Disaster Relief Vehicles - Phone Solutions

We have an oppertunity to pair with another company which builds Disaster Relief Mobile Vehicles and FBI Trucks, ect.

They want a phone system which will be reliable. Think of a disaster situation and what forms of communication would be available or not.

They originally said they wanted to be able to just take some telephone cables and plug into the unit and have it work. I said yes however every time you move the vehicle and you change the lines your connected to the system will need reprogrammed for the new numbers.

I said SIP with 4G would be more reliable. Am I correct in saying that. 4G towers are less likely to come down than Telephone phones with the lines. Is there any other tech they can use. Satellite is also an option but I think the latencies are too high. Anything past 70ms would start causing choppy voice no?

I worked with a company that use to build these. You need multiple options because frankly if you go with 1 it will be that one that always breaks.

  1. Satellite is the most reliable but stupid expensive. Environmental factors can affect this so it shouldn’t be the only option but needs to be present.
  2. Celular networks. Even if the towers are physically operational you will find that in any disaster the entire population gets on their cell phone. This will overload, crash, congest every tower. This overall is an option but a terrible option in most cases.
  3. Physical lines. It takes minutes or seconds to tap in to copper lines. Assuming the infrastructure is present (connectivity and battery) this is one of the better options. Use gateways with analog ports. No reconfiguration necessary ever really.
  4. Microwave towers. This may be more reliable than cellular as well.

With most of these options everything should be generally static so I am not sure why you would ever need to reconfigure. Even with endpoints you can use something like the epm. You can quickly map extensions and have dozens of phones up in minutes.

Just to add, something to consider with cellular access in emergency preparedness, you might consider using a cellular gateway for phone calls and not data. Currently, wireless priority service (in the USA) only works for voice service, not data. More on WPS: https://www.dhs.gov/wireless-priority-service-wps

That WPS thing is interesting. @jfinstrom doesnt Sangoma produce 3G Voice cards with SIM Cards in them?

If you are talking about a Critical Center then don’t rely on just one idea, always have a backup plan.

We had configured a Command Center not to long ago, the Phones were registered to a remote server, we used Point to Point antennas for primary data link, and we used a 4G device as a backup solution.
We tested a day before the event, it worked like a charm - ZERO static/choppy sounds.

However, at the event, there was too much “noise” which caused the PTP Antennas to make some trouble, and this 4G Device did the job perfectly. (There was actually thousands of cellphones at the event, but we still had a stable connection)

What i would suggest as far as technical setup:

  • Use SIP phones connected to a remote server which has a backup power generator and has a secondary internet line. [There’s a lot of Data Centers who are offering power and data backup] (You can also register the phone to a secondary SIP Server in case the Primary goes down)

  • Always have more then one Internet Connection Available.

  • Would suggest considering calls going to cellphones in case of no internet connectivity available (We have setup at a client, where users can reach a IVR, and let’s them add Cellphone numbers to a Queue to receive calls)

I this scenario i would invest in a enterprise SIP provider with has a reputation of fully redundancy. and would also invest in two solid SIP Servers which as mentioned above, can be Generator Powered and have a secondary internet line, and register the Phones to both servers.

(Again, I would strongly recommend to have the servers at a remote location, and not on the vehicles, so they will be available to receive calls at all times, and in worst case if you won’t manage to get the SIP Phones talking to the PBX, you’ll Route the calls to Cellphones)

Much luck.


You asked a really loaded question here, as the scenarios are almost endless. I am the IT guy at a radio communications company, and (along with my Ham Radio training), there are arguments for radio communications. If all the chips are down, a true emergency, is it critical for the infrastructure to support point to point communications, whereas a radio system might suffice? Your customer will be able to identify if full duplex calls are required, or if a two-way radio system will suffice.

To cover all the emergency bases, you should assume that public resources will get shut down. This includes the cellular network. I work with international folks who have suffered in other areas of the world the loss of GSM networks to control widgets in the power transmission lines and sewer systems, and when a terrorist incident occurred, the government shut down the cellular networks. There went the controls for the power and sewer.

Your group may need to plan completely around the public infrastructure to ensure communications. This likely means your own radio system, including microwave. You will also need to identify who these people want to talk to. All in the same group? Perhaps you can host a server at the tower, and make all connections there, and treat the system as a big office. But if calls need to leave the organization, you will need a trunk to the outside phone network, assuming it is still working.

You may need to look into radio solutions, such as TETRA, which will support telephone calls using a device that looks like a walkie talkie. TETRA is the public safety standard everywhere outside of the US… you may have heard of P25… that is what the US uses, but it doesn’t support full duplex telephone calls. TETRA is the wrong medium to use, however, if you are looking to replicate an office environment with lots of full duplex calls.

I apologize if I added to the complexity of your mission, but to be truly sufficient in a “anything possible” disaster, a plan around public infrastructure is required. Remember that in any battle, the enemy gets a vote (natural enemy or human one) and your system will need to respond to it. You may find that an easy simple two way radio is best to get the messages out. All depends on the customer requirement.