IoT - Smart Plugs Bringing Down Bandwidth/Internet Speed

Hello Everyone,

Recently I installed some extra smart plugs in my room which are very handy but are affecting my bandwidth. I thoguht this could be the case but I wasn't expecting such a huge hit so I am looking to see if anyone can recommend a better wifi solution to reduce the impact of the plugs.

I performed ookla speed tests (Melbourne-Telstra Server) on my laptop to illustrate the impact of the plugs in my room.

No IoT - 23.45mbps
Google Mini - 22.93mbps
Mini + 1 plug - 23.54mbps (strange)
Mini + 2 plugs - 20.92mbps
Mini + 3 plugs - 14.70mbps
Mini + 4 plugs - 11.62mbps

My current wifi soltuion is quite terrible. Our router is the stock Huawei HG659 that tpg installed and in order to get wifi to my room I am using power-line Ethernet adapters. With that being said our internet plan is 25/5 so without the smart plugs my speeds are perfectly fine, but with the plugs not so much. My initial thoughts are that my wireless power-line adapter can't handle so many connected devices at once because even if I limit the download speed on the plugs from the router the performance hit is still there. Perhaps there are too many wifi signals in the room? Perhaps the router is the limit, perhaps the power-line adapter, I think I need someone with more knowledge or a better experience to help me out on this one. The plugs aren't actually using any bandwidth for the speed tests, they're just connected. What do you guys think would be a good solution?

  1. Better power-line adapter with dual-band
  2. Better router
  3. Plug a dedicated wireless access point into power-line adapter Ethernet just for the plugs and mini
  4. Other ideas?!


  • When you performed the speed test, was it Wi-Fi or Ethernet? (I am assuming Wi-Fi)
    What's your powerline adapters and smart plugs brand/model?
    Where do the smart plugs, Google Mini, and the laptop get their Wi-Fi?
    Is everything connected to the wireless powerline adapter?

    I think you need a proper wireless router or AP in your room (connected to the powerline adapter, if it has a LAN port).
    The technology you need is called MU-MIMO.
    It sounds like the wireless capability of your powerline adapter is the issue.

    Before purchasing anything, have you tried relocating the wireless powerline adapter?
    Can you provide MS Paint of all your networking hardware + location.
    Are you on ADSL/NBN? FTTP/HFC?
    If you want to confirm if it's actually the wireless powerline adapter that's causing the issue, you can try bringing your main modem/router into your room.

    I think your current setup is:

    Try doing it this way:

    • The technology you need is called MU-MIMO.


      MU-MIMO is not backwards-compatible. The client devices in a transmission group must all support the 802.11 TxBF feedback mechanisms in order for the AP to know the location of each client device. While TxBF was introduced in 802.11n, most 802.11n and 802.11ac Wave 1 client devices did not support the feedback mechanism. Only very new 802.11ac client devices have the hardware and drivers that actually enable this TxBF feedback. While the proportion of client devices that support TxBF will increase over time as users upgrade their devices, the benefits of MU-MIMO can only be achieved if both the access points and the client devices support it.

    • Thank you for your response!
      The ms paint setup can be found here:

      The smart plug brand and model can be found in the image, yes everything is connected to the wireless point that is created by the Ethernet power-line adapter in my room.

      Currently on HFC with a NBN 25/5 plan so I am unaware of being able to move the router to my side of the house as it has to connect to what I like to call the NBN box that receives the cable connection.

      Current Setup is:
      HFC MATE Modem <-WAN-> MAIN MODEM ROUTER <-ethernet-> POWERLINE ADAPTER #1 <-powerline-> POWERLINE ADAPTER #2 <—WIRELESS—> Laptop/Mini/Smart Plugs

      The wireless adapter does have a LAN port so I am thinking the easiest solution would be to get a AP with dual band, plug it into the ethernet adapter and then put the IoT devices on 2.4ghz, but I have no way of testing if it will work as desired or if the router is the choke point.

      ALSO, the upload speed was a steady 4.60mbps for all of the tests. So it wasn't impacted but I'm not sure if that's because it's low anyway.

