PSA: Please Please Please Shutdown Wi-Fi At Detroit!

#1

Please, There is no reason to have your Wi-Fi on at Cobo. Their Wi-Fi, If they have any, doesn’t work in in the stands or pits. This PSA goes not only for Hotspots, this also goes for having your Wi-Fi on in client mode.

Your phone is always looking for Known or Unlocked Wi-Fi networks. If your Wi-Fi is enabled, it will cause issues, Especially with the number of other people who will have their Wi-Fi on.

Not only are you looking for Known or Unlocked WAPs, Your phone also will query the Field AP for network names, Causing congestion and eating bandwidth that is at a premium at events like this.

No device is immune from this, All 802.11 Wi-Fi devices should have it disabled. Please be courteous to your fellow robotics teams and just shut it down. We can all prevent a repeat of Houston.

54 Likes
Field issues in Houston
#2

am i missing something? ive only heard of 3 or 4 matches out of the 500+ matches that had problems. And i dont think everyone turning off their wifi in the venue would have changed those situations

#3

Yes, you are. Many replays were held in Houston due to interference and bad pings. Galileo got off easy with only two or three on our field, but we lost time on occasion waiting for pings to calm down. One team on our field decided to leave their GoPro on with the wifi, which was right on top of our channel. Thankfully, they also named it after their team.

Shut it all down and make everyone’s life better. :slight_smile:

17 Likes
#4

Could a mod pin this thread?

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pinned globally #5
#6

Yes, absolutely you are missing something.
Newton alone had ~8 rematches, all of which were caused by FMS network issues.

2073 was asked to reduce our bandwidth utilization from 3.1Mbs, well within our 4Mbs allocation, to under 2Mbs. This was due to the huge load the FMS was dealing with from Cell Phone queries.

By way of comparison, the Monterey Bay Regional had a Cisco provided public WiFi set up for everyone in attendance. Exactly zero matches had network issues. In addition, the same number of announcements went out asking people to turn off their WiFi.

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#7

I was watching streams so it seems like i only caught a few of these

#8

I’ll note that Cobo Center also has public WiFi throughout the facility.

1 Like
#9

I think they turn it off or it breaks about 1-2 days in.

1 Like
#10

Sadly, this message wouldnt of helped us in HOU.

4513 was in Turing, and for most of the weekend i heard no issues about lag on any team in our division. We had some camera issues, but nothing major, and ended 15th. We got picked by the 7th alliance of 6672, 4451, and wrapped with 3196. After a surprise win against the #2 alliance, we went onto semis.

Our first semis, we experienced consistent lag for over 40 seconds in the match. The lag caused us to create two fouls, and descore a hatch panel/Cargo on our cargoship, arguably making the match winnable if those things didnt happen. The FTA/Head Ref told 6672 that 40s was not long enough to warrant a replay, even though the other alliance experienced nothing of the sort. We also broke chain on the bot, which was fixed, but 3196 was sent out anyways in our place.

In the 2nd match, 3196 experienced the same issues we did. Im fuzzier on the details of SF2 (and PHX Wifi is garbage so i cant rewatch) but IIRC without lag in that match it was also winnable. This time though, the FTA Told us that it was a “Venue Fault”, or that the wifi that GRB provided was interfering with our and 3196’s robots, and only ours in the Semis. They also told us that this didnt warrant a replay either, and AFAIK didnt affect our opposing alliance in the slightest.

Its frustrating that there was literally nothing we could do, and we were brushed away with terms and explanations of something that isint even in the manual as the excuse for our issues. I have no ill will to the #6 alliance, they played a great game, but the way we lost shouldnt of happened.

8 Likes
Field issues in Houston
2019 lessons learned: the negative
#11

Newton had to replay 9 matches for this reason.

2 Likes
#12

Thanks for the reminder, sending an email to the team members now…

#13

Can someone comment on tethered connections? Will a tethered connection between a phone and a laptop interfere with match play?

I’ve heard varying answers, just want to know if this is a potential solution.

#14

If the tether is via Wi-Fi, it will interfere with match play.

#15

I meant a physical connection via USB, not an access point.

#16

For those of you who weren’t at Houston, here are a couple of match logs that we had on Carver showing ping spikes during matches:

These ping spikes lasted almost 5 seconds normally, and strange robot behavior was the result. There were several watchdog errors during these ping spikes.

For instance, there were several instances where our robot would keep the last command issued, such as “full speed forward”, and slam into player stations, or, when our driver would try to slightly turn to the right, the robot would do a complete 180 degree turn.

We also had issues with our limelight and other things during these ping spikes.

I’m sure that the fields in the middle at Houston we’re considerably worse as they had large crowds on both sides of them, which led to them having to replay 10+ matches. Carver wasn’t as affected since we were all the way at the end, but there were still some issues.

It’s simple guys and gals. Turn WiFi and hotspots off. 30k 802.11 devices in a small confined area causes massive interference on the 5GHz band.

In the meantime, FIRST needs to be researching another communication protocol to use for FRC. 5GHz 802.11 is so widely used now that it is going to be hard to prevent this in the future.

6 Likes
Field issues in Houston
#17

I hear the 900 mhz band is not so bad…

(we didn’t have these issues 10+ years ago when we used dedicated radios, instead of WiFi, to control the robots)

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#18

This is a match log from the Roebling subdivision field. The robot was basically undrivable.

This was a field in the middle of the 6 fields at Houston and therefore had a large number of replays. Hopefully the folks in Detroit are considerate toward competing teams by turning off their WiFi and hotspots. No-one wants >100 ms of latency while driving their robots.

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Field issues in Houston
#19

Am I understanding this correctly? The FTAs told you that the venue interfered with your ability to connect to the field in two eliminations matches, and they also said that this interference did not warrant a replay? If this is an accurate and complete version of the story, it’s troubling.

It seems like “Venue Fault” is a way to avoid saying the phrase “Field Fault”…

6 Likes
#20

I wouldn’t be opposed to going back to one of these radios.

The issue with that though is that so many of our components and interfaces use web servers - our limelight, roboRIO, etc all have configuration UI through the web browser and the IPv4 system.