Order Tray | Contact Us | Home | SIG Lists

[aprssig] NEW! IC-V82 - VHF/APRS Transceiver

Gerry Creager n5jxs gerry.creager at tamu.edu
Thu Mar 3 11:51:31 UTC 2005


Based on seeing it in action... a couple of friends have been 
using/testing for over a year... I respectfully disagree.  There are 
some interesting quirks indicating they snagged technology from other 
sources: using ATM for the RF portion is consistent with other wireless 
applications I've worked with in the licensed and unlicensed world.

Audio sounds pretty good, deployment isn't difficult.  Data works.

Gerry

Stephen H. Smith wrote:
> After wading through all the broken English in the technical description 
> and PowerPoint presentation on the Icom site,  my conclusion was that 
> the whole D-Star system is far too complex for widespread adoption by hams.
> 
> It turns out there are TWO separate on-air transmission formats - a 
> 4.8Kb/sec stream for low-speed data (like callsign ID, selective calls 
> and GPS posits) and AMBE-vocoded digitized speech   --and--   a 
> high-speed 128KB/sec mode that amounts essentially to ".1BaseT"  
> Ethernet.    Separate receivers and transmitters are used at the 
> repeater site for each format.; i.e. you have to somehow combine two RX 
> and two TX into your antenna system(s) for a single "channel".
> 
> The low-speed format is for use on 2 and 440 while both the low and 
> high-speed formats would be available on 1260 only.
> The system architecture  (clusters of 144/440/1260 repeaters in one area 
> tied together by 10 GHz RF links  are  connected to clusters in other 
> geographic areas via high-speed Internet connections)   has a strangely 
> close resemblence to the architecture of Motorola SmartZone commercial 
> networks, even to the QOS prioritizing of voice vs non-voice packets in 
> it's IP neworks.
> 
> Oddly,  one of the most interesting documents on the Icom site (though 
> incredibly dry) was the "history" of the development of this system 
> which involved an absolutely ludicrous amount of politics between JARL 
> (Japan Amateur Radio League), various government ministries and Icom to 
> be authorized to put this experimental system on the air on existing ham 
> bands.  It appears that there was a lot of support and seed money 
> provided by the Japanese Communications Ministry.  Near the end of this 
> account was the final outcome that no more than two hops over-the-air 
> would be allowed (more than that would require Internet linking) because 
> more than that would constitute "a commercial communications 
> company"!     [ At least it addresses abusively long paths .... ]
> 
> ------ BOTTOM LINE ------
> 
> I wonder if this whole thing is kind of a beta test for a kind of  
> Made-In-Japan "Smartzone Lite" to be sold in the commercial landmobile 
> market to public safety users in smaller communities  that can't afford 
> the incredible complexity and expense of Motorola's current offerings.  
> [ Motorola has completely abandoned the analog and small-systems market 
> already to the Japanese land-mobile mfrs and New Zealand's Tait Radio.   
> Moto quite making analog base stations last September.]
> 
> 
> 
> 
> Stephen H. Smith             wa8lmf (at) aol.com
>                                                    Home 
> Page:                   http://wa8lmf.com
> 
> New/Updated "Rev G" APRS     http://webs.lanset.com/wa8lmf/aprs
> Symbols Set for UI-View,
> UIpoint and APRSplus:
> 
> 
> 
> 
> _______________________________________________
> aprssig mailing list
> aprssig at lists.tapr.org
> https://lists.tapr.org/cgi-bin/mailman/listinfo/aprssig

-- 
Gerry Creager -- gerry.creager at tamu.edu
Texas Mesonet -- AATLT, Texas A&M University	
Cell: 979.229.5301 Office: 979.458.4020
FAX:  979.847.8578 Pager:  979.228.0173
Office: 903A Eller Bldg, TAMU, College Station, TX 77843




More information about the aprssig mailing list