N9KOJ 로버트 최 오엠님이 미국의 DV4mini 공급사인 Wireless Holdings 에서 받은 메일을 중계해 주셨습니다.
1) 이 메일의 첫번째 내용을 보면 DV4mini 2015년 12월 1일 테스트버전에서 D-Plus based 시스템에서 리플렉터로
연결을 하고 연결을 끊는데 무전기에서 명령을 내릴 수 있다고 소개되어 있습니다.
Link 와 Unlink 명령은 구현되었고 Info 명령은 나중에 추가될 거라고 쓰여 있네요.
D-Plus Based System 이라면 REF 리플렉터를 이야기 하는데...
URCALL에 "REF001CL" 또는 "_______U" 식으로 사용하게 되겠지요?
사용법에 대한 설명이 없어서 자세히 알기가 어려운데...
제가 테스트해 봤을 때 제대로 작동되는지 확인할 수가 없네요.
테스트 가능하신 분들께서는 테스트 해보시고 댓글 부탁드립니다.
2) 메일의 두 번째 내용은 일부 DPMR 무전기 (SELP 칩을 사용하는 무전기)는 DV4mini와 호환되지 않는다는 내용입니다.
-----Original
Message-----
From: "Wireless Holdings"<monika@wirelesshold.com>
To: <n9koj3@naver.com>;
Cc:
Sent: 2015-12-09 (수) 11:03:30
Subject: DV4mini - Nets & Facts
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DV4mini - RF Reflector switching and DPMR
Now that there
are many DV4minis out in the field and people are playing with it, we
have decided to inform you about some upgrades which have been made
in the meantime.
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This is a
typical DV4mini setup with a Raspberry Pi and a Windows tablet.
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D-Plus RF Reflector Linking
As you all know, the DV4mini was originally developed in Europe
and it used DTMF commands to switch between DCS reflectors.
However, in the US there are many D-Plus based systems which use
RF switching to link and unlink reflectors. To accommodate
these installations a new software version has been developed and is
available as a test version at http://dv4m.ham-dmr.ch/Testversionen/windows/ dated
December 1.
The Link and Unlink commands are already implemented. The Info command will be added later.
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pDMR
There are different versions of DMR radios available.
The Motorola and Hytera radios, which we currently use, have a
channel bandwidth of 12.5 kHz and 2 time slots. This is called tier 2
DMR, There is a simpler version, tier 1 DMR, available which uses
just a 6.25 kHz wide channel, similar to D-Star. This is called
private DMR or pDMR.
The pDMR radios are cheaper than the DMR radios, however the codec in
DMR is not standardized. While all the tier 2 radios use the AMBE
chip, the manufacturers of pDMR radios use both AMBE
and sometimes SELP. Using SELP makes the radios
cheaper but they are not compatible with AMBE based codecs.
In the latest version of our software we offer pDMR support as an
experimental mode. It will give the amateur radio community access to
more affordable equipment.But keep in mind, this is experimental and
there are no guarantees for compatibility between manufacturers and
codecs.
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