Wireless Networks at Competitions

[Ctrl Alt Delete]

If all the controls are running on 2.4, I would just get a new 802.11n router that can run on the 5.0Ghz band. That should eliminate interference and create a really large coverage area.

[rdlevy1215]

Based on what I heard from NI, they believe that 802.11 A is an "old" technology and not worth using for the robots ... therefore, all you need to do is use A (5.8 Ghz) and there will be no interference issues and no problem

[cooker52]

So the general idea here is that it is unlikely that they will allow wireless networks next year. It's a real shame because that's how a lot of teams are probably going to start doing their scouting.

Now, was wireless networks allowed this year?

[NickE]

Originally Posted by cooker52

Now, was wireless networks allowed this year?

I believe they were allowed at regionals, but not the championship

[Nibbles]

It depends on the system FIRST/NI goes with. It has been explained in other threads there are three non-overlapping channels (11 total, but some overlap), channel... 1 for example, could be set aside for team use. I don't see this happening as it is too confusing, if non-interference is essential, but it would work. Then again, if non-interference is essential, you shouldn't be using the 2.4Ghz band.

I hope we go with a 5.0Ghz system (I believe 802.11a does and with some configuration, n does too), with a single FIRST-controlled access point that all the control stations plug into (that means 7 wireless broadcasting devices total), and use a small Wifi-Ethernet bridge to use with the robot, which would look very much like the older transmitters. Lots of bandwidth, less interference then having an access point on each robot and 12 broadcasting nodes, simple, one network to connect to, no confusion. Hopefully. I have no clue how this will all be zero configuration. Each robot connects to a authentication-required access point, always called "FRC" or something, and gets an IPv4 address with DHCP, then discovers the driver controller with a service discovery protocol, driver controller pings back, station light stops blinking. Hm, idk how I feel about using WiFi after all :-/

I am also awaiting the return of Sundial, that would mean reserving a channel if not the entire 2.4Ghz spectrum, for team use. On a side note, I hope the field controller is free software along with the robot controller library (right now only the programming library has been mentioned, and it has only been called open source, of which free software is more or less a subset). Maybe I will start a thread on the field controller exclusively.

So, 900Mhz video systems are looking like a good possibility, but could find another use in FRC besides personnel two-way-radios. Dial up modems anyone? Don't worry, the theoretical speed from a 900Mhs two-way-radio is orders faster then telephone.

You could use Light for medium distance communications: http://ronja.twibright.com/

Whichever band of Wi-Fi FIRST uses (2.4Ghz vs 5Ghz), use the other. If the field controller uses a single access point, that means one channel, so you could use a different channel, 1, 6, or 11 depending on what FIRST is not using. Again, this could get confusing, even using a different band entirely, so not even that may be allowed.

The Short answer: Plan on using good ol' Ethernet, but wait and see. Ethernet attached to a plain old router (even a wireless one with WiFi turned off) saves lots of time and hassle anyways, if three extra cables are not too much work for you.

[AndyB]

I'd say start working on other forms of wireless communication. Scout using Morse Code, hand signals, light flashes (LOST anybody?)... Paper cups and string are cheap too...

[Ctrl Alt Delete]

Originally Posted by AndyB

I'd say start working on other forms of wireless communication. Scout using Morse Code, hand signals, light flashes (LOST anybody?)... Paper cups and string are cheap too...

We should create string networks at Nats. Just have miles of string running between the Georgia Dome and the GWCC.

[cooker52]

"Need a query, ask the cup!"
Now that would be fun . Now all we need is a sponsor crazy enough to supply us with the few hundred cups and the couples miles of string.

[Richard McClellan]

Originally Posted by EHaskins

Personally I don't think that any such restrictions would be practical or even possible to enforce, and if the new control system can't handle some other networks in the same area, then we're going to have some big problems next year, especially with the number of wireless networks growing like they are.

According to Bill Miller, Director of FRC, at the Mentor Q&A during this year's Championship, they would be policing the air waves with some powerful tracking system that would allow identification of a wireless router or something in a team's pit. I'm not exactly sure of the details, but it sounds like it will be enforced.

[EHaskins]

Originally Posted by Richard McClellan

According to Bill Miller, Director of FRC, at the Mentor Q&A during this year's Championship, they would be policing the air waves with some powerful tracking system that would allow identification of a wireless router or something in a team's pit. I'm not exactly sure of the details, but it sounds like it will be enforced.

They may be able to control the networks within the competition venue, but there is no way they could restrict networks in the surounding area. I know that at the Milwakuee regional I was able to detect 5 to 15 non-team networks at any time, depending where I was in the venue.

Even if they did somehow manage to eliminate ALL team networks (which will not happen*) and all of the non-first related networks, they would still have issues with other 2.4ghz devices.

As I said before, if the new system can not handle other devices operating in the same band, then, no matter what rules they put in place, the system should not be used. Especially when the band they're using is so heavily occupied.

* Not all teams read the rules thoroughly. Some people will break the rules without even knowing it.

[NickE]

Originally Posted by EHaskins

Even if they did somehow manage to eliminate ALL team networks (which will not happen*) and all of the non-first related networks, they would still have issues with other 2.4ghz devices.

As I said before, if the new system can not handle other devices operating in the same band, then, no matter what rules they put in place, the system should not be used. Especially when the band they're using is so heavily occupied.

