ARLA/CLUSTER: Recomendações sobre sistemas Digitais da Connecticut Amateur Radio Emergency Service (ARES)

[João Gonçalves Costa]

 Prezados Colegas,

Chamo a vossa especial atenção sobre as recomendações referentes á " DIGITAL VOICE ".

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     CT1FBF / João Gonçalves Costa
     QRA-Locator : IM58kq
     CQ Zone: 14  /  ITU Zone: 37
     E-mail and Adress, see in:
     www.qrz.com
     QSL Card via Eqsl: www.eqsl.cc
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RECOMMENDATIONS

Please note that these recommendations exist so that we can work well together today. Nothing here should be taken as an attempt to limit experimentation with any software, any hardware, or any modes. Experimentation is how we learn what we should do next. Please let us know of any new or exciting experiments you are doing, and we will do the same!

PACKET HARDWARE AND SOFTWARE
Packet Hardware Recommendation: For VHF/UHF TNCs we recommend Kantronics TNCs such as the KPC-3 or KPC-9612. The KPC-9612 will do 9600 baud and should be considered for new purchases, especially in EOCs. We hope to get some 9600 baud links up late this year or early next year. This is not to say that users cannot use other TNCs, just that we recommend these for new purchases, especially in EOCs or other places with multiple operators.

Packet Software Recommendation:
For VHF packet we recommend the following software be loaded on all EOC and shared computers. Having more than one package available allows for some operator preference and also allows for using the most appropriate software for a given task:

- AirMail - this free software can be used for station-to-station, station to Flexnet/FBB and station to Winlink communications.

- Hyperterm - This free software module comes with many versions of Windows and is the ultimate fall-back. Also useful for troubleshooting

- Pacterm for Windows for Kantronics - This commercial fee-based package ($100) works with many TNCs and supports sound card as well as Kantronics TNCs.

This is not to say that users cannot use other software, just that we recommend these packages be installed in EOCs and other places with multiple operators.

DIGITAL VOICE
We reviewed Alinco's digital radios, the P-25 standard used in Public Safety and by some Amateur Radio operators, as well as the D-Star standard which has evolved within the Japanese Amateur Radio League (JARL).

The Alinco digital radios do not have a corresponding repeater and have not received good reviews.

 The P-25 standard radios are very expensive, single band units and we feel are impractical for general amateur use. Therefore, we are recommending that anyone considering digital voice use the D-Star standard.

 While Icom is the only company currently making these radios,(before July 2007) there are rumors that other manufactures will soon make them as well.

JARL is a legislative group in Japan and has decreed that any digital voice radio sold in Japan support D-Star.

 Since almost all VHF/UHF amateur radio gear is manufactured in Japan, the JARL decree should result in compatible radios for us as well.

 JARL controls the D-Star standard, not Icom.

**What are the benefits of digital voice instead of FM?** Digital voice uses less bandwidth while providing superior voice quality and allows for low speed (1200-baud) data at the same time the station is transmitting voice. Future use of D-Star could allow us to put three D-Star repeaters where two FM repeaters are currently in place.

**When will we be switching to digital voice?** Like any major move, we see this being something that will happen over a decade or more. We expect very slow adoption of digital voice. Please note that the D-Star radios also do FM, so they are backward compatible (can be used with the older standard - FM.)

*Do I need to buy a new radio?* *There is no new need to go out and buy a new radio. However, for those wanting to experiment with the leading edge technology, the D-Star radios are about $100 more than a comparable FM only radio. (D-Star radios do FM and D-Star.)

We do recommend that people buying a digital radio buy a VHF/UHF dual band radio since initial repeaters will likely be UHF, but eventually we expect to see VHF as well.

**What do I need to do today?** There is no need for any particular action. There are people and clubs that want to begin working with digital voice, and we felt it appropriate to come forward with a recommendation so that anything that is done will be compatible with each other. Like any other Amateur Radio mode, it is up to each operator when and if they want to pursue using that mode.

HF DIGITAL COMMUNICATION
For HF digital communications we do not currently have a complete set of recommendations, but AirMail and HyperTerm will fill many needs for HF, including Winlink classic and Winlink 2k. If you are using Airmail for HF, please install the optional propagation prediction module. We are studying WinPSK and MixW at this time, but are not prepared to make a recommendation.