S17 ORA 1 2014 ICF Feature_Layout 1 2/6/2014 1:40 PM Page 84
ICT
BP in Cairo is using free space optics (FSO) for reliable high-speed connections between its various offices. However, as Vaughan O’Grady explains in the second part of his discussion of the subject, the need for ever-higher volume and faster links — from both businesses and consumers — is driving growth across all forms of communications media.
From the wellhead to
the rooftop: part two I
N THIS TWO-PART discussion of wireless communications we have focused on free space optics (FSO), which uses infra-red laser technology to transmit data. It’s a technology that BP is using to transmit high-speed data between a number of its offices or buildings in Cairo. In this case the advantages of FSO over other wireless technologies — it is usually licence-free and spectrum is uncongested — outweigh the disadvantages — most notably the need for line of sight transmission. In any case line of sight can be achieved by installing equipment on rooftops from which data can be transmitted across a largely unimpeded space. Nor are thick fog or heavy snow — which can limit FSO — likely in much of the Middle East and Africa.
All a matter of physics Equally important, FSO is not affected by rain, which can be a problem for a number of technologies (readers of our features on satellite communications may remember that Ka band can be interrupted by West Africa’s monsoons). It’s all a matter of physics, which is why no wireless technology is totally reliable and also why companies like Wireless Excellence work with a number of them. As Stephen Patrick, the CEO of Wireless Excellence Limited, a leading designer and manufacturer of professional wireless products for a wide variety of applications, says, “There isn’t just one technology that just works and one that doesn't.” Wireless Excellence, through its local partner, supplied the FSO system that BP uses. However, while FSO may be the ideal choice for wireless, why did BP not go for wired? Fibre, for example? “Fibre is a perfect medium,” Patrick agreed. “When it’s installed and not interrupted you have a piece of glass that carries gigabits, even, terabits.” The trouble comes when you have to dig the street up — and get permission to do so. The upfront costs can be huge. And if you move offices what do you do with the cable? If you’re using FSO, of course, you just take your boxes and reinstall them. Patrick added, “Apart from the disruption caused to traffic and other street users, there will be pre-existing underground services, ducts, drains and other pipes which have to be worked around. And there is always the very real risk that subsequent work by other providers digging in the same locations may break.” Of course, Patrick adds, “Diverse resilient media is always a good thing to have in any network – wired or wireless.” That is, if the rooftop connection
84 Oil Review Africa Issue One 2014
Line of sight can be achieved by installing equipment on rooftops from which data can be transmitted across a largely unimpeded space.
A private fibre system just isn’t possible in Cairo. is undermined the underground connection probably won't be, and vice versa. But a private fibre system just isn’t possible in Cairo. In any case, BP has appropriate back-up for its FSO system in the shape of lower-speed leased lines, just to keep basic services ‘up’ should the high speed gigabit FSO network experience any downtime, such as planned maintenance. FSO also involves a financial incentive for a corporate customer. Rather than a lease on its balance sheet as an ongoing loss every month it is buying an asset. ”That’s a capital purchase,” Patrick explains. “They own the boxes — a tangible asset — which increases the net worth of company. Leased lines do not.” Of course what the BP offices are transmitting to each other may come to the FSO boxes from undersea cable, the PSTN’s own fibre links, a dedicated circuit, satellite, you name it. The point is that when it is passed in between buildings the wireless connection needs to be able to handle
high speed and high volume in order to cope with the sort of data that could be involved. With FSO you have up to a gigabit a second to play with. So, Patrick says, “What can a gigabit do for you?” Answering his own question, he continues, “It can connect thousands of people — not just a few people in a branch office. And these are big BP offices.” Would that include a high definition rich multimedia file or high-resolution photography of a wellhead? “You could share extremely rich multimedia content instantly without slowdown. That gigabit is the same speed that you have in your core switch in your network. It’s the same speed coming out of the server where that data is. We're not providing a bottleneck. So the user who’s in the building without the wireless is having the same speed experience as the guy who's at the other end of the wireless link.“
Demand for wireless alternatives growing Demand for wireless alternatives is unlikely to slow down. After all, everything now goes down one channel. “We used to sell products that had 100 megabits of data and a side channel of two megabits to the telephones. You knew from installation that one lot would be plugged into an
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