Vulnerabilities of Wireless Two-way Communications

In a communications black out, two-way radio communications are the main alternative to modern conventional communications such as land line phones, cell phones and internet connections. However, no communications system is without short falls and vulnerabilities. Assuming that some attack or disaster knocks out conventional communications channels, alternative communications via two-way radios have a number of vulnerabilities and short falls.

Below is a list of vulnerabilities attributed to two-way communications.

1. Electro-magnetic Pulses
2. Lightning Strikes
3. Power Outages
4. Earthquakes
5. Destructive Storms
6. Jamming Interference

Electro-magnetic Pulses

Solar EMPs
Although unpredictable, solar EMPs can be anticipated if the solar storm cycle is high and the damaging solar flares (known as coronal mass ejections or CMEs) are detected before hitting the earth. If the CME is detected then the EMP intensity and effected areas on earth can be determined just before the damage can occur. If the coronal mass ejection emitting an EMP is detected as it happens and it is facing the earth, then it will only take an average of eight and a half minutes to hit the planet. The time can be longer depending on the angle of the flare, current distance from the sun and what side of the earth is facing the sun.

Obviously there will be little time to react considering the public will most likely be informed last during such an event. In a best case scenario you will hear about the incoming solar flare at night while you’re on the shaded side of the earth. In any case it would be best to take precautions long before any type of solar EMP threat is identified.

Nuclear EMP Attack
Although the effects of a nuclear EMP attack are nearly the same as a high intensity solar flare, once the trajectory is determined, there is more certainty about the intensity, duration and area covered. Concerning the amount of time to prepare for such an attack, a missile launched from Russia would take about 30 minutes to reach the U.S. However, there is time needed to determine if there was an attack launched and more time needed to inform military defenses. Then there is the possibility that the launch could occur from a country or a submarine closer than Russia or that the missile could come from somewhere based in orbit.

Once again, given all the factors there will be little time to react considering the public will likely be last to know and it would be best to take precautions before hand.

In an EMP event, most antenna towers, including cell phone, wireless internet, commercial broadcast radio and amateur repeater towers would likely suffer the most damage. Unless hardened against EMPs, even satellite internet and phone systems could suffer damage to the land-sat stations. Fortunately, these systems are well protected from lightning strikes that will help protect them during an EMP as well.

What precautions can be taken to protect two-way equipment from EMPs?

Storing your two-way radios and equipment in a Faraday cage will protect them from EMPs. Other than burying them underground, this is the best way to protect your equipment. However, if you use your two-ways on a daily basis, esp. if you have your radio connected to an outdoor antenna, without protective gear and protective grounding methods you will get your equipment fried in an EMP event.

The best thing to do to protect equipment that is in use is to have your antenna mast properly grounded, your radio in a shielded room, your equipment disconnected from the antenna coax and unplugged from the electrical outlets when not in use. EMPs will be attracted to your antenna and any wires or cables that are not buried or otherwise protected making your antenna, coax cable and electrical wires the most vulnerable things in your communications system.

Lightning Strikes
A lightning strike to an outdoor antenna will fry your system in an instant and potentially cause a fire or electrocute you . This can be mostly avoided with using lightning arresters and having a well grounded antenna mast. Without the proper arresters, disconnecting your antenna coax from your equipment during a lightning storm will at least spare your radio during a lightning strike. Without arresters and enough precautions, a good lightning strike would cause severe damage to your coax cable and outdoor antenna making them useless.

Both lightning strikes and EMPs cause a similar effect and can be prevented with the same methods and safety equipment. There are instruction guides available online about how to set up your equipment to save it from damage in both scenarios.

Power outages
Long term widespread power outages are a problem, but not as nearly severe as an EMP. Most communications systems will have battery or generator backup systems that kick in during a power outage. These will only last so long unless they are using solar or wind generated backup power. Once there is no fuel available for generators, systems that rely on those will go down after awhile.

Earthquakes
A massive earthquake would take out most of the communications systems in the region of the quake. A shattered infrastructure would be a problem for any surviving systems. The best protection from an earthquake disaster would be storing equipment in an earthquake proof building or bringing in equipment from unaffected areas. Mobile two-way systems would be best for surviving an earthquake scenario.

