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RF Spectrum Allocation for teams at RobotX 2018

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  • RF Spectrum Allocation for teams at RobotX 2018

    Hi All,

    My name is Brennan and I am from the University of Hawaii RobotX team (Team Kanaloa). For those who were present during either of the last two RobotX video calls, I volunteered to help sort out RF spectrum allocation during the RobotX event. As most of you know, RF spectrum allocation is a tough topic to nail down, since you need to consider constraints both in science, and in governmental regulation. For our foreign teams who typically abide by a different set of regulations abroad, this problem is made more complex still. The purpose of this thread is not necessarily to preemptively eliminate all possible interference problems, rather it is a starting point to guide your hardware selection process, e.g. if we see a lot of teams on 2.4, you may decide to avoid that band altogether.

    So some thread rules:
    • I will identify the usable spectrum in the 915 MHz, 2.4 GHz, and 5 GHz bands, because these are the most common. At a minimum, please reply with what RF devices you're utilizing (this can include your high-bandwidth data connection, manual controller, and remote kill switch), and what frequency it operates on. Other information of use includes:
      • What spectrum are you utilizing specifically, and what is your channel width?
      • Does your radiator support frequency hopping?
      • What is your radiator output power in [dBm] for both your WAM-V and your ground station?
      • What is your antenna gain in [dBi], and what types of antenna are you using (onmi, sector, yagi or dish)?
      • The more information you provide about your system, the better.
    • Once I have your information, I will add it to this original post as promptly as I see it; if you would like to edit your slot(s) on the list, just let me know in the thread.
    • It is very possible that my understanding/interpretation of the FCC regulations is incorrect, if you spot something that looks wrong, please let me know so I can fix it.
    • If your team is new, or your understanding of wireless systems is rusty (exactly where our team was at one month ago), I recommend taking a quick read of the primer document we wrote internally for our own team here: https://github.com/riplaboratory/Kan...rumRegulations. It's not perfect, but a good enough reference to get you started. Hopefully you will also be able to see the hardware other teams are using to guide your own internal decisions.
    • Please feel liberal about providing tips and advice, particularly from the returning teams--I'm sure most of you have much more experience in interop than I do. Conversely, feel free to ask any questions you think myself, or any other teams may be able to answer...we're all in this together.
    So without further ado, here is the spectrum list:

    915 MHz (902 MHz to 928 MHz):
    No formal channel standard for this spectrum, and the majority of devices at this frequency employ frequency hopping, so for now, we will just list all of the devices teams are using in this spectrum. Due to low total bandwith in this spectrum, my recommendation is to avoid this frequency for your high-bandwidth data connection; however, this is a good choice for your manual controller.
    • University of Hawaii (Team Kanaloa) using FrSky R9M/R9 Long Range Radio System + FrSky Taranis QX7 (internal 2.4 GHz radiator disabled).
    • University of Michigan using XBee (915 MHz) + 2 dBi antenna
    2.4 GHz (2400 MHz to 2483.5 MHz):
    • Channel 1 (2412 MHz): [empty]
    • Channel 2 (2417 MHz): [empty]
    • Channel 3 (2422 MHz): [empty]
    • Channel 4 (2427 MHz): [empty]
    • Channel 5 (2432 MHz): [empty]
    • Channel 6 (2437 MHz): Tournament Director Wi-Fi (for course equipment). Will share bandwidth with channels 5 through 7, and parts of 4 and 8.
    • Channel 7 (2442 MHz): [empty]
    • Channel 8 (2447 MHz): [empty]
    • Channel 9 (2452 MHz): [empty]
    • Channel 10 (2457 MHz): [empty]
    • Channel 11 (2462 MHz): [empty]
    • Channel 12 (2467 MHz): "low power" only
    • Channel 13 (2472 MHz): "low power" only
    • National University of Singapore (Bumblebee) some kind of 2.4 GHz xBee system
    Frequency hopping devices:
    • National University of Singapore (Bumblebee) FrSky X9D, 2.4 GHz @100 mW EIRP

