| |
ZL3AI > APRDIG 26.09.03 12:20l 188 Lines 7899 Bytes #999 (0) @ WW
BID : 1987-ZL3AI
Read: GUEST
Subj: TAPR Digest, Sep 23, 7/7
Path: DB0FHN<DB0RGB<DB0FSG<OE7XLR<DB0PV<DB0MRW<OK0PKL<OK0PPL<DB0RES<ON0BEL<
VK7AX<ZL2BAU<ZL3VML
Sent: 030925/1624Z @:ZL3VML.#80.NZL.OC #:9015 [Chch-NZ] FBB7.00i $:1987-ZL3AI
From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: Re: Tactical RF Networking !!!
From: "Scott Miller" <scott@opentrac.org>
Date: Tue, 23 Sep 2003 14:18:01 -0700
X-Message-Number: 33
Check out 'Extensive Simulation Based Evaluation of MANET Broadcast
Protocols using a Simulation Framework' at
http://voop.free.fr/Teaching/2002/manet_broadcast.shtml.
----------------------------------------------------------------------
Subject: Re: Tactical RF Networking !!!
From: Wes Johnston <wes@johnston.net>
Date: Tue, 23 Sep 2003 19:42:41 -0400
X-Message-Number: 34
For ACK'ed packets you need to use a connected mode protocol. If we use
AX25, then you have the issue of 5 packets to connect. If you use TCP,
then you still have to establish the connect, BUT (the big BUT), you can
now move around the network and still get ACKs if RIP is implemented.
Consider: AX.25: you connect to the EOC via several digpeaters....
kd4rdb>EOC v digipeaterA, digipeater B, digipeater C. Now, if i move out
of range of A, but am right under the EOC's nose, my packets don't get
ACKed. We need to use TCP or design a more "promiscuous" version of AX25
which will allow connected stations to ACK a packet early. This would
allow us to use connected mode over generic digipeater names.
Once connected, a string would go out via generic names....
kd4rdb> EOC v relay, wide3-3
The EOC may hear it as
kd4rdb>EOC v relay*, wide3-3:$GPRMC......
or as
kd4rdb > EOC v relay, wide3-0:$GPRMC.....
in either case, it would respond with it's generic path ACK
EOC > kd4rdb v wide3-3: RR0
my station can hear the ACK anywhere along it's return hops....
This was one of the aggravations of connected mode packet for me. I'd
connect to the local BBS (which I could hear some of the time direct) via a
local digipeater. Even though I'd seen the BBS's packet sent to me direct,
my station wouldn't ACK the packet until it came from the digipeater which
was mentioned in the connecting path. It's crazy. It needs changed. When
it is changed, your tracker could establish a connection with a particular
station and travel (don't the call it roaming now?) over a pretty large
area.
Wes
----------------------------------------------------------------------
Subject: Re: Tactical RF Networking !!!
From: "Spider" <spider@rivcom.net>
Date: Tue, 23 Sep 2003 17:27:42 -0700
X-Message-Number: 35
I think people expect too much of APRS and are expecting to use it totally
out of it's bounds.
I think it is VERY UNREASONABLE to expect all traffic coming in on one
channel (144.390) in a tactical environment. I think it is VERY REASONABLE
to expect traffic coming in on several channels, properly designed to
minimize RF interference to each other. This DOES NOT split up the
'network' as Bob points out. I think Bob, you constantly forget LOCAL and
TACTICAL. The 'network' is local. That could mean 20 SAR members being
tracked by a remote command vehicle using 1 portible digi...or maybe not
even 1 digi at all. Local could mean 5 fire teams being tracked on 144.39.
Sensor data coming in on 145.55 and in/out messaging traffic being done on
a 145.07 connected mode packet (or how about an email link like they are
playing with in Colorado!) Local could mean 5 hams getting together for an
eyeball at a local coffee shop. (I might add NONE OF THIS needs to be seen
clear accross a state and more than likely only needs to be seen with some
form of boundry like a county or city, etc. Still, this is only part of
your tactical RF network! You'd be nuts not to expect voice channels
handling most of the demanding urgent traffic.
