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3G Network Operators In Search of the Missing Link
examines the options for linking 3G towers to backbone networks With licenses to operate third generation mobile networks being pocketed worldwide, the spotlight is now falling on the infrastructure required to actually provide services to end-users. The race for the world's first 3G network looks to be between BT's Manx Telecom arm, which will offer services in the Isle of Man, and the Spanish operators, with all looking to offer services before the end of 2001. Mobile phone users are significantly more sophisticated than when 2G first appeared and much more demanding in the quality of service they receive as a result. The disdain with which the public met WAP, the mobile internet in its earliest, flakiest form is proof that slow connections will not be tolerated. According to research among the Communications Managers Association (CMA), only 29% will implement 3G immediately with most taking a more circumspect, 'wait to be convinced' approach. Success in 3G will as usual depend on skilful marketing and aggressive pricing but more than ever on the reliability of service provided. The network operators are therefore dependant on the robustness of the infrastructure they use and the capacity and solidity of the bandwidth it generates. Also, the information services and content offered by mobile Application Service Providers will require much higher bandwidth per user. As you'd expect, the networking industry has thrown itself into meeting the operators' needs for more bandwidth. MobileOne has said that delivering 3G services will need a 70% increase in base stations, while others have estimated the need at between three and five times the current number. The demand seems to be being met. In the UK for example, The Lattice Group, demerged infrastructure business of British Gas, has set up a joint venture with US specialist, SpectraSite to rollout a 3G towers network. And BT has followed suit, announcing a 10-year deal with Crown Castle to build mobile phone masts on 4,000 of its exchanges. Even the Church of England has entered the market, issuing an invitation to tender for space on the towers of several hundred parish churches. These projects and others around the world suggest there will be no shortage of 3G-ready towers when the technology is ready for rollout. The situation with backbone networks, to where the traffic is transfered from the towers for national and global transit, is even more secure. New IP-focused backbones, designed to carry huge quantities of mobile internet traffic, have sprung up globally from the likes of Cable & Wireless and KPNQwest. The number of backbone providers is so great that even big names, like self-proclaimed 'super-carrier' PSINet are struggling to stay afloat. So all the infrastructure's safely in place for 3G and there's no danger of congestion from the huge surge in data and video traffic? Well not quite. The tower sites then need connecting back into the backbone network via high capacity broadband links often running over relatively short distances, between 500 and 1500 metres. This is the 'missing link' in the 3G infrastructure chain. Without enough bandwidth running between towers and backbones, there's a risk of bottlenecks. Huge amounts of data and video traffic could be 'log-jammed' at the towers end because an adequate stepping stone to take it onto the backbones does not exist. Whereas in a 2G network each 'back-haul link' was typically 2 Mb/s, the requirement for 3G is more likely to be 34 Mb/s. The options for providing this vital link may be myriad but choosing the right one is difficult. Each technology has pronounced pros and cons so it's necessary to study the options in more detail. First to come under scrutiny is the fixed leased line circuit. Leased line circuits tend to be copper wire links provided by the local telephone company. Relatively easy to upgrade for greater capacity, leased lines are a viable way of coping with the increased bandwidth demands of 3G. And once installed, leased lines tend to deliver the kind of high performance levels that a Mobile Operator requires. However, leased lines do have two notable drawbacks - speed of delivery and price. The price also tends to escalate dramatically as the bandwidth increases from 2 to 34 Mb/s. In Europe and even more so globally, there are still many areas, rural and urban, that don't have a high density of copper in the ground. This means that to obtain a leased line link, the local telephone company must install the cable required first. This can take weeks, sometimes months, denying the mobile operator rapid access to greater network coverage. What's worse, there's no guarantee the telephone company will be allowed to install more copper anyway. Many cities with heavily built-up urban centres often cannot withstand any extra construction work. Leased lines also tend to bring hefty rental costs, a very serious issue for companies that had to spend billions to obtain a 3G license in the first place. KPN, for example, has had to raise an additional 5.5 billion Euros to repay