| |
ZL3AI > APRDIG 30.09.03 10:50l 234 Lines 9250 Bytes #999 (0) @ WW
BID : 2030-ZL3AI
Read: GUEST
Subj: TAPR Digest, Sep 27, 6/7
Path: DB0FHN<DB0RGB<OK0PPL<DB0RES<ON0BEL<ZL2BAU<ZL3VML
Sent: 030929/1358Z @:ZL3VML.#80.NZL.OC #:9308 [Chch-NZ] FBB7.00i $:2030-ZL3AI
From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: RE: More Complexity-Yes, was Re: APRS Grass growing...
From: "Scott Miller" <scott@home.miller.org>
Date: Sat, 27 Sep 2003 10:39:44 -0700
X-Message-Number: 26
I agree, we're never going to get past the ALOHA limit without some
agressive timeslotting. Of course, the TX-only trackers have trouble with
that, but everyone seems to neglect the fact that even those units still
have access to a very accurate clock reference through GPS.
Now, without having a 1-pps or IRIG output or something, I don't think
you're going to be able to get resolution of better than 1 or 2 seconds. My
Garmin eTrex puts out an NMEA burst every two seconds or so, and I have no
way of knowing if the time reported was the time at the beginning of the
sentence, the time at the beginning of the cycle, or something else
entirely.
Even with limited resolution, though, you could still say, for example, that
all TX-only trackers will only transmit during the top half of the minute,
and in a slot designated by the low four bits of an XOR hash of the
tracker's callsign+ssid, plus or minus a random value of up to half a slot
time. (For the non-programmers out there, this would have the effect of
assigning one of 16 possible slot times to trackers, with a fairly random
distribution, and the random element would keep you from always doubling
with someone else assigned to the same slot.)
I think the tricky part in any master/slave timeslotting is going to be
dealing with stations that can be heard by more than one 'master'. Don't
cell sites handle this with a back channel between sites for coordination?
Scott
N1VG
----------------------------------------------------------------------
Subject: Re: More Complexity-Yes, was Re: APRS Grass growing...
From: "Georgette Sampson" <georgette.sampson@cox.net>
Date: Sat, 27 Sep 2003 13:07:43 -0500
X-Message-Number: 27
>Even with limited resolution, though, you could still say, for example, that
>all TX-only trackers will only transmit during the top half of the minute,
I like it, as it would provide limits even in the current environment.
>I think the tricky part in any master/slave timeslotting is going to be
>dealing with stations that can be heard by more than one 'master'.
Yes, everyone would want to download the code and put up masters
everywhere :-)
>Don't cell sites handle this with a back channel between sites for
>coordination?
Don't know, but I was just assuming some sort of UHF/Inet table based
filter, as one tracker joining four Net's in the same 25 miles would really
generate a lot of noise!
----------------------------------------------------------------------
Subject: Funny! Paths!
From: "Spider" <spider@rivcom.net>
Date: Sat, 27 Sep 2003 11:29:08 -0700
X-Message-Number: 28
Typical conversation about paths! I changed the other fellows call!
Kxxxx ³<A45>There is no one there. I just left after setting it up.
WA6OFT-1 ³<A24>hi
WA6OFT-1 ³<A25>just testing paths
Kxxxx ³<A47>ok, have fun. do you want me to increase my probe's path?
<g>
WA6OFT-1 ³<A26>WIDE,WIDE seems to work well
Kxxxx ³<A49>yeap, my none probe station posit only goes to XXXXX.
WA6OFT-1 ³<A27>I see your probe as TRACE4-2
WA6OFT-1 ³<A28>Your probe covers about 800 miles
Kxxxx ³<A50>yes, i've been going to some ui-view webservere pages to see
how
Kxxxx ³<A51>often i go 800 miles. i'd day about 60% of the time.
WA6OFT-1 ³<A29>why do you need to cover such an area?
Kxxxx ³<A52>i don't.
WA6OFT-1 ³<A30>???
Kxxxx ³<A53>have to have something you can complain about.
WA6OFT-1 ³<A31>Best answer I've heard yet!
----------------------------------------------------------------------
Subject: RE: Emergency Power lights.
From: "Sean \\The RIMBoy\\" <sean@rimboy.com>
Date: Sat, 27 Sep 2003 13:07:35 -0500 (CDT)
X-Message-Number: 29
On Fri, 26 Sep 2003, Ken Brown wrote:
>When I ran my 3500 Honda generator I noted that my regular 4 foot
>fluorescent tubes were very sensitive to voltage swings, so I used only
>incandescent bulbs.
This is getting a little OT, but fluorescents will do a full on off on a
60Hz cycle while the incandescents have less of that because of the
filament. Explains why some people have a hard time working in
environments with fluorescent lighting, especially where computers are
involved (such as me).
Sean...
--
Believing I had supernatural powers, I slammed into a brick wall.
