Olympic Spectrum Planning

Mostafa Relmy & Nigel GunnLondon 2012 Olympic Games & Paralympics

28th November 2012

Content

1. Introduction/overview

2. Licensing strategy / Approach

3. Assignment criteria

4. Wireless Microphones and In Ear Monitors

5. Semi-coordinated Spectrum

6. Assignment stats and usage

7. Interference management

8. Q&A

1. INTRODUCTION/OVERVIEW

The role of Ofcom

UK Government guaranteed that

spectrum would be available for the

Games and would be provided free of

charge.

Ofcom is the agency responsible

for the frequency plan and licensing -

part of the UK Government’s

operational delivery function for the

Games.

Ofcom is responsible for keeping all

frequencies free of interference – so

we worked closely with LOCOG to

minimise any interference to

radiocomms at the Games.

Operational Model

•Spectrum Acquisition.

•Spectrum Planning.

•Licensing and formal

authorisation.

•Licensing management.

LOCOG OFCOM

•Stakeholder Management

and Comms .

•Requirement Capture.

•Prioritisation.

•Management of order

portal.

Stakeholder Management Model

Key Observations and learning

Adoption of a single contact route (or “shop”) for each stakeholder group.

Spectrum for guaranteed and non-guaranteed users was managed as a single resource.

Special consideration was given to the national broadcaster who holds Games rights –

requires maximum spectrum continuity between their “in venue” and “out of venue”

operations.

2. LICENSING STRATEGY /

APPROACH

Olympic Authorisation Regime - Overview

An authorisation regime specifically developed

for Olympic related activity.

New co-ordination arrangements for BaU

spectrum during period of Olympics.

Specifically tailored licence products for all

types of Olympic related spectrum use (open

only to LOCOG accredited applicants).

Licences provided free of charge by Ofcom.

No access to certain controlled areas (e.g.

venues) for equipment without appropriate

licence.

Creation of “Regulatory Islands” at key sites.

These will provide specific arrangements

including support for an Olympic equipment

regime and may include withdrawal of normal

licence exemption arrangements in Olympic

venues.

Proactive management of SNG and other radio

deployment.

Regulatory Islands

Why was it difficult?

London is among the most congested

RF environments in the world.

A three year process to acquire enough

spectrum, define usage rights, match

demand with supply and make the

assignments

For the Games we doubled the number

of technical assignments we usually make

in a year (14,000 in-venue, 13,000 out-of

venue).

In parallel we had to maintain the

wireless requirements for Games-critical

services (police, transport) and all the

other London users (such as West End

theatres).

© Simon Engel

Overview of Spectrum Planning and licensing process

Stage 1 - High Level Spectrum Plan

Ofcom developed, and widely consulted on, a Spectrum Plan for the London Games -

Final confirmation of the Plan in February 2012.

Demand studies.

Acquisition of spectrum from public sector.

Set out the frequency bands available to the Games.

Encouraged spectrum users to adapt their requirements to match the available

spectrum.

All bands conventionally used for Programme Making and Special Events (PMSE)

purposes were included in the plan.

Major components of the band planBand (MHz) Application Source

174-230 Additional PMR Channels available in Band III

385-430 Police and LOCOG PMR

networks

Additional frequencies borrowed from

Government and Military

430-500 Talkback Channels borrowed from Military, Radio

Amateurs and TV after switchover

494-862 Microphones and IEMs Available after TV switchover

494-862 OBS’s WCATV product Available after TV switchover

1452-1492 Fixed video links Borrowed from commercial user

2000 Wireless camera Borrowed from Military

2500-2690 Wireless cameras Available prior to 4G auction

2700-3100 Low-power wireless cameras Sharing with aviation

3400-4200 Airborne wireless cameras Borrowed from Military and commercial

users

5000, 6000 and 7000 Additional wireless camera

frequencies

Frequencies unused or borrowed from

Military

Stage 2 - Define Spectrum Resource

Defining the specific channels available to the Games at specific locations.

Defining the terms under which use could be permitted.

Understanding and defining the environment/sharing conditions under which Games use

would be operating.

Defining the risk profile of the spectrum.

Worked to acquire spectrum from donor organisation in response to specific requests.

