Author Topic: When cell towers and landlines are overloaded  (Read 22847 times)

Offline DonC

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When cell towers and landlines are overloaded
« on: September 30, 2016, 05:12:39 AM »
So, I heard a question posed by someone and I decided to create this post! Hey, I need to be more proactive in the forum anyway!

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

I've found and used several different options. Yes, of course, that's where HAM radio comes into play. But how, what modes, where to listen, what equipment do you need? All good questions and I'll try to start a good thread! Keep it going!

When I think of cell phones, I don't think of calling, rather, text messaging. This is a readily available option via RF! So much so, we have a national frequency for it (146.390-U.S.)! The APRS frequency along with APRS DROID or APRSISMO, a radio, and a simple interface (TNC or homebrew), provide a way to send text messages when cell towers are down. Of course, this will work locally and only if someone is on the other end listening.

A new Ham and I are going to build an easy interface and test this option. More to come!

Then, there's email, fax, and video chat via RF as well. Finally, just jumping on frequencies during such a situation and listening would help. HF, VHF, UHF, etc.

Of course, if we don't practice utilizing these options, when an emergency arises, you may find yourself stuck!

What's needed recap?
1. Radio
2. Computer or other mobile device
3. Interface
4. Antenna (it's a lot of fun testing antennas).
5. PRACTICE
« Last Edit: September 30, 2016, 05:27:43 AM by DonC »

Offline Carl

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Re: When cell towers and landlines are overloaded
« Reply #1 on: September 30, 2016, 05:31:22 AM »
It would be so easy to build VHF or UHF UNLICENSED MESH into cell phones,but the cellular company has no need to do this as they can't bill you for usage then.
The most important bit of wisdom is to have an alternate means to know what the other person or people are doing , even if it is due to having a written/pre-arranged plan
of what to do in the times that communications is interrupted. Society has become so dependent on the cell phone to 'selfie' their lunch and put their face in some kind of 'book'
Most will just PANIC  :zombie: when the dependent system that is now so big a part of their lives (if you call that living)tumbles from it's precarious perch.


WOW,I wrote this all without SPHELL CHEXKER... :egyptian:

Offline iam4liberty

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Re: When cell towers and landlines are overloaded
« Reply #2 on: September 30, 2016, 07:18:03 AM »
When I think of cell phones, I don't think of calling, rather, text messaging. This is a readily available option via RF! So much so, we have a national frequency for it (146.390-U.S.)! The APRS frequency along with APRS DROID or APRSISMO, a radio, and a simple interface (TNC or homebrew), provide a way to send text messages when cell towers are down. Of course, this will work locally and only if someone is on the other end listening.

95% of my ham activities are now APRS.   Rarely do i listen to the repeaters just ocassionally checking in on the nets.  My ham buddies just text me on APRS and we jump on our predetermined frequencies.

There are four big additional advantages to APRS.   One is that it listens when you are asleep or otherwise engaged.  So you never miss a message.  The second is that you can send precise gps location information.   Third is that you can send messages to other non-ham devices.  This includes email and cell phone text messaging.  So while the cell tower may be down in your area you can still reach out to those in other areas to, for example, message you are ok.  Fourth you will directly receive the transmissions of local aprs weather stations.  i live in tornado land so it is nice to know where the wind speeds are picking up.

If you want to use your existing transceivers with android devices i highly recommend the moblinkd tnc.  It just flat out works great.  If you want to home brew they provide all the circuit details and open source software info on the website.  See here: http://www.mobilinkd.com/.

If you want a dedicated transceiver, check out the yaesu ft1dr.  Not only does it do aprs but it can do many of the other digital items you mentioned.  One of our local repeaters in my neck of the woods is a Yaesu system fusion. It is amazing.  Finally, it also supports dtmf which I need for my local repeaters' land line patch and a few other things.

Offline Cedar

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Re: When cell towers and landlines are overloaded
« Reply #3 on: September 30, 2016, 07:51:51 AM »
.

Offline Carl

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Re: When cell towers and landlines are overloaded
« Reply #4 on: September 30, 2016, 08:20:02 AM »

Offline DonC

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Re: When cell towers and landlines are overloaded
« Reply #5 on: September 30, 2016, 03:09:54 PM »
Cedar, you wisdom is wise and brief! What would we do without you!