--Paul Simon
_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_
KG4NRC http://www.rimboy.com Your source for the crap you know you need.
----------------------------------------------------------------------
Subject: RE: Emergency Power lights.
From: "Mark Fellhauer" <sparkfel@qwest.net>
Date: Sat, 27 Sep 2003 15:41:15 -0500
X-Message-Number: 30
At 01:07 PM 9/27/2003, Sean \\The RIMBoy\\" <sean@rimboy.com> wrote:
>This is getting a little OT, but fluorescents will do a full on off on a
>60Hz cycle while the incandescents have less of that because of the
>filament. Explains why some people have a hard time working in
>environments with fluorescent lighting, especially where computers are
>involved (such as me).
Yeah, in 1950...
Depends on the ballast. Most newer Flourescents and CF's do not cycle at
60 Hz - more like between 18,000 and 100,000 Hz. Enought to trigger or
interfere with many IR remote controls...
Mark
KC7BXS
----------------------------------------------------------------------
Subject: RE: Emergency Power lights.
From: "Spider" <spider@rivcom.net>
Date: Sat, 27 Sep 2003 14:01:46 -0700
X-Message-Number: 31
From: "Mark Fellhauer" <sparkfel@qwest.net>
To: "TAPR APRS Special Interest Group" <aprssig@lists.tapr.org>
Sent: Saturday, September 27, 2003 1:41 PM
Subject: [aprssig] RE: Emergency Power lights.
>Depends on the ballast. Most newer Flourescents and CF's do not cycle at
>60 Hz - more like between 18,000 and 100,000 Hz. Enought to trigger or
>interfere with many IR remote controls...
Hey! If your Flourescents do not flicker, you ain't running enough power!
13 watt flourecent bulbs are used by some in RF radiation safety classes to
give public service types an idea of why you do not want to always stand by
your antenna while talking on the radios! 100 watts at 150 mhz will light
a bulb just fine! ;)
Jim
WA6OFT
----------------------------------------------------------------------
Subject: LANn-N routing.
From: Bob Bruninga <bruninga@usna.edu>
Date: Sat, 27 Sep 2003 17:14:12 -0400 (EDT)
X-Message-Number: 32
Here is another WIDEn-N alternative:
If you have a large but contained area of cooperating SYSOPS that can
agree that they want their large area to share traffic, yet be immune to
out-of-area QRM, then change UIFLOOD from WIDEn-N to XXXn-N in their area.
Lets use New Mexico as a good statewide system with something like about
15 digipeaters that can get traffic anywhere in the state with a path of
WIDE5-5 (or whatever).
PROBLEM is, that having UIFLOOD set to WIDEn-N allows all kinds of out-of-
area QRM to FLOOD their nice network. But if they changed UIFLOOD to
something like NMn-N, then their users could use a path of WIDE,NM4-4 and
know that their packets would cover the entire state, would NOT QRM
surrounding states, and WOULD keep their state from seeing QRM from 800
miles away.
In otherwords, we are "SQUELCHING WIDEn-N" but doing so by replacing it
with something far more valuable to the LOCAL area that implements it.
San Diego for example is a nice "isolated" area maybe. Maybe they dont
want to see all the routine traffic from LA. So they just change their
UIFLOODS to SDn-N and now they have CONTROL of what their network does AND
it is self limiting, both on INBOUND traffic and OUTBOUND traffic. Yet it
does do the original intended job of WIDEn-N locally.
BUT ALL SYSTEMS MUST CONTINUE TO SUPPORT THE UNIVERSAL RELAY/WIDE callsign
substituting digipeating and all these UIFLOOD's must have ID OFF! This
assures two things 1) SUpports the UNIVERSAL APRS standards for Everyone
and 2) assures that WIDE,LANn-N packets are always identified as to where
they entered the network.
Now the big question, is can we ever find ANY area of "cooperating" digi
sysops that agree on anything...
Good luck!
de WB4APR@amsat.org, Bob
----------------------------------------------------------------------
Subject: RE: LANn-N routing.
From: "Scott Miller" <scott@home.miller.org>
Date: Sat, 27 Sep 2003 14:43:59 -0700
X-Message-Number: 33
A big problem with regional settings like this is that when people want to
know how to set up their equipment (if they bother to find out at all),
they're going to go look on the web. And what they find isn't likely to be
specific to their area. Those that know where to look, and what they're
looking for, are probably not the ones likely to be causing a problem in the
first place.
----------------------------------------------------------------------
Subject: Re: LANn-N routing.
From: "Spider" <spider@rivcom.net>
Date: Sat, 27 Sep 2003 14:47:32 -0700
X-Message-Number: 34
From: "Bob Bruninga" <bruninga@usna.edu>
To: "TAPR APRS Special Interest Group" <aprssig@lists.tapr.org>
Sent: Saturday, September 27, 2003 2:14 PM
Read previous mail | Read next mail
| |
