Jim:
I would like to begin this story by telling you why I felt it was needed. I was reading the blog and saw the post from R.H. “When the lights went out in the southwest” and how they had a very hard time getting in contact with his nephew. And also a recent post on CME and nuclear power plant failures and grid down type situations. And it got me thinking about how little some people know about how the traditional communications grid in this country works.
To qualify my position on this subject I will tell you that I’m a network technician for a very major telephone company (Telco) that serves all of Jim’s American Redoubt states and many others. I have 11 years here and love my job and I have been everything from an installer/repair tech to the guy that splices the cable and installs high speed data lines.
So where to start? I would like to tell you all there is to know about how this stuff works, but I don’t want to bore you all to tears so I’m going to leave most of the technical terms and stuff like that out. I’ll start with R.H. and his trouble getting in touch with his nephew.
In his story he talks about getting texts and some calls on his cell. So we can assume that he had a signal from a cell tower and his cell phone was in good working order. But there was a problem with one town not getting or sending cell calls and texts. This was possibly a tower that served that area had lost grid power and had no battery or generator back-up. Or it was over loaded with call volume. See in a typical cell site there are pretty much three major components that make the whole thing work.
1. The tower, This guy sends out and receives radio like signals to and from your cell phone.
2. The switching equipment in the building on the ground. This takes the signal and turns it into a call or SMS message and routes them out to the world.
3. The tower’s connection to the world. This is typically a couple T-1s or a fiber optic connection.
Sometimes part #2 or #3 will become over loaded with volume and that’s why you’ll get that message “sorry but all circuits are busy” when you try to make a call. The switch may not have enough spots free to connect you out but the tower can make a connection to your phone. Or the T-1 or fiber connection to the world doesn’t have enough bandwidth to handle all the calls if its being overloaded with calls. This is why sometimes you can send a SMS message but not make a call. Because the message needs less bandwidth to send compared to a voice call.
Visualize bandwidth like a pipe. If its big enough to handle the traffic on a normal day but all of a sudden you start cramming more stuff in it it just can’t fit sometimes. Like trying to use a garden hose to fight a house fire, its just not big enough sometimes. Now land lines are a little bit different, and have some advantages for preppers over the cell phones. Don’t get me wrong they both have good and bad sides. If you have a land line great but if you don’t I’ll let you know why you might want to consider getting one.
First off the whole problem of signals and battery power on your end are almost nil. If you have a hard wired or “corded phone” it will use the electric signal that’s on the line from the Telco‘s own equipment. Assuming everything is working correctly at the central office, or some of the more rural areas are served thru what we call “pair gain” or a R.T. (short for Remote Terminal) more on this set-up later as there is a difference between Central Office (CO) based and R.T./pair gain based services.
Second, the whole bandwidth issue is not as bad because the CO for your area is where most cell towers get their fiber/T-1’s from. Now CO switches can also become bogged down buy call volume also but most of the time they have extra capacity built into them because of this. And if you are making a call to another line that is from the same office the switch will make the connection in the same office. A long distance call or one that has to be sent to another office is more susceptible to volume problems due to the trunk lines used to connect the CO’s to each other becoming overloaded.
Third, The COs have a big generator that kicks in when the office loses grid power. The offices I work out of have either a 72 hour supply of diesel fuel or run on utility-piped natural gas. But the diesel is most common as you can see the disadvantage to the gas option, I only know of one that is like that. Additionally, hey also have a 8 hour back-up battery bank.
This is where the difference between CO-based service and R.T.s kicks in. First off the R.T. is usually connected to the CO by a dedicated group of T-1s that have one time slot per line in the R.T. so you don’t have the problem of “all circuits are busy” or a fiber optic connection that is for our sake the same. The trouble kicks in when these guys lose grid power, They typically have a 8-to-24 hour battery back-up in them and that’s it. We have to go out with our trucks and charge them back up with the gensets on our trucks. You can see where that could get tricky. Most newer DSL service is provided by a R.T. and some of them don’t even have a battery back-up as the companies are not required to have it on them by most regulations. My own line is like this, the dial tone is provided straight from the CO but my DSL comes from an R.T. So when my part of town loses grid power the phone still works but my DSL doesn’t. This is something you might consider if you are using a VOIP type system.
The next thing you might think about is 911 service, your land line is tied to your address so if you call 911 from your land line the dispatcher on the other end knows where the call is coming from as soon as it’s received. This is why a 911 hang-up still brings the cops to your house. The cell phones are getting better about knowing where you are with GPS and other things being used to tell where you made the call from.
I’m not to well-versed on how reverse 911 works with the cell’s but I do know it works well with the land lines. This could be a double edged sword for preppers as the cell or land line could give up your location if you want to be all secret squirrel, but I have personally installed lines to addresses that are something like: “County Road 21 pole 5 second gate on the left.” We don’t care where the house is, just where the N.I. (short for Network Interface) is. I have seen these little gray boxes on fence posts and we take it to there and the customer takes it past that point. There are other ways around this but it usually requires you to use VOIP to get a fake area code and number. I know of guys that use this type of stuff but that’s for another post.
This is just some info on why, during a short term SHTF you have problems using traditional communications. Be it a hurricane or another 9-11-01 type situation you’ll be better prepared for them. In a TEOTWAWKI type of scenario your pretty much doing the YOYO thing but I hope this helps for the minor emergencies you run into in you lives.
And you can always stop one of us out on the road and ask questions to find out info on your setup. I would have to say that maybe 50% of the guys I work with are preppers and even more are ex-military so we would not think it strange at all if you wanted to know how it works! Hope this helps, – The Phone Guy