Emergency Communications Media
There are many ways to communicate. Methods that we use daily may or may not be available during an emergency. Each communication medium has advantages and disadvantages for various uses before, during, and after an emergency. No medium is perfect, so it's important to have redundancy in our plans. As an Emergency Communications Specialist, it's important to realize that since not everyone has access to all media, key people need to be able to have "above average" access to resources in order to serve as communication bridges.
Media Classification
Some ways of classifying communication media (Yes, some pairs are related):
Analog vs. Digital
Broadcast vs. Two-way
Electronic vs. Low-tech
Fixed vs. Mobile
Infrastructure-dependent vs. Independent
Licensed vs. Unlicensed
Local vs. DX
Paid/Expensive vs Free/Cheap
Point-to-point vs. Broadcast
Professional vs. Amateur/Consumer
Real-time vs. Store/retrieve
Robust vs. Fragile
Voice/video vs. Text/data
Wired vs. Wireless
Characteristics that may be desirable in on circumstance might not be in another. For example, the point-to-point nature of the telephone is great when you want to have a private conversation with a single person, but it's terrible when you want to let 100 people know something. Graffiti on a building is gaudy, not easily removed, and certainly not mobile, but spraying the damaged wall of a meeting place is a handy way to notify everyone of an alternate location or warn of danger, and will serve the function faithfully for days, weeks, or months.
When planning for an emergencies, It's sometimes assumed that everything's a disaster that completely destroys all popular ways of communication, particularly those that rely on high-tech infrastructure. This is false; while it's certainly one possible scenario -- and one that you should indeed be prepared for -- it's much more likely that some conventional media will be available -- especially before, but even during and after an event, and you should not overlook technologies that, while viewed as fragile, may be especially useful to you. Never rely on a single medium; plan for the most effective means in various situations, with a hierarchy of fall-backs.
Media List
Here's a list to give you some ideas of available communication media, some more useful than others. Feel free to submit additional ideas!
Low-tech
High-tech
[under construction]