      • No worries mate. Great Paint!
        I think at this stage it's important to determine where the issue lies - I am really hoping it's the wifi from the powerline adapter because that's easy to test with your current setup.

        I am unaware of being able to move the router to my side of the house as it has to connect to what I like to call the NBN box that receives the cable connection.

        You can literally powerline the WAN that comes from the black HFC ARRIS modem.
        Please see these diagrams I hope it makes sense to you.
        All of the settings should work as-is. Only difference is that the IoT devices need to connect to Huawei HG659's Wi-Fi.

        The smart plug brand and model can be found in the image

        I think you missed this xD

        • Hahah, I did miss it damn!
          I think they're just Kogan rebrands of Tuya plugs using a esp8266 for wifi. Only 2.4ghz compatible.

          I'll try the router in my room then, thanks for the tip!
          I'll put them on the 2.4ghz network and my personal devices on 5.8ghz and run the same tests. Will report back! Thanks again, great picture!

          • @Castcore: Cheers mate! Looking forward to the good news. If this doesn't work, please don't give up, there are many ways to test where the problem lies.

            • @brokenglish: Okay so I decided to do a little extra testing to help get to the bottom of this.

              Scenario 1: Router In room (thr powerline) - All on 2.4ghz

              No IoT - 23.35mbps
              Google Mini - 23.54mbps
              Mini + 1 plug - 23.45mbps
              Mini + 2 plugs - 23.39mbps
              Mini + 3 plugs - 19.56mbps
              Mini + 4 plugs - 15.16mbps

              Scenario 2: Router in room (thr powerline) - IoT on 2.4ghz, personal on 5.8ghz

              No IoT - 23.46mbps
              Google Mini - 23.43mbps
              Mini + 1 plug - 23.47mbps
              Mini + 2 plugs - 23.55mbps
              Mini + 3 plugs - 19.28mbps
              Mini + 4 plugs - 15.85mbps

              Scenario 3: Router in living room (no powerline, devices moved to living room) - IoT on 2.4ghz, personal on 5.8ghz

              No IoT - 23.51mbps
              Google Mini - 23.42mbps
              Mini + 1 plug - 23.50mbps
              Mini + 2 plugs - 23.47mbps
              Mini + 3 plugs - 23.48mbps
              Mini + 4 plugs - 23.34mbps

              Interesting results! I wonder if it's the powerline adapters that are the problem then. The only difference between scenario 2 and 3 is that in scenario 2 the WAN from the HFC modem is going through the powerline and in 3 it is directly plugged into the HG659 router.

              What are your thoughts? Thanks

              • @Castcore: Good results! I was actually about to tell you to do something similar to Scenario 3.

                The Wi-Fi source you are using to do the speed test matters, please take this into account.
                I think the problem could be wireless congestion in your room, not the powerline.
                Also I forgot something very important, are the Wireless SSID of the main router and the wireless powerline adapter the same? For testing purposes, please make them different.

                For future speed test just do:
                (1) no IoT and
                (2) Mini + 4 plugs

                From Scenario 3, we know for sure it's not the main router nor the number of devices connected concurrently.

                Can you confirm in Scenario 1 and 2 above, that the Wi-Fi used by the IoT and for the speed test, is the main router's Wi-Fi? (not the wireless powerline adapter)

                Can you try going back to your very first original setup?.
                This time do your speed test directly using the living room router's Wi-Fi (also direct LAN if possible).
                I am expecting you to get full speed in the living room (via main router's Wi-Fi) even with every IoT connected in your room (via wireless powerline adapter).

                Edit: sorry a lot of edits.

                • @brokenglish: Scenario 4: IoT in bedroom (thr powerline), laptop connected to main router in living room (5.8ghz and LAN tested)

                  All IoT off: 23.44mbps (5.8ghz test)
                  All IoT on: 23.46mbps (5.8ghz test)
                  All IoT on: 23.48mbps (LAN test)

                  The SSID of the wireless adapter is different, so is the password. All devices connected to it appear under the 1st ethernet port when I log onto the router. Eg, Nest_MINI_Ethernet1, ESP8266_Ethernet1 x4.

