Omnia WiFi6 to tri-band

Omnia hardware Omnia HW help
#1

Because of constant issues with my Asus AiMesh setup I have moved to a Turris Omnia WiFi6 with three cheap Totolink X5000R to check if have more success - and actually all of the old problems are gone! Now I would like to upgrade the new system to improve WiFi bandwidth (this was better with the Asus routers). I use the 5GHz band as wireless backhaul (wired is no option). With my limited knowledge of setting up a proper network I believe that a dedicated 5GHz radio for the backhaul would be ideal, next to 2.4GHz and 5GHz (on a separate frequency) for the clients to connect. I guess that I would need new mesh APs and an additional WiFi card for the Omnia. Am I on the right track? If so, is it true that with another card for the Omnia (the AsiaRF AW7915-NP1 for instance?) I would need additional antennas (and diplexers) as the current antenna/diplexer setup is maxxed out)? Or is there another possibility? In terms of mesh APs I guess that I could either invest in MOXes or something like the Linksys MR8300? What would you recommend?

Apologies if the above sounds confusing - I am trying to learn but most likely mixing things up :frowning:

Cheers
Torsten

How can I setup a wireless mesh for a larger building?
#2

Yes, you need additional equipment :wink:
My instructions are valid for one or more customisable devices like Turris Omnia, Turris MOX or boxes running OpenWrt natively (there are a few available out there). I’d never again myself buy a fixed/locked device like all the Linksys, TP-Link, etc out on the market - they are not open for adjustments/upgrades and thus not future proof. If you want to go with Turris devices, look out for some used Omnias which are much cheaper than the MOX variant you would need (basis+SFP-addon+SFP-module+2PCIe-addons).

Start with two AW7915-NP1 or 1xAW7915-NP1 + 1xAW7916-NPD on each access points.
1xAW7915-NP1 needs to run in 5GHz 802.11ax-mode on each AP to serve as backhaul and 5GHz-network for clients (you can have multiple SSIDs on one physical WiFi card). For this you need 4 antennas (see below) for best connectivity/throughput of the mesh network. Number of APs needed depends on the area you are about to cover - I’d at least have one full equipped Turris Omnia to move around and check coverage and signal strength with a smartphone (which have normally only 16-17dBi sending power and such limit the APs sending radius). If the outcome is bad (thick concrete walls e.g.) you might need to switch to 2,4GHz as backhaul which reduces throughput considerably (in that case below instructions need to be adapted).

For mesh setup itself consult OpenWrt wiki: [OpenWrt Wiki] 802.11s Based Wireless Mesh Networking

For second WiFi card you need to decide about future network considerations. Two options:

  1. AW7915-NP1: add this card for best legacy-devices (keep in mind even state of the art IoT-devices most often still only run on 2,4GHz) coverage. With that you could use 4 diplexers and the respective MHF-cables to have the least antennas equipped (shared between 5GHz-backhaul/client SSIDs and 2,4GHz client SSIDs).
  2. AW7916-NPD: this DBDC allows you to run SSIDs on two frequencies and (still under development) one of them being 6GHz. In this case you would need for first WiFi card (NP1) 4 dedicated antennas and for second (NPD) 3 antennas which are operating on two frequencies simultaneously (2,4GHz and 5GHz for now, maybe other antennas in the future for 2,4 and 6GHz; but there seems to be also an option for 5GHz and 6GHz, which is right now not supported).
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#3

Many thanks - that is very useful advice! I am stuck at this sentence

Does that mean that the (currently installed) NP1 can run the 5GHz backhaul SSID as well as the 5GHz client SSID without(!) performance penalty? This is how my Omnia is configured right now with the second installed DNXA-97-H for the 2.4GHz clients (plenty of esp8266 in my network).

I was fearing that backhaul and client traffic on the NP1 would lead to a performance penalty and a dedicated second 5GHz card would be required.

If I misunderstood this, then I guess the recommended setup is to use the NP1 serving 2.4 and 5GHz client SSIDs at the same time and an NPD for the backhaul (maybe at 6GHz in the future, 5GHz otherwise). For that scenario I am not fully getting the antenna setup. In my Omnia the NP1 is connected to all four antennas and shares two of them with the DNXA using diplexers. When removing the DNXA and adding the NPD the NP1 would need to share three antennas with the NPD? Is that possible if the NPD is also running at 5GHz? I saw diplexers combining 2.4 and 5GHz. Does that work for two different channels on the same band, too?

#4

Hard reality fact first: a WiFi mesh network does by no means warrant a perfect connectivity. If you want to have high and stable transfer rates, there is no way around cabling (for running WiFi 6 on 5 or 6 GHz even normal 1GBit-cabling is insufficient btw). If you have a new electric installation, you may also consider installing powerline communication equipment as a compromise (I never had a new installation in the flats I rented, so this was never a option for me).

WiFi-mesh networking highly depends on what data you are trying to access, which transfer rates you want to achieve and the reality of your house’s/flat’s architecture. The following figures assume you have thin and mostly drywalls instead of concrete with steel structure and an ISP provided 400/200 connection:

  1. Internet access speed/streaming quality: no impact
  2. Accessing internet files (cloud storage etc): there might be negligible performance impact.
  3. Accessing files stored on a local drive: depending on the distance and number of access points between client and server, there can be a performance impact.

If 3. is part of your usage scenario (or you often use 2. with a higher ISP provided connectivity), use option 2 of my provided answer and install 1x NP1 as backhaul and 1x NPD as client device. As NPD is DBDC, you can have both 2,4GHz-SSIDs (legacy client devices) and 5GHz-SSIDs being served by this card.