Iam, good post! I agree with the moblinkd TNC. I heard they were second to none. I have a new Ham in our area who is really good with electronics. That's why I chose to homebrew.
APRS is great. However, here, no one uses it except for gps tracking.

On another note, there is the national vhf psk31 frequency that is rarely used. I performed a test about a year ago using droidpsk and my mobile in my truck and my Baofeng.  It worked flawlessly even with VOX. My point is we have all these options available and not used. If we don't use them, we'll lose them to big business.

I try to exercise as many of the different modes as possible. I'm hoping Smurf will chime in with Winmor and etc. He's used it more than I.

Good comments and discussion, let's keep it up!

-Don

Offline r_w

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Re: When cell towers and landlines are overloaded
« Reply #6 on: September 30, 2016, 03:26:11 PM »
The cell phone companies wanted to do mesh, but the Fed's won't let them.  Wiretapping law, CALEA.

Offline RitaRose1945

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Re: When cell towers and landlines are overloaded
« Reply #7 on: September 30, 2016, 03:37:22 PM »
This happens all the time when the Consumer Electronics Show comes to town.  It's almost impossible to use a cell phone anywhere within 5 miles of the Vegas Strip for close to a week solid.


If you don't have a radio, then sometimes a simple text will make it through when a call is impossible.


But I do need to save up for a real radio.  I miss the ones I used to have.

Offline jerseyboy

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Re: When cell towers and landlines are overloaded
« Reply #8 on: October 01, 2016, 07:19:59 AM »
This happens all the time when the Consumer Electronics Show comes to town.  It's almost impossible to use a cell phone anywhere within 5 miles of the Vegas Strip for close to a week solid.


If you don't have a radio, then sometimes a simple text will make it through when a call is impossible.


But I do need to save up for a real radio.  I miss the ones I used to have.

My wife has been watching a lot of 9/11 shows and they mentioned how cell phone coverage went down that day in the effected areas but pagers continued to work, including 2-way pagers.

For a cheap radio, the Baofeng 888s is about $18 on Amazon. It covers the UHF region and you can program the 16 channels for both Ham and/or FRS/GMRS listening.  Ham transmitting needs a Tech license but FRS transmission is against regs due to a removable antenna lest you put a high-gain antenna on it and you transmit too far.  Also, GMRS transmitting is against regs because it is FRS capable.  Channel 16 can be programmed to a freq or programmed to scan channels 1-15.

Jerseyboy

Offline Cedar

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Re: When cell towers and landlines are overloaded
« Reply #9 on: October 01, 2016, 09:45:26 AM »
.

I just do that for a marker.

On one of my search missions during this terrible ice storm for a hunter with a broken leg in really rough country, cell phones were not working, but texting on them was to a point. I was pretty torqued about this search, as having been on multiple real SAR events as a dog handler for 15 years, this pretty much was the most unorganized one there could have been, as my VFD is not SAR. I was bemoaning the fact we did not have ham radio operators out there, I was bemoaning the fact we did not have a SAR dog...

But that is the night I was determined to get my Ham license, and I did pass my test a month later. I do not want to go into what I am being trained for currently, but it is for something cool... I will let you guys know later.

I have been around a few events where the cell phones were overloaded. I know when there is a school shooting or a protest, that cell phones are difficult to get through on. When we have our large earthquake, I know we will be without much communications for up to months.

Cedar

Offline Sailor

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Re: When cell towers and landlines are overloaded
« Reply #10 on: October 02, 2016, 07:48:47 AM »
95% of my ham activities are now APRS.   Rarely do i listen to the repeaters just ocassionally checking in on the nets.  My ham buddies just text me on APRS and we jump on our predetermined frequencies.

There are four big additional advantages to APRS.   One is that it listens when you are asleep or otherwise engaged.  So you never miss a message.  The second is that you can send precise gps location information.   Third is that you can send messages to other non-ham devices.  This includes email and cell phone text messaging.  So while the cell tower may be down in your area you can still reach out to those in other areas to, for example, message you are ok.  Fourth you will directly receive the transmissions of local aprs weather stations.  i live in tornado land so it is nice to know where the wind speeds are picking up.

