want to use, so it already knows what is available and could, in theory, check GPS or it could check to see if there's a usable signal on a given channel. ...but it already knows the channels.

So, that'd be nice and all, but that wouldn't be enough to be useful.

Imagine this: you're in coverage area of one repeater. Now you're getting closer to a different repeater and want to use that instead.

To be useful, you need a lot more than switch your radio's own channel: the moment you roam, you don't want to become "disconnected" from your original communication partner, and that means that you either need to stay on the same relay "output channel" on these two different relays, or you need to tell your partner that you're now on a different channel. Both impossible with an analog system, because:

  • Staying on the same relay output channel is impossible, because these two relays are analog and hence shouldn't share the same channel if they're so close to each other.

  • Signalling that you'll be receivable on a different channel is impossible because an analog network doesn't have the signaling backend for that.

Auto-discovery would be one Hell of a feature, though, huh?

Not very complex to implement if your signal was digital. So anyone would do that with a digital signalling protocol, because:

To implement such a complex system as hand-off between relays, you'd need to have all the tools to do digital speech. So you'd do just that.

To give you a bit of historical insight:

Germany used to have C-Netz, from around 1984 to 1990, with about 750000 subscribers. That was the third generation of analog telephony networks, and the first one to support handover between different relays (which would be called base stations in cellular telephony parlay).

It was also the the last analog cellular network (that was 29 years ago, so we can safely assume it's pretty obsolete, even by ham standards). And it was the only generation to support handover – because you really needed digital signalling to achieve that, and as soon as Siemens and others really had that technology figured out, it became obvious that a digital system would be vastly superior. So, C-Netz became a tremendously popular, but quickly superseded (only after six years – imagine that speed for a behemoth like the German Postal service, which run it) system. Simply because that if you have the digital signal processing capability to do the call management in a handset, you'd really want to make use of that and do digital voice, which has several advantages over analog.

TL;DR: You want to build something like a trunked/cellular analog network. You need to go digital to achieve that. So you usually drop the analog speech in the process.

Hence, your handset is unlikely to support anything like that. It's not a feature of DMR alone (any cell phone standard does that since '90), but it's certainly not an analog thing.

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – Kevin Reid AG6YO
    Oct 23 '19 at 17:51

The radio can be programmed for DMR operation, or for standard analog repeater (or analog simplex) transmissions; you do not gain any DMR features while using analog.

  • $\begingroup$ Clearly, I agree that this is the case, however as a new HAM I do not know that roaming cannot be done on Analog. As a software developer of +10 years I can think of some ways that I might design something like that. So I'm looking for a conclusive statement that this is currently not the case. ...and if it isn't, maybe we can fix that! ;-) $\endgroup$ Oct 22 '19 at 20:27
  • $\begingroup$ why would you want to fix that? If you need something that could very likely do digital communications, why would you want to do analog? Sure, for the last mile of who you'd want to talk to, if that person only "understands" analog, you'd want to convert that last mile to an analog modulation. But, if you need features of a digital system (and saying "as a programmer, I can think of ways" almost certainly means you want to bring digital logic into this!), you'd want to make your end (i.e. your handset and the relay you're talking to) digital. $\endgroup$ Oct 24 '19 at 17:27
  • $\begingroup$ I hope you don't mind me making an analogy: "This 1920 tractor doesn't have blind-spot radar with automated emergency power braking. But we can fix that!" makes about as much sense: You'd need so many features of a modern car for that to work (and be of any benefit) that it'd really not make much sense to stay with the motor and chasis of a 1920 tractor. If you want that feature set, drive a car. Don't try to make a 100 year old thing have oddly specific features of a car by bolting on half of a car. $\endgroup$ Oct 24 '19 at 17:29
  • $\begingroup$ You guys are way over-thinking this. With analog, I don't have a connection. Therefore there is no connection to break. All I have to decide is which signal is stronger/better and switch channels. Ker-chunk the repeater once every X minutes or do something else to get a response from it and Bob's your uncle. You CAN do more but this is all you really need. APRS can help, if your radio already has it. Any radio that has both digital and analog already has this. $\endgroup$ Jan 2 at 19:25
  • $\begingroup$ "Why would I do this?", you might ask. This will add capability to my radio, so why wouldn't I? Not everyone can be reached on digital and not everyone has the same digital protocols available and in an emergency, I need to talk to whomever to get the job done. $\endgroup$ Jan 2 at 19:34

DMR. It scans DMR signals on the available channels and selects the channel with the best signal

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    $\begingroup$ Please expand your answer a bit to explain how DMR works compared to an analog repeater. $\endgroup$
    – rclocher3
    Mar 17 '20 at 18:41

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