DSTAR Vs C4FM Vote

[ADMIN]

VK2MJM has requested his posts be deleted - all three of them.
Done.

[VK2AAH]

A fellow ham who works at Tait in Christchurch told me today that a 70cm DMR network is being rolled out for their equivalent of WICEN... ease of networking & access to cheap radio equipment were behind this.

Cheers


Richard
VK2AAH

[VK3AP]

Hey Richard. That wasn't the real reason. Not here to start any arguments nor thread wars etc. regards ARES in NZ, they're a great group of people. and managed by like minded individuals, this thread had gone off track already..


Sent from my iPad using Tapatalk

[VK2AAH]

No problem, just relating what I heard but I plead guilty to going off topic...

Cheers

Richard
VK2AAH

[VK4BQ]

I can't seem to see this cheap 2nd hand dmr equipment anywhere? maybe I'm looking in the wrong place. All i see is some Chinese handhelds and no repeaters. Can someone please post the links to this market of well priced 2nd hand digital gear? Can you buy a p25 or dmr in a dual band 70cm / 2m ? are there any dmr or p25 radios with built in gps?

[VK2AAH]

You just need to know where to look... and both DMR and P25 radios are available with built in GPS.

No DMR repeaters? OK... Google MARC and in terms of large Australian DMR networks take a look at Orion

http://www.orionet.com.au/

The hardware is out there... all of the major manufacturers are investing very heavily in DMR product. Motorola sell a DMR repeater for a fraction of the cost of a new P25 base.

I bought a TYT DMR handheld rather than opting for a 2nd hand commercial radio because for $170US (delivered) I couldn't see any point in not buying a new radio.


Richard
VK2AAH

[VK4BQ]

All digital voice modes are interesting technically and worthy of testing / experimenting. This includes P25, DSTAR, C4FM and DMR. But in practical terms, which one we implement all comes down to $$$...a single DMR repeater might be significantly less than the cost of a single P25 repeater, but if a P25 repeater costs $10,000 and a DMR repeater costs nearly $5,000 – for just one site – they might as well both cost $10,000 because they’re both astronomically out of reach for amateur radio clubs, which rely on donated money, time and equipment.

And that’s just talking about one repeater site. I live in regional central QLD and we need way more than one repeater for a system to be of any use. We have the largest linked repeater system because we need it (I won’t go into all the reasons, but they include inflexible factors like sheer geographical size and terrain).

People who are interested in experimenting with digital voice want to use a repeater and talk to other likeminded individuals. Depending on the site conditions (for example, frequencies available for allocation/existing services) this could necessitate 2m or 70cm, or both. It doesn’t matter if the mode is P25, DMR, Dstar, whatever…people won’t buy a radio unless there is a repeater to use it with. And for our region at least, because of the conditions, a single band radio just doesn’t cut it.

Our version of “pure economics” is making a Dstar repeater from two analog radios (donated), GMSK modem and a Raspberry Pi for a total of about AUD150. (Not theoretical, this is how we built VK4RBY, VK4RUS, VK4RBD and VK4RAS.)
For our region, purchasing a single band handheld radio with no GPS for USD170 (AUD220) would not be “pure economics”. We would need two handhelds to cover both 2m and 70cm. This would take us close to the cost of a Dstar handheld anyway, and the Dstar handheld has the additional advantage of doing analog mode as well.

The point I would really like to get across is that all the other options are just too expensive. Dstar works for us because we can cover large areas very effectively with minimal upfront and ongoing costs.

[VK4VIP]

I feel that D-STAR has too much of a grip on the ham market for C4FM to take its share back easily. Also the repeaters and building has happened due to the open source ability of it

[ZL4JY]

Having read through the thread this morning I thought I’d offer some observations, having been involved in the development of both P25 linking and the ZL TRBO DMR network I feel I’m qualified for at least an opinion! I don’t want to comment on the original vote because this is a VK forum and there were not enough choices for my interests (P25 and DMR).

DMR vs D-STAR vs P25

It not’s a competition! Each technology has it strengths and weaknesses...

DMR

There is no doubt now that DMR has taken the ‘appliance operating’ approach to the high ground (I mean this is a good way). Users simply need to select a channel (actually a combination of repeater frequency and talkgroup) and they're good to go. At the time of writing there are 1,652 amateur DMR repeaters registered on the DMR MARC worldwide network (not all will be reachable via DMR MARC as some are on isolated networks). In terms of users there are 23,535 registered IDs. A year ago there were 30,000 DSTAR registered IDs but team DMR has done some serious catching up. However, the figures are not as simple as they seem since both P25 users and more recently DSTAR users have started to use DMR MARC IDs for their respective networks, replacing homemade or country specific ID system of client ID and the like. Now one ID serves for all amateur digital modes.

