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Telecommunications … Future developments and potential ...

  1. 1. TELECOMMUNICATIONS - FUTURE DEVELOPMENTS AND THE POTENTIAL IMPLICATIONS FOR THE NATURAL HERITAGE Report No. F00AA514 For further information on this report please contact: Simon Brooks Scottish Natural Heritage 9 Culduthel Road Inverness 01463 239431 e-mail This report should be quoted as: ECS Limited (2001) TELECOMMUNICATIONS – FUTURE DEVELOPMENTS AND THE POTENTIAL IMPLICATIONS FOR THE NATURAL HERITAGE. Scottish Natural Heritage Commissioned Report F00AA514 This report or any part of it should not be reproduced without the permission of Scottish Natural Heritage which will not be unreasonably withheld. The views expressed by the author(s) of this report should not be taken as the views and policies of Scottish Natural Heritage.  Scottish Natural Heritage 2001. COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001
  2. 2. COMMISSIONED REPORT Summary TELECOMMUNICATIONS – FUTURE DEVELOPMENTS AND THE POTENTIAL IMPLICATIONS FOR THE NATURAL HERITAGE Report no: F00AA514 Contractor: ECS Limited BACKGROUND Developments in mobile communications continue at an unprecedented pace. This report provides information on many of the technical issues surrounding current and future mobile communications systems. MAIN FINDINGS There will be continuing pressure from mobile phone companies and their customers to provide good coverage in all areas where people live and work and along the roads connecting these places. The next generation (3G) of mobile systems will require more aerials if the same level of coverage that people have become accustomed to today, is to be provided. Mobile phone systems are not the only systems needing aerials in the countryside. A new radio system is planned for the Emergency Services in England and Wales. If this is adopted in Scotland, it will also require new radio sites to be located in the countryside. For further information on this project contact: Simon Brooks, Inverness (01463 239431) e-mail For further information on the SNH Research and Technical Support Programme contact The Co-ordination group, Advisory Services, 2 Anderson Place, Edinburgh. Tel: 0131 446 2400 COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 2
  3. 3. CONTENTS ABBREVIATIONS AND ACRONYMS ii ACKNOWLEDGEMENTS ii SUMMARY iii 1 MOBILE PHONE SYSTEM DEVELOPMENT............................................................. 6 1.1 First Generation Systems – 1G ........................................................................ 6 1.2 Second Generation Systems – 2G ................................................................... 6 1.3 Third Generation Systems – 3G....................................................................... 8 1.3.1 3G Technology .................................................................................. 9 2 SCALE OF FUTURE DEVELOPMENT FOR 2G NETWORKS................................. 10 2.1 Coverage ....................................................................................................... 10 2.2 2G functionality .............................................................................................. 13 3 COMPATIBILITY BETWEEN 2G AND 3G SYSTEMS ............................................. 13 4 DIFFERENCES IN NETWORK DEVELOPMENT BETWEEN 2G AND 3G SYSTEMS ................................................................................................................................. 14 5 3G ROLLOUT IN SCOTLAND ................................................................................. 15 6 DIFFERENCES IN NETWORK DEVELOPMENT FOR 3G SYSTEMS IN URBAN AND RURAL AREAS ............................................................................................... 15 7 POTENTIAL FOR DISGUISED 3G INSTALLATIONS.............................................. 16 8 NETWORK ROAMING ............................................................................................. 18 9 LANDSCAPE IMPACT............................................................................................. 18 9.1 Where will new mast be located?................................................................... 18 9.2 How many new masts are likely to be required and how many existing masts will need to be extended? ......................................................................................... 18 9.3 What will the new masts look like? ................................................................. 19 9.4 In what ways will it be possible to reduce their impact on the landscape? ...... 19 9.5 Over what period will new mast applications come in?................................... 19 10 DIGITAL SCOTLAND TASK FORCE....................................................................... 19 11 OTHER MOBILE SYSTEMS .................................................................................... 20 FIGURES Figure 1 UMTS Channel Plan .............................................................................................................5 Figure 2 Vodafone's 2G Coverage - 21st February 2001 ................................................. 11 Figure 3 Orange's Coverage - 7th February 2001 ............................................................ 11 Figure 4 Space Diversity Aerials ...................................................................................... 17 Figure 5 Aerials Located on Pylon.................................................................................... 17 COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 3
  4. 4. TABLES Table 1 Data Rates 3 Table 2 Vodafone’s network in Scotland 7 ABBREVIATIONS and ACRONYMS USED IN THIS REPORT 1G First generation mobile systems (analogue telephony) 2G Second generation mobile systems (digital telephony and data) 3G Third generation mobile systems (high speed digital data) BT British Telecom DPM Disruptive Pattern Military (camouflage) ECS Engineered Communications Solutions EDGE Enhanced Data rates for GSM Evolution ETSI European Telecommunications Standards Institute GPRS General Packet Radio Service GSM Global System for Mobile communications MHz Mega Hertz – a measure of radio frequency in millions or cycles per second PCN Personal Communications Networks RA Radiocommunications Agency SNH Scottish Natural Heritage TACS Total Access Communications System TIW Telesystem International Wireless UMTS Universal Mobile Telecommunications System (or Service) COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 4
