Author Topic: When cell towers and landlines are overloaded  (Read 21062 times)

Offline DonC

  • Survivor
  • ***
  • Posts: 143
  • Karma: 35
  • We have met the Enemy and he is us......
Re: When cell towers and landlines are overloaded
« Reply #30 on: October 05, 2016, 10:53:01 AM »
The company sells different cables for different radios. That shouldn't be an issue. If you ask them, they'll build you whatever cable you need.

Offline Smurf Hunter

  • Survival Veteran
  • ********
  • Posts: 7172
  • Karma: 334
Re: When cell towers and landlines are overloaded
« Reply #31 on: October 05, 2016, 11:10:09 AM »
I built one to connect to the old fashioned KAM: http://thesurvivalpodcast.com/forum/index.php?topic=57631.0

I may use a female DB9 that mates into the cable shown in the HOWTO.
I think soldering a stripped CAT5 cable to both a mono 3.5mm audio jack (for mobile radio speaker out) and to the TRRS 3.5mm (like a smart phone headset) would get flimsy.
So all I need is a raw TRRS male connector (which mobilinkd sells https://store.mobilinkd.com/products/3-5mm-4-pole-trrs-male-plug-tnc-connector), a 3 conductor wire and a female DB9.



Imagine this layout, but instead of the Kenwood/BaoFeng plug on the left, a female DB9:


Offline DonC

  • Survivor
  • ***
  • Posts: 143
  • Karma: 35
  • We have met the Enemy and he is us......
Re: When cell towers and landlines are overloaded
« Reply #32 on: October 05, 2016, 11:14:18 AM »
That would be a much more solid cable.

Offline iam4liberty

  • Survival Demonstrator
  • *******
  • Posts: 4033
  • Karma: 321
  • New TSP Forum member
Re: When cell towers and landlines are overloaded
« Reply #33 on: October 05, 2016, 08:37:02 PM »
"packet" radio is analogous to IP or "Internet protocol", which has connections (TCP) and connection-less (UDP). 
Then there are application protocols on top of each.  HTTP (which your web browser is using to read this) rides on top of TCP.
UDP is used for broadcasting data, sort of like a beacon. 

Exactly the same arrangement.  Though APRS messaging does use ACKs which adds another protocol layer.  So it hugs the middle ground between connection and connection-less.  This addition of ACKs is why it is important to limit the length of APRS messages.

Good stuff.  Seems I just need to make sure a windows laptop can talk bluetooth with the mobilinkd and RMS express should work.
Only other hurdle is building an interface cable to connect to a full power mobile radio.  Winlink Packet will probably cook a Baofeng HT after a

Yes.  This will work.  RMS Express software no longer exists under just that name.  It was changed to Winlink Express.  It works great. 

There are a couple of additional watch-outs.  One is that some inexpensive radios (specifically some of the Chinese handy talkies) have difficulty switching fast enough between TX and RX.  They work fine for APRS applications but not for traditional packet radio.  The second is that some of the older software packages require the serial port to be manually chosen.  The problem with this is that the PC can change assignments each time you connect a bluetooth device.  So if you are trying a piece of software and it works but then doesn't after a reboot this is the thing to check.  It drove me crazy the first time it happened to me.

So, I couldn't just rely on one quote alone. So I emailed Mobilinkd LLC, last night. See the reply below. Much as I expected, if you use the device for its intended purpose, you shouldn't have any issues. Don't get me wrong, the folks in yahoo groups can be insightful. I belong to a few different groups. But they're filled with folks trying to figure out other uses for apps, devices, etc.

I just want to reiterate: the issue is that there is no kiss terminal software on android for traditional packet radio.  What Rob Riggs says above is that a program with KISS TNC capability should work.  This is correct.  But unless something has recently changed, none exist.   Windows, check.  Linux, easy-peasy.  Android, no go.

I just worry that some reading this post may think that they can get a mobilinkd, download an app from the app store, and do traditional packet radio via an android tablet or smartphone.  They can easily get APRS up an running in this manner.  It is really simple.  But they can't do traditional packet radio this way.

Offline DonC

  • Survivor
  • ***
  • Posts: 143
  • Karma: 35
  • We have met the Enemy and he is us......
Re: When cell towers and landlines are overloaded
« Reply #34 on: October 05, 2016, 08:49:09 PM »
I haven't tested this app yet, but here is a great article. It's a little dated. But the link to download is still available. I imagine there's an app or 2 floating out there that would work alright. I did a Google search to find packet radio app for android. A few sites popped up like this one. I didn't bother going through them all. Hope this helps.