If you want to use your existing transceivers with android devices i highly recommend the moblinkd tnc.  It just flat out works great.  If you want to home brew they provide all the circuit details and open source software info on the website.  See here: http://www.mobilinkd.com/.

If you want a dedicated transceiver, check out the yaesu ft1dr.  Not only does it do aprs but it can do many of the other digital items you mentioned.  One of our local repeaters in my neck of the woods is a Yaesu system fusion. It is amazing.  Finally, it also supports dtmf which I need for my local repeaters' land line patch and a few other things.

Your post has motivated me to get off my ass and dive back into APRS.  Been focusing on RMS Express for the last 6 mo and have only dabbled into using my two mobilinkd tnc's.   Need to do some reading. 

Offline machinisttx

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Re: When cell towers and landlines are overloaded
« Reply #11 on: October 02, 2016, 03:18:23 PM »
The local hams don't use aprs for anything more than position data when watching storms. As far as I know, most of them are running a second rig dedicated to aprs, mostly out of sight of the operator. I've heard more than one complain about how awkward it was to send messages with their rig, and I don't doubt it. My FTM400 is equally awkward to use for that purpose, even with prewritten canned responses.

Frankly, I don't understand the obsession with it. It's far easier to simply key the mic and call. Also much more likely to get a response around here.

The other thing that occurs to me is that it is relatively easy to teach someone how to select the necessary frequency and parameters for phone operation, and maintain comsec. Troubleshooting is relatively easy as well, since not much needs to be changed. Troubleshooting radio problems, plus tnc problems, plus pc problems adds a lot more complexity than might be overcome by an unskilled radio op who is also completely uneducated with TNCs and can't do much more than turn on a PC to surf the web. You might not be there to operate it or fix it, so IMO, it's best to plan for a worst case scenario and keep it as simple as possible.

JMO *shrug*

Offline Carl

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Re: When cell towers and landlines are overloaded
« Reply #12 on: October 02, 2016, 04:23:14 PM »
The Texas wrench bender has an important point ,that a radio should be simple to operate...most radios with deep menus don't often  need to be adjusted
and as such are still simple to operate ,though maybe not ideal.I believe a radio should be used and not saved for an emergency because Ham radios don't have
a reputation for long distance operation...Ham radio OPERATORS do. It is through practice and operating skill , along with good antennas and knowledge of
propagation that Ham's get the message through, the radio does nothing without the SKILLED HAM.

 I do think that DIGITAL MODES just as CW are under utilized as many digital modes allow messages to get to where they are needed and this is important
during emergency operations. Many rescues that i passed direction and verified messages for were done by EchoLink TEXT,PSK,and even telephone to a
Coast Guard Person on his private cell phone as he then passed location and information to helo crews ,I learned of him and his phone number through his
father who was a recruiter in Ohio and with just my word directed many successful rescues and sadly ,a few recoveries .

  While digital really is not for a vehicle in motion, unless a non-driver radio man is in the passenger seat,their are times that the greater sensitivity and
error correction can often get the message across and somewhat more privately than voice as even CW has a 10 DB or so advantage over voice and
many digital modes are even more capable.

  The same thing with QRP...while I LOVE LOW POWER OPERATION , I feel that you should have low power as a power saving OPTION and not as your ONLY option.
This gives you the best ability to get the message where it needs to go...save the low power for FUN operating....unless it is your only option.

MURS and FRS operators who want some security might look into PSK for your smart phone and have some text message capability on radio though with little
radio range improvement. NVIS HF could have made communications much faster and reliable during Katrina/Rita though so few Ham,s seemed aware of the
local 50 to 500 mile capability that could have allowed for direct,rather than Ham to Ham relay,of important information.

 

One of my home made repeaters was placed on this building and helped with communications.

Offline iam4liberty

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Re: When cell towers and landlines are overloaded
« Reply #13 on: October 02, 2016, 07:02:35 PM »
I've heard more than one complain about how awkward it was to send messages with their rig, and I don't doubt it. My FTM400 is equally awkward to use for that purpose, even with prewritten canned responses.

Hmmm...sounds like sub optimal equipment setup for texting.  What you mentioned used to be the case when APRS first started out and people were trying to use left over TNCs from the packet radio days.  But now that is rarely done.  APRS messaging today can be as easy as texting on a smartphone.  You just choose the call sign of who you want to send the message to, type in the message, and hit send.