Yes, as you have said, it would be impossible to restrict all 2.4ghz devices. Therefore, instead of b or g, 802.11a should be used as the primary means of wireless communication for the 2009 FRC Control System.

802.11a runs over the 5.0ghz band. This band is much less congested than the 2.4ghz band.

It has 12 non-overlapping channels (compared to 802.11g's 3). Therefore, come time for championships, each field could have its own channel (or even one per alliance per field), reducing almost all network channel interference

Also, there are very few wireless networks that use 802.11a. Therefore, FIRST would have practically no work to do when it comes to wireless network policing, as just about all teams with networks of their own would be using b or g on the 2.4ghz band.

[UndergroundVoid]

I'm surprised in the no fate it technology and programming here. This is a guess but they might do a lock out system where once a robot is connected and confirms by some code them it will block out all other possible connection attempts. kinda how when you sync up you blue tooth phone to a computer it give you a pass key for confirmation.

As for pit wireless, come on people suck it up and just use a Ethernet cable for programming because:
1. You have nothing to lose.
2. You stay out of trouble in the long run.
3. Your programming should have been completed during build season and only should require tweaking.
4. What internet service are you going to be broadcasting out.
So in the long run people just bring a cable and stop trying to be lazy, we have gotten this far with daisy chains of serial cables, so why not buy a 2 foot Ethernet cable for the pit and a 30 foot for the practice field which together would cost less than 15 dollars.

So the real question is not that is it allowed but do you really need it and why a debate over a nonexistent rule? I get the impression here that people want to do things just because they are lazy but yet fear it since they don't trust the technology and programming.

This goes back it to the old fashion "what if this, what if that" but you will never know till it happens yet you can always dream.
Please people think before writing and consider all the possibilities and outcomes and do some research in the technology in this field you may be surprised on what you may find.

[Nibbles]

Originally Posted by EHaskins

...
As I said before, if the new system can not handle other devices operating in the same band, then, no matter what rules they put in place, the system should not be used. Especially when the band they're using is so heavily occupied.
...

It seems like if it uses electricity, it interferes with the 2.4Ghz range (Alright, maybe not that bad).
You are exactly right, if it is any critical reason, they should be using something else.

This makes me wonder how robots will be controlled in the pits, obviously not with WiFi. The upshot of using IP is that the transport layer is irrelevant, be it Ethernet or WiFi (which borrows quite a bit from Ethernet, such as MAC addresses), IP doesn't care. How you connect to the robot will be interesting, there are two Ethernet ports on the robot controller, one it is very strongly hinted will be used for an Ethernet camera. The other then has to do to the communication mechanism, so maybe the Wi-Fi node or access point has a hub or switch inside it. I'll ponder this a little more.

Couldn't they just enclose all the robots in a Faraday cage and not worry? Actually, covering the field would be impractical, but surrounding the team pits, with two equal size foil walls on each side, connected together, that would work (kinda)... Then again, scouting isn't restricted to the pits, all of the scouting I directed was in the stands, except a total of one minute at the scores and results display. Luckily you don't need Wi-Fi for the stands, you are staying in one place. Or at least I didn't.

Originally Posted by NickE

...
Also, there are very few wireless networks that use 802.11a. Therefore, FIRST would have practically no work to do when it comes to wireless network policing, as just about all teams with networks of their own would be using b or g on the 2.4ghz band.

N also supports 5Ghz according to the standard, but idk if it requires special configuration, or if devices even support the channel, some types of antennas have to be built differently for different frequencies.

[EHaskins]

Originally Posted by NickE

Yes, as you have said, it would be impossible to restrict all 2.4ghz devices. Therefore, instead of b or g, 802.11a should be used as the primary means of wireless communication for the 2009 FRC Control System.

I don't disagree 802.11a would be the practical choice based on interference, but there are othe issues with 802.11a.

My big issues with 802.11a are that relativily few computers have 802.11a cards, and 802.11a has limited bandwidth, which could limit possible uses(video streaming maybe).

Originally Posted by UndergroundVoid

So the real question is not that is it allowed but do you really need it and why a debate over a nonexistent rule? I get the impression here that people want to do things just because they are lazy but yet fear it since they don't trust the technology and programming.

This goes back it to the old fashion "what if this, what if that" but you will never know till it happens yet you can always dream.
Please people think before writing and consider all the possibilities and outcomes and do some research in the technology in this field you may be surprised on what you may find.

I think very few people want wireless programming in the pits. The concern I have is that if this type of rule were enforced it would prevent many of the scouting and collaberation systems teams have delevloped from being used.

And your other point, "why a debate over a nonexistent rule?". Its summer, we're not building robots, and we're geeks. What else are we supposed to do?

[NickE]

Originally Posted by Nibbles

Couldn't they just enclose all the robots in a Faraday cage and not worry? Actually, covering the field would be impractical, but surrounding the team pits, with two equal size foil walls on each side, connected together, that would work (kinda)...

Sounds expensive, but anyway...

Originally Posted by Nibbles

N also supports 5Ghz according to the standard, but idk if it requires special configuration, or if devices even support the channel, some types of antennas have to be built differently for different frequencies.

Yes, N can also be configured to run on the 5ghz band. However, as time goes on, more and more devices will likely start using 802.11n, whereas 802.11a is probably not prone to nearly as much expansion (and interference)