APRS is an excellent protocol to see objects and stations. However, for a
total Tactical RF Network, it's only a small part of the total picture and
at 1200 baud your network is going to be limited no matter what, regardless
of what fancy software you can dream up. You can increase your throughput
by just simply adding channels to your local network! That is kinda like
how a dumb form of multiplex works. If they all come together in your
'local RF network' who gives a darn if they do not come in on 144.39.
Want a cleaner 'local' network, add a SENORS channel and move all the
weather stations, gaging stations, telemetery stations to it. Want a
messaging channel? Move all messaging to a MESSAGE channel. Move your
traffic counters to a STATUS channel Your 'network' will work better!
Nobody but hams try this all on one 1200 baud channel! As long as all your
traffic comes together somewhere where it's needed, (an ICP, EOC or even a
connection point to a real WAN), your 'local RF network' will work much
much better.
Quit thinking 1 channel! Free your minds, the rest will follow.
It's absolute rocket science, I tell you!
Flame suit on
Jim, WA6OFT
----------------------------------------------------------------------
Subject: TRACKING THIEF IN CARMEL, CA
From: "Syms, Robert" <R3Sr@pge.com>
Date: Tue, 23 Sep 2003 17:56:30 -0700
X-Message-Number: 36
I spent my anniversary in Carmel, CA this past weekend. Saturday I had
been riding my bike with my wife KD6RVK around down town Monterey.
Carrying in a forest green backpack like computer bag was my digital
video camera, digital camera, binoculars, two cell phones equipped with
aGPS, and of course my Kenwood D7g HT. After riding for the day we were
packing our bikes into our Heep, I mean Jeep. My bag was ripped off full
of electronics during daylight hours on a busy street near Cannery Row.
The balls it takes to pull this off amazes me to no end! I was no more
than 3 feet from the bag and turned for only seconds as it disappeared.
Well this is where you all are asking if the tracker was active... No I
had not turned the beacon on to send locations. But wait, the cells have
aGPS and one phone was left on. A simple call to Verizon should do the
trick. "Sorry sir we can't track your phone. The Laws prohibit us." What
a crock of poop. I am out of luck I guess the only way this thief will
get caught is if he calls to 911 on my phone and basically turns his/her
self in. If any of you see on E-bay or other place a Kenwood D7g for
sale in the Monterey, CA area please send me the information so I can
investigate. The radio display when first turned on shows my name "Rob
Syms" and is programmed to beacon out KO6ZL.
My E-mail: RSYMS@PACBELL.NET
Thanks,
Robert Syms KO6ZL & Betsey Syms KD6RVK
----------------------------------------------------------------------
Subject: Excessive packet lengths
From: Wes Johnston <wes@johnston.net>
Date: Tue, 23 Sep 2003 21:39:19 -0400
X-Message-Number: 37
Wow... look at this one... heard locally on my station in sumter SC. The
packet originated 200 miles north of me.
K4**>APU25H,KD4HTW-9*,WIDE3:
<<UI>>:}WG4R>APU256,TCPIP,K4***:@221627z3646.18N/08024.09W_016/001g003t063r001p1
00P001b10192h99Mabry
Mill, Blue Ridge Parkway, VA {UIV32N}
He's IGATEing wg4r wx station with an enormous path.... 170 bytes takes 1.5
seconds / hop... any idea how many hops this could have taken other than
the 3 it took to get to me?
Wes
----------------------------------------------------------------------
Subject: South Carolina Digital Day
From: Wes Johnston <wes@johnston.net>
Date: Tue, 23 Sep 2003 23:01:59 -0400
X-Message-Number: 38
SC Digital Day will be comprised of a demo of PSK31, Echolink and APRS.
One of the seminars will be located at SC Forestry Commission HQ on Highway
52 Florence SC this is next to Florence Darlington Technical College on the
right.
Should last from 9am until.
2.5 miles from I-95 travel on Hwy.52 toward Darlington, when you past the
last Tech entrance you will cross over into Darlington Co. You need to turn
the very next driveway into the SCFC HQ. This is before you past Yellow
Freight Trucking.
34 14 49N 79 49 07W
The other will be held in Charleston, not sure where exactly....
---
END OF DIGEST
Read previous mail | Read next mail
| |