I haven't had the chance to play with the FTM-400.  On a handy talkie like the ft1dr you simply hit the keys multiple times to cycle letters just like you used to do on cell phones prior to when smart phones became popular.  It isn't as easy as using a smartphone for an interface, but it is definitely not hard or anti-intuitive.  But I agree with Carl that APRS and other text based systems are not the best for sending messages from vehicles.  But it is great for receiving information.  For example, with most mobile units you get a splash screen showing the direction and distance of the transmitting ham as well as other information they choose to send such as the simplex frequencies they monitor.  One place where I find a lot of APRS use is in RV parks because it allows roving hams to easily meet up.

Troubleshooting radio problems, plus tnc problems, plus pc problems adds a lot more complexity than might be overcome by an unskilled radio op who is also completely uneducated with TNCs and can't do much more than turn on a PC to surf the web.

Actually APRS can be a lot easier than other forms of ham activity to learn.  After all, there is only one frequency.  And TNCs are pretty plug and play now and once set up do not change.  And you don't even need a transceiver to start.  You can simply use an application like APRSdroid or an aprs website to send messages from your smart phone to other hams.  Which is a great way to get new hams active.

Which is another great thing about APRS, you can monitor the packets from any computer, tablet, or smartphone.  So, for example, I can send a message from my 2 meter handy talkie to my sister-in-law ham 5 hours away and have it pop up on her computer, smart phone, and handy talkie.  And with APRS my non-ham wife always knows where I am.  With a double click of a shortcut on her laptop she can see the location of my car (when I travel by land) or my handy talkie (if I travel by air).

MURS and FRS operators who want some security might look into PSK for your smart phone and have some text message capability on radio though with little
radio range improvement.

I use APRS software on MURS in much the same manner.  You can also do encryption on MURS for pretty close to complete security.

Offline DonC

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Re: When cell towers and landlines are overloaded
« Reply #14 on: October 03, 2016, 04:33:15 AM »
Well, I've read down the posts, (more than once), all good points. Not just anyone can plug a cable in, turn on their phone, and start sending digital modes......wait, yes they can. It's highly recommended that people read up on these modes 1st. There's plenty of free and paid media on the subjects.

As for things being difficult, let me explain how simple my DroidPSK setup was. I put my tablet in my truck, in front of my radio. I opened the DroidPSK app, shut the doors, and grabbed my HT and my cellphone, (similar setup), and walked up the street. I set my HT to VOX and proceeded to send messages. Near perfect copy! Very similar setup for APRSDroid. Then I reversed the operation by leaving the HT up the street and sent messages via my tablet.

The more you add to the setup, the more "troubleshooting" you'll eventually end up doing.

I'll re-quote this: "to have the capability isn't enough, you need to practice!" Read all you can, practice often, and remember, your mind is the best tool you can carry!"

Thanks to everyone for the replies and keeping this going! It's all worth it if it helps even 1 person! Keep up the good work!

Offline DWSDVSE

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Re: When cell towers and landlines are overloaded
« Reply #15 on: October 03, 2016, 07:13:41 AM »
Cedar is a Ham of few words...

Or really slow CW   ;D


I'm working downtown in a highrise and my wife is about 8 miles as the RF flies and within line of sight.  Our plan is if cell networks are down are to go to some pre-defined frequencies and I’ll call in to her and update her on my situation. I know the signal works from my direction to her, but she can’t transmit back yet…did I mention she needs to get her test done…I’m also teaching her to use fldigi’s tools and we can communicate that way, even if the signal quality isn’t great. My assumption is that if things are bad enough to kill cell networks in our area a) the repeaters will either by offline or handling ARES/emergency traffic and b) even if it happens before she gets liscensed it will be an emergency so she can transmit anyway.

But, as always practice is great. One-ended practice is the best we can do now since she’s not liscensed. But she knows how to operate our HTs, so that’s a big step in the right direction.


Also, I'm just getting started with digital, but man it's pretty amazing what you can do.

When my cellphone is up with it's 2 years this December, I'm looking into turning my old Android phone into a dedicated SDR/Digital powerhouse.

