Microwave v leased line
The UK leased line market - According to an OFCOM survey* in 2006, over 30% of SMEs have leased lines. Over 200 of the SMEs with leased lines were asked to identify the types of services they received and their attitudes towards these services.
The average spend on leased lines by medium sized businesses was an amazing £18,000 per year, although this average varies quite considerably in different UK regions. The South, for example, shows a significantly higher annual spend of £22,000 compared to the North/Midlands that averaged an annual spend of £13,000.
Despite these high recurring costs for their leased lines, many customers stick with their current suppliers for an average of seven years; significantly longer than the average contract length of two years. There were a range of reasons why companies stayed with their existing suppliers, but when asked the question “Would you choose different suppliers in different areas to take advantage of any price differential?” just over half (53%) said they would choose a different supplier.
It is also interesting to note that despite the very high annual premiums these companies continuously pay their leased line suppliers, the bandwidth obtained for this price is very low by today’s broadband standards. Of those companies that knew the capacity of their leased lines, 71% received a service that was between 64Kbit/s and 2Mbit/s. Less than 10% reported a service with speeds of 8Mbit/s or more.
Technology - By far the most common question asked about wireless propagation is ‘how far can a link go?’ However, the range depends on the expected availability and data rates required, as well as governing factors of the environment such as the height of the equipment used and how clear the line of sight is. Thankfully, modern planning tools can correlate the technical performance of the systems with the topographical terrain data of the locations in order to reliably predict the bandwidth of the link as well as calculate the availability, usually desired to be 99.999%.
Modern technology also allows microwave systems to benefit rather than suffer from reflections off surrounding buildings. This means that reliable links can still be established even in non line of sight conditions, with many examples of links in the field delivering reliable connections at distances of up to 1Km or more. Of course, the clearer the line of sight the further the range thus interconnecting taller buildings with clear line of sights can reliably deliver 10Mbps or more, at distances of over 10Km.
The technology can therefore deliver very fast speeds with high levels of reliability even in very low-lying urban deployments.
Convergence - Before convergence microwave systems were mostly used as part of an organisation’s data network, the IP native systems provided cost effective links in places where traditional infrastructure did not exist. However, the convergence revolution is rapidly turning the world to IP. Waves of new solutions are being deployed in the telecoms and security markets which are now based on IP networks. All of these systems crave the same things: high bandwidth, low latency networks and true Quality of Service. Microwave links, which have been delivering these fast high quality links for some time, can now provide a solution to a much wider range of applications. Examples include the traditional voice and data needs of an SME organisation; backup systems to fibre networks as well as providing backhaul for large metropolitan security or telecom networks. Where a microwave link is feasible it will offer a true alternative to leased lines.
Return on investment - The strength of the return on investment for microwave systems lies in the speed and simplicity of their deployment compared to the alternatives. Historically, microwave links were only deployed on very tall masts or towers that were usually owned by a third party and attracted fairly expensive annual site fees. However, as modern systems can now be easily mounted on a roof top, equipment can be simply deployed on the user’s own building, similar to a residential satellite dish. This enables a system to be installed very quickly with little or no recurring costs (depending on the equipment/labour support contract required). A microwave link can deliver over ten times the capacity of a normal 2Mbps leased line. However, the fully installed cost can be as low as £6,000, which is a fraction of the cost of a leased line installation. Furthermore as a capital expenditure the system is owned by that organisation, is not subject to third party service rates and does not attract the expensive recurring costs of a leased line.
Regulation - Licensed microwave bands at various frequencies in the UK are available following a licence application to OFCOM. However, the process is specific to the intended location and the desired performance of the link, which can be time consuming. The advent of the Fixed Wireless Access 5.8GHz Band C, released by OFCOM in early 2004, has opened up the market to the masses. Under this new light licensing scheme, users must utilise compliant equipment and then simply undertake an online registration process. The band also allows transmitter powers up to 2 Watts (20 times the power limits for WLAN devices at 2.4GHz).
The professional systems that operate in the market today can offer speeds up to 200Mbit/s, however, new higher frequency microwave bands are soon to be released in the UK. Some very high frequency bands, such as the 80GHz band, already widely used in the USA, will allow faster systems to offer speeds of over 2Gbit/s. Microwave Links offering truly “fibre” speeds will become an alternative to fibre lines in the very near future, just as they are alternatives to leased lines today.
* Use of leased lines amongst medium businesses, Continental Research on behalf of Ofcom March 2006
