Walkie Talkies

I was thinking about how team members would communicate during the tournament, and I realized that using walkie talkies would make it much faster and more efficient to communicate during the tournament. Whether that may be between Scouters and teammates. Therefore calls don’t have to be made continuously, and all team members can be notified immediatly if something were to occur. Does anyone have an opinion on this? Will it even be legal?

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I think that’s a good idea, but it might interfere with the field control system or the robot wireless.
Also if a lot of people are on the same frequency it can jam it up
(Is that how it works)
I believe it is legal, since it isn’t match affecting or anything, unless you end up jamming a bots communications.

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You may not use wireless communication devices in the Alliance Station.

At events we have seen people use wireless communications to communicate.

If an EP is having VEXnet communication problems, they will ask teams and spectators not to use personal hot spots and other wireless interference sources.

Speak to your EP and check what is ok.

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Why not just text back and forth? Unless there’s some messaging premium, that seems to me to be the easiest answer.

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I mean if there was some sort of emergency, or if there was something which could be more quickly described using a walkie talkie.

At worlds, since almost none of us had an American phone plan, we used walkie-talkies to communicate. It was fairly effective, and we were even able to communicate from our pit to freedom hall.
It was extremely valuable at worlds for coordinating with teammates, for example asking for a battery when waiting in the practice field line, or having a team member scout while waiting.
I would definitely recommend having some form of team communication, as our first year at worlds was slightly hectic due to always trying to find someone before a match.

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I believe that a walkie talkie would be very useful especially If you need to get someone’s attention and you don’t know were he or she is.

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At worlds I saw a few teams using walkie talkies. So I believe it would be fine. If there are connection problems you may be asked to turn them off, but you probably will be fine.

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yes I’m also from Canada, and that was something I was thinking of.

Neither FRS nor GMRS should cause any interference with VEXnet. The power is too low and the frequencies are grossly different.

Do note that, in the US at least, GMRS users are supposed to be licensed. You can read more details about licensing on the FCC’s website.

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There are many factors that come to play with “interference”…

most importantly, perception… Moreover, communication with people outside of Alliance Station is prohibited…

Communication with team during alliance selection to/from team representative is permitted.

So sometimes it is not the technology used for communication, but the context with regards to the tournament which is at issue.

As for signals - emit a huge spectrum burst, you can be problematic with communications to the field…

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I don’t know why, but whenever I go to a competition there is no cellular connection. Mainly because of the locations of the schools being in more rural areas. This makes it nearly impossible to communicate with my team because the wifi isn’t always distributed to the teams. I think this would be a good solution for large competitions. Maybe not necessary for small competitions.

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They painted walls in our middle school with a paint that was absorbing phone signals.

You couldn’t get any internet on your phone unless you step outside or hang out next to the large window in the cafeteria.

Then new iPhones came out that use different frequency bands… sucks to have an old iPhone.

I think they do this in a lot of schools. I notice my cellular reception gets dampened the moment I walk into school. Not a huge issue is you have access to the school wifi, but it is frustrating for competitions. Especially when the Vex Via app won’t update.

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Usually most walkie talkies have both cb and GM’s, in Canada GM’s signals don’t need to be licenses however in the us they do, that why I used different channels when in the us specific channels are cb not gms

The frequencies being different doesn’t automatically mean that it won’t interfere though. And, two-way radios are actually quite a bit more powerful than VEXnet - typically 1 or 2 watts, and many of the radios I’ve seen at Worlds are configurable to 4 or 5 watts [cough Baofeng*], while VEXnet power is measured in milliwatts. If used close enough to a robot they could potentially cause interference by desensitizing the VEXnet receiver**. Also, harmonics are a thing, so if VEXnet is running on a multiple of the radio frequency it can still “appear” to VEXnet to be on the same frequency.

Since VEXnet does frequency hopping etc. the likelihood of interference causing any issues is low. Still, if it were up to me I’d ban team use of hand-held radios at events. Especially since quite a few that I’ve seen (specifically at Worlds) are being used illegally. But then again VEX surely has access to some great RF engineers and presumably they’re comfortable with the way things are, at least at Worlds where they are in charge.

By the way, if you’re not from the US and you bring radios and use them here, you should exercise extra caution. The radios you’re using may very well not be allowed to be used here, or they may be for frequencies that are not available for unlicensed usage. The fines from the FCC can be very large, and while the likelihood that they’ll track you down isn’t high they can and do find violators, especially if you’re interfering with a legitimate user who complains.

*If you’re using a Baofeng radio and you’re not a licensed amateur, you’re almost certainly in violation of the law.

**The FRC Midwest Regional is held at the UIC Pavilion in Chicago, which is in close proximity to some of the super-powerful broadcast transmitters for television and radio on top of the Sears Tower. We had a broadcast engineer who worked for one of those TV stations on our team who would help teams diagnose radio issues. He often talked about how radio spectrum so close to Sears was a mess (very high noise floor, etc.) and was very likely causing some of the problems, even though everything was on different frequencies. We sometimes brought spectrum analyzers and indeed the entire radio spectrum in that area was really bad. Lots of powerful two-way radios in a small area could create a similar environment.

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I’ve done research about the FCC radio requirements. And what I’ve got is that the CB radios are allowed to be used, however GMS does require a license. The walkie talkies that I’ve got have both GMS CB radios.

I wasn’t referring to you specifically, just that in general taking a portable radio to another country can be dicey as each country has different laws.

Out of curiosity, what radio do you have that supports both CB and GMRS? I’ve never seen a portable like that - the frequencies are so different that I think it’s hard to design a radio (and antenna) that operates decently on both bands.

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A basic motorola walkie talkie, that cost 30 each at costco.

I think you are referring to FRS/GMRS radios. CB is a completely different frequency range.

FRS/GMRS share 22 channels in the 462 and 467 MHz range.

  • FRS does not require a license, but is limited to either 0.5W or 2W, depending on channel. FCC FRS page
  • GMRS does require a license. It covers all of the channels of FRS, as well as some additional channels. It also allows a higher transmit power. FCC GMRS page
  • CB does not require a license to use. It covers 40 channels between 26.965 MHz and 27.405 MHz. FCC CB page

Please note that all of these services require the use of transmitters certified by the FCC. I don’t think Baofeng radios are legal for any of these services.

If the students get amateur licenses (ham radio), then all sorts of radios become available. Interestingly, amateur radio is one of the only places you are not required to use a ‘certified’ radio. The test is usually pretty inexpensive and the license is good for 10 years. Amateur radio is specifically forbidden for any business purpose. FCC Amateur page

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