  5. 5. ACKNOWLEDGEMENTS I would like to thank the Radiocommunications Agency, Vodafone, One2One and Orange for their assistance in the preparation of this paper. Figure 1 was supplied by the Radiocommunications Agency. Figure 2 was supplied by Vodafone. Figure 3 was supplied by Orange. Other figures were supplied by ECS Limited. COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 5
  6. 6. 1 MOBILE PHONE SYSTEM DEVELOPMENT Engineered Communications Solutions (ECS) Ltd was commissioned by Scottish Natural Heritage in February 2001 to provide a review of the future development of the mobile telecommunications industry, in particular the technical requirements of the ‘third generation’ technology, and identify the implications of these for the future planning and roll out of telecommunication networks. As an introduction, a description of the development of mobile systems will help in giving a better understanding of the current position. 1.1 First generation systems – 1G In 1984, the Government issued two licences for companies to set up mass-market mobile telephone networks. These were taken up by Vodafone (then part of the Racal Group of Companies) and Cellnet (a joint venture between BT and Securicor). Vodafone and Cellnet launched their systems at the end of 1984 and in early 1985. These were the first mobile phone systems aimed at the mass-market. There was a mobile phone system in operation before that, operated by the Post Office. It was crude and very expensive and the number of users was in the low hundreds. Because Vodafone and Cellnet were breaking new ground, no-one was quite sure how successful they would be. The mobile system made use of analogue radio technology in the form of a system called TACS (Total Access Communications System). The TACS system had few features beyond allowing users to make and receive telephone calls. At first, there were only high-power mobile phones suitable for use in cars, these then progressed into transportable units (basically a car unit with a battery attached). The early users were mainly senior management in large companies. Mobile phones cost over £1,000 and call charges were very high. The use of high-power mobile units meant that fewer base stations were required to give adequate coverage than are needed today. In- building coverage was not required as the call charges were so high that no-one who had access to a fixed-line telephone would consider using a mobile phone. The mobile phone system was very rapidly a great success. The initial investments by Cellnet and Vodafone were paid back in a matter of months. It was soon apparent that the analogue systems had limitations that would not allow all of the potential market for mobile communications to be met. In response to this, the European Telecommunications Standards Institute (ETSI) convened a working group called the Group Special Mobile (GSM) to develop a digital system for mobile communications. The TACS networks are now at the end of their lifetime. BTCellnet has announced that their TACS network will be closed this year (2001). I would expect Vodafone to close its TACS network soon after that. 1.2 Second generation systems – 2G The GSM standard took a long time to complete and to implement. It was often referred to by engineers as the Great Software Monster. But it marked a significant change in mobile communications – away from pure mobile telephony toward a more fully featured mobile environment capable of carrying both voice and data communications. These changes are what made GSM a second generation mobile system. COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 6
  7. 7. Vodafone and Cellnet were quick to see the advantages of GSM. It offered performance improvements over the analogue systems but also it offered the mobile companies the possibility of charging for many different types of services (text and data messages for example). Vodafone’s GSM services were launched in 1993 with Cellnet launching in 1994. At that time the Government had issued two further licences for companies to set up PCN (Personal Communications Networks). The reason that these licences were issued was that up to that point there had been little real competition in the market, with the charges from Vodafone and Cellnet being very similar. The PCN licences were taken up by One2One and Orange, who launched their systems in 1993 and 1994 respectively. The PCN systems used by One2One and Orange also use GSM technology but differ from the systems used by Cellnet and Vodafone in that they make use of a different frequency band1. The PCN licences contained an obligation for the operators to provide coverage of 90% of the population by 31st December 19992 - a target that was easily met. Operators have a continuing obligation under the terms of their telecommunications code act licences to provide coverage where it might reasonably be expected by customers. By this time, the size of mobile phones had reduced dramatically and almost at the outset, GSM users expected to use hand-held phones. As call costs fell, due to increased competition, users started to want to use their phones indoors as well as outside. This meant that coverage standards had to improve – meaning more base station sites in or close to built-up areas. As each base station site can only handle a certain maximum number3 of simultaneous calls, as the numbers of users have grown, so the number of base stations has had to increase to carry the calls. The GSM standard has not stood still in this time and further developments have been incorporated. These have been particularly aimed at increasing the capability of GSM to handle data traffic of various types. The basic GSM standard had a very low data rate of 9600 bits per