Serial remote access

[luka]

Have you considered to make support for cell-phone remote access to remote wrap/war console?

It would be very helpful to be able to access cell phone (via standard dial up) which is connected with wrap/war via serial console. This way users may be able to remotely change ie channel or some basic settings in the case board/os cannot be accessed remotely on standard way (ie: big interference problem).

[lonnie]

Do some cell phones have serial ports? I am not a cell phone user so I know very little about the features available.

[luka]

Here in Europe we GSM phones are used widely. Most of them have installed modem inside and can be connected to computer via serial cable. These modems supports standard commands and can be considered as ie standard pc modems.
If we could connect those phones to wrap, war or other board and then dial into it we could be able to change some settings (alterable via serial) and thus repair things in the case of big interferences, some mistake or similar failure.

[titan_wireless]

If we could connect those phones to wrap, war or other board and then dial into it we could be able to change some settings (alterable via serial) and thus repair things in the case of big interferences, some mistake or similar failure.

Luka,

Are you suggesting that you would install a cell phone with every AP and use it in case of emergency recovery? Or are you suggesting that you just use a cell phone to recover it instead of using a laptop?

[luka]

I would use it in the case of unreachable location, ie ap on tower or high mountain in the winter. In some locations it may take a many hours or half a day just to get on mountain top at -20 C and do thing like pushing button etc..
Cell phones are cheap, monthly charges are low so why not to use this option as backup in some cases?

[Stratolinks]

I would use it in the case of unreachable location, ie ap on tower or high mountain in the winter. In some locations it may take a many hours or half a day just to get on mountain top at -20 C and do thing like pushing button etc..
Cell phones are cheap, monthly charges are low so why not to use this option as backup in some cases?

I don't see the advantage of getting serial access to a device in a remote location, unless you can get full console access.

Besides the cell phones that can be used as a serial modem are no longer availabe withe the advent of bluetooth and USB.

If you need to reset a device, then why then don't you make this solution hardware based. Set the cell phone to auto answer whenever a call comes in and feed the audio to a DTMF decoder that is then waiting for the correct 4 digit dialing sequence to be received. When this is received, it can close a relay contact for lets say 15 seconds, and then release it. This relay could be used to break the power connection to the device, or to activate a reset button. With multiple DTMF decoders you could have different options depending upon what you need to do. If your system has a micro speaker, you could place the microphone near it so you would hear when it got the reset. Then you end your call and the cell phone would then disconnect as well.

Just think...
Your router located on the top of a mountain a half day away in good weather just locked up. Pick up your telephone, call its number and when it answers, just type in your reset code and hangup.

Of course if there is a hardware problem preventing it from booting, there is no way to avoid the trip up anyway.

[luka]

Yes it is not problem to make remote reset via cell phone and we have done that, but one step further would be possibility to change channel or some basic things. Sometimes there can happen big interference problem so box simply cant connect withoud changing channel, or ssid, or wpa and so.

[georgew]

I don't see the advantage of getting serial access to a device in a remote location, unless you can get full console access.

Besides the cell phones that can be used as a serial modem are no longer availabe withe the advent of bluetooth and USB.
.

First of all, the whole point is to get a full console when you have a dead radio or backhaul. You can often reconfigure to get back up.

Second, you are wrong, cellular "modems" are more and more available, and they no longer look like cell phones with adapters, they are dedicated data/voice devices. They are used for both data and voice applications, they can plug into a pbx as an emergency line for when the T1 trunk is taking errors, and any one with a public safety mandate will have one to 20 of those in their pbx room nailed to the wall next to the pbx.

Of course you can use a cellphone with built in modem, but the dedicated devices usually have better support for things like external antennas and 12v power WITHOUT clunky adapters. And since they are designed for this use, they don't have features that get in the way, or drive up cost, like cameras or display screens or buttons... so they are mid-priced, not as expensive as most of the fanciest of phones. Put them on a family plan to bank your minutes, and buy the lowest minute plan, and pay only a few dollars for each one you add. Anything that you can get a serial console on is remotable.

Balance the cost against running a phone line (and the added lightning danger a phone line brings with it) and the cellular method isn't very expensive, and it gets cheaper the more of them you have, using family plans. On a plan that charges $5 or $10 for extra phones, this is cheaper than phone lines and analog modems, and more likely to still be working after a storm.