Destructive Storms
Damaging storms could knock out antenna towers and land-sat antennas as well as cause power outages. Some area road ways could become impassible after such storms. Hurricanes and tornados would be the worse type of storms to affect communications. As with an earthquake, a shattered infrastructure would be a problem for any surviving systems.

Jamming Interference
Solar and nuclear EMPs will cause interference that jams wireless frequencies by exciting the ionosphere. This will certainly jam distant two-way communications that rely on skipping signals off the ionosphere.

Solar EMP interference will last as long as the solar storms do. During a nuclear EMP, communications can be disrupted for a period of time varying from seconds to hours. Local two-way “line of sight” communications at higher frequencies will experience little or no disruption during EMPs.

The use of radio frequency jamming equipment is something that can take out all two-way communications. A high power, broad band, radio frequency pulse generator will jam radar, data links, voice communications or other radio signals. Even someone using normal two-way radios can jam communications by simply transmitting over the other signals with a stronger signal.

Such signal jamming must be located and disabled to restore normal two-way communications. Locating a land based line of sight jamming signal can be done by triangulating on the signal with two receivers using directional antennas. A land based jamming signal shooting a signal straight up to the ionosphere and back down again (near vertical incident sky wave propagation) would be harder to locate. A jamming signal from an orbiting satellite once located would of course be impossible to disable without specialized weapons like missiles and space based or high powered energy weapons.

a reply to: MichiganSwampBuck

They could just throw the big switch to put everyone in the dark, too.

On 911 communication was effectively shut down by everyone trying to call everyone else, which happens in a disaster.

All they had to do was look uptown though and see what was happening for themselves.
In an intentional nation wide "go dark" scenario, though, it might not be as clear. Its times like that you want a basic AM, ham radio or cb rig. Anything that isn't dependent on the internet the electrical grid, satellites or repeaters.

Keep it twelve volt. You can always hook it to your car battery for power and find out whats going on.

a reply to: MichiganSwampBuck

You don't get an EMP from solar storms.

a reply to: intrptr

Thanks for the reply post Intrptr, that is a very good addition to the thread. I had a few more scenarios to consider but wanted to keep the OP as short as I could by referencing what I felt were the main vulnerabilities of two-way radio communications. I had posted on this possibility in an earlier thread I created, but I actually didn't consider it for this one. Thanks again for posting that.

Really Chadwickus? I guess I was making an assumption there. Perhaps you could elaborate what causes a solar EMP? I still have time to correct the OP. Thanks.

ETA: A quick Google says it is a coronal mass ejection (CME) that causes a solar EMP.

While a solar flare alone might not be enough to cause problems on Earth's surface, a powerful CME is another story.

Solar EMPs

Storm from the sun or pulse from bombs, both have electromagnetic 'fronts', the results are similar when it comes to electronics.

I guess a CME is what Chadwickus was talking about, so I added the correction.

It's great how someone can be so critical of a minor detail and yet offer no useful information to help the thread. Thanks Chadwickus, at least you pointed out a minor error and put me on the correct path. Anything else I got wrong here?

a reply to: MichiganSwampBuck

Excuse my briefness, I posted and disappeared.

CME's, solar storms, geomagnetic storms. Whatever you want to call it, won't fry your electronics, the EMP from a geomagnetic storm is completely different to that of a nuclear blast, it only affects long conductors, such as long distance transmission lines and steel pipelines.

The only way a geomagnetic storm could damage a 2 way radio is if you're in an area with long span powerlines, like most of the US, China and Australia for example, and it was plugged in to mains power when a power surge from an exploding transformer hit it.

Is this a bit more to your liking?

I wouldn't consider it a vulnerability, more of a downside, but on two-way comms you are also using public waves which means anyone can be listening to your conversation.

a reply to: MichiganSwampBuck

And in reference to walkie talkies over say several miles...as they are device to devices. Electromagnetic interference rendering them un-communicable between each other? Or no?

originally posted by: Chadwickus
a reply to: MichiganSwampBuck

Excuse my briefness, I posted and disappeared.