    5 GHz (4910 MHz to 5875 MHz):
    • Channel 36 (5180 MHz, 20 MHz): [empty]
    • Channel 38 (5190 MHz, 40 MHz): [empty]
    • Channel 40 (5200 MHz, 20 MHz): [empty]
    • Channel 42 (5210 MHz, 80 MHz): [empty]
    • Channel 44 (5220 MHz, 20 MHz): [empty]
    • Channel 46 (5230 MHz, 40 MHz): [empty]
    • Channel 48 (5240 MHz, 20 MHz): [empty]
    • Channel 50 (5250 MHz, 160 MHz) DFS Required: [empty]
    • Channel 52 (5260 MHz, 20 MHz) DFS Required: [empty]
    • Channel 54 (5270 MHz, 40 MHz) DFS Required: [empty]
    • Channel 56 (5280 MHz, 20 MHz) DFS Required: [empty]
    • Channel 58 (5290 MHz, 80 MHz) DFS Required: [empty]
    • Channel 60 (5300 MHz, 20 MHz) DFS Required: [empty]
    • Channel 62 (5310 MHz, 40 MHz) DFS Required: [empty]
    • Channel 64 (5320 MHz, 20 MHz) DFS Required: [empty]
    • Channel 100 (5500 MHz, 20 MHz) DFS Required: [empty]
    • Channel 102 (5510 MHz, 40 MHz) DFS Required: Tournament Director Wi-Fi (teams to use internet). Will share bandwidth with channels 100 to 104.
    • Channel 104 (5520 MHz, 20 MHz) DFS Required: [empty]
    • Channel 106 (5530 MHz, 80 MHz) DFS Required: [empty]
    • Channel 108 (5540 MHz, 20 MHz) DFS Required: [empty]
    • Channel 110 (5550 MHz, 40 MHz) DFS Required: [empty]
    • Channel 112 (5560 MHz, 20 MHz) DFS Required: [empty]
    • Channel 114 (5570 MHz, 160 MHz) DFS Required: [empty]
    • Channel 116 (5580 MHz, 20 MHz) DFS Required: [empty]
    • Channel 118 (5590 MHz, 40 MHz) DFS Required: [empty]
    • Channel 120 (5600 MHz, 20 MHz) DFS Required: [empty]
    • Channel 122 (5610 MHz, 80 MHz) DFS Required: [empty]
    • Channel 124 (5620 MHz, 20 MHz) DFS Required: [empty]
    • Channel 126 (5630 MHz, 40 MHz) DFS Required: [empty]
    • Channel 128 (5640 MHz, 20 MHz) DFS Required: [empty]
    • Channel 130 (5650 MHz, 20 MHz) DFS Required: [empty]
    • Channel 132 (5660 MHz, 20 MHz) DFS Required: [empty]
    • Channel 134 (5670 MHz, 40 MHz) DFS Required: [empty]
    • Channel 136 (5680 MHz, 20 MHz) DFS Required: [empty]
    • Channel 138 (5690 MHz, 80 MHz) DFS Required: [empty]
    • Channel 140 (5700 MHz, 20 MHz) DFS Required: [empty]
    • Channel 142 (5710 MHz, 40 MHz) DFS Required: [empty]
    • Channel 144 (5720 MHz, 20 MHz) DFS Required: [empty]
    • Channel 149 (5745 MHz, 20 MHz): University of Hawaii (Team Kanaloa) using Ubiquiti Rocket Prism AC Gen2 radiator (@30 dBm) + Ubiquiti RD-5G30-US RocketDish (30 dBi) for ground station, and Ubiquiti Rocket Prism AC Gen2 radiator (@23 dBm) + Ubiquiti AMO-5G13-US AirMax Omni Antenna (13 dBi) for WAM-V. Will share bandwidth with channel 151.
    • Channel 151 (5755 MHz, 40 MHz): [empty]
    • Channel 153 (5765 MHz, 20 MHz): [empty]
    • Channel 155 (5775 MHz, 80 MHz): National University of Singapore (Bumblebee) using Ubiquiti Rocket Prism 5AC radiator (@27 dBm) + sector antenna (21 dBi) for ground station, and Ubiquiti Rocket Prism 5AC radiator (@27 dBm) + omni antenna (@13 dBi) for WAM-V. Will share bandwidth with channel 149 through 159.
    • Channel 157 (5785 MHz, 20 MHz): [empty]
    • Channel 159 (5795 MHz, 40 MHz): University of Michigan using Ubiquiti Bullet AC (@22 dBm) + Altelix 12 dBi antenna. Will share bandwidth with channels 155 through 161.
    • Channel 161 (5805 MHz, 20 MHz): [empty]
    • Channel 165 (5825 MHz, 20 MHz): [empty]
    Other considerations:
    • Wi-Fi will be broadcasting an internet connection for teams (2.4 and 5 GHz) will be used in the team village. This system will be frequency hopping, and is low power, and therefore should not pose an interference issue on the shore where teams will be communicating.
    Last edited by brennan; 10-16-2018, 09:39 PM.