                  In scenario 1 and 2 all my devices and IoT were connected to the router that was moved to my room and I swapped out the powerline adapter in my room to another AV200 which just has ethernet and no wifi so that the devices would only connect to the router. So the only difference between scenario 2 and 3 is routing of the WAN connection from the HFC modem to the router.

                  Sorry for the delayed response, had to set it up again haha

                  • @Castcore: OK mate, great testings! 100% wireless congestion/interference in your room. Powerline is not an issue.

                    Scenario 1 and 2, it's a simulation as if you have a separate router/AP for your bedroom. The results are not good. Powerline only carries WAN and results should be constant.
                    Huawei HB659 wireless specs is standard dual band 802.11a/n/[email protected] 5GHz up to 1300Mbps; 802.11/b/g/[email protected] up to 300Mbps.

                    • @brokenglish: Thank you for your help with the testing ideas!
                      The results are very interesting, might be something to do with the location of my room.
                      If it is wireless congestion/interference do you have any ideas for options moving forward? I really don't know what to do, tempted to just get a mesh wifi system and hope it works, but that's very costly an I don't know it will work.

                      • @Castcore: I was still doing research about esp8266 to see if too many of it causes wireless congestion but you replied quicker before I can suggest anything 😂
                        Looks like Mini + 2 plugs is the sweet spot (you get better performance with router in room).
                        Best thing you can do is try:
                        1. Different power socket of wireless powerline adapter (if you want to keep your original setup)
                        2. Different location of the main router in bedroom
                        3. Lessen the amount of smart plugs in your room

                        Wireless devices don't like anything metal near it.

                        I only found people with congestion if more than 20 smart plugs are connected.
                        This one has 9.
                        I think most of them don't really compare the speed test while the IoTs are plugged in, i.e. most of them are Scenario 4.
                        Do you mostly use your laptop in your room?

                        tempted to just get a mesh wifi system and hope it works, but that's very costly an I don't know it will work.

                        If you want to try using a more capable wifi router/mesh, get it from Officeworks, but open it slowly and keep the box and everything intact, 30 days change of mind return.

                        What exactly is connected to the 4 smart plugs?! You lazy 😂

                        • @brokenglish: sorry for the length of this comment

                          Yeah it's looking like I might have to reduce the plugs for now. I definitely don't need them all so I can get away with 2 if I need to. Currently using them on my 3D printers and planing to use IFTTT with a smoke detector to turn them off if something goes south. They've also got built in power meters so I was using them to track usage of an oil heater and a projector.

                          I did some further testing to really get to the bottom of this and I am now really confused. To completely eliminate the fact it could be the powerline adapter I decided to run a long power extension cable so that I could do a mix between scenario 2 and 3. Basically have router, HFC modem, IoT devices in the living room. Run a long power extension cable from the bedroom to the living room with the powerline adapter plugged in and have the WAN connection between the router and HFC modem running through the powerline adapters technically to the bedroom but then plugged into the router in the living room with the long extension cable…

                          Scenario 5: Router in living room, IoT in living room. Long ass extension cord getting powerline adapter from bedroom to living room so plugged into same socket.
                          All IoT off, Router direct to HFC modem: 23.45mbps
                          All IoT on , Router direct to HFC modem: 23.45mbps
                          All IoT off, Router thr powerline to HFC modem: 23.47mbps (same living room, same device locations)
                          All Iot on , Router thr powerline to HFC modem: 23.45mbps

                          This made me think it definitely wasn't the powerline adapters. But then I did another scenario where I moved everything to my room including the HFC modem (ran a long tv cable through the house) and removed the powerline adapters from the link entirely…

                          Scenario 6: Router and HFC modem in bedroom using long ass tv cable no powerline adapters at all.
                          All IoT off: 23.42mbps
                          All IoT on: 23.45mbps

                          Dude what?!, working completely fine in the bedroom (ran multiple tests). These results can be directly compared to scenario 2 and would suggest the powerline adapters ARE the issue (contradicting scenario 5). So while I had it all setup in the bedroom I decided I should move the wireless powerline adapter to the living room and take more results…

