Bug found with bridge mode

[jonstatt]

I was scratching my head for a good part of an hour trying to work out why my second RT-AC66U refused to successfully work in bridge mode with my first one (in router mode).

I finally found out why. I am in the UK, so I assume the firmware conforms to the appropriate channel approval regulations.

On the router side I can configure 5Ghz on the following channels
36,40,44,48 and 149,153,157,161

The AC66U running in bridge mode will ONLY successfully find and connect to the router if it is using 36,40,44,48. It refuses to connect on the higher channels numbers which is annoying as I am likely to get better throughput on those.

In the meantime I am using channel 36 and getting a test throughput of 550Mbits using LAN speed test. This is about double what I got using Wireless N and my original Netgear N900 router. I have also found the 5Ghz penetration throughout the house to be much much better.

The bridge mode is interesting, because it also creates another 2.4Ghz network at the bridge (acting as a repeater I guess). I don't really have a need for that but couldn't see any way to switch it off! The bridge I need is wireless to LAN only.

 

[SoCalReviews]

In the meantime I am using channel 36 and getting a test throughput of 550Mbits using LAN speed test. This is about double what I got using Wireless N and my original Netgear N900 router. I have also found the 5Ghz penetration throughout the house to be much much better.

Are you using fixed channel or auto channel? If you aren't using the 2.4 Ghz band at all can't you just turn off the 2.4Ghz radio in the router? 550Mbps is actually really good for a first generation wireless ac router. Remember that 1.3Mbps is the theoretical maximum throughput for an 802.11 ac router using a multichannel 80Mhz bandwidth and the 5Ghz frequency band signal will be about half the strength at longer distances in a house compared to the 2.4Ghz band. You can't expect to get close to that maximum throughput unless conditions are ideal. The 5Ghz range does have better signal scatter which is generally good for locations such as residences requiring short to medium range coverage and it has different wall and object penetration characteristics depending on the material (for example it is suppose to be less prone to absorption by objects containing water than 2.4Ghz).

 

[jonstatt]

Are you using fixed channel or auto channel? If you aren't using the 2.4 Ghz band at all can't you just turn off the 2.4Ghz radio in the router? 550Mbps is actually really good for ac. Remember that 1.3Mbps is the theoretical maximum throughput for an 802.11 ac router using a multichannel 80Mhz bandwidth and the 5Ghz frequency band signal will be about have it's strength at longer distances in a house than the 2.4Ghz band. You can't expect to get close to that maximum throughput unless conditions are ideal. The 5Ghz range does have better signal scatter which is generally good for locations such as residences and it has different wall and object penetration characteristics depending on the material (for example it is less effected by objects containing water).

I can turn the 2.4Ghz off on the Router. But when you set up the second AC66U as a bridge, it forces you to create yet another 2.4Ghz network from the bridge unit, and it cannot be switched off because almost all of the menus are missing when in bridge mode.

For the 5Ghz radio, if I set it to Auto, then it is always choosing one of those high channel numbers, and the bridge unit won't find it at all. The only way I can get the bridge to work is to force it to 36,40,44 or 48.

I know the speeds I am getting are good for ac although I have seen reports of people hitting around 700. I was wondering if I could get the units working correctly at those higher channel numbers, whether I might stretch nearer to it. I have no real complaints with what I am getting though.

I do wonder, once ac technology matures, whether they will eek much more out of it, or whether these draft standard implementations are pretty much all we can expect anyway...

 

[SoCalReviews]

As you speculated there probably are some limited options when using bridge mode with the latest firmware release. If the 2.4Ghz radio can't currently be turned off in bridge mode on this router maybe future firmware releases will allow the option to turn off 2.4Ghz radio. Regarding the future...from what I read unlike when the draft N was being hammered out these first generation wireless ac draft devices are using known technologies already built into the hardware (such as 802.11ac using 256-QAM instead of 64-QAM for 802.11n). Many of the future changes and improvements should be available through firmware updates. This first generation of ac devices use 80Mhz bandwidth but future generation wireless ac devices may be utilizing 160Mhz of bandwidth and will require more antennas (four or more dedicated to 5Ghz compared to the current standard of three) to utilize that broader bandwidth.

 

[jonstatt]

As you speculated there probably are some limited options when using bridge mode with the latest firmware release. If the 2.4Ghz radio can't currently be turned off in bridge mode on this router maybe future firmware releases will allow the option to turn off 2.4Ghz radio. Regarding the future...from what I read unlike when the draft N was being hammered out these first generation wireless ac draft devices are using known technologies already built into the hardware (such as 802.11ac using 256-QAM instead of 64-QAM for 802.11n). Many of the future changes and improvements should be available through firmware updates. This first generation of ac devices use 80Mhz bandwidth but future generation wireless ac devices may be utilizing 160Mhz of bandwidth and will require more antennas (four or more dedicated to 5Ghz compared to the current standard of three) to utilize that broader bandwidth.