second. While this has allowed a limited amount of data use, the operators have long felt that there was a greater demand for higher speed data services. The growth of the internet has driven this belief. It is interesting to realise that data is now the main use for the ordinary telephone network, primarily because internet calls last so much longer than standard telephone calls. Developments to the GSM standard have been dubbed Phase 2+ and 2++. They will offer greatly improved data capabilities together with other enhancements to the GSM system. I expect that developments of the GSM standard will continue but that there will be few additional major enhancements. The GSM platform is not suitable to provide the high- speed and high-capacity access that is necessary for convergence. Many of the speed enhancements are at the expense of network capacity. For example, one high-speed GSM service, the General Packet Radio Service (GPRS) can only achieve its full potential by making use of 8 voice channels. Table 1 shows the relationship between speed and range for 2G 1800MHz system. It is based on figures supplied by an operator and on a d-4 propagation model. The predicted ranges are indicative only. Local conditions will modify them significantly. The key point to note is that the range reduces significantly as the data speed rises. 1 This split is less clear now in that both BTCellnet and Vodafone also have frequency allocations in the PCN bands. Some sites are equipped with both bands to increase traffic capacity beyond the limits of a single band site. This does not generally introduce any new problems with sharing sites between operators. 2 Source Radiocommunications Agency 3 This number varies depending upon the type of base station and the operator. COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 7
  8. 8. Table 1 Data Rates Service Speed (bits per second) Range (km) Range (km) Urban (in building) Rural (outside) GSM Speech 2.1 9.7 GSM GPRS CS-1 14000 2.5 >10 GSM GPRS CS-2 28000 1.8 9.2 GSM GPRS CS-3 42000 1.6 8.2 GSM GPRS CS-4 55000 <1.0 5.8 It is perhaps also worth noting that 2G base station have a theoretical maximum range that is determined, not by how strong the signals are, but by timing constraints within the system4. This means that no base station can cover further than 35 kilometres5. 1.3 Third generation systems – 3G One of the main drivers in the development of third generation systems has been the feeling in the telecommunications industry that eventually all our communications needs might be met by a single solution. This theory gives rise to the push toward convergence. While GSM was a useful step towards convergence, it was not thought to be a suitable platform for the next generation of mobile communications. GSM was also not a global standard as other technologies were in use in the key markets of the USA and Japan. Development of a standard for third generation systems began a few years ago and have culminated in UMTS (Universal Mobile Telecommunications System). UMTS is being adopted all across the world as the next generation system. As you might expect, it is able to carry data at very high rates indeed – up to 2Mbs. These are data rates that are currently unachievable on standard telephone lines and so UMTS is a bold step towards a mobile convergence solution. It may seem strange that the major benefit of 3G is only higher speed, but 3G needs to be considered as a bearer, not a service in its own right. The important improvement is in the range of services that can be offered on the high- speed bearer. The UK led the way in auctioning the licences for UMTS, and perhaps as a result achieved the highest prices paid for UMTS licences. The competition was fierce, not least because the four existing mobile companies had to win licences to maintain the confidence of their shareholders. In the event, the five licences that were auctioned were won by the four current mobile phone companies and the fifth licence was won by Telesystem International Wireless, a Canadian company. These five companies have paid £22.5 billion between them for the licences. The licences will be issued for the period to 31 December 2021, allowing for 20 years of commercial services. Third Generation Systems will probably start to become available in 2002/3. They have an obligation under their licences to provide service to 80% of the UK 4 Digital system rely on accurate timing to determine the length of each digital “bit”. The finite delay between a signal being transmitted and received can upset this timing. A certain amount of tolerance to delay is built in to GSM but this only extends to the delay associated with the signal travelling a maximum of 35 kilometres. 5 Similar constraints will apply to 3G base stations although to-date I have seen no maximum range figures published. COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 8
  9. 9. population by December 31st 2007. This is not a difficult obligation to meet given that 80% of the population live in a geographically small area compared to the total land-mass. What determines range? Range in radio systems is determined by many factors. These include the transmitter power and receiver sensitivity as well as the height and types of aerials and the terrain. Even the weather sometimes plays a part. In a cellular system range is generally limited by the uplink. That is the link from the mobile phone transmitter back to the base station receiver. Because this is the limiting factor, range cannot be increased by increasing the transmitter power at the base station. As mobile phones have got smaller so their aerial have become smaller. Just a few year ago, mobile phones had telescopic aerials, now the aerials are almost always internal. These internal aerials have tended to be less efficient than their external counterparts – contributing to reduced ranges. Another factor is that phones have got smaller quicker than battery technology has been able to develop but at the same time, people’s aspirations about how long the batteries should last have grown. Very few people use external aerials on their cars – which would improve range, instead phones are just put on a seat. These factors coupled with health concerns may lead to mobile phones that are even less good at transmitting than the current generation of 1.3.1 3G Technology At present there is no 3G equipment in mass production and so what information there is on the performance and size of equipment is very sketchy and subject to change. 