Develop the formal sharing arrangements that underpinned access to key bands which

defined the specific channels/frequencies available for use and the technical conditions

under which use was permitted - “Spectrum Usage Right”.

Stage 3: Spectrum Configuration

Spectrum bands were distributed and reserved for particular uses and licence products,

and the definition of technical rules and policy about access to particular bands. Key

elements of our spectrum configuration for the Games include:

The reservation of certain bands for particular applications. For example, the band

450 - 470 MHz was reserved for production talkback due to high demand for this

service in this band.

Identifying where some demand could be met from shared spectrum (such as licence

exempt spectrum) or an OCOG provided resource (for example, the LOCOG Tetra

network or analogue trunked network) and the spectrum set aside to provision these

solutions.

The allocation of a proportion of the available resource for non-guaranteed

stakeholders. At this stage of the process we allocated certain channels for non-

guaranteed use (for example, a proportion of talkback channels).

The reservation of certain bands for key applications. For example, TV channel 21/24

was reserved for ceremony use to ensure that appropriate isolation was achieved

between this critical use and other broadcast applications.

Stage 3: Spectrum Configuration - Continued

Detailed configuration of microphone and IEM spectrum. Particularly within the Park, this

enabled efficient marshalling of sharing between different types of use and technologies

(for example microphones to IEM).

The configuration identified exactly what channels would be used for ENG

applications, for venue based use, and studio based use. It also worked to

accommodate popular configurations of specific equipment types such as telex.

Demand management strategies and equipment prohibitions.

Maximum ERP restriction: Wireless Cameras at 100mW, IEM and W MIC at 10/50

mW and Talkback/PMR at 5W.

Narrow Band Equipment (where possible): Talkback/PMR at 12.5 kHz and Wireless

Cameras at 10 MHz (8MHz occupied bandwidth).

Equipment Prohibitions: Family Radio service (primarily used in the USA) was

prohibited in the UK as this band is used by MoD.

An initial detailed demand planning analysis supported the above tasks, which aimed to

identify as early as possible bands under demand pressure. This facilitated stakeholder

communication to be undertaken and solutions to be developed.

Stage 4: Licensing Assignment Plan

This stage describes how spectrum was allocated to specific stakeholder requirements

in the form of spectrum licences.

Stakeholders requested spectrum - Demand capture through LOCOG “Ratecard”.

Assignment planning.

The provision of licences to stakeholders.

The basic strategy adopted for this phase was to plan the totality of demand as a single

exercise (i.e. to gather all spectrum requests and produce the best fit plan to meet this

demand).

In general only orders received by the deadline date were part of this initial assignment

plan and consequently prioritised over post-deadline orders.

Where there were competing demands for spectrum prioritisation decisions were

informed by the needs of the Games with advice on these matters provided by

LOCOG.

Stage 4: Licensing Assignment Plan - Assignment Criteria

Set of rules were developed validated and implemented to mitigate the risk of interference

between radio systems.

Geographical separation required between co- and adjacent channel usage.

Frequency separation between assignments within the same location/region.

Intermodulation planning: Analysis to reduce any potential risk from Intermodulation products

being transmitted and subsequently received.

The re-use criteria.

Developed using a combination of information gathering, consultancy projects, and using

propagation modelling tools.

The criteria were then further refined by undertaking site surveys and field trial measurements

(of the new and existing venues).

The intermodulation strategy.

Developed in accordance with industry best practice.

Refined in order to cater for the extreme demand and ensure critical systems were protected

adequately.

Only undertaken for equipment with constant transmits and for high-power services or audio

sensitive equipment (covering production talkback systems, wireless microphones and in-ear

monitors).

Where possible kept the channel reuse within the same organisation.

Stage 5: Games Time Authorisation

Developed a separate assignment process for orders received during Games time.

Orders processed on a first-come-first-serve basis and were subject to a radio

coordination assessment with other Games and other spectrum users. The primary

focus for this activity was the protection of the integrity of the existing plan.

Developed a contingency plan approach to support any request for an alternative

assignment in the event of an interference case.

Reserved a small number of cleared channels.

