On a hill just to the west of Stratford-upon-Avon, wireless network vendor Airspan is working with broadband provider Pipex to test Airspan's AS.MAX WiMax system on a farm and the surrounding areas.
ZDNet UK went along to see the technology — which is being pitched as a major competitor to next-generation 3G networks such as HSDPA — in action.
Airspan is conducting its tests on 3.5GHz, although it has licences to use spectrum between 3.5-3.7GHz.
Product marketing manager Stephen Lightley explained that the company also had a 4.9GHz licence and could use 5.8GHz if telecommunications regulator Ofcom was informed first.
"When we have 5.8 systems available we’ll bring them up here," said Lightley.
The site has already been used to test equipment for the Urban WiMax system in Westminster, and Yozan’s WiMax deployment in Tokyo.
At the heart of AS.MAX is the MacroMax base station. This one is using DSL supplied by Pipex.
It contains a Forum-certified 802.16-2004 fixed WiMax chip, although it is soft-upgradeable to the 802.16e mobile WiMax standard.
Lightley highlighted this upgradeability as a key strength for WiMax in its fight against the rise of HSDPA (or next-generation 3G), especially as HSDPA will beat mobile WiMax to the marketplace.
The large size of the base station is due to its built-in power amplifiers.
Airspan is also trialling Internet telephony (VoIP) over its network. A multi-protocol iTone Prime gateway (blue and green, top) links the base station into the public switched telephone network via a soft switch (silver, bottom).
A call-controlling software package called VoiceMax is incorporated into both the soft switch and the base station, ensuring quality of service for voice.
Airspan plans to have about two dozen trial subscribers using VoIP and streaming video over the network within the next few weeks.
It has already had success using WiMax to provide the backhaul for Wi-Fi-enabled devices such as Sony’s PSP, Nintendo’s DS and a Sony location-free TV box.
Of course, something has to pick up the signal on the other end, and here are a few of Airspan’s Easy-ST subscriber terminals.
At a cost price of $400 (£217) each, the plug-and-play terminals provide easy connection (via Ethernet cable) and set-up, although they have to be externally powered.
That’s the main reason for calling fixed WiMax "nomadic" rather than "mobile", which will be the next stage in the technology’s evolution.
Lightley told ZDNet UK that the terminals can be moved between base stations, but operators may want to limit this or charge their subscribers for the privilege.
Although many manufacturers will be bringing out PCMCIA cards to implement this, Airspan intends to go for USB connectivity instead as it’s a “much more flexible” solution, not only for laptops but also for handheld consoles, MP3 players and so on.
ZDNet UK then took a laptop and Easy-ST terminal out into the field. Well, a car park rather than a field, but it was around 900 metres away from the base station.
With three FTP processes going (two down, one up), the system managed a fairly impressive download speed of 10Mbps and upload of 600Kbps.
Lightley attributed the speeds to fixed WiMax’s use of FDD, which uses two frequencies to provide an uplink/downlink duplex channel. Mobile WiMax, on the other hand, will use a system called TDD, which uses one frequency and relies on quick swapping between uplink and downlink to provide a seamless connection.
TDD is economical on spectrum, but requires some additional synchronisation of the base stations, perhaps by GPS, to remain in step.
Airspan then took us to a house in Stratford-upon-Avon where a couple of its Pro-ST terminals have been installed, about 1.3km from the base station.
The terminals convert WiMax to Wi-Fi, and tests within the house using a Wi-Fi-enabled laptop worked very well.
Switching between two Wi-Fi access points involved a handover of 0.2s (although this would be longer with encryption) and no packet loss.
Lightley said the team was "pleasantly surprised in terms of indoor coverage" of the WiMax signal, even through double-glazed windows.