Difference between revisions of "Digital 2-Way Radio"

Revision as of 12:36, 15 April 2016

Digital radio communication on FCC Part 90 (Land Mobile Radio Service) and Part 97 (Amateur Radio Service).

Although DStar was developed for ham radio the other standards here were developed for commercial use and later adopted by ham radio. This often leads to commercial gear being modified for ham radio, a less than desirable option when compared to the flexibility of actual ham gear. Proprietary elements of much of the digital equipment is not compatible with the spirit and meaning of ham radio, yet that is being overlooked for some reason as more of these digital standards are being used by hams.

DStar

DStar ( Digital Smart Technology Amateur Radio / D-STAR / DSTAR ) was designed for amateur radio and uses both RF and the Internet. D-STAR compatible radios are available for HF, VHF, UHF, and microwave amateur radio bands. D-STAR generally operates on VHF and UHF frequencies and allows repeaters to link with each other over the Internet. There are currently two types of DTMF switching being used with Star.

DV is used rather than FM. DV stands for Digital Voice. In Digital Voice mode, D-STAR supports voice as well as slow speed data transmissions.

DStar is NOT an open standard. DSTAR uses a closed-source proprietary voice codec (AMBE) that's patented by Digital Voice Systems, Inc. (DVSI). Even though D-STAR is not only an Icom system, the word DStar is a registered trademark of Icom. Because the voice codec is technically a form of encryption, the use of DStar shouldn't even be permitted by FCC rules.

DMR

DMR is an open and published international digital radio standard that specifies the 2-slot (channel) TDMA communications. D It was developed for commercial use, however, ham radio now has approval to use DMR. MR is amateur radio's newest digital protocol.

TDMA

Motorola does not own the DMR standard. MotoTRBO is DMR. The manufacturers of DMR equipment have agreed to use the ABME2+ vocoder algorithm from DVSI Inc. - ABME2+ is licensed by DVSI Inc.

If you intend on Using DMR you can register with the DMR-MARC Worldwide Network, which will allow you access to the many DMR repeaters available worldwide. DMR-MARC is for MotoTRBO radios as well as compatible DMR clones including the Tytera MD-380.

TRBO / MOTOTRBO

Motorola digital radio. Compatible with the European 2-slot DMR standard and uses Time Division Multiple Access (TDMA). MotoTRBO has a few more features than a standard DMR radio including IP Site Connect. Motorola maintains two-slot 12.5 kHz TDMA-based systems, providing 6.25 kHz equivalency.

MOTOTRBO radios have the ability to scan an analogue and digital channel for activity.

Like DStar, Mototrbo uses a proprietary codec. The voice codec is technically a form of encryption, the use of Mototrbo shouldn't even be permitted by FCC rules. In this case Motorola has enough financial muscle to encourage the FCC to "bend the rules."

Motorola MOTOTRBO radios are expensive and for many cost prohibitive for ham radio operators. However, there other manufacturers introducing DMR units for amateur radio and the cost is considerably less than DStar. Hytera and Vertex produce compatible radios. These are commercial radios that can be adapted for ham use, which is not as flexible as radios designed for ham operators.

Hytera makes a mototrbo compatible clone radio. The Hytera PD362 Digital DMR is a compatible HT. Tytera MD-380. The Tytera MD-380 digital radio uses Digital Mobile Radio (DMR) Tier 2 Standard protocol. It is compatible with the popular MOTO TRBO series Tier I and II using standard encryption, as well as other makes and models of DMR supported radios

dPMR

dPMR is an open, non-proprietary standard that was developed by the European Telecommunications Standards.

FDMA

Radios using dPMR are not compatible with DMR radios.

NXDN

Institute. NXDN is intended for commercial Private Land Mobile Radio (PLMR) and some public safety communications systems. NXDN uses Frequency-Division, Multiple-Access (FDMA) technology. NXDN is digital and can be either 12.5 kHz or 6.25 kHz wide. The AMBE+2 voice codec is used.

NexEdge

Kenwood NEXEDGE is a digital radio brand from Kenwood which uses the NXDN Common Air Interface. NXDN CAI uses Frequency Division Multiple Access (FDMA), employing a 4-level FSK modulation scheme.

IDAS

Icom's brand for NXDN equipment is "IDAS", or Icom Digital Advanced System. NXDN is implemented by Icom in their IDAS system.

Fusion

Yaesu Fusion aka System Fusion is Yaesu company's entry into the digital mode ham radio market. It has a feature missing from many of the other digital modes in the repeater, and that is the ability to operate in mixed mode digital and analog.

Fusion makes it possible for you to send digital pictures if your fusion radio has a camera.

All System Fusion radios, (FTM-400DR mobile, FT1D and FT2D) radios can operate in fixed FM mode, DN (Digital Narrow @ 6.25 KHz ) or VW (Voice Wide 12.5 KHz signal).

Questions:

1) Did fusion come from the Part 90 world like DMR/MotoTRBO, or was it developed for ham radio like D-Star? 2) Does fusion support data roaming like D-Star and MotoTRBO? 3) Talk groups and IP packet support?

C4FM FDMA

System Fusion C4FM by Yaesu is the current implementation of Yaesu's digital radio for ham.