Offline iam4liberty

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Re: When cell towers and landlines are overloaded
« Reply #16 on: October 03, 2016, 10:50:20 AM »
Our plan is if cell networks are down are to go to some pre-defined frequencies and I’ll call in to her and update her on my situation. I know the signal works from my direction to her, but she can’t transmit back yet…did I mention she needs to get her test done…

Excellent.  In the mean times have you thought about using MURS or GMRS?  It would be good practice while she is prepping for the exam.

Thanks to everyone for the replies and keeping this going! It's all worth it if it helps even 1 person! Keep up the good work!

I think it may be hard for people to visualize what we are talking about.  So I spent 10 minutes last night taking some screenshots on my tablet to help explain some of the useful things you can do with digital, specifically APRS.

This first image shows a few hours of APRS data displayed via a mapping application.  Each icon represents a ham station.  There are different types of icons to represent different types of stations.  The "WX" ones are weather stations which are periodically transmitting their data.  The cars/trucks/boats/planes represent stations which are operating from that type of vehicle.  The towers represent repeaters and similar items.  Homes represent base stations.  Handy talkie operation is represented by a person walking/jogging.



Each of these stations is transmitting useful information.  For example, the weather stations are sending out temperature, wind speed, rain level, etc.  Some even send out earthquake information!  In this application you can click to see the most recent info and click again to see trends.



Obviously, another use of APRS is to track movement.  Last night some of our Search and Rescue units were out including one of the canine units.  Their command can use APRS to track these units to coordinate movements and see precisely what areas have been covered and if any areas haven't been covered (e.g. due to terrain).




The same goes for personal vehicles.  As I mentioned my wife monitors my APRS signal when I travel so she always knows my progress.  She can see where I am, what direction I am heading, and even my rate of travel.  Here is an example of a truck which I clicked on to show the path it took (obviously it was a round trip).



Oftentimes the stations will broadcast information on how to reach them.  For example, repeaters will often include information on their frequencies, tones, net times, modes (analog and digital), network (e.g. earthlink or linked to repeaters), etc. RV'ers and base stations will often include what simplex frequencies they monitor so you can call them.  This is really good when traveling as you can turn on aprs and within an hour or so have a way of reaching out via repeaters and to individuals.  Even if you don't have mapping software (e.g. you are using a handy talkie) you will get this information in the stream of data.   





There are plenty of survival situation benefits too.  Obviously you have a way of sending out a precise GPS location.  But thinking about one TSP episode when Steven Harris and Jack discussed contacting airplanes, you oftentimes will pick up planes flying.  In fact, while I was typing this a plane flew by.  So I snapped a shot so you can see what that looks like on a handy talkie.  Notice that I know its precise location via the compass arrow, its direction, and speed. Normally for small planes this is well over 100 mph but in this case it was moving slowly so it might have been taking off or landing at our local airport.



All of this is the tip of the iceberg when using APRS.  Obviously there is the text messaging apps we talked about, but there is all sorts of other things, even using satellites to repeat your signal anywhere in the world!  If you want to check out what type of APRS activity is in your area, you don't even need to set up an APRS station.  Because much of APRS is gated to the internet, you can view this info on APRS websites.  For example, you can go to www.aprs.fi, type in your city/state, and choose "show last: 24 hours" to see what a typical day of APRS looks like in your area.
« Last Edit: October 03, 2016, 10:58:03 AM by iam4liberty »

Offline iam4liberty

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Re: When cell towers and landlines are overloaded
« Reply #17 on: October 03, 2016, 11:15:27 AM »
Oh.  I forgot to mention how FUN this is.  Like right now I am trying to figure out what this plane is doing:



Good way to spend a vacation day.  :)

Offline machinisttx

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Re: When cell towers and landlines are overloaded
« Reply #18 on: October 03, 2016, 05:20:40 PM »
Again, I don't understand the obsession. I don't find observing other people's travels "fun", I find it to be none of my business 99.9% of the time....and I have many other things to occupy my time and interest. Along the same line, I bought a rig so I could communicate....not so that I could connect it to one or more other devices in order to communicate. Different strokes for different folks, I just don't see the draw.

I think this evening was the first time I ever got on the aprs.fi site. APRS has been turned on in my rig for several months now. Tomorrow morning I am going to turn it back off and forget it exists until the next time I go storm spotting, and I'm likely to forget it then unless they ask me to turn it on. Outside of that or SAR, I have no real use for it.

