Broadcom Takes The 4x4 Road For 802.11ax

[RTN]

Asus RT-AX88U
https://wikidevi.com/wiki/ASUS_RT-AX88U

For me 2.5Gbe/5Gbe would be moore interesting sence i have most
off my clients on the cable side, but anyway most off them are 1Gbe.
But still it would require switches who could handel the 2.5Gbe/5Gbe speed.

https://wikidevi.com/wiki/H3C_WA6528

 

[pege63]

Asus RT-AX88U
https://wikidevi.com/wiki/ASUS_RT-AX88U


https://wikidevi.com/wiki/H3C_WA6528

Where did you see the support for the IEEE 802.3bz-2016, 2.5G/5GBASE-T standard on the router (2.5Gbps / Cat 5e, 5Gbps / Cat 6)?

 

[thiggins]

Quantenna's response regarding uplink MU-MIMO support:

For Quantenna 11ax chips, HW support is already there for uplink MU-MIMO. SW support is planned for 2018.

No reply yet from Qualcomm.

 

[RMerlin]

Quantenna's response regarding uplink MU-MIMO support:

I remember last time Quantenna said something similar about "hardware support is there, software support will come in later". It was also related to MU-MIMO technology...

I don't want to be mean, but their past record would immediately raise some warning flags to me if that's their answer.

 

[thiggins]

I remember last time Quantenna said something similar about "hardware support is there, software support will come in later". It was also related to MU-MIMO technology...

I don't want to be mean, but their past record would immediately raise some warning flags to me if that's their answer.

I didn't think that point would be lost on those of us who pay attention...

 

[sfx2000]

The upside is 11ax will be better when LTE-LAA/LTE-U is deployed in your neighborhood...

And LTE-LAA/LTE-U is coming soon to a network near you - most wireless carriers have this in their 2017 device requirements now for devices launching in Q1-2018 and beyond.

 

[80211WiGuy]

ks is a more pragmatic approach to getting a slice of the 802.11ax pie.

They keep trying to increase the speed over wifi but still leaving the wired ports at 1 gig. When are these companies gonna start making routers with 10 gig ports or higher.

The problem is in what I call "marketing math". Advertised WiFi speeds are nowhere near what actually translates to the wire. Look at all of the high end WiFi router maximum 5GHz Downlink and Uplink speeds, they all top out at ~600Mbps. Disregard the Peak tests, some actually do push the max throughput of a 1Gbpp wired connection (~941 Mbps), but they have no bearing on actual real world use. The peak test is almost like a wired radio test going from digital->analog->digital on a shielded wire, no bearing on any scenario with even 1cm of air between transmitter and receiver.

Some will argue "what about aggregated throughput?" but to that I say "bah humbug!" You have to have a high end client locked to 2.4GHz and the other on 5GHz right next to the AP running a pretty hefty throughput test in tandem to even reach ~700-750Mbps. "But what about Tri-Band?!" What a crock of !$# Tri-Band is. Anyone who understands RF physics knows how bad hooking two transmitters up to the same antennas on the same band is, even if you space them out on opposite ends of the 5GHz channel range. Transmitting on one will cause errors in reception on the other. This can easily be proven by running speed tests on a triband router with 2 clients connected to opposite 5GHz SSIDs. Run the tests individually, then run them at the same time, the second results won't add up to the throughput of the first. Triband was a great idea by someone who doesn't understand RF, then the marketing heads got a hold of it and took it to the moon. Don't trust any vendor that sells Tri-Band or Dual-5GHz radios, they don't know what they're doing - they're just trying to ride the bad marketing wave.

To make matters worse, marketing departments are actually forcing engineers to add second gigabit uplink interfaces for SMB and Enterprise APs because of the mess they've created. Smart IT guys are saying "well if your AP can do 1Gbps+, why am I hooking it up to a 1Gbps ethernet link?". Instead of telling them the truth, they'd rather add the extra port or start introducing 2.5-5Gbps interfaces.

Sorry for the rant, as you can see this is a topic that infuriates me
If I'm wrong, please send me some reference material that's backed up with evidence. I genuinely would love to find a router/AP that can push more than 1Gbps of wired throughput!

Maybe they'll start getting close with .11ax on 160MHz channels but who's going to install +1Gbps adapters everywhere in their home network?

Any WLAN admin will tell you that using 160MHz or 80MHz wide channels in an office/business is not smart at all.

 

[RMerlin]

Anyone who understands RF physics knows how bad hooking two transmitters up to the same antennas on the same band is, even if you space them out on opposite ends of the 5GHz channel range.

Depends on the quality of the pass-band filter used on the amps. Would be interesting seeing technical data on these filters, to see how much "bleeding" there is (in addition to any potential harmonics).

I wouldn't be surprised if modern pass-band filters were good enough to work reasonably well in these scenarios. Next thing to worry would be potential cross-talk.

 

[thiggins]

Not to take away from your rant. But there are a few clarifications needed.

Look at all of the high end WiFi router maximum 5GHz Downlink and Uplink speeds, they all top out at ~600Mbps.

Remember these benchmarks are done with 2x2 AC STA.

Some will argue "what about aggregated throughput?"

I might be misunderstanding the aggregation you are referring to. But there are no STA that will aggregate 2.4 and 5 GHz.