It is actually quite weird with the forced 2.4Ghz mode. You cannot choose the wireless channel, or any other aspects of its configuration. The only adjustments are the SSID and the password.

I agree that the current device should be able to do pretty much everything in the final standard. I understand the Asus should be capable of MU-MIMO once properly implemented. The only thing of course it cannot do is 160Mhz bandwidth. I really wonder what will happen with that. With only one set of 160Mhz channels available in some countries, you would completely lock out your next door neighbour from doing the same. Similarly even with the two sets of frequencies available in the UK, it could become problematic very quickly. I think you need to be living in an isolated castle somewhere to be able to use the 160Mhz bandwidth!

 

[SoCalReviews]

I don't think 802.11 ac with 160Mhz bandwidth will be a problem for most users since the indoor signal on the 5Ghz frequency loses a significant amount of strength at short to medium distances and becomes extremely weak at longer distances compared to 2.4Ghz. Moderate crowding on the 5Ghz band might be a problem if users bump up their broadcast power much higher than 250mw or if they use a high gain antenna outdoors. In very high density residential or commercial areas the eventual ac specification will benefit from channel conflict safe guards and automatic lower bandwidth fall back to make it "neighbor friendly" which the wireless N specification already uses and because of the nature of 5Ghz losing it's intensity more noticeably with distance it will be much more effective than it is with the 2.4Ghz band.

It will probably be at least five to ten years before 5Ghz becomes as commonly utilized in products as 2.4Ghz and by the time it does there will be the next wave of closer range wireless wide band technologies commonly available such as the proposed 802.11 ad specification utilizing the open and unlicensed 60Ghz frequency band which will likely only have an effective range of connection similar to today's Bluetooth enabled devices. The ad devices will probably use a combination of 2.4, 5 and 60 Ghz and will automatically negotiate and adapt on the fly simultaneously with one or more of these frequency ranges depending on the strength of the broadcast signals it is connected to.

 

[ascanio1]

Very upset with a/c66 5GHz strength/range!

I don't think 802.11 ac with 160Mhz bandwidth will be a problem for most users since the indoor signal on the 5Ghz frequency loses a significant amount of strength at short to medium distances...

Exactly: I have 2.4GHz overcrowding in my home so I bought the new a/c66 hoping to exploit the 5GHz band. Unfortunately this signal is so weak that I can hardly stream low def Youtube, at a reasonable speed, @ 9m with only 3 or 4 plaster walls in between. However, under the floors and above the ceiling, there is lots of insulation, cables, A/C ducts, pipes etc).

Please, advice me the best replacement antennas, make/model, with high-gain, 250mw booster, to replace the original ones and improve the signal's strength/range:
No neighbors to worry about;
802.11n & 802.11a/c adapters/laptops (very soon);
Only indoor;
360°;
Elevation of clients within -1.5m of the antennas.

I also use a completely separate network for (one) old 802.11g client.

I would really appreciate if you could point me to the right forum(s) to find a/c specific antennas, if you cannot advice me here. Thanks.

 

[Danielkl]

It is actually quite weird with the forced 2.4Ghz mode. You cannot choose the wireless channel, or any other aspects of its configuration. The only adjustments are the SSID and the password.

I agree that the current device should be able to do pretty much everything in the final standard. I understand the Asus should be capable of MU-MIMO once properly implemented. The only thing of course it cannot do is 160Mhz bandwidth. I really wonder what will happen with that. With only one set of 160Mhz channels available in some countries, you would completely lock out your next door neighbour from doing the same. Similarly even with the two sets of frequencies available in the UK, it could become problematic very quickly. I think you need to be living in an isolated castle somewhere to be able to use the 160Mhz bandwidth!

Hi Jon,

I thought a similar thing as well, but I discovered a way around. In your scenario with a 5Ghz master router, if you change the second router into "Wireless Router" mode, you can turn on/off/adjust the 2.4Ghz radio, before returning it into "Media Bridge" mode. What you cannot do on the current firmware is have the second router act as a 5GHz wireless AP.

Hope this helps.

 

[nexus7]

Registered just to thank you for this tip. I assumed that changing modes would "start from scratch" and re-enable the radio, so I was looking for a way to do it from the CLI when I stumbled upon this thread. I did a quick flip back into router mode, disabled the 2.4GHz radio and switched back. Voila.

I actually wanted 2.4GHz roaming to work, but was dismayed I couldn't control the channel selection in bridge mode either.

Anyway, I have the 5GHz bridge I was looking for in the first place.

Thanks again!

Hi Jon,

I thought a similar thing as well, but I discovered a way around. In your scenario with a 5Ghz master router, if you change the second router into "Wireless Router" mode, you can turn on/off/adjust the 2.4Ghz radio, before returning it into "Media Bridge" mode. What you cannot do on the current firmware is have the second router act as a 5GHz wireless AP.

Hope this helps.