Offline iam4liberty

  • Survival Demonstrator
  • *******
  • Posts: 4033
  • Karma: 321
  • New TSP Forum member
Re: When cell towers and landlines are overloaded
« Reply #35 on: October 05, 2016, 09:39:51 PM »
DonC, i am not seeing a link.  It might have gotten dropped.

Back on the original thread topic, I just came across an interesting thread on eham.net regarding digital modes in emergencies. 

http://www.eham.net/ehamforum/smf/index.php?topic=44617.0;wap2

This one post talks about the New Jersey APRS system:

In New Jersey, we currently use a digital mode for messaging that most hams don't often think of. That's messaging via APRS.

If you read the APRS protocol, you'll find APRS was originally designed as an emergency communications tool, not just a location reporting display. It has a a bunch of built-in messaging formats, including NTS formats. It also has the benefit of bulletins and a single message to an entire group of stations with simple acks back from each of them, something full AX.25 packet doesn't provide.

The APRS system uses UI frames for rapid communications, but the status of whether your message has been received is easily determined by it's change in color on your screen when the ack comes back from the recipient station.

Distribution of graphical weather bulletins is also done this way.

Also, the APRS protocol makes for a pretty redundant and self-healing network where the density of stations is sufficient, as is the case in NJ

NJSP OEM funded and established APRS stations at each of the 21 county EOC's in the state. They are used in all drills and tested monthly. It's a great system.


« Last Edit: October 05, 2016, 09:46:49 PM by iam4liberty »

Offline DonC

  • Survivor
  • ***
  • Posts: 143
  • Karma: 35
  • We have met the Enemy and he is us......
Re: When cell towers and landlines are overloaded
« Reply #36 on: October 05, 2016, 10:11:04 PM »
Sorry, I forgot to pasterisk the link.

http://www.amateurradio.com/fldigi-ported-over-to-android/

As for APRS messaging. I agree! When I 1st discovered APRS, I didn't like the "tracking" portion of the program. I don't much care for anyone knowing my location unless I tell them. But after messing around with APRSDroid, I found the embedded messaging app. It works like a charm. I'm glad to hear others use it for messaging across the nation. Of course, it's only good if others monitor the frequency, much like they seem to do in NJ.

The only thing that monitors APRS Messages in my area is the digipeater.  But that's soon to change.

Offline iam4liberty

  • Survival Demonstrator
  • *******
  • Posts: 4033
  • Karma: 321
  • New TSP Forum member
Re: When cell towers and landlines are overloaded
« Reply #37 on: October 08, 2016, 10:39:20 AM »
fldigi is a fine program but I don't think it will help us with packet via a mobilinkd.  fldigi uses the sound card of the device rather than an external TNC.

On a different note I have started compiling a list of prepper applications of VHF/UHF APRS:

Telemetry
  • Monitor weather information: wind speed, temperature, barometric pressure, solar radiation, etc.
  • Monitor earthquake information
  • Monitor radiation levels.  This is a fairly new capability coming online in response to Fukushima incident. See here for example:http://aprs.fi/telemetry/a/KI6TSF-8
  • Personal sensors.  Motion detectors, door sensors, glass break sensors... pretty much anything 'state-based' can use the APRS system for relaying over the airwaves or gating to the internet.
  • Monitor the range capability/quality of your vhf/uhf by seeing what stations are receiving your beacons.  With APRS you always know if your station is operational and working properly.
  • Quickly find the repeaters and their frequencies/tones/nets when you enter a new area by reading their beacons

Messaging
  • Text messages to other hams locally via direct RF.
  • Text messages to other hams in remote locations via RF with relay via internet in between
  • Text messages to other hams in remote locations (anywhere in world) via VHF/UHF satellite relay
  • Text messages to cell phone (SMS) and email via RF with internet relay

Tracking/Position Mapping
  • Track your own autos, boats, planes and other assets.  It is has even been used to recover stolen vehicles: http://www.eham.net/ehamforum/smf/index.php?topic=51268.0;wap2
  • Share positions with other group members.  When hiking, Rv'ing, etc. you will know where your team members are. 
  • Beacon out your position and voice frequencies you monitor so other hams can contact you on voice, and vice versa.
  • See other people's assets near your location.  An example application would be seeing nearby airplanes so you can send out an emergency call to them in an emergency.

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13105
  • Karma: 714
  • COW?...No ,I haven't seen your cow.
Re: When cell towers and landlines are overloaded
« Reply #38 on: October 08, 2016, 10:59:30 AM »
What could the emergency be if all of that technology still was working?

Offline iam4liberty

  • Survival Demonstrator
  • *******
  • Posts: 4033
  • Karma: 321
  • New TSP Forum member
Re: When cell towers and landlines are overloaded
« Reply #39 on: October 08, 2016, 11:24:40 AM »
What could the emergency be if all of that technology still was working?