3G systems have been designed to have high capacity and high data speeds at the outset. This has meant that the way they are implemented is very different from 2G systems. At a 2G base station there will be several “carriers” which are discrete radio channels, each will be capable of carrying a number of simultaneous phone calls (typically 8). This technique for carrying several calls on a single frequency is called Time Division Multiple Access. Because there are only a limited number of frequencies available, they have to be reused in a very careful way so that the coverage of a cell using certain frequencies does not overlap with those of another cell using the same set of frequencies. 3G systems will have very few carriers – two or three for each operator (Figure 1). This number of channels would not be sufficient for a viable 2G system but 3G works in a very different way. In 3G systems the information to be sent is spread over a large part of the radio spectrum. Interference is avoided by the use of a system called Wideband Code Division Multiple Access. It is beyond the scope of this paper to discuss how W-CDMA works. However, it does mean that it is much easier for the operators to have greater capacity at individual sites. COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 9
  10. 10. Figure 1 UMTS Channel Plan6 2 SCALE OF FUTURE DEVELOPMENT FOR 2G NETWORKS 2.1 Coverage The 2G networks are already well developed in Scotland. In most populous areas coverage is good. Figure 2 and figure 3 show the current 2G coverage of Vodafone and Orange in Scotland and have been used with their permission. In the Vodafone diagrams, red areas indicate coverage, in the Orange diagram orange areas indicate coverage. The geographical coverage of Scotland is significantly less than is available in England but similar to that in Wales. 6 Diagram from Radiocommunications Agency COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 10
  11. 11. Figure 2 Vodafone's 2G Coverage - 21st February 2001 Figure 3 Orange's 2G Coverage - 7th February 2001 COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 11
  12. 12. It is clear from these diagrams that coverage is not complete across Scotland for either of these 2G networks. However, the operators have met their initial licence obligations for coverage of percentage of the population7. Vodafone covers a greater part of Scotland than Orange. This may be due, in part, to their participation in the Highlands and Islands coverage scheme, which was a part-funded Government initiative to bring mobile communications to the Highlands and Islands. I would expect that Vodafone and BTCellnet have broadly similar coverage to each other and that both Orange and One2One have less coverage. 2G Rollout continues in the Highlands. In a press release dated Friday 24 November 2000 The Highland Council said that between August and November 2000 they had received 106 applications (of which only 4 required planning permission)8. Within the timescales of this research, only Vodafone was able to provide figures for the number of masts that they have in Scotland. Table 2 summarises their installations at 20 February 2001. One2One advised me9 that they have less than 500 sites in Scotland at present. Table 2 Vodafone's Network in Scotland Total number of in service Macro/Micro sites in Scotland 1019 Total number of shared sites (not controlled by 299 Vodafone) including masts and other structures (water towers, pylons) Total number of Vodafone operated sites 720 sites of which approx. 548 are masts and 171 are rooftops Extrapolating this data for all operators is not simply a matter of multiplying up, due to the impact of shared sites. The total number of sites in use by the mobile phone companies in Scotland is likely to be between 2,000 and 2,500. Coverage tends to be provided by the operators in populous areas and along the main through-routes. Small, isolated communities will not tend to get coverage unless the operators are encouraged to provide it by some of the costs being covered by the Government. The provision of isolated pockets of coverage is difficult in that the site providing the coverage needs to be linked to the greater network in some way. This is usually done by microwave radio in remote areas. As microwave radio only works with a completely unobstructed line-of-sight, one or more radio repeaters (similar to base stations) may need to be installed to relay the signals back to the main network10. The need to improve coverage along through routes and to improve the capacity of the networks to handle simultaneous telephone calls will mean that the operators will continue to extend their networks. We would expect to see further sites added for the foreseeable future. As each new site is likely to add coverage as well as capacity, it will tend to creep 7 Which applied across the UK – not just in Scotland 8 Source 9 Telephone conversation with John Woodhouse, 27-2-2001 10 It is difficult to generalise about the range of a microwave link. Ranges vary from a few kilometres to some tens of kilometres. COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 12
