802.11ac 5GHz Backwards Compatability

[apeofjungle]

Hi all.

Quick question. 802.11ac (aka 5G) is backwards compatible on the 2.4GHz band. Is it backwards compatible on the 5GHz band? Or is it just 2.4GHz for n, 5GHz for ac?

Cheers

ApE

[chip]

Originally Posted by apeofjungle

802.11ac (aka 5G) is backwards compatible on the 2.4GHz band.

You sure about that?

[apeofjungle]

Yep. It's one of there big selling points.

[chip]

Weird, all the actual draft standard documents mention is 5GHz transmission.

[apeofjungle]

"Will 5G WiFi be backward compatible with 802.11a/b/g/n?

Yes. Devices implementing 802.1ac will be backward compatible with legacy standards."

from here.

But doesn't say if the 5GHz is ac only.

[chip]

Ahh...the important word there is 'devices'. While the IEEE standard doesn't include 2.4GHz transmission, to get the '5g wifi' certification from the industry body they'll need to include 2.4GHz capability.

I suppose you'd need to look at what the silicon manufacturers (broadcom, atheros etc) are putting in their silicon to see if 802.11ac devices will be able to do legacy 5GHz 802.11a/n.

[Quadbox]

As I've read it it's got mandatory fallback on both bands. Ie, an 802.11ac device will definitely have support for 5GHz 802.11n and 11a

[itsmydamnation]

ac is just an extension of N there is nothing massively new. it standardizes somethings that aren't standard in N but really just just increased bandwidth (from 40Mhz upto 160Mhz), more spatial streams and more advanced encode/keying.

AC will be useful for home deployment, 80Mhz with two spatial streams hitting around 800mbits but not really for enterprise wireless networks.

[evilasdeath]

Originally Posted by apeofjungle

"Will 5G WiFi be backward compatible with 802.11a/b/g/n?

Yes. Devices implementing 802.1ac will be backward compatible with legacy standards."

from here.

But doesn't say if the 5GHz is ac only.

I think it might be the other way around 802.11ac is 5ghz only.

I know 802.11n is written and supported on both 2.4ghz and 5ghz bands however not all radios support both, to be honest the specifications could work on just about any frequency its just regulations only allow those free frequencies to be used.

There are routers today that support 802.11n/g/a on 5ghz and 2.4ghz, some only support 5ghz some only support 2.4ghz, some are exclusive 1 or the other.

unless it is a mandatory requirement that both frequencies are available all the time then i think it will be upto the router manufactures to include or not include 2.4ghz support, since it requires more antennas.

It's one thing about wireless permformance that really bothers me, its always up to but to get the full speeds you must have the correct devices with the correct number of aerials and thats always hidden in the product documentation. In this day and age everyone just looks at the price and thinks all 802.11 devices are created equally but they arn't.

[dracoMJB]

The devices I've looked at only have n on 2.4, 5 is ac only

[Zardoz]

2.4 will still be there on most devices for b/g/n but 802.11ac will only operate over 5GHz.

Cisco have announced an 802.11ac-only module for their 3600 series APs due Q1 next year:

http://www.cisco.com/en/US/prod/coll...78-686782.html

This is a "wave 1" generation which won't support multi-user MIMO (the real black magic that makes 802.11ac rock for high density).

[LostBenji]

Google is your friend..................

http://en.wikipedia.org/wiki/IEEE_802.11