For video links where spare capacity was a premium in the 2 GHz band we

developed a shared and bookable approach to accommodate any late or alternative

assignment requests for both guaranteed and non-guaranteed stakeholders.

We recognised that these arrangements would not be adequate for all eventualities

and that any complex change would require the intervention and support of a

technical planning co-ordinator expert.

3. ASSIGNMENT CRITERIA

Indicative Re-use Criteria

*Consideration of high sites may result in more conservative re-use distances required.

• Building Losses were considered on case by case basis.

Intermodulation Strategies

* Where possible

The most complex events for RF - Road races

• About 38 channels of 10 MHz

•All in the 2 GHz band

•Equipment constraints

•Frequency separation requirement

•Receivers constraints

•This was in conjunction of other

events and non competition

requirement in central London

Wireless Cameras Road Races

Set-up

24

Talkback Example 1 – LOCOG Ceremonies – Special case

LOCOG Ceremonies undertook detailed planning within Spectrum configuration and

channel plan framework provided within the TV channels 21, 24 and 27.

28 Duplex “Matrixed” Pairs (26 x 12.5 kHz (inc. 2 contingency) + 2 x 25 kHz).

28 Simplex “Matrixed” Pairs (12.5 kHz).

29 Handheld (12.5 kHz).

All frequencies required to be 2 frequency third order intermodulation product free

(where possible – use of filtering).

The plan required

Reviewing the availability/usability of CH21/24 in London and undertook a field

measurement programme to ensure interference to/from DTT repeaters was not a

risk.

Protect the BaU use.

Spectrum was Isolated from Main Broadcasters assignments.

Any use in CH21, 24 and 27 need to be coordinated including rehearsals.

CH22 CH23 CH25 CH26

450 460 470 470 478 478 486 494 494 502 502 510 518 518 526

Talkback Duplex Mobile DTT DTT DTT DTT

DTT Guard Band

Guard Band

BaU User

Crystal Palace Crystal Palace Crystal Palace Crystal Palace

CH27

Wireless Mics

Talkback Simplex PMR HandheldTalkback Duplex Base Talkback SimplexTalkback Duplex Mobile Talkback Simplex

UHF-2 CH21 CH24

Talkback Duplex Base TelemetryPMR Handheld

Requirements for Olympic Stadium: 10 Duplex and 10 Simplex pairs (12.5 kHz).

User want to use same equipment used in Beijing – late requirement/confirmation.

Requirement for 2 and 3 frequency third order intermodulation product free (where possible

and where filtering can not provide the necessary isolation).