Offline DWSDVSE

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Re: When cell towers and landlines are overloaded
« Reply #19 on: October 04, 2016, 06:33:05 AM »
In a post-SHTF situation, assuming you could get power *yes big assumption*, it would be useful to find out where anyone who forgot to turn APRS off (ie any stolen radios) are going to in your AO.

Perhaps a small probability, but if you can't run it now, then it seems difficult to suspect you'll be flawless when it matters.


Offline Carl

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Re: When cell towers and landlines are overloaded
« Reply #20 on: October 04, 2016, 10:44:30 AM »
That will only tell you what Ham's (small percentage of the population)
SURVIVE and have power (smaller percentage of the small percentage)
and are too dumb or forgetful to turn off their transmitter/APRS beacon
( how many do you think that is when compared to a herd of zombies?)
Without power to run repeater stations you would be very limited in range.

I think that you will SEE them coming before you would hear them on a LINE OF SITE radio.

Offline Smurf Hunter

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Re: When cell towers and landlines are overloaded
« Reply #21 on: October 04, 2016, 02:05:30 PM »
I've had APRS on my phone (full version) for some time, and it's a curiosity.
I also had a very old KAM TNC that I used to receive APRS into a terminal window on my laptop.

Our EMComm team does a lot of RMS express work (VHF and HF) for reporting up and down the .gov chain of command.

I would like to get a modern TNC that still handles RMS packet, and could integrate with my android phone potentially.
Anyone know if a Mobilinkd TNC can do RMS packet winlink ?

Offline iam4liberty

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Re: When cell towers and landlines are overloaded
« Reply #22 on: October 04, 2016, 04:54:44 PM »
Anyone know if a Mobilinkd TNC can do RMS packet winlink ?

Mobilinkd is a KISS tnc so can do VHF packet with terminal software which supports KISS tncs. In fact, shortly after the mobilinkd was released tweaks were made to the popular winlink express program to optimize its use. 

But there is a big watchout for android.  To my knowledge there is no KISS compatible packet terminal software available on android.  The problem apparently is that when google ported linux over to android it dropped some parts of the inherent AX.25 support in the standard compile.  So that has slown down the development of KISS packet software on android.  Some have carefully used non-kiss dumb terminals for some applications but I believe a warning was issued that this could potentially brick the mobilinkd if certain strings were sent.

I would love to here if anyone has gotten around this issue on android.

Offline DonC

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Re: When cell towers and landlines are overloaded
« Reply #23 on: October 04, 2016, 06:57:28 PM »
I'm not sure where that comes from, nor have I heard of anyone having an issue with Android and Moblinkd TNC. It was designed specifically for Android! I have a few friends that use both, flawlessly together! There are about 11 android apps that work with the Moblinkd TNC. No port or string issues have been reported.

Surf,
There are several articles available regarding the Moblinkd TNC. It works great with APRSDroid and APRSISMO with no known issues I've heard of. It's reasonably priced. The best part is the TNC is completely open source. So, if you want to improve upon it, and have the knowledge, you can. I have not bought one yet, for no other reason than, I haven't needed one as digital modes aren't very popular around here. Good luck.

-DonC

Offline iam4liberty

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Re: When cell towers and landlines are overloaded
« Reply #24 on: October 04, 2016, 08:11:23 PM »
I'm not sure where that comes from, nor have I heard of anyone having an issue with Android and Moblinkd TNC. It was designed specifically for Android! I have a few friends that use both, flawlessly together! There are about 11 android apps that work with the Moblinkd TNC. No port or string issues have been reported.

He wants to do packet, not APRS.  I have been a member of the yahoo! Mobilinkd group from the start.  To my knowledge noone has succesfully set up an android with mobilinkd for packet yet.  But I would love to know if someone has! 

The warning on non-kiss terminal software came from Rob Riggs the designer of the moblinkd:

https://groups.yahoo.com/neo/groups/mobilinkd/conversations/messages/64

This is a product bulletin for the Mobilinkd Bluetooth TNC with firmware build 349 and lower.  The purpose of this bulletin is to make users aware of a potential issue with the TNC, provide advice on how to avoid and correct the issue, and to let you know what Mobilinkd is doing to address the problem.

