[Xastir] A good time for APRS at 9600?

[Andrew Rich]

Nah - go ADS-B speeds 1 Mb/s up on 1296 Mhz


----- Original Message ----- 
From: "Tom Hayward" <esarfl at gmail.com>
To: "Xastir - APRS client software discussion" <xastir at lists.xastir.org>
Sent: Sunday, November 13, 2011 4:01 AM
Subject: Re: [Xastir] A good time for APRS at 9600?


> On Fri, Nov 11, 2011 at 21:20, Guy Story <kc5goi at gmail.com> wrote:
>>
>> This question comes up every so often. I use to wonder the same thing 
>> years ago. If memory serves me correctly, and I know this is not 
>> verbatim, WB4APR said that given the length of a posit in relation to the 
>> transmit time and the txdelay, 9600 does not really pay off. The txdelay 
>> would eat up more time than the actual posit.
>
> 9600 baud data is 8 times as fast as 1200 baud. When you factor in the
> txdelay and length of an average APRS packet, 9600 baud APRS comes out
> to about twice as fast as 1200 baud. To me, that seems significant
> enough to be worthwhile.
>
> In the Pacific Northwest, there are a number of people experimenting
> with 9600 baud APRS. They have a reasonable network of i-gates and
> digipeaters. They've shown a couple of things: 9600 baud works for
> APRS; it can be more reliable for mobiles (less chance flutter will
> corrupt the packet, because the data burst is so short); and it ends
> up doing more for the network than halving the bandwidth because it
> moves a lot of stations off 144.39 and onto an alternate channel. Most
> of that network is Kenwood D700's, D710's, D7's and D72's.
>
> Tom KD7LXL
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