Spectrum Allocation Global Standards and Strategies

1. Spectrum AllocationGlobal Standards and Strategies Peter Darling, Network Insight

2. Spectrum Allocation As you have already seen, Spectrum Allocation is a fascinating mix of • Science and technology • Politics (national and international) • Economics • Negotiation • Compromise(and sometimes people even look at end user requirements!) Spectrum is a resource, not an end in itself. It is valuable based on the use that can be made.

3. Not All Spectrum is the same Taking into account • The physical characteristics of different parts of the spectrum • The services and the technical standards developed to deliver those services optimised for different parts of the spectrum • International arrangements • International and national regulation

4. Physical Characteristics of Spectrum • Frequency is the main defining parameter for the radio spectrum. The spectrum is divided into bands by the ITU • Very Low Frequency (VLF) 3-30 kHz • Low Frequency (LF) 30-300 kHz • Medium Frequency (MF) 300-3000 kHz • High Frequency (HF) 3-30 MHz • Very High Frequency (VHF) 30-300 MHz • Ultra High Frequency (UHF) 300-3000 MHz • Super High Frequency (SHF) 3-30 GHz • Extremely High Frequency (EHF) 30-300 GHz

6. Propagation The uses of different parts of the spectrum are largely determined by their propagation characteristics. • VLF and LF travel long distances, following the earth’s curvature.

7. Propagation The uses of different parts of the spectrum are largely determined by their propagation characteristics. • Some bands (MF, HF) are reflected by layers in the ionosphere, bouncing back to earth thousands of kilometres from the transmission site

8. Propagation The uses of different parts of the spectrum are largely determined by their propagation characteristics. • Very short wavelengths (SHF, EHF) are similar to light, travelling only to the horizon, and blocked by “solid” objects.

9. Interference Marconi’s original radio transmissions were low power, but were able to be heard over trans-continental distances, because they only had to compete with natural radio noise. Multiple users of the same frequency increase noise, and cause mutual interference. Planning at international and national level is designed to maximise usage by minimising interference. (HF radio shows the alternative – the “cocktail party effect” where no-one can hear despite everyone shouting)

10. International Issues • Radio waves do not stop neatly at political borders • VLF, LF, MF and HF travel trans-continental distances • VHF and UHF (as well as higher frequencies) overlap national land borders • There is never enough spectrum to meet demand • The (incomplete) answer – International Radio Regulations, set at World Radio Conferences • National spectrum plans are based on, and consistent with, the International Regulations • A binding treaty, but where is the policeman?

11. Types of spectrum usage • Spectrum can be used for • Point-to-point services (for example, microwave communications links) • Point-to-multipoint services (for example, radio and TV broadcasting, mobile services)

12. Point-to-Point Links The one frequency can be reused multiple times in the same area with careful planning to minimise interference.

13. Point-to-Multipoint Links • The traditional means of providing wide area service has been to place a high-power transmitter on a high tower to cover the service area. (Sometimes the coverage is enhanced by using a near-by mountain)

14. Broad-area Coverage • Because of the likelihood of interference, a frequency cannot be reused until a considerable distance beyond the service area • (This is the basis for TV and radio band planning) • [New technology, such as Digital TV, tries to maximise re-use]

15. Mobile Services • The first mobile services used VHF or UHF frequencies and broad area coverage, to serve several thousand customers • Based on traditional spectrum allocation, there was not enough spectrum available for a mass-market service. • The solution was to use low-power transmitters and re-use frequencies in a cellular pattern. • The cost was very much greater complexity.

16. Cellular Concepts A user is connected to an available frequency in the cell covering their location

17. Cellular Concepts When the user travels outside the cell, the user’s equipment and the network switch the call to another frequency in a new cell

18. Cellular Concepts The same process continues as the user moves location

19. Cellular Concepts Frequencies can be reused multiple times in the one area

20. Cellular Concepts Cellular mobile • Allows much greater use of spectrum. If microcells are used, the potential number of users from a spectrum allocation could be in the millions rather than thousands • Trades increased infrastructure (cell sites, control equipment, etc) for maximum usage of spectrum • Requires a very complicated set of standards, very complex customer equipment and complex network equipment

21. Cellular Standards • A cellular handset is a powerful computer, a versatile radio transmitter, and a voice encoder/decoder • Large production runs, based on stable standards and using very-large-scale integration, reduce a cellular handset to a commodity item (indeed, a fashion statement) • This requires very large markets, in major, affluent nations (USA, Japan), regions (Europe), ideally global markets.

22. Cellular Standards – 1G • The first generation of cellular mobile systems were analogue, and generally were based on national standards with using different frequency allocations, for example • AMPS in the USA, using 800 MHz; • Nordic Mobile using 450 MHz • The standards for these systems mainly covered the air-interface and cellular control, not the supporting network • The structure of first generation mobile networks was strongly influenced by regulatory decisions e.g. US service areas

23. Cellular Standards – 2G • Second generation mobile networks • were designed to use spectrum more efficiently (support a larger number of users); • used digital transmission for low bit-rate voice and low-speed data • The European standard, GSM, used 900 MHz (and later 1800 MHz), with a fully specified network • USA standards were designed to co-exist with 1G in 800 MHz and also use 1900 MHz

24. Alternate Approaches • Europe combined resources (under CEPT and later ETSI) to produce a single standard, with encouragement at the European level for GSM as a European champion in other markets • The USA decided to let the market determine, with an initial eleven candidates reduced to three incompatible standards, all now in service • Some countries, particularly in the Asia-Pacific region, have allocated spectrum for both GSM and US standards

25. The Move to 3G • The ITU’s World Radio Conference in 1992 allocated 230 MHz of spectrum for worldwide use for what is now known as IMT-2000. • The obvious ITU aim was for a single air-interface. 2G developments made this very unlikely • The ITU’s attempt to standardise 3G has highlighted problems in their standards process. Much of the work has been done at the regional level. • IMT-2000 is now a family of air-interfaces. The extent of interworking is still not clear

26. The ITU’s Road to IMT-2000 Source: ITU Web Site

27. Australian Licences for Spectrum Access • As you have heard, Australian Legislation provides for three sorts of licences • Apparatus Licence • Best for point-to-point services with many users in a single area (e.g. microwave links) • Spectrum Licence • Best for point-to-multi-point services run by one user (e.g. mobile services) • Class Licence • Best for mass market, low power, “non interfering” applications (e.g. cordless telephones)

28. Spectrum Licence Considerations • A spectrum licence is issued for a fixed term (normally fifteen years) with no provision for automatic renewal (despite the comment in today’s Financial Review). • If traded the licence will only be valid for the remainder of the original term. • Investment in the last third of the licence term will often be uneconomic • In theory, a spectrum licence can be used for any purpose. In practice, the definition of the licence and its core conditions often will provide severe limits to multiple uses without major change to the licence • The 2GHz auction has been optimised for 3G mobile

29. Interference • How is interference to a spectrum right defined?

30. Interference • How is it enforced?

31. The Boundary Problem (1) • Even with land, there is a history of boundary disputes

32. The Boundary Problem (2) • Radio propagation does not follow simple surveying rules

33. The Boundary Problem (3)

34. Other Points to be Considered In deciding if an area of spectrum is suitable for spectrum licensing, the ACA must consider • International agreements for radio-communications, telecommunications and broadcasting • Conversion of multi-party systems • Applicability with new techniques such as spread spectrum, single frequency digital systems, etc • Linkage between broadcasting, telecommunications and radiocommunications regulation Spectrum licensing is a tool, not the tool!