global standards and strategies

Spectrum Allocation March 2001 NI

Spectrum AllocationGlobal Standards and Strategies

Peter Darling,

Network Insight


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.


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


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


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.


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


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.


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)


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?


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)


Point-to-Point Links

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


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)


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]


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.


Cellular Concepts

A user is connected to an available frequency in the cell covering their location


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


Cellular Concepts

The same process continues as the user moves location


Cellular Concepts

Frequencies can be reused multiple times in the one area


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


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.


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


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


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


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


The ITU’s Road to IMT-2000

Source: ITU Web Site


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)


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


Interference

How is interference to a spectrum right defined?


Interference

How is it enforced?


The Boundary Problem (1)

Even with land, there is a history of boundary disputes



Radio propagation does not follow simple surveying rules


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!

global standards and strategies

Technology

radio spectrum

spectrum available

greater use of spectrum

maximum usage of spectrum

available frequency

high frequency uhf

high frequency vhf

cellular standards