Overview

The Mobilinkd TNC may inadvertently have its firmware erased or damaged when using non-KISS software with the the TNC.  We have one confirmed case and at least 2 other suspected cases where this has occurred.

Symptoms

The TNC no longer functions.  The TNC will not decode packets and will not transmit.  The power-on banner is no longer displayed in the APRSdroid log view.

Diagnostic Steps

To confirm whether you are experiencing this problem, follow these steps:

1. Start with the TNC powered off.
2. Start APRSdroid and go to the APRSdroid log display.
3. Turn on the TNC.
4. Select "Start Tracking" in APRSdroid.
5. The startup banner "== BeRTOS AVR/Mobilinkd TNC1" is not displayed.

If the startup banner is printed, the TNC's firmware is intact.

Cause

The cause appears to be related to use of non-KISS software with the the TNC.  The primary suspect at this point is terminal emulation software using ANSI or VT-100 control codes.  So far this has only been reported with TNCs that have been connected via Bluetooth to a computer.

The KISS protocol is a binary protocol which is generally not suitable for use with a terminal emulator.  A single "ESC" character, such as those used as ANSI terminal control codes, outside a KISS frame will cause the TNC to reboot and enter the bootloader.

The bootloader is what allows the firmware on the TNC to be upgraded.  It uses a very simple protocol that will ignore any characters it doesn't understand and immediately execute any that it does understand.

For example, connecting to the TNC with a VT-100  emulator which sends an ANSI/VT-100 escape code and then typing "exit" will result in the TNC entering the bootloader and executing the "e" (erase) command.

Recommendation

Avoid using any software which sends non-KISS data to the TNC.

Recovery

The TNC firmware may be erased (best case) or partially overwritten (worst case).  It is far more likely that the TNC firmware has been erased rather than partially overwritten.  This is because a valid multi-byte sequence needs to be sent to overwrite the firmware.  It is possible to recover from either condition, but recovering a TNC with partially overwritten firmware is more difficult. 

A TNC with erased firmware can have the firmware reloaded over the Bluetooth connection with the Windows configuration utility.  This is because the TNC is permanently running the bootloader when the firmware is erased.

With damaged firmware, the TNC firmware can be reloaded using "avrdude" programming software over the Bluetooth connection.  The TNC enters the bootloader for only 3 seconds at power-on, so the timing for such a recovery can be tricky.  Please email mobilinkd@... for detailed recovery instructions.  "avrdude" can be used to reprogram the firmware from Windows, Mac OSX and Linux.

Mobilinkd will also reprogram TNC with damaged/erased firmware for free.  Send email to mobilinkd@... to arrange the reprogramming.  You must ship the item to us and we will pay for return domestic shipping back to you.  For our international customers, there will be a $10 return shipping fee.

Resolution

Mobilinkd is working to provide a firmware update available which will make it more dificult to inadvertently cause the TNC to enter the bootloader while running.  We are also working on completing the firmware upload feature of the Android app so that firmware updates can be uploaded via an Android device.

--
Kind Regards,

Rob Riggs
Mobilinkd LLC


Offline DonC

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Re: When cell towers and landlines are overloaded
« Reply #25 on: October 04, 2016, 08:18:26 PM »
Iam,

Good article. It is something I'll keep a close on eye. Only 1 confirmed case is promising. The key is not to send non-KISS related data. (Packet is APRS and vis-versa).

Offline iam4liberty

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Re: When cell towers and landlines are overloaded
« Reply #26 on: October 04, 2016, 08:41:24 PM »
Packet is APRS and vis-versa

That depends on who you ask.  :) 

i have probably been told by a dozen hams that "APRS is not real packet radio".  There is some technical truth to that.  This is how the two are typically talked about:

https://en.m.wikipedia.org/wiki/Automatic_Packet_Reporting_System

APRS (Automatic Packet Reporting System), is a digital communications protocol for exchanging information among a large number of stations covering a large (local) area, often referred to as "ey-pers". As a multi-user data network, it is quite different from conventional packet radio. Rather than using connected data streams where stations connect to each other and packets are acknowledged and retransmitted if lost, APRS operates entirely in an unconnected broadcast fashion, using unnumbered AX.25 frames.

But i lean more towards your way of thinking about it.  If it quacks like a duck...