  13. 13. towards smaller communities which may eventually prove economic for the operators to provide with coverage. 2.2 2G functionality The next major upgrade is called EDGE (Enhanced Data Rates for GSM Evolution). I believe this is likely to be the last major enhancement implemented in the UK 2G networks before UMTS rolls out. EDGE adds greater data rates to the GSM networks. In general, as the data rates increase, the range that can be achieved from a site (for users making use of the higher data rates) tends to decrease. So as users try to use EDGE technology, the operators may have to install more base stations to make up shortfalls in coverage. This effect is unlikely to be pronounced however, as few users will want to use EDGE while on the move and most EDGE users are likely to be found only in the most populous areas of Scotland, such as the Central Belt and Aberdeen. I do not expect that existing base stations will change in appearance when EDGE technology is implemented. 3 COMPATIBILITY BETWEEN 2G AND 3G SYSTEMS Rolling out 3G networks will be a major logistical challenge. Initially I would expect that existing base station sites will be used for 3G. It is likely that at first, this will mean that new aerials have to be installed to allow 2G and 3G services to run in parallel. I would expect that eventually dual or even three-band aerials will be produced, allowing GSM, PCN and UMTS to be transmitted from the same aerial. Prior to that happening, existing towers may need to be extended to allow for the additional aerials to be accommodated. This may be practical where a tower holds just a single operator but may not prove possible where two or more operators share a tower. In such cases, new sites may be necessary. The distribution of 2G base station sites in built-up areas may well be adequate for UMTS. It is likely that the range achieved for EDGE on 2G networks and for UMTS will not be very different. This, coupled with the need within 2G networks to have overlapping coverage in built-up areas11 to get sufficient traffic capacity, will probably mean that few new sites are needed in these areas to make up coverage shortfalls. 2G and 3G networks are not compatible in any simple way. The new UMTS operator (TIW) has been granted some level of access for its users to the existing 2G networks while its 3G network is rolled out. For this to be a viable method of operating, dual-mode handsets will be needed. These will be able to make use of 2G or 3G networks. These are likely to be developed quickly as they will probably form a vital part of the migration plan for all of the operators. Fortunately, the move towards very cheap handsets means that their lifetime is limited, often to that of the battery. Rechargeable batteries typically work for two to three years before they stop holding a charge effectively. It is nowadays often more expensive to buy a replacement battery than to replace a complete phone. Hence the product life is limited to the battery life. The fifth operator, TIW, will inevitably need some new sites, but mindful of their need for revenue, they are likely to concentrate on the most populous areas at first. The access arrangements that they have with the existing 2G networks will not require any change to 11 A technique that is often used to increase the capacity of networks to carry telephone calls, especially in populous areas, is to allow the coverage of base stations to overlap. This can effectively double the number of “telephone lines” available at locations served by two base stations. COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 13
  14. 14. the existing sites that will alter their appearance. The facility will be provided by means of software changes within the 2G systems. It is likely that 3G base station equipment will initially be larger than current 2G equipment12. This may create the need for new sites to be developed where an existing site has insufficient space at ground-level for one of more sets of 3G equipment in addition to the equipment that is already there. I have discussed mast sharing with the Radiocommunications Agency13 (RA). They confirm the sharing of masts by several 3G systems should be possible. They did, however, say that there were still some technical issues to be resolved before 3G and 2G systems could share. If these issues are not resolved, then the number of masts required could increase significantly. I would be surprised if these issues were not resolved however. The RA confirmed that mast sharing, where technically possible, is a condition of the Telecommunications Code Licence. In the future it may be possible for aerials to be used at base stations that can work on GSM, PCN and UMTS. This would obviously reduce the need for operators to extend towers to add aerials for each band. At present however, there are difficulties in this approach, not least being that the UMTS and PCN bands are close together (in terms of frequency) which makes combining both difficult and expensive. 4 DIFFERENCES IN NETWORK DEVELOPMENT BETWEEN 2G AND 3G SYSTEMS The main difference between the roll-out of the networks is likely to be that at the start of the 3G rollout, there will probably be less planning applications for greenfield sites than was necessary with 2G systems. This is because, the 3G network operators are likely to seek to take advantage of the many existing towers and aerials support structures to enable them to establish their networks as quickly as possible. The use of dual mode (2G-3G) phones will allow operators to provide higher data rates in built-up areas while providing 2G services in the other areas. This may be a viable way for mobile phone services to be provided in the rural areas of Scotland – taking advantage of the fact that less 2G infrastructure will be required to provide basic voice-telephony coverage than would be required for 3G services14. This will, of course, disadvantage the rural areas in terms of high-speed data access via the mobile networks. It is also rather inefficient in terms of the use of the radio spectrum as the two systems would need to run in parallel. However, since in rural areas of Scotland the signals will often be well contained by mountains and hills, this may not be a significant issue. The Radiocommunications Agency has confirmed that there are no plans to make the 2G licence holders relinquish their existing spectrum at present. Operators will be keen to close their 2G networks as soon as there are clear economic advantages in doing so. 12 Since no 3G equipment is in production at this time, it is not possible to be sure how much larger it might be. 13 Telephone conversation with Mike Shute, 12 February 2001. 14 There may well be legal implications of such an approach in terms of the licensing of 2G and 3G. COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 14
