How does this all work?

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MOTOTRBO (a.k.a. TRBO) is a Motorola Solutions branded DMR Radio. MOTOTRBO has a few more features than a standard DMR radio including IP Site Connect, which we use to network our repeaters in the USA, Germany, Australia, New Zealand, South Africa, Spain, Canada, Switzerland, Austria, Finland, Sweden, Italy, Mexico, the United Kingdom, Romania, Chile, and The Netherlands, Hong Kong, Brazil, and France. When one person transmits, multiple repeaters are keyed up on our network (like a reflector) without the user having to fumble through finding node numbers or access codes. All of our repeaters are networked 24/7. Our network is 100% DMR digital with no analog connections.

.. Our network has some innovative features such as 2 slot communications, location finding, and text messaging capabilities. DMR, as you will read more about below, supports 2 time-slotted channels from one repeater. Many of our repeaters have time slot 1 linked to the national and international networks and use time slot 2 for local and regional communications. This means each repeater supports 2 unique voice channels at the same time!

Our repeater owners and trustees constantly monitor network and repeater performance using several diagnostic tools such as RDAC and GW3-TRBO. TRBO also has an extensive 3rd party Application Developer Program. These innovators design many hardware and software accessories for the TRBO platform.




DMR (Digital Mobile Radio)

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DMR is an open and published international digital radio standard that specifies the 2-slot (channel) TDMA communications. DMR is amateur radio's newest digital protocol. DMR radios are produced by several manufacturers and they all work on our TRBO system. DMR is not compatible with Icom's D-Star technology. Competition between manufacturers is a big reason why DMR radio prices are fair. DMR is here to stay since it is not a single manufacturer technology.

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DMR also satisifies the FCC's narrowbanding mandate by being 6.25 kHz equivalent. It's actually more spectrum efficient than other 6.25 kHz modes since no guard band is needed for the two channels. Think of DMR as 1/3 the channel bandwidth of a 25 kHz analog signal with TWICE the number of voice channels. It also offers extended battery life, and did we mention it has superior voice quality over other digital voice modes?

Another advantage of most DMR radios is supurb RF performance. Many DMR radios have to satisfy both ETSI and TIA specs to perform in the most challenging RF environments. When you use a commercial radio for amateur radio you'll notice it has better intermod rejection, better selectivity, less spurious emissions, and it is mechanically a very well designed radio. Tired of the "turkey talk" and loss of signal sync from older digital technologies? Well, DMR (and in particular MOTOTRBO) has 2 layers of packet recovery: Forward Error Correction and Cyclic Redundancy Codes. DMR has better RF coverage than older digital technologies.

Could there be more? Of course there is! Motorola DMR radios feature roaming. Roaming works similarly to mobile/cellular phone technology. If you program your radio properly it will find the repeater with the best signal in your local area and without your intervention, it will roam to that repeater. Lately, distracted driving and safety have become very important issues. MOTOTRBO DMR allows you to focus your attention on driving and not on changing repeater channels. Roaming is used extensively in Northern California, New England, and Chicagoland.



How many DMR repeaters and users are there?