In the later half of the 20th century communications came of age. Before that for centuries we had men riding the length and breadth of the land with pieces of paper. If the later half of the 20th century we developed systems that enable us to communicate real time in person, audio or audio/visual or via store and forward text/audio/video messages. Almost everyone, including those in third world countries, have access to communications systems. Subject, as usual, to government monitoring and control.
Now, imagine if that system is suddenly removed. How would you get on? Well, in the first instance it is not usually a life or death situation. You are just unable to contact someone and give them an update. In most cases, in the UK, lack of communication is just an inconvenience. Only in a serious physical situation would the lack of communication be an issue. We would be back to the times before phones were in common use.
So what would that mean? For one thing it will take the police longer than the current 3 days to respond to a break in attempt. However, they certainly will not be there if you are being attacked or raped. On the plus side your invaders screams will be unlikely to be responded to as quick as they do now. To arrest you btw.
If comms goes down short term then we will just get by and hope that nothing serious happens. If longer term then you need to adjust your requirements to suit. No phones, no readily available information and no rapid responses by officials who can help in an emergency.
So, looking at the longer term, what can you do to help yourself? You need some way to gather information from outside and you need a way to communicate with friends and family both local and distant. You want to be able to contact emergency help.
There will be people out there broadcasting on radio stations if civilisation still exists. You will simply need a standard radio, remember them? To pick it up you simply tune in and listen. You can get reasonably priced radios that are wind up. You don’t need batteries. Get a couple and store in your car and at home.
For personal communication you either need walkie talkies or CB radio for short distance and side band CB or ham radio for long distance. Walkie Talkies are good for a few miles and CBs for maybe two or three times that distance depending on atmospheric conditions and the type of CB. (In the UK the worse option was chosen by UK Gov, who would have thought it, which limits the range). Side band radio and Ham radio are licensed in the UK and you have to sit a test to get a license. You can still buy the equipment though so if you have the funds then buy at least one, for storage and use if things go really pear shaped. Make sure to get rechargable batteries for the walkies while the CBs run off car batteries.
As an aside there are still many old style US CBs in the UK with sideband options around. Have a look for some second hand ones of these. They can be bought at very reasonable prices and those with FM are also be legal to use now. Win Win.
Now as far as the emergency services go, if they are not available on CB or via an alternative put in place after the event, like old style phones, then there isn’t going to be any available. Make sure your medical situation is such that you can look after your own.
Now for short term communications loss on a local area. If you have done all of the above then you should be in a good position. Pass a CB or walkie talkie to someone with a working phone and call them in an emergency. If they are like you they will already have one and will be glad to help.