Many thanks for that. What is the maximum throughput you can get with 802.11a?
802.11a is the original 5GHz Wi-Fi standard - 54Mbps maximum bit rate, around 24Mbps maximum real life throughput. It is almost exactly what became 802.11g on the 2.4GHz band, though 802.11g includes support for old 802.11 and 802.11b clients (which weren't needed in 802.11a as there was no earlier 5GHz standard).
802.11n came next. The throughput on 2.4GHz and on 5GHz depends on the width of the channel used and how many simultaneous streams are supported. 3 streams in 40MHz tops out at 450Mbps bit rate - it's much easier to find room for a 40MHz channel on 5GHz than on 2.4GHz. Few clients support three 802.11n streams (though I'm sat at the keyboard of one that does - it has an Intel 5300 card with three antennas connected - the much more common 5100 and 6100 cards only support two streams).
802.11ac - it's far too early to know. There's some gear available to early draft specifications, but I'd steer clear until the standard is ratified.
I'm considering whether to replace our old 802.11a/g dual band simultaneous access points and replace them now or wait for 802.11ac. I suspect I'll jump sooner rather than later - it's going to be at least another year for 802.11ac to be ratified and mature, and when it arrives I'll have no 802.11ac clients for a while.
We use business grade access points, as we use features like dynamic VLAN allocation by our RADIUS server, which aren't supported by consumer gear. Cisco have an access point that will have a slot in module to upgrade the 5GHz radio to 802.11ac, but there's no controllerless version, and we certainly can't justify a Wi-Fi controller (the biggest Wi-Fi installations have special access points co-ordinated by an outboard controller - these things cost thousands).
In truth, 450Mbps on 5GHz should be enough for our wireless needs for a while, especially as we use cables wherever possible, and I'd rather go with mature 802.11n kit that's hopefully well debugged than early adopter 802.11ac kit with a load of hassles.
The slightly broken WPA2 implementation of what I've got (3Com 8760 - now an HP product after the HP take-over) sometimes leaves clients connected but unable to pass traffic, with modern tablets and smartphones we have several devices permanently connected, also they are now too slow (we have 80/20 FTTC at maximum available speed and gigabit LAN infrastructure). I've updated these access points to the latest firmware available from HP, and though they're more robust, they're still not right. It isn't worth spending any more effort on obsolete technology - and I doubt HP will issue any more firmware updates, especially for legacy products like these where they don't charge for updates.
I am thinking about replacing the main AP with an
HP MSM460 on a five year Care Pack, so I will have access to software updates and speedy hardware replacement for the usable life of the product. I'll keep the 8760s for fill-in coverage in fringe areas (on a different SSID, so that I can set my devices to prefer the MSM460) - it isn't worth the cost of a second expensive MSM460.
I had also looked at the standalone version of the
Cisco Aironet 2600i (about the only other full feature 450Mbps business-grade access point in the market), but by the time you add on a SmartNET contract for software and hardware support, the already eye-watering price becomes near obscene.
The
Netgear WNDAP660 doesn't appear to support VLAN allocation by RADIUS server, also it needs more power than my 802.3af Power over Ethernet infrastructure can provide for 450Mbps operation (four options - supply local power, two 802.3af ports, one 802.3at high power port or limit the device to 300Mbps). However, it looks to be a more cost-conscious option for a simultaneous dual band 802.11n access point with 450Mbps support.
The cheapest dual band access points operate on one band, rather than both simultaneously - you have a choice of which band. I'd recommend simultaneous dual band gear, as 2.4GHz covers a wider area and some clients lack 5GHz support.