(Natural News) With threats by North Korea to drop a nuke on the U.S., and hopefully this is just saber rattling, plus escalating tensions with Russia over the Syria missile strike, it may now be an appropriate time for some advance planning about backup communications options in a grid down scenario.

In some kinds of disaster events, whether man-made or natural, your smartphone may be useless, at least in a worst-case scenario. (RELATED: Read about more prepping at OffGrid.news.)

That's because cell towers are particularly vulnerable to disruption, OffTheGrid News explains, thereby taking out the network.

Cell towers need AC power to operate, and most don't have an automatic backup system. Even those that have emergency generators are only on during short-term emergencies. Many cell towers are also easily susceptible to physical attack beyond storms.

To avoid complacency about the viability of cell phone service during a widespread power outage, OffTheGridNews suggests four alternative emergency communications devices to include in your bug-out bag containing emergency supplies.

Citizens Band (CB) radio. Operating on the 27-MHz band, CB has faded in popularity since its heyday; it's conceivable that you may be listening to a lot of dead air. A CB's radio's range is generally limited. However, they are better than nothing, and inexpensive.