Technology Forum Has Moved!

The FIRST Tech Challenge Technology forum has moved to a new location! Please take a look at our forum blog for links and instructions on how to access the new forum.

The official blog of the FIRST Tech Challenge - a STEM robotics programs for students grades 7-12.

Note that volunteers (except for FTA/WTA/CSA will still access their role specific forum through this site. The blog also outlines how to access the volunteer forums.
See more
See less

Interference issues with WiFi direct vs traditional Accesspoint/Client connection.

  • Filter
  • Time
  • Show
Clear All
new posts

  • Interference issues with WiFi direct vs traditional Accesspoint/Client connection.

    I was wondering how the change from Samantha module to WiFi Direct might affect the WiFi climate off the field (as it relates to interference and prohibition).

    I’m not sure how the power/interference aspects of a HotSpot/Client setup varies from a WiFi Direct system, but we all know how Hot Spots are currently banned from FTC Events.

    With the new system, it would appear that the ONLY method of controlling the robot will be WiFi Direct, (no option for Bluetooth or tethering) so will there be a problem with 50 teams all using WiFi direct to run their robots in the PITs , while matches are going on in the next room? (Pits routers have been prohibited at all my recent FTC events)

    To compound this issue, I will suggest that since we will all be learning how to develop apps using Java and WiFi direct, many teams will be thinking about what other useful apps could developed to be used in the stands (like scouting software, or team social networking, or even gaming).

    Even though WiFi direct is a point-point protocol, each link still has to share the available bandwidth, so are there any official thoughts on what sort of restrictions will be placed on the teams and the spectators regarding prohibitions on wi-fi usage (Hot Spots or WiFi direct apps)


  • #2
    WiFi is using radio waves. I'll quote an old RF engineer I knew. "Sometimes RF is just FM - and FM stands for Fine Magic". :-)

    So - with that I'm hopeful we don't have to be patrolling the stands looking for the odd hotspot (or Nintendo DS - I think those are the worst). At the FRC events I was at over the weekend there were no signs or announcements I heard about turning off phones, etc. So I am guessing that we'll be in a similar (or better) situation as the FRC tournaments. That is - I'm hoping we won't have to be telling people to shutdown their hotspots, etc.

    The reason I hope better is that these devices should be able to use 5GHz band and that means we'll have access to a lot more non-overlapping channels. There is also that being newer WiFi chipsets they should play nicer with one another which means we shouldn't have some of the problems that seemed to be because of the Samantha chipset.


    • #3
      Originally posted by DanOelke View Post
      Nintendo DS - I think those are the worst
      Leapfrog Tablets are more evil than any hotspot or DS. One of them on and waiting for another Ad Hoc connection can jump your channel utilization from the single digits up to over 80%. Finding the tablet is easy but odds are the kid using the tablet is not gonna be happy. A bit of diplomacy is required then. Add in the Wi-Fi settings for the tablet are hidden behind a password the kid's parents have set and some apps seem to override the settings to turn off Wi-Fi and they can be an utter nightmare. (They should put a piece in the FTA manual about diplomacy when it comes to the No Wi-Fi rule.)

      I'm hoping it expressly uses 5 GHz band. That's the first thing I'm looking for on the official spec sheet when it is finally released. (Sooner rather than later I hope)


      • #4
        Leapfrog Tablets - hmmm - not one I've run into. The Nintendo's I could recognize easily because the OUI was decoded by WiFi analyzer. It wasn't so easy to find them in the stands. Before the new platform was announced I was seriously looking at getting a highly directional antenna so I could better find the problem devices.

        You are SO right about the diplomacy thing. I just assume that FTA's should be diplomatic when approaching someone about a WiFi device. It's that gracious part of gracious professionalism after all. :-)