Tech note: The DSATR users adoption of DMR MARC IDs has come from a decision to change the DSTAR interconnection system to use the well-organized 7 digit DMR MARC IDs in what called CCS7 (although I’m told the US DSTAR guys are in two minds on this).

Undoubtedly a lot of the growth has been driven by low cost Chinese made handhelds. Repeaters are available from Hytera, Motorola, and Tait (and others) but at present the largest amateur network allows only Motorola repeaters while there is also dedicated Hytera network. I see this incompatibility as purely a matter of technology maturity, one day we’ll all play in the same sandpit. For those interested in a DMR primer see here:

http://www.trbo.org/docs/Amateur_Radio_Guide_to_DMR.pdf

The author, John W2XAB, has kindly granted permission to distribute electronic copies. While focused on US amateurs it still makes for an interesting read. Paper copies are available from John for two bucks plus postage.

DSTAR

The Icom DSTAR system offers huge potential for experimentation. While Icom makes the radios and indeed repeaters, you can easily build your own infrastructure. Access points and repeaters using all sorts of kits and modules are widely available with Raspberry Pi implementations especially popular. Icom radios are not cheap but they are cheaper than new high tier DMR or P25 radios. However, new and quite well made Chinese DMR radio are just a couple of hundred dollars. There is a nice irony that currently the two most ardent DMR users here in ZL spend all their time on DMR discussing DSTAR hotspot implementations. No worries, that's exactly what our DMR network was intended to do, provide reliable wide area hand held coverage with as close to 100% uptime as possible.

P25

APCO P25 is way behind in popularity but the mode appeals to both the technically minded and those looking for a low cost digital experience. Most use retired public safety radio from eBay although in VK you’ve been fortunate with surplus police Astro Spectra radios to get the ball rolling. Linking of the most commonly available P25 repeater, the Motorola Quantar, was not practical until some serious effort was put into developing an interface to the machine by various amateurs include VK2LK and myself. I developed a Cisco implementation for transport of Quantar P25 packets over the Internet with initial testing was done via a facility at NH6X0 in Hawaii linking VK, ZL, USA, and Canada. Dave NX4Y then rolled out a Windows server based implementation which works extremely well. Dave’s efforts have been truly amazing and now the network connects repeaters in Europe with the countries mentioned earlier.

ZL TRBO

Mention was made in an earlier post about the ZL TRBO network. New Zealand joined the DMR MARC network on 23 August 23 2011, directly connecting to the K9MOT Motorola Amateur Radio Club master repeater in Schaumburg IL. At that time VK6ZTN in Perth was the only other Oceania repeater in the network. At the time this was simply technical experimentation but the utility and practicality of 24/7 networking made it an obvious emergency asset and remember the NZ city of Christchurch had just suffered a deadly earthquake in February 2011 killing 185. Since then AREC, the ZL equivalent of WICEN, has adopted the technology and we have 12 repeaters in the network including one in each major city. You can read about here:

http://arec.info/arec-dmr-network/

While using Motorola infrastructure, the network supports radios from a wide range of manufacturers include the New Zealand made Tait radios. I should say here Tait have been very supportive of our efforts. Codeplugs and some locally developed instructions are available here:

http://arec.info/downloads/

While our cBridge operation can be viewed live here:

http://trbo.arec.info:42420/MinimalNetwatch

An interesting lesson form the Christchurch earthquake was that the telco Internet infrastructure only failed in the city itself so linking repeaters via the Internet is not as risky as it might seem. In any case some of the machines in our network are linked via 5.8GHz amateur kit reducing reliance on the ‘net. Finally a nice feature of DMR is that each DMR repeater can support two simultaneous QSO, so we can have AREC operational traffic operating on one timeslot while general amateur traffic occurs on the other timeslot.

73, John ZL4JY

[ZL1SWW]

Hi,
I think DSTAR is good in that you have the ability to link to wherever you like. Also the fact that most rigs doing DSTAR these days are dual banders. I have had experience with DMR as well and use it and develop application platforms using DMR specifically the Mototrbo kit due to the nice CDC_Ether interfacing. I'd like to embark on DMR from a ham aspect as well but in ZL, the cost of radios is still 'up there' in the cost department. I hear of other countries getting cheap used DMR but thought it was still to young to see old kit falling out the bottom of the refresh cycle. Sure there are Hytera and TYT units but would prefer to wait until the dual band options become more prevalent. In ZL, have some repeaters but are predominantly running on 70 cm.

Still a bit of waiting to be done in my books...

Cheers,

Simon
ZL1SWW

[VK2ZIW]

DMR, because WICEN are interested.

Why are DMR and Codec2 not included in the vote question?

DMR can support two talk groups on the one frequency.
That's the BIG advantage of DMR.

[VK2CSW]

Why are DMR and Codec2 not included in the vote question?

Mostly, I would guess, because this topic is over three years old...