CME's, solar storms, geomagnetic storms. Whatever you want to call it, won't fry your electronics, the EMP from a geomagnetic storm is completely different to that of a nuclear blast, it only affects long conductors, such as long distance transmission lines and steel pipelines.

The only way a geomagnetic storm could damage a 2 way radio is if you're in an area with long span powerlines, like most of the US, China and Australia for example, and it was plugged in to mains power when a power surge from an exploding transformer hit it.

Is this a bit more to your liking?

All good points, thanks for participating. I haven't looked into nuclear EMPs in comparison to solar EMPs.

I do know that there are surge protectors for your electrical, but I have no idea how effective they are against an EMP of either type. That's why a put out the suggestion to unplug your equipment when not in use. There are protectors for every line or system in your house though. Once again, thanks for the reply.

ArnoldNonymous, privacy was a point I was going to make here, but decided to keep the OP as short as possible. There are ways around the privacy issue, though most are not very legal to do under most circumstances. Still, glad that you brought that issue up as it is one downfall of two-way comms.

Mysterioustranger, as far as I know, the higher the frequency used within line of sight, the less interference from EMPs. The lower frequencies used for long distance communications by skipping off the ionosphere would be though.

a reply to: MichiganSwampBuck

Hiya SB. Thanks....Did you ever get involved with that emerg/disaster ham radio stuff up there? I think it was you ....

a reply to: mysterioustranger

I have posted a number of threads on the subject but shy away form getting a Ham ticket or being involved with those guys. In my opinion the amateur radio scene is counter productive for an open source network and it makes your personal information available to anyone who wanted to look up your call sign.

IMO, the ham crowd would be in the pocket of Uncle Sam during an emergency or crisis, not to mention a government crack down on dissenting citizens. Plus many of the ham operators have an exclusive attitude that sticks in my craw.

I'd rather use unlicensed frequencies and stick to personal matters if normal lines of communications were blacked out for any reason. Not that I wouldn't help on occasion if the hams were to talk on the unlicensed frequencies in such situations. I also believe that the F.C.C. is over restrictive and don't want to play their games either if I can avoid it.

a reply to: MichiganSwampBuck

I agree with you there. Although my team-mate...the director of the ham emergency network SKYWARN would disagree with both of us...you and I know better about the personal stuff getting away from us and directly to them.

Hey, though Im associated with Homeland Security and FEMA, Citizen Corps etc...I dont agree with everything either. And with that...and the possibility of losing my security clearances...Ill be quiet now...

Thanks SBuck...................

a reply to: mysterioustranger

It's great to know that not everyone will drink the cool aid. I have my opinions about the ham club and figured you probably had a ham ticket. I'm glad that I didn't insult you with my point of view on that subject.

I really have thought about taking the test and getting licensed. If I did do that, IMO there is no reason to ever even use it unless I had to. Actually you can buy a license to use the General Mobile Radio Service (GMRS) frequencies on VHF. The license cost is $65 for 5 years. The wattage is from 5 to 15 watts, less interference, more private than MURS, FRS or CB, and you can use repeaters in your network. The radios for GMRS are common and rather cheap as well. That seems like a good way to go for a private use network, one that wouldn't get much attention. Seems like a good choice for prepper or survivalist groups.

originally posted by: intrptr

Storm from the sun or pulse from bombs, both have electromagnetic 'fronts', the results are similar when it comes to electronics.

Not really, they are quite different, both in cause and effect.

eta: a second, longer term, and perhaps less avoidable issue is going to be the damage to the ionosphere itself. This will cause all sorts of mayhem, unless you're using ground wave communication.

Welcome Bedlam, I thought I see you here soon. I still appreciate the PM discussion on single side band. Have a good one.

PS: Before I get in to any trouble, I better do this, just in case.

Ego te absolvo, in nomine Einstein, et Neumann, et spiritu Feynman

Not really, they are quite different, both in cause and effect.

I believe I said, "when it comes to electronics".

Induced current in conductors like circuits, wires and even railways… zzzt.