When the first 802.11b wireless networking products appeared back in the late 1990s, the 11Mbps speeds on offer seemed impressive compared to the still-widespread 10Mbps Ethernet wired networks. Since then, Gigabit Ethernet has become the most common wired technology, but wireless standards have dallied along behind, only recently reaching 450Mbps with three-stream implementations of the 802.11n standard. And with the extra protocol overheads needed to ensure your precious data doesn’t simply disappear into the ether, real-world data throughput in wireless networks still languish way below the 100Mbps mark for even the fastest multi-stream implementations.
How 802.11ac works
Buffalo’s Airstation 1750 claims speeds of up to 1,300Mbps (it also has a separate 450Mbps 802.11n radio, giving rise to the 1750 in the name), and is the first router on the UK market to implement the new 802.11ac Wi-Fi standard. Strictly speaking, it is 802.11ac Draft 2.0, as the final ratified standard isn’t expected to be approved until the end of 2013 (those who remember the early years of 802.11n will recall a similar early appearance of ‘Draft N’ products prior to final ratification in 2009).
This standard incorporates many features of the 802.11n standard, but uses wider channels and various other tricks to increase the PHY link speed (which is the connection speed reported by Windows, not the actual data throughput rate). For example, 802.11n can use either 20MHz or 40MHz-wide channels. Each data stream at 40MHz operates at up to 150Mbps, whereas in 802.11ac a 40MHz channel can connect at up to 200Mbps. This doesn’t sound like a massive improvement, but 802.11ac has more tricks up its sleeve. It can use 80MHz or even 160Mhz channels (although this first wave of products only uses 80MHz), giving 433Mbps and 867Mbps per stream respectively. And that’s not all - 11n allows up to four streams, giving an absolute maximum of 600Mbps, whereas 11ac can use eight streams for a dizzying maximum of 6.93Gbps.
There are many other deeply technical aspects, but they need not concern us here, except to say that many features of 11ac are intended to improve the reliability of data transmission to multiple clients. One such feature is called multi-user MIMO, or MU-MIMO. In effect, this enables a router to locate where each connected device is located, and focus the radio signal (using a technology called beamforming) directly at them. It’s all clever stuff, but as ever the proof of the pudding is in the eating.
At the time of writing, there were no other 802.11ac products around, and are not likely to be for some time, so Buffalo has simultaneously launched a matching four-port 11ac wireless bridge device, the WLI-4H-D1300-EU (costing £129.99) , which we used for out tests. This is a very simple device to use - plug in a wired client, turn on the bridge and associate it to the router. It uses 5GHz channels by default, but can be forced to 2.4GHz 11n mode if needed.
Features and design
The design of Buffalo’s Airstation range has always been a little quirky, but the Airstation 1750 is actually quite elegant. The sides have a soft-touch black paint finish, and are held together by a continuous grey plastic band. Two plastic clip-on feet are supplied to allow vertical or horizontal mounting, but these kept falling off our sample when we moved it.
Four Gigabit Ethernet ports are provided at the back in addition to a dedicated Gigabit Ethernet WAN port (there’s no ADSL modem). There is also a USB 2 port for sharing storage and printers (including multifunction devices), although it’s a bit disappointing that a cutting-edge model like this doesn’t have two ports or even USB 3. Printer devices are shared via by installing the Network USB Navigator utility on each networked PC. Also at the rear is a button that switches the device between router and bridge mode.
The front status LEDs are blue and unobtrusive, and the white-illuminated Buffalo logo also doubles as a status indicator. A quick-connect button supporting WPS and Buffalo’s own AOSS sits above the LEDs, and the reset button is under the base.
Setup is easy, with a wizard launching when a browser is first opened after installation, or when first accessing the web configuration menu. You can also use the supplied Airstation Configuration Tool to detect the router and access the web settings page. MAC address spoofing is supported for those (like us) with MAC-tied ISPs.
The settings menu is a riot of colour, and looks a little cluttered. But there is decent help and plenty of handy advanced features such as a VPN server, Bittorrent client, NAS, media server and more. The settings for the two wireless radios default to 20MHz channels on the 2.4GHz band and 80Mhz on the 5GHz (11ac) band. For our tests, we changed the 2.4GHz band to 40MHz channels so we could test with a 450Mbps client, but otherwise used default settings.
How fast is it?
Although the marketing bods will have a field day with 802.11ac’s ‘Gigabit’ links speeds, we’re old and wise enough not to be expecting miracles. The main improvement affecting throughput is the wider channels, but all the extra gubbins involved for MU-MIMO and so on incurs significant processing overheads.
Initially we were quite disappointed, as at close range (1m) the 5GHz throughput averaged just 102Mbps (see above). This is excellent, but we have seen faster 5GHz 11n routers. But as we increased the range, we became more and more impressed, with it maintaining 96Mbps even at 10m range. At 25m, (see below), the limit of most 5GHz 11n routers, we achieved a whopping 44Mbps. Moving even further to 30m, beyond the range of any router we’ve tested, it still delivered a respectable 19Mbps, with the bridge device’s monitoring software indicating a 29Mbps link speed and 18 per cent signal strength. And more importantly, as the throughput plots shows, during each test data transmission was rock-steady apart from a very occasional dropout. This seems to show that beamforming does offer tangible benefits.
For comparison, we tried our standard 5GHz 11n 450Mbps adapter (an Intel Wi-Fi Link 5300AGN). At 1m, this managed almost 60Mbps, at 25m 16Mbps, but it couldn’t even connect at 30m. The 2.4GHz performance (using the same Intel adapter) was unremarkable, with 47Mbps at 1m, 20Mbps at 25m, and 16Mbps at 30m, albeit much less reliably than the 11ac tests.
So the 802.11ac wizardry does seem to work, at least for single clients - we weren’t able to test with multiple PCs in different locations to see how well MU_MIMO works. It may be a bit of a ‘leaky bucket’ approach to improving range (the fuller it is at the start, the more will be left after a certain distance), but nevertheless it will be welcomed by those struggling with coverage problems.
To buy or not to buy?
Buyers might be understandably wary of investing in 'draft standard' kit, although competing products will be appearing later in 2012. As a router, the Airstation 1750 has a decent set of features, and it is fully backwards compatible with existing Wi-Fi kit. If you only have 802.11n devices, its performance can be bettered by some cheaper 11n routers, so you should only consider it if you can afford the Airstation 1300 as well. But for those with deep pockets, it is an excellent way to get high performance wireless coverage.
A good taster for what’s to come, and capable of excellent range and performance, but the lack of other 802.11ac devices means you will need to shell out another £129.99 for the matching bridge to fully benefit.