debt from the 3G auctions. For many 3G Operators, trying to capitalise in a nascent market, the price factor and the possible slow delivery time can put them off leased lines. Fibre optic connections tend to multiply the strengths and weaknesses of leased lines. Many telecom operators in Europe are investing heavily in fibre optic cable, which delivers high-capacity, reliable performance. Unfortunately fibre optic lines, at the moment at least, are expensive to install and tend to be deployed in the backbone network rather than as a 'last mile' network link. Fibre-to-the-tower is not yet a viable option for most 3G operators. As a result, enterprising financial directors look more closely at the cost-effective wireless alternatives. It's from within this area of technology that we must focus next, starting with microwave radio. Microwave is a proven technology with a long track record of successful implementations. Most of the major telecommunications companies use microwave systems for the transmission of telephone communications, facsimile transmission, as well as video and data. But while microwave technology has performed a useful service until now, particularly linking corporate premises, it's not ideally suited to the demands of Mobile Operators. Though cost-effective over distances up to 100km, it becomes expensive when transmitting over shorter distances, 2km and below. However, the biggest question mark over microwave concerns availability. In most countries, the use of microwave systems is strictly monitored by the government, with licenses being required before installations can take place. The reason is that demand has outsripped supply with growing pressure on the valuable radio spectrum over which microwave services are delivered. The result is that issuing of licenses by the government can take years and isn't even guaranteed. In addition, microwave does have a capacity question mark over it. Are there sufficient frequencies available to allow, say, five mobile and three fixed network operators to deploy radio base stations in cities as diverse as London, Rome or Athens? This would be a radio planning headache that operators can well do without. A new addition to the options available is broadband optical wireless access (BOWA), a 'new kid on the block' for supplying broadband connectivity. Using infra red, this technology works in the same way as fibre optic cable except that the beam is transmitted through free space rather than glass. Because of this, the cost benefit for BOWA technology is far greater than that of fibre. Already able to reach a capacity of up to 622 Mb/s, and with bandwidth capabilities of 1 and 2,5GB being developed, optical wireless is certainly capable of satisfying the bandwidth thirst of tomorrow's technology. Optical wireless excels in speed of installation. Because the systems use very low power laser diodes, radio licenses, right of way permits and other approvals are not required. This means optical wireless technology can be rolled out to provide network links in hours, not months. The common concern with optical wireless is with reliability. In the early days, the optical wireless industry suffered from bad press due to the introduction of systems which have failed to meet exagerated operational specifications. Over the years, this has changed and solutions today can offer industry-accepted performance availability figures in excess of 99.98% within the UK and better elsewhere, world-wide. The biggest obstacle for optical wireless is probably lack of industry awareness though this is rapidly changing. South Africa's Vodacom already uses optical wireless to roll out its network further into the country and Motorola is now using the technology to build a major GSM network in Egypt. The customer list is growing month by month. As public concern rises about the environmental impact of propagating all this additional radio transmission, broadband optical wireless plays very much to the 'green' agenda. By transmitting in the infra red light spectrum, there are no electromagnetic waves to worry about. This factor alone may help to ease the local government planning applications for the increased number of towers. The network operators can demonstrate their willingness to lower the environmental impact by declaring a 'microwave-free' policy. As Mobile Operators 'soup-up' their networks in advance of 3G, high capacity short distance connections that link cell sites back to the core network are crucial. Optical wireless is the rising star of this area of networking, faster to install and higher capacity than its wireless competitors. Though slow to deploy, leased lines also represent a reliable solution. In many cases, 3G Operators should use the two technologies as cavalry and infantry, employing optical wireless where network links are needed quickly, before sending in the leased lines later. For new players needing to build advanced networks from scratch but offlay the costs of buying a 3G license, this fixed and wireless approach could be the best combination for speed of rollout and value for money. |
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