Well that is a point.  Since APRS is decentralized it has built in redundancy.  So it gives great peace of mind knowing i can always reach my comrades without having to worry if they are actively monitoring a voice channel or not. People work, they cant always have voice up.  But they can always have aprs text running silently.  So many emergencies are averted by faster response.

But one of the reasons emergency organizations around the world have aggresively added APRS is that the mesh network actually grows stronger in times of emergencies.  Each additional station turned on adds to the strength and capacity of the network.  A good example are the avalanche response teams who use APRs.  The more searchers the better the ability to find signals.  And by monitoring the locations of the searchers it helps ensure the rescurers dont become victims themselves.

This said with the new amateur satellites coming online in 2017 things are really going to get moving.  With PSK31 and even dtmf supported via APRS pretty much every amateur will have the means of relaying over the air messages around the world.  Right now a lot of activity revolves around using 19.5 inch antennas on ground planes (even a car roof) for access to these satellites. 

Offline backwoods_engineer

  • Survivalist Mentor
  • *****
  • Posts: 978
  • Karma: 43
  • An engineer trying to get back to the woods
    • Backwoods Engineer's Blog
Re: When cell towers and landlines are overloaded
« Reply #40 on: November 30, 2016, 08:42:39 PM »
95% of my ham activities are now APRS.   ...

If you want a dedicated transceiver, check out the yaesu ft1dr.  ...

Question: do you use the tracking feature?  Do you use SmartBeaconing?

Offline Davew223

  • Survivor
  • ***
  • Posts: 100
  • Karma: 12
Re: When cell towers and landlines are overloaded
« Reply #41 on: December 01, 2016, 07:06:46 PM »

So, what to do when phones, (mobile or landline), become overloaded. Feel free to add and discuss.

                  sound
                                       sci-
Enjoy the                of
                                               lence

Offline iam4liberty

  • Survival Demonstrator
  • *******
  • Posts: 4033
  • Karma: 321
  • New TSP Forum member
Re: When cell towers and landlines are overloaded
« Reply #42 on: December 01, 2016, 10:35:41 PM »
Question: do you use the tracking feature?  Do you use SmartBeaconing?

My vehicle is tracked using a dedicated APRS device from argent (older model opentracker).  It uses smartbeaconing including for turns.  I highly recommend using the turn angle function otherwise your paths can look funny when plotted on the map, eg. Track cutting diagonally over roads.  I do not transmit speed though.  For my handytalky I do tracking but do not use smartbeaconing.  It is set to beacon once every 30 minutes.  This is so the network knows where i am for relaying text messages.  Though i use a privacy setting on the HT which limits the accuracy of the position report to a few block area.  I think that is a prudent security feature when traveling by foot.  My home unit pings out my location via a fixed gps coordinate i entered which is about a quarter mile off. Again a bit of a privacy protection, though my address is listed on my FEC callsign record so anyone could look it up that way.  I only use my tablet and smartphone ocassionally to gate via IP when i am experimenting (e.g. testing messaging).  Right now my two mobilinkd tnc devices are being used for experiments on a non-aprs call frequency.

I just received directly from the manufacturer in poland a digipeater/igate standalone device: http://microsat.com.pl/product_info.php?products_id=62  Another ham and i will be installing it in February in an outbuilding on one of our properties.  We are adding it to improve packet capture from the HTs as our wide area repeater is only getting about 70% of them.  So it will act as a fill in to relay the packets but will also igate them.  The rest of the system will consist of a tram antenna at 30 feet, a samlex powersupply/battery charger (it supplies power directly but also simultaneously charges a battery as backup), and a yaesu 2900. 
« Last Edit: December 01, 2016, 10:43:11 PM by iam4liberty »

Offline backwoods_engineer

  • Survivalist Mentor
  • *****
  • Posts: 978
  • Karma: 43
  • An engineer trying to get back to the woods
    • Backwoods Engineer's Blog
Re: When cell towers and landlines are overloaded
« Reply #43 on: December 02, 2016, 09:30:01 PM »
My vehicle is tracked using a dedicated APRS device from argent (older model opentracker).  It uses smartbeaconing including for turns.  I highly recommend using the turn angle function otherwise your paths can look funny when plotted on the map, eg. Track cutting diagonally over roads.