#5

With both NP1 and NPD installed you need to have 7 antennas installed - 4 for NP1 and 3 for NPD. As those are all dedicated antennas (5GHz for NP1 and shared 2,4/5GHz for NPD), you don’t need diplexers any more.

Now it is time to think about antennas. Directional antennas are to cover a plane and thus can reach up to +12dBi, omni-directional antennas aim to cover also upper und lower floors and therefore only reach +4-+5dBi signal strength.

Do you need to cover one or more floors? For one floor make sure you go with external antennas for the NP1 to make use of the higher gain of directional antennas. If it is more than one floor I’d really try and see if at least one AP for each of the additional floors could be connected by wire and the other ones then using directional antennas as well - otherwise you need to have omni-directional antennas (see above, this will lead to performance penalty) on all floors.

For the NPD it does not matter that much what antennas you use as in this case the sending/receiving bottleneck are the client devices. A laptop can handle some 20-23dBi, but smartphones only reach 16-17dBi which is why you would not want to have a too high TX-power from the access point’s side.

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#6

In your use case with several APs available, you would want to look into getting DAWN ([OpenWrt Wiki] Setting up DAWN and band-steering in OpenWrt) installed and configured - this makes client devices roam smoothly between the APs.

#7

Many, many thanks again! This helps a lot. My ISP downlink is just 250MBit/s but I will upgrade in the near future. However, moving files across the LAN is the major concern, hence scenario 3 applies. Up to now (with the Asus setup) I had sufficient speed with one AP on each floor of my house (about 90 years old, mostly bricks, some steel in the floors). However, I had lots of issues with 2.4GHz clients disconnecting randomly and refusing to reconnect for hours. This is all gone with Omnia and the cheap OpenWRT routers. Unfortunately, wiring the AP is no option.

I have ordered a 7916-NPD and think I found the Omnia antennas on eshop.sectron.eu. On their site I have been looking for adaptors U.FL(f) to SMA(m). Is there a special feature I should be looking for?

Update - I found your recommendation for Delock adaptors in a different thread!

#8

Yes, there were several recommendations throughout a couple of threads :wink:

So your setup is something like

  • ground floor: router&AP (Turris Omnia)
  • floor 1: AP (?)
  • floor 2: AP (?)

In is case a real mesh has no benefits - here you would want to connect the AP floor 1 directly as client to the router’s 5GHz backbone SSID and the AP floor 2 as client of AP floor 1. So no reason to install OpenWrt mesh software.
In this case you could make use of high gain directional antennas if you wish.

#9

Apologies for remaining silent for the past week - I had ordered stuff and wanted to wait how things turn out. You are right - your description is very close to my setup. It’s probably not logical but I wanted to continue with the mesh software to see how things work compared to the Asus setup and to the initial try with the Omnia and cheap dual-band mesh-nodes.

I received the 7916-NPD and installed it in the left slot. I originally wanted to go for the right slot but the sockets were in installed to match the short card (are they soldered?). The 7915 pigtails remain connected to the same antennas as before. I kept the diplexers (2.4GHz connectors unused) as I ordered three new antenna sockets only. The NPD is connected to three new antennas sitting in the pre-drilled holes on the back. I had to install the kmod-mt7916-firmware package to get the new card recognized:

lspci
02:00.0 Unclassified device [0002]: MEDIATEK Corp. MT7915E 802.11ax PCI Express Wireless Network Adapter
03:00.0 Network controller: MEDIATEK Corp. Device 7906

and

[    9.881807] mt7915e 0000:02:00.0: HW/SW Version: 0x8a108a10, Build Time: 20211222184017a
[    9.920769] mt7915e 0000:02:00.0: WM Firmware Version: ____000000, Build Time: 20211222184052
[    9.951895] mt7915e 0000:02:00.0: WA Firmware Version: DEV_000000, Build Time: 20211222184111
[   10.208149] mt7915e 0000:03:00.0: HW/SW Version: 0x8a108a10, Build Time: 20211230135620a
[   10.270890] mt7915e 0000:03:00.0: WM Firmware Version: ____000000, Build Time: 20211230135720
[   10.321480] mt7915e 0000:03:00.0: WA Firmware Version: DEV_000000, Build Time: 20211230135808

The backhaul is running on the 7915, AP for 2.4 and 5GHz clients on the 7916.

Because I have already spent too much money I wanted to first check how a tri-band router supported by OpenWRT performs, so I got a Linksys MR8300 which has an Atheros QCA9886 for 5GHz channels >100 and an Atheros IPQ4019 for 2.4GHz and the lower range of 5GHz channels. I chose 5G ch 48 for the backhaul and 104 for client AP.

The problem is that the connection is incredibly slow via the mesh node. Whilst indicated client <> mesh-node connection speed is about 860MBit/s and mesh node <> Omnia about 650MBit/s the datarate client <> Omnia (iperf) or WAN is a fraction (80kB/s). It gets better for larger downloads but smaller transfers. e.g. reloading a grafana dashboard on a Raspberry on LAN or accessing files on a samba share are unacceptable.

In order to rule out any HW issues: is it OK to install the 7916-NPD as described? Is it OK it is listed as as “Generic MAC80211” in the wireless overview?

Edit - upon further inspection I believe the MR8300 is the issue. I will set it up again tomorrow. However, the question remain, wether the 7916 is recognized as expected or if I need to upgrade something. Turris OS 6.4.1 (kernel 5.15.120).

#10

Final notice: Omina acting as WDS server and three MR8300 WDS clients have been successfully set up and have been working w/o issues for the past days. 802.11s mesh is problematic with the MR8300 (23.05rc3) but I will come back again and check with future releases. Many thanks to @ssdnvv for the advice and patience.

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#11

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