Amount of antennae (signal mixers)?

Continuing the discussion from Is the wifi dual band or single band?:

When I look at some of the cheaper AC routers (e.g. TP-Link AC1200) they often have 2 or more internal antennae (in addition to their external antennae). As I understand the Turris Omnia has a metal case (and therefore internal antennae seem impossible to me). Instead, to my understanding, the Omnia uses “signal mixers” to be able to use its three antennae for both 2.4 and 5.0 Ghz frequencies.

  • How does this influence WiFi performance (in comparison to 5 (3ext+2int) dedicated antennae)?

Is this only marginal? Or, if not, what type of effects are to be expected?

Or am I mistaking and do we have internal antennae in addition to the 3 external ones (are there any more specific specifications available than those presented on the marketing site)?

In my understanding, they won`t actually mix anything.

They should be simple combiners, taking 2.4 GHz signal from one card and 5 GHz signal from second card, since 5 GHz card is dual-band, but cannot operate on both simultaneously, hence 2 wireless cards are required and combiner to direct both frequencies to same three (Actually 2) antennas…

Which means, they do not have any performance impact.

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So we’ll be able to submit on the 5Ghz band on all three antennae (the WLE900VXcard supports 3 channels) and simultaneously on the 2.4 Ghz frequency on two antennae (using the WLE200N2)?

Hmm? How so (if only two are used simultaneously why do we have a third)?

[quote=“woosting, post:3, topic:579, full:true”]
Hmm? How so (if only two are used simultaneously why do we have a third)?[/quote]

Because 5 GHz radio is 3x3 MIMO it requires 3 antennas, 2.4 GHz is 2x2 MIMO and it requires two.

So it would actually need only 2 Combiners/Mixers for 2 antennas not 3 for 3 antennas.

I must say, I’m only speculating as there is no proper HW diagrams available…only some screenshots from prototype boards, but I’m quite familiar with Wireless equipment internals…
And it would make perfect sense, not to have anything which is actually not used on board, as it would make board layout more complex, without any real benefits.

DOH! :blush: Of course (thanks…); the third would simply be dedicated 5Ghz in this case .

And its appreciated; I’m learning by the minute!

So, physically, an antenna can submit/receive radio waves on both 5Ghz and 2.5Ghz combined/simultaneously without them interfering with each-other much (and the signal processing is subsequently done by the radio chips).

In that case; could you maybe comment on how well you think the Omnia would perform ethernet/WiFi _routing_wise (so not taking into account the fact that it is FOSS/H and flexible / extendable) in comparison to e.g. the Asus RT-AC68U (not FOSS etc. but about €100,- cheaper).

How much better / or worse would the Omnia perform (it should have very strong CPU/RAM hardware in comparison).

Not sure about wireless performance, as Broadcom has pretty good chipsets (I own RT-AC68U myself), altough their SDK has drawbacks…it is closed source, everything is compiled against ancient (2.6 branch) kernels and routing performance is achieved via proprietary “hackish” stuff, called CTF.

CTF itself is an odd beast, it is basically linux conntrack hack and it is not compatible with lots of stuff, for example QoS. If you enable QoS you will loose CTF, which limits RT-AC68U to max 400Mbit/s NAT troughput instantly.
So NAT, Firewall and VPN performance wise, Omnia should be quite much faster, as it packs much more powerful CPU and has more RAM.

Wireless performance would depend on too many factors, including enviroment…so it is hard to tell, I would expect the performance would be quite similar to RT-AC68U on same enviroment or slightly less, as broadcom has lots of experience with wireless chipsets and they tend to perform better than most other vendor chipsets.

EDIT: AsusWRT is FOSS, it is OpenSource so you can download source code, alter it and compile it by yourself.
It is actually based on Tomato, with revamped GUI and some Asus and Broadcom proprietary stuff.
Also they do accept fixes and patches from community.

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Thanks for all your insights mate!

The good stuff!

Out of curiosity; did you “order” the Turris Omnia? And if so; why (maybe best to reply, if you are, in my other topic about the Omnia’s appliance)?

[quote=“woosting, post:7, topic:579, full:true”]Out of curiosity; did you “order” the Turris Omnia? And if so; why (maybe best to reply, if you are, in my other topic about the Omnia’s appliance)?

Yes I did, with 2GB and LTE, why else would I be around here… :grin:
And it is worth the price, trust me…I have seen lots of devices, which are much cheaper and ofc perform accordingly.
Powerful HW is costly…and you pretty much “get what you paid for” from all the vendors…

Ditto (for LXC purposes mainly)

You addict! :wink:

Yeh; I’m very much looking forward to it (even the more I learn / read-up)!

You addict! ;)[/quote]

For backup connectivity, also I’m planning to move from apartement to house in countryside next year, where fiber is not available and then I won`t have to hunt down compatible LTE module or fiddle with its drivers and I would not loose any functionality, except uplink speed ofc.