  • #2
    Second post saved for FAQs and such...

    Comment


    • #3
      For The University of Michigan, we're using the following:
      915 Mhz: Arduino XBee Pro (Kill Switch), I can try and figure out the exact frequency, I know it's reconfigurable. 2 dBi antenna
      5 GHz: Ubiquiti Bullet AC 22 dBm, we can use 5195, 5200, 5205, 5210, 5770, 5775, 5780, 5785, 5790, 5795, 5800, or 5805 MHz (same for operator station and on WAMV) with Altelix 12 dBi antenna.

      Edit: We'll claim Ch. 159 for now for our 5 GHz radio.
      Last edited by jcoller; 09-25-2018, 06:43 PM.

      Comment


      • #4
        Yay!

        Some points:

        USA bands for 5.8Ghz start at channel 36 and end 165. The rest are not allowed. Also your convention is a little odd, as usually you just say it like "Channel 36, 20Mhz" instead of +/- 10Mhz. Nit picky, just a readability and industry convention thing.

        If it's not obvious, the bandwidth is important. If I say I'm on channel 42, an 80 Mhz channel, I'm actually using channels 36 through 50, so my name would have to be written down for all those channels.

        Click image for larger version  Name:	graphic-80211-acChannels-all.png Views:	1 Size:	214.3 KB ID:	808

        The block in the middle that says "DFS" is something fun. It means you can't guarantee your radio will stay on that channel. If a device is set to any of those DFS frequencies, and it detects ship's radar in the area, it will change it's channel to a new random non DFS channel. Fun right?

        5.8Ghz bandwidth can be set to either be 20 Mhz, 40 Mhz, 80 or 160. But the more you are, the more channels you use up. I'll recommend that all teams try to stay 40Mhz or below. There's 9 unique 20Mhz channels, but only 4 40 Mhz ones (not counting DFS).

        2.4Ghz is easier to understand, but more scary. There's only 3 non-overlapping channels! Typically deployments only use channel 1,6 or 11 for that reason. If I use channel 1, and you use channel 2, we are interfering with each other anyway.


        Ok, so what am I doing for TD stuff?

        We will have Wifi internet in the team village. It will be on multiple channels and multiple frequencies (on both 2.4 and 5.8), as that is how high density wifi works. The system works best if we don't constrain it be fixed channels, but we do keep them low power. Because of this I'm confident you will have no interference issue out on the water caused by internet wifi in team village.

        In the field tents, there will be two different types of wifi.

        A) Course equipment wifi. Our system communicates with the light tower and pinger system over 2.4Ghz wifi. It's very low bandwidth, so there's little risk I will cause you interference.But, for the sake of this effort, let's say I'll use channel 6 for all courses. Keep in mind anyone that uses 5,6,7 and parts of 4 and 8 will be sharing the band with me.

        B) Internet for you guys. I wanted to offer you a good internet connection while you are sitting at the course tent all day, so I will have radios for that as well. Since it will be short range, and less of a chance to detect radar and flip out, let me reserve (in 5.8Ghz) channel 102 for that in all courses. (meaning I'm also on channels 100-104). I'll also use channel 6 (in 2.4Ghz) for the same reason. This won't interfere with the course equipment, because of my antenna approach. (will talk more about that later).

        Comment


        • #5
          For Harbin Engineering University,
          The communication between the OCS and the USV is 436.92MHz (433 MHz, channel 23).
          In order to facilitate debugging, we also use routers, compatible with 2.4G and 5G.

          Comment


          • #6
            Originally posted by HEU heading View Post
            For Harbin Engineering University,
            The communication between the OCS and the USV is 436.92MHz (433 MHz, channel 23).
            In order to facilitate debugging, we also use routers, compatible with 2.4G and 5G.
            Harbin,

            Please make sure you 433Mhz radios are approved for use in the United States, as 433Mhz is heavily regulated here. If you use them you need to apply for a license.

            See https://en.wikipedia.org/wiki/LPD433

            " In the United States LPD433 radios can only be used under FCC amateur regulations by properly licensed amateur radio operators."