  15. 15. 5 3G ROLLOUT IN SCOTLAND None of the operators has made public details of their 3G rollout plans15. A requirement of the 3G licences is that they should cover 80% of the UK population by 2007. This is not a difficult requirement to meet (it is much more difficult to measure). To meet this UK-wide objective, operators will only need a small number of sites in Glasgow, Edinburgh and perhaps Aberdeen. They are unlikely to limit their coverage to these areas however and the major roads to Scotland from England will probably be early candidates for 3G coverage. Vodafone advised me16 that their initial plans would be to provide coverage in Edinburgh and Glasgow and along the major routes between these two cities, it would then extend out to Dundee and Aberdeen. They pointed out that as yet there was no 3G equipment available so their plans were at a very preliminary stage. However, they advised that their 2G sites currently have three aerials and that they would need to add another three to provide 3G coverage. They also advised that where an existing site made use of a pole to support 2G aerials, this would need to be replaced with a lattice tower to carry the additional load of the 3G aerials. In addition to changing masts where necessary, he said that Vodafone was installing larger cabinets that would accommodate 3G equipment. In the view of Mr Mitchell, the potential new planning legislation for mobile phone masts would slow 3G development down to a significant extent in rural areas. Mr Mitchell would not comment upon Vodafone’s likely response to the Scottish Executive Consultation on Telecommunications Development17. One2One advised me that their plans were very similar to those described for Vodafone. I would expect the plans of the other 2G operators to be similar. 6 DIFFERENCES IN NETWORK DEVELOPMENT FOR 3G SYSTEMS IN URBAN AND RURAL AREAS 3G networks offer a variety of different data rates. In general the maximum rate that can be achieved increases as the distance from the base station decreases. The UMTS standard envisages that the highest data rates will be used in more static applications. Hence for mobile rural coverage, lower data rates (and more range) will be the norm. Unfortunately, the 2G networks are likely to have their base station sites too far apart in many cases to allow continuous 3G coverage to be achieved from the same sites. Hence, more sites will be needed. Generally, the gaps in coverage are likely to be larger for Vodafone and Cellnet than for One2One and Orange18. The reason for this is that Vodafone and Cellnet tend to use a lower frequency for their sites19 (900MHz) than One2One and Orange (1800MHz). Lower frequencies travel further than higher ones. UMTS uses a frequency of around 2000MHz 15 During this study we requested information from BTCellnet, One2One, TIW/Hutchison, Orange and Vodafone. Information was received from One2One, Orange and Vodafone. 16 Telephone conversation with Daniel Mitchell, 12 February 2001 17 18 The situation can be complicated in hilly or mountainous areas where the landforms are the major limiting factor on the achievable range, however, the general point remains valid. 19 The situation is rather confused in that Vodafone and BTCellnet also have higher frequency allocations but the general conclusion remains valid. COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 15
  16. 16. so, all other things being equal, it would achieve a similar range to the PCN operators. However, the inherently higher data rates will reduce this range somewhat compared to the 2G networks, particularly where simple telephony on 2G networks is considered. The drive toward convergence means that UMTS is likely to be planned for in-building coverage at the outset – even in small communities adjacent to major through-routes. One of the major selling points for UMTS is the very high data rates that can be achieved for static users (2,000,000 bits per second). These rates exceed those available over standard telephone lines. There is the potential for 3G systems to be enhanced by the integration of satellite technology. Satellite mobile phone systems have had a very difficult history. While several systems have been launched, they have not proved economically viable yet and many billions of dollars have been lost. Technically, satellites are not viable alternatives to the use of fixed infrastructure in populous areas as they cannot handle sufficient simultaneous calls. However, they might be suitable for the provision of coverage in remote rural areas. Satellites are also not able to provide in-building coverage for users with hand-held phones. As the systems developed to date have not been commercially successful, we would not expect UMTS satellite systems to be developed in the foreseeable future. Rural development of mobile phone systems does not only require masts. Other factors may be equally intrusive. For example, most radio base station sites will have to be provided with external power. Where an existing mast is to be shared, we would not expect there to be any additional impact due to the need for additional power in most cases. New sites present problems, we have seen sites where the impact of the provision of power by means of overhead cables has been more obtrusive than the site itself. Where power is not provided in this way, the alternatives are to bury the cables or to install generators at the sites. Buried cables have little impact but generators may prove harmful to the environment for several reasons. Generators will emit fumes and noise and they will have to have a fuel supply which must be replenished regularly. This will tend to mean that a good quality access road must be built up to each site. Some access roads are attractive to walkers and other users of the countryside. They can also cause an added environmental impact. I should add where generators are not required, an access road to a site is not absolutely essential in all