As for reboot devices, there is one of those for every method of communication... But nothing is more expandable than a home-grown design based on one of these new ethernet enabled microcontrollers. Of course with the cellular modem, the cheaper serial console on the basic stamp from parallax gived you a easy to grow system that can control power to hundreds of devices, and even do so with some degree of autonomy if rigged with a dead-stick watchdog system and a few lines of basic code. One basic stamp for $29, with a few transistors can power cycle anything you need for 1/10th the cost of an off the shelf systems that does much less. Wire into the led's on your hardware, and detect unusual conditions, and fix them, without waking the boss.

My first router, a 8088 machine running a rommed dos and KA9Q was plauged with lockup problems when we got our first "high speed" dedicated Internet connection (56k) back in te late 80's. So I had a unix box rigged to ping the net, and if the ping failed, it would open a serial port, which had DTR wired to a relay that would disconnect power from the router/csu pair. After 10 seconds the unix machine would hang up the port, restoring power. This is easy to do, and still works today on a typical linux box.

This was my ping watchdog, which inspired me to ask for a similar feature in StarOS...

Of course that is another option, instead of using the serial port for a console, you can use it as a smart output to talk to a relay or reboot device.
StarOs could reboot external devices using it's serial port outputs to control relays. I think you could control 3 or 4 relays with a typical 9-pin serial port
directly, or more if you talk to them with commands...

StarOS could come up with a simple serial api to query and command a basic stamp to do your bidding.

For complex tasks like cold weather starting a diesel generator, and maintaining it's block temperature, a basic stamp is much simpler to work with than the old method that required a box crammed full of expensive timer and sensor relays. And you can talk to it with a computer, something difficult to do with older methods.

The same time I was running the first modern ISP on a KA9Q box, I was designing the hardware interface for a chipset for the first generation digital cellular system to be first deployed in Japan. The system was modular, and each processor fully capable of crashing on it's own, so two layers of watchdogs were designed in to recover dead ppu's.

But if you are going to do it with DTMF, then don't use a cellphone at all. Use radios. Any radio can be rigged to do dtmf, and you don't need speakers and mic's, just couple the decoder directly to the radio output with a capacitor. A cb radio, or one of the better FRS radios would work. I helped put on a show where robot builders put on a gladiator-style show, with the robots all fighting to the death... and they were controlled with a combination of RC plane gear, or 2 meter ham radios with dtmf decoders wired to the controls. We did a wireless link to the show for a webcast, my first wireless network link, 7 miles using wavelan 2megabit frequency hopping radios in a router very similar to my original KA9Q box, back in '95. There was fire, explosions and mahem, spectators were injured, the only indestructable robot was the van-deGraph generator, and the guy in charge of the show was told to "git" out of town, and never come back to Texas.

[Faisal]

Do some cell phones have serial ports? I am not a cell phone user so I know very little about the features available.

Hello,
I have been a lurker for a bit, and this is my first post -:)

Let me add some information here that others may find useful on this topic.

There are a number of devices called "Cellular Modems" in existance, and availability. They seem to have been more popular in Europe, but now showing up in the US. Wavecom was one of the first producer of these devices, originaly was sold as an OEM or a specialty product. But Today one can get these from Digiboard (http://www.digi.com/products/wireless/digiconnectwanfamily.jsp)
or Multitech http://www.multitech.com/PRODUCTS/Categories/Device_Networking/external_wireless_modems/

Services are provided by the major Cellular Carrier, and I understand that depending upon the data plan one commit to, they could be as little as $20 / month. These devices are not too expensive either somewhere between $300 to $600.

These days the folks who are deploying these are the Utility companies (Electric Utility, Water Utitily etc).. monitoring and meter reading etc. I understand from the modem mfg, that these connections (on Cell network) can be with static ip's. etc.

I had been looking into these for remote access to the management console(s) for times when things get real ugly... Interesting to see that there are others who have been thinking along these lines as well.

[georgew]

Yeah, I guess serial ports are getting passe... Now cellphones come with ethernet running tcp/ip and "always-on" connections.