SIM cards in traffic signals (robots)

[Didditmiself]

I'v heard that one of the reasons why robots go out of order in the new SA is because they are controlled from a central point and the reasons for this is that then they can be adjusted for the traffic flow at peak times etc. (Pre 1994, there were no such things as SIM cards and the robots were programmed to work in a sequence until they packed up). In order to do this, signals are sent to a control box which uses a SIM card the same as a cell phone. The only difference with these SIM cards is that they only carry (transmit) data and no voice information. Now when the lowlifes decide to steal the SIM card (for whatever reason - it's apparently pointless as they will not work in a cell phone), this is when the robots 'go on the blink'. As soon as the SIM card is replaced, the affected robot functions properly again.
Is this 'urban legend' or is there some truth in this scenario?

[adrianh]

I think that it is a Bigtime urban legend. Traffic lights go into blink all red mode if anything goes wrong the system. The biggest cause is power outages. When the power comes back on the lights go into a failsafe mode, blinking red, until they are reset. It could be done this way so as to allow for a controller to set up the correct syncronization cascading from a given point. Another reason for going into this mode is that the system (intersection controller) doesn't know what caused the fault, could have been that a pole got smashed or bent so it simply defaults to failsafe. I would be very surprised if traffic lights are dependent on the GSM network given that the lights were around, and syncronised, long before cellular phones came onto the scene.

[Didditmiself]

adrianh, thanks very much for that explanation. It's amazing how pointless information gets started and spreads like a wildfire. I'm involved in engineering matters, not electronics as such, so that's why I had to check it out to establish whether it's 'fact'.

[CLIVE-TRIANGLE]

In 2010, there were already just over 600 of these GPRS enable traffic lights in greater JHB. Just on 400 had been looted by December 2010.

At the moment there are about 180 missing in Pretoria North.

These modem enabled controllers are also used extensively in .... this is scary ... sewerage pumping installations all around Gauteng and soon the thieves will catch on to these, and I guess it will then really hit the fan.

Most intelligent traffic lights use Movac controllers and the first one was used in 1989 in the Cape.

[Didditmiself]

Clive, can you explain to me (us) a bit more about GPRS enabled traffic lights. How do they work? You say there are about 180 missing in Pta Nth. What is/are missing? How do the modem controllers work?

[CLIVE-TRIANGLE]

I recall that when the Johannesburg story broke, it was mentioned that council was still incurring network costs i.r.o of the stolen SIMs. Whether it was due to data or voice I don't recall. SIMs have an EPROM list of services; how easily this can be hacked I have no idea.

The Pretoria story broke in September. In their case it affected traffic management's ability to synchronize the lights remotely, as the cards had been stolen and the modems damaged. R4950 per light was the number mentioned.

There are quite a few local companies that offer management technology. The most famous is TMT, the RSA subsidiary of the Austrian outfit doing the e-tolling.

These modern systems basically collect data, report the data, and receive control instructions. Basically a pc in a pole, they can be hooked up to traffic counters, CCTV, speed control equipment and a bunch of other stuff way over my head. They use various communication methods and topologies; ethernet for http and ftp and secure GPRS. Here is a schematic I found:


I also found a specification list for a 2010 Cape Town tender. If you peruse the equipment list you get an idea of what these things are capable of:

[Justloadit]

It is very difficult to break into these systems, simply because the SIM card is set up in data mode, and paired to a modem device. In other words, if you remove the SIM, they can not work in another phone/modem. Secondly, being data they require to connect to a private network, or VPN, which requires a user name and password, when registering onto the network. With out this, you can not join the data network. Thirdly, the SIM cards are allocated an IP addresse, so when they connect to the network, through the VPN, they must log onto the main server before data can be up and downloaded.

What I am not sure off right now, is if the SMS side of the data card is enabled. In the case that it is, then there is a back door, however, the network should have disabled this function on request from the client. The question asked is then, "What is the SMS used for?", quite simple, they use the SMS for gaming, and may set up a Value added service number, and send as many SMSs as possible to this number, and collect the accrued income at the end of the month.

However the SIM card is paired to the modem, then they would require to take the modem with the SIM card. This would still require the username and password and VPN address to be able to connect the card on the network, which is usually resident in the system software, which is locked from the inside.

So all in all not a simple task.

[Didditmiself]

Thanks for that comprehensive info Justloadit. So it's not that easy to use once you've managed to pinch one. At least now I know that it is NOT urban legend (Bigtime or not). And I can explain it to someone else who doesn't know about it or how it works!!

[adrianh]

Given that a SIM card is essentially a Microprocessor that has a bit of EE memory, why don't the companies agree on a standard for industrial application cards that simply don't fit into cellular phones. Then the card would have no value to a thief when he lays eyes on it.

[Justloadit]

Many of the new modems do not have a SIM card, and use the internal processor to act as a SIM card. Going this route is far better.

[mthenjanakp]

hlw there can u plz help me



we have sim cards which are on site sending an Sms if there is a fault. The problem we have is that the sim cards are being stolen and those who steal them use them on there phones
i was hoping if you can tell me how to fix a sim card to only work on our modems only and not on the phone like if you remove the sim card from the modems(field modems) it does not work not even on a portable modem

[Justloadit]

Simply ensure that your SIM card requires a PIN number. You can program the SIM card for this action. It will require that the software in the modem on boot up to request if the SIM card requires a PIN number to continue, and then the modem sends the pin number.

I am sure that the modem has this already built in, and requires you to select the PIN number to program into memory.

Of course if the PIN number is incorrect, after 3 attempts, the SIM card will lock out and require the PUK number to open.

[mthenjanakp]

how is this done " The only difference with these SIM cards is that they only carry (transmit) data and no voice information" ?

[mthenjanakp]

like do i have to consult the service provider or find a way to do it my self

[Justloadit]

The SIM cards currently come with no PIN number of '0000'.
Either you use a standard cheap cell phone in which you insert the SIM card, and manually program a new PIN number, or alternatively the modem you are using has a service function in which you use to program the PIN number. Of course your software must have the facility to request the requirement of a PIN number by the SIM card, and then sending the PIN number to the SIM when it requests it.

The service provider does not get involved in this matter.