            Comment


            • #7
              I'm glad we have something like this going! I'll be sure to check our current configurations in the next couple of days and adjust them if needed. To my knowledge we have a single 900Mhz link, a 5.8 link for our data link (with a 2.4 backup system) and then a 5.8 and 2.4 transmission at our ground station (low power) for a wireless device.

              Comment


              • #8
                Originally posted by Bill Porter View Post

                Harbin,

                Please make sure you 433Mhz radios are approved for use in the United States, as 433Mhz is heavily regulated here. If you use them you need to apply for a license.

                See https://en.wikipedia.org/wiki/LPD433

                " In the United States LPD433 radios can only be used under FCC amateur regulations by properly licensed amateur radio operators."
                Thank you for your answer.
                ​​​​​​​Is the 433Mhz strictly restricted in Hawaii? How do I need to apply?
                433 Mhz is available in China and Southeast Asia, 915 Mhz is not available. We tested locally, 433MHz was selected. At the beginning of the project, I checked it(see the photo).
                if 433 MHz is not allowed in the competition venue, we will temporarily replace the 915 Mhz radio module. but this still spend a little more money. So, it can help to confirm the venue, can 433MHz be used?

                Comment


                • #9
                  Originally posted by jcoller View Post
                  For The University of Michigan, we're using the following:
                  915 Mhz: Arduino XBee Pro (Kill Switch), I can try and figure out the exact frequency, I know it's reconfigurable. 2 dBi antenna
                  5 GHz: Ubiquiti Bullet AC 22 dBm, we can use 5195, 5200, 5205, 5210, 5770, 5775, 5780, 5785, 5790, 5795, 5800, or 5805 MHz (same for operator station and on WAMV) with Altelix 12 dBi antenna.

                  Edit: We'll claim Ch. 159 for now for our 5 GHz radio.
                  Added to the list!

                  Originally posted by Bill Porter View Post

                  USA bands for 5.8Ghz start at channel 36 and end 165. The rest are not allowed. Also your convention is a little odd, as usually you just say it like "Channel 36, 20Mhz" instead of +/- 10Mhz. Nit picky, just a readability and industry convention thing.
                  Change made!

                  ​​​​​​​
                  Originally posted by Bill Porter View Post

                  We will have Wifi internet in the team village. It will be on multiple channels and multiple frequencies (on both 2.4 and 5.8), as that is how high density wifi works. The system works best if we don't constrain it be fixed channels, but we do keep them low power. Because of this I'm confident you will have no interference issue out on the water caused by internet wifi in team village.

                  In the field tents, there will be two different types of wifi.

                  A) Course equipment wifi. Our system communicates with the light tower and pinger system over 2.4Ghz wifi. It's very low bandwidth, so there's little risk I will cause you interference.But, for the sake of this effort, let's say I'll use channel 6 for all courses. Keep in mind anyone that uses 5,6,7 and parts of 4 and 8 will be sharing the band with me.

                  B) Internet for you guys. I wanted to offer you a good internet connection while you are sitting at the course tent all day, so I will have radios for that as well. Since it will be short range, and less of a chance to detect radar and flip out, let me reserve (in 5.8Ghz) channel 102 for that in all courses. (meaning I'm also on channels 100-104). I'll also use channel 6 (in 2.4Ghz) for the same reason. This won't interfere with the course equipment, because of my antenna approach. (will talk more about that later).
                  Added, please double check me,

                  Originally posted by GCDelp View Post
                  I'm glad we have something like this going! I'll be sure to check our current configurations in the next couple of days and adjust them if needed. To my knowledge we have a single 900Mhz link, a 5.8 link for our data link (with a 2.4 backup system) and then a 5.8 and 2.4 transmission at our ground station (low power) for a wireless device.
                  Will wait until you have some more details. If you're not sure yet, I can add you to the list generically, but if you provide a more detail, that will help us isolate ourselves better (and getting your channel and bandwidth settings correct significantly helps you pull more range out of your system).

                  Originally posted by HEU heading View Post
                  Thank you for your answer.
                  ​​​​​​​Is the 433Mhz strictly restricted in Hawaii? How do I need to apply?
                  433 Mhz is available in China and Southeast Asia, 915 Mhz is not available. We tested locally, 433MHz was selected. At the beginning of the project, I checked it(see the photo).
                  if 433 MHz is not allowed in the competition venue, we will temporarily replace the 915 Mhz radio module. but this still spend a little more money. So, it can help to confirm the venue, can 433MHz be used?
                  I'm not too sure about 433 MHz; when I have more time, I look into it with more depth, but for a quick push in the right direction, I pulled up the FCC (federal communications commission) CFRs (code of federal regulations) that are relevant to that frequency. They are CFR 15.231 and CFR 15.209. Links here:

                  https://www.law.cornell.edu/cfr/text/47/15.231
                  https://www.law.cornell.edu/cfr/text/47/15.209

                  Comment


                  • #10
                    For Bumblebee,

                    We will be using channel 155 on 5GHz .