cases. There are a number of sites across the UK in sensitive areas where the operators have agreed that access for maintenance purposes will be on foot only. 7 POTENTIAL FOR DISGUISED 3G INSTALLATIONS The same opportunities for the disguise of installations are likely to be available for 3G systems as have been available for 2G systems. The history of design development thus far is that every few months a new design of mast and/or aerials comes out. I would expect this to continue with aerials getting smaller, and poles getting slimmer. There are currently masts disguised as trees (living and dead), telegraph poles and lamp posts. Vodafone announced early in 2000 that it had installed an installation on a living tree – but I would doubt that this would be possible in many cases. All of these options are likely to be available for 3G systems. I should add that most disguised installations cannot be shared and some may give more limited coverage than an overt radio tower or mast, due to the use of smaller aerials or siting that is technically less than optimal. COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 16
  17. 17. During the development of 2G systems, aerials Figure 4 Space Diversity Aerials have got significantly smaller. The original cell sites generally made use of a technique called space diversity to improve uplink performance. This required the use of large triangular head- frames. On each face of the frame there were two aerials, spaced some distance apart. By combining the signals from these aerials correctly, uplink performance is improved. This is because spatially separated aerials will receive uncorrelated signals from mobile terminals – that is to say that where the mobile is in a bad spot for one aerial, it may be in a better spot for the other. Hence by selecting the best aerial at any point in time, the effects of fading on the uplink are reduced. Space diversity aerials have to be separated by a large distance20 to work effectively. More modern sites make use of polarisation diversity. This relies on the fact that signals are scattered from obstructions which change their polarisation. The great advantage of this technique is that the aerials are smaller. However, the gains from this technique are often less than space diversity – especially in rural areas where there are less sources of signal scatter. Hence, although the sites may be slightly less obtrusive, slightly more may be needed. The idea of “radio barns” has been put forward recently in some of the more sensitive areas of England; BTAirwave has received planning permission for several such installations in the Yorkshire Dales where the concept was arrived at during discussions between the operators and the National Park Authority. A “radio barn” is either an existing barn or new barn that is used to house aerials and equipment for mobile radio systems. The aerials can either be external (slender collinear aerials mounted on the eaves of the barn) or might even be internal. It is possible that a well designed “barn” might be able to accommodate more than one operator Figure 5 Aerials located on a pylon although the examples so far have only been for a single operator. In towns and other built-up areas, there are many more opportunities to disguise installations. Some base stations have been designed for 2G networks that look like burglar alarm boxes and can be mounted relatively unobtrusively. Products such as this are very likely to become available for 3G networks in the next three or four years. In some areas it is possible to use pylons to accommodate aerials. Vodafone, has agreed with Scottish and Southern Energy to make use of their pylons and sites across the country21. Scottish and Southern Energy has 20 Several wavelength separation are necessary. A figure often used is 7 wavelength which equates to 2.3 metres at 900MHz and 1.2 metres at 1800MHz. 21 Source COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 17
  18. 18. 1000 sites and 10,000 pylons. The impact of the use of aerial installations on pylons has been quite limited. In April 2000, Vodafone stated that they have 160 installation on pylons (out of a total of well over 3000 installations). The use of pylons presents several problems. Installation and maintenance of the aerials is relatively easy if the pylons can be isolated from the grid for the duration of the work. However, often this is not possible and the work has to be done with the pylons “live”. Where this is necessary, only specially trained and equipped aerial riggers can be used. There are not many of these, and the whole exercise becomes very expensive and time-consuming. 8 NETWORK ROAMING With five 3G operators, each independently rolling out their networks, there will inevitably be more masts than would be necessary for any single operator to provide the same level of coverage. One possible way to reduce the overall number of masts is for operators to share not only the masts but the equipment as well. This would mean that mobile phone users might be on the Vodafone network in some areas and, for example, the Orange network in others. This is already possible on 2G networks and indeed overseas visitors to the UK will often have this facility. The operators appear to discourage this sort of use in the domestic market however, perhaps for competitive reasons. The operators claim that such an arrangement makes little difference to the number of masts22 because, as each mast can only handle a finite number of calls, the increased capacity would dictate that more mast were needed. However, in my opinion, this argument does not hold up for 3G systems. Because of the way that 3G systems work, each site has a much greater overall capacity to handle calls. Hence network roaming could make a valuable contribution to reducing the overall need for sites and for reducing the size of those sites. A single operator site can be much smaller than one that would accommodate two or more operators as the number of aerials is reduced which in turn means that a slimmer pole or tower could be used. 9 LANDSCAPE IMPACT This section summarises many of the findings of the report and seeks to answer the key questions that may be asked by those tasked with protecting the natural heritage of Scotland. 9.1 Where will new mast be located? New masts will be located in areas where people might reasonably expect to get good mobile phone coverage. These areas will be in towns and villages and along roads. The presence of 2G coverage does not mean that the same sites will be suitable for providing 3G coverage. 9.2 How many new masts are likely to be required and how many existing masts will need to be extended? 3G is likely to have a shorter range than 2G systems. Hence more masts will be necessary to give the same level of coverage than is currently available. Users of mobile phone 22 The Scottish Parliament Research Note RN 00/111 COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 18