Great. Glad you like it.  I designed the SmartBeaconing algorithm, including the turn angle function. 
--Kilo Alpha Nine Mike Victor Alpha (not spelling out callsign because the fed data hoovers look at everything)

Offline iam4liberty

  • Survival Demonstrator
  • *******
  • Posts: 4033
  • Karma: 321
  • New TSP Forum member
Re: When cell towers and landlines are overloaded
« Reply #44 on: December 03, 2016, 11:15:35 AM »
Great. Glad you like it.  I designed the SmartBeaconing algorithm, including the turn angle function. 
--Kilo Alpha Nine Mike Victor Alpha (not spelling out callsign because the fed data hoovers look at everything)

That is awesome! What a great contribution you have made. You managed to not only improve the effectiveness of the system (ensuring packets are sent when they are most needed) but you improved its efficiency by eliminating traffic (and therefore packet collisions) when it is not needed.  I would love to hear how you came up with these ideas and how they ended up embedded in pretty much every piece of APRS software out there including pre-installed by the OEMs.

Offline backwoods_engineer

  • Survivalist Mentor
  • *****
  • Posts: 978
  • Karma: 43
  • An engineer trying to get back to the woods
    • Backwoods Engineer's Blog
Re: When cell towers and landlines are overloaded
« Reply #45 on: December 05, 2016, 07:46:48 PM »
I would love to hear how you came up with these ideas and how they ended up embedded in pretty much every piece of APRS software out there including pre-installed by the OEMs.

Don't want to hijack the thread, but... Back in 1998, I was using APRS mobile, but there were no APRS radios from any manufacturer.  Back then, people connected their GPS's directly to their TNCs, and transmitted at a fixed rate.  This produces very bad tracks when viewed on a map, because there was no relationship between when the radio transmitted a position and the direction or speed of your vehicle.

Since there were no mobile APRS terminals (or even trackers) at the time, I created HamHUD, built the prototypes and wrote the initial firmware.  I didn't like the idea of just blindly transmitting GPS data and spamming the network, so I programmed a variable-rate beacon, based on the speed.  I was corresponding with another ham, Tony Arnerich KD7TA, at the time, and between us, we started testing various versions of what is now SmartBeaconing.  We tested and tuned the algorithm by actually driving around, then going home and looking at how the positions were presented on the map.  We eventually dialed it in.

Eventually, over 400 people built HamHUD kits.  Then, a couple of APRS tracker manufacturers, Argent Data and Byonics, added SmartBeaconing to their firmware, as did several APRS software authors.  Even now, my license terms are easy for individuals or very small companies.

Those guys brought SmartBeaconing to the attention of Bob Bruninga, WB4APR, and he introduced me to an engineer at Kenwood, the first company to build in SmartBeaconing into a radio.  Then, Yaesu followed. 

Just goes to show that you can achieve at least a modest level of success by staying at it, sometimes for years.

Offline Sailor

  • Senior Survivalist
  • ****
  • Posts: 205
  • Karma: 15
Re: When cell towers and landlines are overloaded
« Reply #46 on: December 06, 2016, 12:42:04 PM »
AndFLmsg opens up a lot.  HT and a smart phone. 

Offline iam4liberty

  • Survival Demonstrator
  • *******
  • Posts: 4033
  • Karma: 321
  • New TSP Forum member
Re: When cell towers and landlines are overloaded
« Reply #47 on: May 16, 2017, 05:52:21 PM »
Since there were no mobile APRS terminals (or even trackers) at the time, I created HamHUD, built the prototypes and wrote the initial firmware.  I didn't like the idea of just blindly transmitting GPS data and spamming the network, so I programmed a variable-rate beacon, based on the speed.  I was corresponding with another ham, Tony Arnerich KD7TA, at the time, and between us, we started testing various versions of what is now SmartBeaconing.  We tested and tuned the algorithm by actually driving around, then going home and looking at how the positions were presented on the map.  We eventually dialed it in.

Just wanted to give you an update and another shout out.  I have had a career change which allows me to go for a walk every day but the time varies.  This also has become my ham time.   So I am now using APRS SmartBeaconing so my buddies know when/where I am in my walk and to give a shout out if they like.  I am using a Yaesu ft1dr.   The default 'type 3' setting works amazingly well for walks/hikes:

Low Speed: 2mph
High Speed: 12mph
Slow Rate: 30 min
Fast Rate: 120 sec
Turn Angle 28 degrees
Turn Slope: 7
Turn Time: 30 sec

The only sad thing about this is that it has made me retire my trusty Garmin 12xl as the Yaesu GPS functionality works well enough.  The Garmin has just worked fantastic over two decades and, strange as it sounds, it is sad to shelve it.

Offline armymars

  • Survivalist Mentor
  • *****
  • Posts: 822
  • Karma: 23
  • New TSP Forum member
Re: When cell towers and landlines are overloaded
« Reply #48 on: May 16, 2017, 06:40:31 PM »
I don't know if I said this before, but if you use text it takes up less band width and is more likely to get through.