                          Scenario 7: Router and HFC modem in bedroom using long ass tv cable. Wireless powerline adapter in living room (speed test on adapter)
                          All IoT off: 23.37mbps
                          All IoT on: 20.99mbps (IoT connected to router in bedroom)
                          All IoT on: 11.06mbps (IoT connected to wirelees powerline aapter in living room - 2.4ghz only)

                          After I got all these results I was a bit baffled and hoped my problem just fixed itself in the bedroom so I went back to the very original setup and got this…

                          Scenario 8: The original Setup. Router & HFC modem in living room. Wireless powerline adapter in bedroom. IoT in Bedroom (2.4ghz only)
                          All Iot off: 22.44mbps (peak hour may be affecting these tests now)
                          All IoT on: 10.57mbps

                          So now I am truly confused as to whether it IS or ISN'T the powerline adapters. Is there anything with these results that you can make sense of?
                          Thank you for taking the time to read that, I know it was a lot xD

                          • @Castcore:

                            Is there anything with these results that you can make sense of?

                            Yes! If I understand right (it was a bit confusing LOL), you discovered what's causing the wireless interference! The wireless of the wireless powerline adapter!
                            When doing testing you need to have an objective (e.g. to prove this works), not just randomly move things that you don't even know what it does in the end 😆

                            Sorry I wasn't clear, when I mentioned powerline is not the issue, it refers to the electrical wiring as makeshift ethernet having no problem. I never used/trusted the wifi capability of any powerline adapter.

                            Can you turn off the wireless capability of the powerline adapter? Either go through the admin settings or through the physical button.
                            It could also be the wireless channel issue on the wireless powerline adapter.
                            For 2.4GHz, if main router is Ch 1, wireless powerline should be Ch 6 or 11.

                            For simplicity, just scrap the wireless function of the powerline adapter. DON'T USE IT!

  • Depending on router you may be able to log in and see if you can drop the priority of the devices, so that it can use more when required but if you need internet for other things it will drop it?
    Then again I'm quite surprised that it needs that much constantly?

    • The stock router is admittedly very bad, there's no QoS, the closest I can get is limiting the speed on certain devices but because the plugs aren't actually using any bandwidth (just connected via wireless) the performance hit is still there.

  • Your 2.4ghz wireless will be saturated.

    You need a better router with better performance and better AC 5ghz. Otherwise if you don't wish to upgrade, ditch the powerlines. Get a separate AP for the bedroom and make sure more devices (not the plugs) are connecting via 5ghz.

    • I was thinking this could be the case. My router is quite bad but I'm not sure if replacing my router at the other end of the house will fix the issue if all my devices are connected to the wireless powerline adapter in my room, but I don't know enough so maybe it will.

      Unfortunately I don't have any cabled ethernet to my room so I can't install a wireless AP directly from the router (hence the powerline adapters) do you think getting a better AP with dual-band and just plugging it into the powerline adapter via ethernet would help the issue? Making sure the wireless on the powerline adapter isn't being used.

      • Avoid using powerline at all costs. They became redundant once AC wireless came out.

      • I have a similar situation at home. Have a few smart light bulbs and wall plugs. I am using a TPlink router, it struggles and some of the smart products loose connection randomly. TPLink CS said most of the entry models have 7-9 MAX devices limit.

        My current Solution:
        Using a cheap router connected to the Primary router to manage all the smart products.

  • Get a better AP, put the plugs on the 2.4GHz network and your laptop on the 5GHz network.

    • I did this at home. All the iot on 2.4ghz in a guest network. Works well.

    • This seems to me like the easier and cheaper options!
      Because I don't have any cabled ethernet to my room I can't install a wireless AP directly from the router (hence the powerline adapters) do you think getting a better AP with dual-band and just plugging it into the powerline adapter via ethernet would help the issue? Making sure the wireless on the powerline adapter is off an all devices are connected to the better AP?

      • Yeah, that should be fine. It's probably just not designed for a bunch of devices and chugs when everything is connected.

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