  19. 19. systems are unlikely to accept reduced levels of coverage. I would suggest, based on figures given by the operators in England, that the total number of radio installations in Scotland will increases by a factor of three to four over the next five years. This demand will continue beyond five years and the systems will never be truly “complete”. Perhaps as many as a third of these installations will be greenfield masts of some sort. Any existing mast that has sufficient space at its base to accommodate 3G equipment, is likely to be extended to meet the needs of 3G coverage. 9.3 What will the new masts look like? In the short-term, new masts are unlikely to look different from the existing masts. Over time, new designs will be developed however. The industry has shown that it is conscious of the need to develop less intrusive structures. For example, monopoles have replaced lattice towers in many situations. 9.4 In what ways will it be possible to reduce their impact on the landscape? Masts can be painted to disguise them. This is effective where they are viewed against a back-drop, such as against coniferous trees. In some parts of Scotland masts have been painted with DPM (Disruptive Pattern Military) camouflage. Masts can, in part, be screened by trees. The aerials must remain above the tree tops for the system to work properly though. 9.5 Over what period will new mast applications come in? Planning is already underway for UMTS systems and applications being submitted at this time are, in some cases, already taking UMTS needs into account. The number of applications is unlikely to fall in the foreseeable futures (three to five years). 10 DIGITAL SCOTLAND TASK FORCE A Government backed initiative called the Digital Scotland Task Force has been looking at the development of information technology in Scotland23. One way in which access to digital information can be provided will be by use of 3G technology. Hence, the findings of the Task Force are important, inasmuch as that they are looking, in part, at the provision of access in rural areas. The summary of their report refers to the benefits of Digital Technology in promoting social inclusion and fostering communities. In the Scottish context, this is likely to include more remote rural communities. In such situations, radio technology may be the cheapest way of providing the sort of access that the Digital Scotland Task Force envisages as desirable. The only mobile operator to respond to the report was Orange. Orange’s response24 to this document makes the case that more restrictive planning legislation will delay the rollout of 3G services. 23 24 COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 19
  20. 20. 11 OTHER MOBILE SYSTEMS It is important to remember that mobile phone companies are not the only organisations who may need masts in the countryside. A major project is underway to install a new radio system for the Police25. The coverage requirements for this system are not driven by commercial imperatives but by the desire for Police Forces to have good mobile and hand- portable coverage everywhere. In England, this has meant that there have been planning applications for radio sites in environmentally sensitive areas where the mobile phone operators would not generally be expected to want to achieve coverage, examples of this include the Yorkshire Dales and the North York Moors National Park. I understand that BTAirwave is discussing over 50 sites within the Lake District National Park with the Planning Authority. The rural installations that I have seen plans of consist of base station equipment within existing buildings and two collinear aerials. Collinear aerials are thin tapering poles; they come in various lengths. BTAirwave has proposed 2.7 and 5.4 metres length aerials on the sites that I have examined in the Yorkshire Dales. The BTAirwave system makes use of a relatively low radio frequency (400 MHz) and so the achievable range from sites in open country is potentially quite large. Police radio systems in Scotland make use of just over 260 larger radio sites to give wide-area coverage and a further 280 to give coverage in cities, towns and villages. I would expect that the overall number of sites required will increase if the very high levels of geographical coverage that will be provided in England and Wales, are to be provided in Scotland. Another technology that may have a impact, albeit small, on the number of radio towers in rural areas is broadband wireless access. This is a method of using radio to provide fixed users (in homes or offices) with high speed data access for applications like internet use. Data rates of in excess of 2Mb/s have been proposed for this service. It will make use of very high radio frequencies (28,000 MHz and 40,000 MHz). Consequently the range that will be achievable from a site will be limited to perhaps no more than 1km. Given that it is only for fixed users, it will not be installed in the open countryside. Base stations will probably look very similar to 2G base stations. I do not expect this technology to have any significant impact on the overall numbers of masts and expect that access will only be provided in the larger towns and cities. 25 COMMISSIONED REPORT F00AA514  SCOTTISH NATURAL HERITAGE 2001 20