Anyone who understands RF physics knows how bad hooking two transmitters up to the same antennas on the same band is, even if you space them out on opposite ends of the 5GHz channel range.

Tri-radio routers use separate antennas for low and high 5 GHz band. Often one of the antenna sets is dual-band and shared with the 2.4 GHz radio.

The Wi-Fi high number game is over, at least as far as SNB is concerned. It's just that the marketeers haven't come up with a good replacement.

11ax is all about more efficient airtime use. It says so right in the standard name. At some point the industry will figure out how to market efficiency/capacity. We've been working on an effective yet simple way to test it that doesn't require dozens of clients.

Our Wi-Fi System Capacity test is very rudimentary, yet the only test I've seen any publication perform that attempts to measure system capacity. It's just the first step. We continue to work on this.

 

[80211WiGuy]

Doh, I feel like a bit of a dummy now

Re: Aggregate throughput - I meant having 2 separate STAs on different bands running throughput tests to see how they aggregate onto the wire.

Re: Benchmarks - my mistake, I forgot these were with 2x2 STAs. In my defence, I've never seen much difference with a 3x3 Macbook Pro.

Re: Tri-radio - thanks for calling me out on this. The truth is I don't know a lot about what goes on inside the AP as far as band pass filters and the split antenna assignment. What I have seen is when running a spectrum analyzer right next to the AP, as the AP transmits I noticed a lot of unintentional radiation on the entire 5GHz spectrum block that only really happens very close to the AP. Something that the other 5GHz radio will get interference from when trying to receive from it's STAs. I believe this is why a lot of WLAN professionals and study guides state that you should never mount 2 APs closer than 10ft from one another. There are so many professionals out there that condemn dual 5GHz radios in an AP for these reasons.

Thank you for the "high number game over" article, I'll have a thorough read through it later today.

802.11ax sounds promising but I think we'll have to wait a few years after ratification before we see OFDMA really start taking effect(client rotation). I'm a little worried it might flop like MU-MIMO or PCF.

 

[thiggins]

Thanks for taking the clarifications as they were meant, i.e. clarifications, not criticism.

I take your point on potential OTA interference effects from having two 5 GHz radios parked within inches of each other. I haven't tried to assess this.

We have a LONG way to go with 11ax. Although Qualcomm tells me smartphone manfs will be more aggressive with adding ax than than they were with MU-MIMO, I'm very skeptical. I think it will be a few years before we see the first models here in the U.S. Asia-only models will probably be first, as they usually are.

 

[80211WiGuy]

Thanks Thiggins,
Have you written up the system capacity test process? I read the capacity section for the WiFi System Roundup, I'll read through it again more carefully.

Also, I'm curious if you've heard of AirTies?

 

[thiggins]

Have you written up the system capacity test process?

https://www.smallnetbuilder.com/wir...est-wi-fi-systems-revision-1?showall=&start=1

Also, I'm curious if you've heard of AirTies?

Yes. Have been trying to get them to submit product for review for a few years. They are primarily focused on Europe. Just started here in the U.S., but focused on service providers. No retail.

 

[sfx2000]

Any WLAN admin will tell you that using 160MHz or 80MHz wide channels in an office/business is not smart at all.

In the corp/enterprise and hospitality markets - I see 11ac mostly deployed 40MHz channels - and some even at 20MHz channels - there's still a lot of benefit with the narrow bandwidths, and it fits their 11a/11n plans that were deployed earlier before upgrades.

 

[sfx2000]

Re: Benchmarks - my mistake, I forgot these were with 2x2 STAs. In my defence, I've never seen much difference with a 3x3 Macbook Pro.

3*3:3 still benefits with a 2*2:2 - the extra radio and spatial stream do improve gain - both in the analog and digital (coding) domains.

In the consumer space - the higher end 4*4:4 Router/AP's - there is a difference - normally enough to jump up one or two MCS compared to a 3:3:3 AP -- while speeds are limited by the smallest radio, the 4 stream AP's generally will give better performance at a given range, and extend that usable range a bit more.

With WiFi - most performance impact is not on the Router/AP - enterprise or consumer - it's the client side that makes more of a difference - in my experience, Apple has done great work here - esp. on the MacBook Airs - even though 2-stream, the antennas there are awesome (maybe too awesome if doing network planning).

I would consider Lenevo and HP (corp laptops, not necessarily consumer grade) to be pretty good as long as the NIC's are good (Intel or QCA 2-stream units).

 

[80211WiGuy]

In the corp/enterprise and hospitality markets - I see 11ac mostly deployed 40MHz channels - and some even at 20MHz channels - there's still a lot of benefit with the narrow bandwidths, and it fits their 11a/11n plans that were deployed earlier before upgrades.

I completely agree, 40MHz channels are good in most distributed deployments.

 

[80211WiGuy]

3*3:3 still benefits with a 2*2:2 - the extra radio and spatial stream do improve gain - both in the analog and digital (coding) domains.

In the consumer space - the higher end 4*4:4 Router/AP's - there is a difference - normally enough to jump up one or two MCS compared to a 3:3:3 AP -- while speeds are limited by the smallest radio, the 4 stream AP's generally will give better performance at a given range, and extend that usable range a bit more.

Thanks for this, I didn't realize they were actually taking advantage of having more Tx/Rx antennas beyond having more radio chains / spatial multiplexing.