Offline DonC

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Re: When cell towers and landlines are overloaded
« Reply #27 on: October 05, 2016, 10:42:05 AM »
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.

Smurf, your peoples should find this of use for RMS Express. That was one thing I didn't know it could be used for.

On Oct 4, 2016 10:23 PM, "Rob Riggs" <mobilinkd@gmail.com> wrote:
Hi Don,

1. Any app that speaks KISS over a serial port should work.  I've had it working with the AX.25 stack on Linux (axcall/axlisten), Xastir, and many others.  People are using it with Winlink using RMS Express.  There are lots of options.

2. You can send messages using APRS.  The TNC is a KISS TNC, so whatever program you are using needs to speak KISS.  You cannot just connect a terminal program and start chatting with others.  I don't see it as an issue, but some people do not want to use APRS for messaging.  I do not understand why that is.

Unfortunately, I do not have any used TNCs here.  But you might check on the Yahoo group or ebay. Every now and again someone posts one for sale.



Kind Regards,

Rob Riggs WX9O
Mobilinkd LLC

Offline Smurf Hunter

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Re: When cell towers and landlines are overloaded
« Reply #28 on: October 05, 2016, 10:43:33 AM »
That depends on who you ask.  :) 

i have probably been told by a dozen hams that "APRS is not real packet radio".  There is some technical truth to that.  This is how the two are typically talked about:

https://en.m.wikipedia.org/wiki/Automatic_Packet_Reporting_System

APRS (Automatic Packet Reporting System), is a digital communications protocol for exchanging information among a large number of stations covering a large (local) area, often referred to as "ey-pers". As a multi-user data network, it is quite different from conventional packet radio. Rather than using connected data streams where stations connect to each other and packets are acknowledged and retransmitted if lost, APRS operates entirely in an unconnected broadcast fashion, using unnumbered AX.25 frames.

But i lean more towards your way of thinking about it.  If it quacks like a duck...

I don't know if any of you folks have an IT background, but the distinction makes sense to me.  They are both birds, but one is a duck, another a chicken. 

"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. 

Financial wire transfers are going to use a rigid connection to ensure both sides agree with the end state of the transaction.  Announcing the time of day, weather or sport scores don't necessarily need guaranteed delivery - you can just get the next broadcasted update.

APRS is rather like a beacon network in that regard.  There's no protocol handshake where each remote host verifies the integrity of each transmission.
If one TX is corrupted, it's ignored with the hope the subsequent TX will be received.

Where all the packet/APRS is similar, the same scheme is used to pack binary 1s and 0s into audio for RF transmission.  AX.25 is a minor tweak of X.25, which was a common wired networking protocol before the internet reached consumer level popularity in the 1990s.  So 30+ years ago there were plenty of networking professionals with X.25 experience who could apply their knowledge to VHF Packet that ran AX.25.

Offline Smurf Hunter

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Re: When cell towers and landlines are overloaded
« Reply #29 on: October 05, 2016, 10:48:53 AM »
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.

Smurf, your peoples should find this of use for RMS Express. That was one thing I didn't know it could be used for.

On Oct 4, 2016 10:23 PM, "Rob Riggs" <mobilinkd@gmail.com> wrote:
Hi Don,

1. Any app that speaks KISS over a serial port should work.  I've had it working with the AX.25 stack on Linux (axcall/axlisten), Xastir, and many others.  People are using it with Winlink using RMS Express.  There are lots of options.

2. You can send messages using APRS.  The TNC is a KISS TNC, so whatever program you are using needs to speak KISS.  You cannot just connect a terminal program and start chatting with others.  I don't see it as an issue, but some people do not want to use APRS for messaging.  I do not understand why that is.

Unfortunately, I do not have any used TNCs here.  But you might check on the Yahoo group or ebay. Every now and again someone posts one for sale.



Kind Regards,

Rob Riggs WX9O
Mobilinkd LLC


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 few weeks of use due to duty cycle.

I understand the KISS stuff.  The original TNCs from decades back were interacted with similar to dumb terminals.  (Anyone old enough to remember those green screen computers in the library?)
That's raw serial I/O communication. As you punched letters on the keyboard they were transmitted as binary over the connection, byte by byte.  KISS cannot do that, but who cares really.  I agree that chatting peer to peer like that is pretty darn antiquated given all the alternatives today.