                    Radio will be Ubiquiti RP 5AC PRISM 27dBm with 13dbi omni antenna on WAM-V and 21dBi sector antenna on shore.





                    Edit:
                    We also have a Frsky Taranis X9D which most likely will be free hopping on 2.4Ghz @ EIRP 100mW,
                    three Xbee Pro S2C digimesh 2.4 @ 63mW with 2dBi duck antenna on remote kill, 10dBi yagi on shore, 8dBi omni on WAM-V
                    where the xbee is in progress to be upgraded to N2420 from microhard which its power will be set at 30dBm

                    frequency channels for 2.4GHz band is yet to be determined, will updated again after
                    Last edited by bumblebee; 10-16-2018, 02:07 PM.

                    Comment


                    • #11
                      Originally posted by bumblebee View Post
                      For Bumblebee,

                      We will be using channel 155 on 5GHz .

                      Radio will be Ubiquiti RP 5AC PRISM 27dBm with 13dbi omni antenna on WAM-V and 21dBi sector antenna on shore.





                      Edit:
                      We also have a Frsky Taranis X9D which most likely will be free hopping on 2.4Ghz @ EIRP 100mW,
                      three Xbee Pro S2C digimesh 2.4 @ 63mW with 2dBi duck antenna on remote kill, 10dBi yagi on shore, 8dBi omni on WAM-V
                      where the xbee is in progress to be upgraded to N2420 from microhard which its power will be set at 30dBm

                      frequency channels for 2.4GHz band is yet to be determined, will updated again after
                      Added, thanks! Will wait on your update.

                      Comment


                      • #12
                        Bumblebee update,

                        Frsky Taranis X9D will be free hopping on 2.4Ghz
                        Xbee Pro S2C digimesh 2.4 will be set at 2.455GHz, channel width 2MHz
                        Last edited by bumblebee; 11-01-2018, 08:41 AM.

                        Comment


                        • #13
                          NaviGator:
                          Ubiquiti rocket ac modems, a 60 degree airmax ac antenna on land and a airmax omni antenna on NaviGator. We claim channel 165.

                          Comment


                          • #14
                            Florida Atlantic University (Team Owltonomous)
                            WAMV:
                            Uniquiti AirMax Omni Dual Polarity MIMO Antenna (13dBi)
                            Ubiquiti RocketAC Lite (13dBi)
                            Ground Station:
                            AirMax ac 5ghz 45 degrees (22 dBi)
                            Linksys WRT 1900 AC 5Ghz (3.8 dBi)
                            Ubiquiti RocketAC Lite (13dBi)

                            Using Channel 42 (5210 MHz, 80 MHz)

                            Comment


                            • #15
                              University of Sydney

                              Will update as soon an channel information becomes available

                              -----------------------
                              2.4 GHz Radios
                              -----------------------

                              WiFi Comms:
                              Base Station: Ubiquiti Rocket M2 w. AirMax directional antenna
                              On Vessel: Generic WiFi unit w. whip antenna (believed to be 3dB)

                              RC Link (2.4GHz Spread-Spectrum Frequency-Hopping):
                              Handheld Radio: Spektrum DX6; 100mW transmit power (FCC ID: BRWDAMTX12)
                              On Vessel: Spektrum 9645; 1mW transmit power (FCC ID: BRWDASRX10)

                              ----------------------------
                              900MHz Radios
                              ---------------------------

                              Remote E-Stop - LoRa:
                              Vessel & Remote: 23dBm transmit power; 3dB whip antennas

                              Ethernet over 900MHz:
                              Vessel & Base Station: FreeWave FGR2-PE-U; 1000mW transmit power; 6.5dB whip antennas

                              --------------------------------
                              161-164MHz Radios
                              -------------------------------

                              AIS Transceiver on Vessel: unknown transmit power; low-gain whip antenna
                              Last edited by AlexanderNorris; 12-13-2018, 12:39 PM.

                              Comment

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