When the going gets tough, the tough get microwave
Forget microwave as ‘second best’ – for critical services it is becoming the number one business broadband enabler.
We’ve all heard statements along these lines: “where there is no fibre or sufficient quality copper access, then microwave can sometimes provide a practical alternative for business broadband”. The statement is literally true, but misleading.
Conventional wisdom used to see microwave as a useful temporary solution for difficult terrain or third world countries – providing a quick, cost-effective connection while cables are being planned and laid. Also true – but equally misleading.
The fact is that the most critical networks required for high speed trading are now abandoning fibre in favour of microwave – because microwave is faster! Taking the world’s most vital financial corridor, Chicago to New York, as an example: when the time for a round trip by the fastest available fibre network stood at 13.1 milliseconds, a microwave network achieved the same in 8 milliseconds. For High Frequency Trading (HFT) that 5.1 millisecond advantage could make or break a fortune.
You could argue that most typical business applications are not as sensitive to the odd millisecond of latency, however the world of finance has a way of setting almost laughably high performance standards that eventually filter down until every business wants them. Already there are applications – such as LTE backhaul, remote data storage and tele-surgery – that benefit a lot from cutting latency by a few milliseconds.
More generally, quality of service (QoS) is a key differentiator in business services, and for data-intensive applications like videoconferencing you need not only low latency but also low jitter (latency variation) to ensure smooth delivery. The human eye is very sensitive to tiny irregularities – our forebears’ survival depended on noticing a tiny movement in the grass that could signal a snake or predator – so the impact of the best video presentation can be ruined by the tiniest glitches.
“But surely, fibre networks transmit at the speed of light. And nothing goes faster than light, does it?”
That’s also true. However microwaves too travel at the speed of light. The difference is that light in fibre is travelling through glass, while microwaves are travelling through air – and the glass fibre slows down the speed of light by 30 to 40 per cent. What’s more, a microwave link travels in a dead straight line between two points, where the typical fibre link has to take a route bound by practical factors such as trenching, rights of way and installation cost.
“What about weather conditions – aren’t they supposed to degrade microwave links?”
That’s an old story, dating back to the days of analogue transmission. Today’s packet microwave links benefit from digital error detection and clever algorithms that allow microwave to be used reliably in parts of the world with extreme weather conditions – where even buried fibre can be subject to things like earth tremors and frost damage. The greater speed, lower cost and flexibility of installing microwave instead of fixed lines also make it a simple matter to add extra redundant links for outstanding reliability.
“So why was I lead to believe that wireless transmission slows down the network and adds latency?”
That’s probably because many people’s experience of wireless access has been via satellite links. These do add latency, because the signal has to travel up to a satellite and back. The typical geostationary satellite as used for communications is over 35 thousand kilometres above the equator and this creates nearly a quarter of a second delay. Lower orbits can be used, but the satellite is then moving and this reduces the possible bandwidth.
So forget the old stories and look back at those figures for Chicago to New York to get a better idea of microwave’s potential – and it is still getting faster as they work on new ways to reduce the number of hops or to speed them up. Meanwhile new microwave links are springing up between other financial centres in the scramble for competitive advantage.
A lot has happened since the days when microwave was a “second best” – and a lot is still happening to make microwave the number one choice for business.