Raw

Channels

IM free

Candidates

Identified

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5.05 MHz

TX D1 415.275 MHz

TX D2 415.800 MHz

TX D3 416.100 MHz

TX D4 416.425 MHz

TX D5 416.650 MHz

COUPLER

3 dB loss

RX A1 406.350 MHz

RX A2 406.400 MHz

RX A3 406.7125 MHz

RX A4 406.750 MHz

RX A5 406.850 MHz

RX A6 406.975 MHz

RX A7 407.725 MHz

RX A8 407.750 MHz

RX A9 408.050 MHz

RX A10 408.575 MHz

415.275-416.650

∆f=1.375 MHz

406.350-408.575 MHz

∆f=2.225 MHz

TX B1 414.225 MHz

TX B2 414.325 MHz

TX B3 414.350 MHz

TX B4 414.400 MHz

TX B5 414.600 MHz

SIM G1 418.425 MHz

SIM G2 418.500 MHz

SIM G3 418.875 MHz

SIM G4 419.175 MHz

SIM G5 419.275 MHz

SIM E1 409.350 MHz

SIM E2 409.575 MHz

SIM E3 409.675 MHz

SIM E4 409.725 MHz

SIM E5 409.850 MHz

414.225-414.600 MHz

∆f=0.375 MHz

418.425-419.275 MHz

∆f=0.85 MHz

409.350-409.850 MHz

∆f=0.500 MHz

TX 415.475 – 416.650 MHz

RX 406.350 – 408.575 MHz

TX 414.225-414.600 MHz

RX 418.425-419.275 MHz

Once

Channels

Found

Equipment

Schematic

Developed

& agreed

With

Stakeholder

Talkback Example 2 – Host Broadcaster at Stadium

4. WIRELESS MICROPHONES

AND IN EAR MONITORS

27

Coordination with DTT

DTT transmissions in London during the Games

21 22 23 24 25 26 27 28 29 30

31 32 33 34 35 36 37 38 39 40

41 42 43 44 45 46 47 48 49 50

51 52 53 54 55 56 57 58 59 60

61 62 63 64 65 66 67 68 69

xx Cleared spectrum - no DTT transmissions in London

xx Interleaved spectrum - DTT relays in London

xx Not available - DTT

Digital switchover was completed in London in April 2012. Several TV channels were

vacated, and provided capacity to accommodate demand for UHF spectrum.

The main transmitter serving London is Crystal Palace, which transmits on six channels

(highlighted red above). No wireless microphone use was possible at any London

Olympic venue in these channels.

The shielding afforded by the IBC meant that co-channel operation with lower-power

DTT relays across London was possible.

28

Assignment Strategies – 1: Spectrum ConfigurationUnavailable:

DTT

Cleared

spectrum

available for

WM/IEM

assignments

Interleaved

spectrum

available for

WM/IEM

assignments

in the IBC

Provisioned for

roaming or

news-

gathering

users

Allocated to

W-CATV

Provisioned for

IEM

assignments

within the IBC

Provisioned for

LMR or

talkback

assignments

Following initial rounds of discussion

with the LOCOG, we proposed a

configuration for the spectrum

available to us.

W-CATV multiplexes were allocated

spectrum where demand for other

wireless services was relatively low.

Separate allocations were provided

for:

Studio and venue-based WM use

(green bands)

Studio and venue-based IEM use

(orange bands)

WM use by news-gathering (ENG)

crews (light blue bands)

Assignment Strategies – 2: Detailed configuration

29

From the UHF band 470 – 862MHz, the following was unavailable for WM and IEM

applications:

Spectrum unavailable due to DTT transmissions from Crystal Palace (6x8MHz

channels with 0.5MHz guard bands).

Spectrum unavailable due to W-CATV transmissions in the Olympic Park (4x7MHz

channels with 0.5MHz guard bands).

Spectrum used for LMR and talkback applications (2x8MHz channels – Channels 21

and 24).

Spectrum allocated to ENG crews (90MHz channelized into 450 x 200kHz

frequencies).

Spectrum available studio and venue-based WM and IEM applications: 200MHz approx.

This was channelized on a 25kHz resolution grid.

Assignment Strategies – 3: Channel Protection and

Assignment Criteria

30

Studio and Venues

Conventional wisdom: maximum occupancy of an 8MHz channel is for 8 “co-located”

200kHz assignments.

Evidence to support or disprove this appears conflicting1, but Ofcom chose to adopt

this rule with respect to studio-based WM/IEM planning for the Games.

No more than 8 assignments in a TV channel per studio.

Minimum spacing between WM assignments in the same studio was 350kHz;

for IEMs a more conservative 450kHz was adopted (primarily due to wider

occupied bandwidth of IEM systems, and a lower stakeholder appetite to

compromise high audio quality for assignment efficiency).

Intermodulation planning, generally taking into account 3rd order, 2 and 3

frequency IPs, was adopted for large RF requirements in individual studios.

Between studios, there was no reuse of frequencies within the IBC, but adjacent

200kHz channels were assigned where required to accommodate demand.

ENG

Usually no adjacent channel was assigned – however due to high demand in some

cases stakeholders and LOCOG agree to use adjacent channel.

Assignment Strategies – 4: Assignment Process

31

Studio (IBC) and Venues

Prioritisation given to:

Large requirements that would require significant intermod planning, e.g. 1

broadcaster had 16 WM and 8 IEM frequencies in addition to in-band stage

intercom systems).

Users with equipment that utilised a small number of presets.

Other requirements could be moulded around these.

Spectrum separation between WM and IEMs afforded by our band configuration

generally allowed us to plan WM and IEM sets for the same user exclusive of each

other (i.e. Intermod products considered independently).

ENG

LOCOG consulted OBS on prioritisation and number of channels to be allocated to

a stakeholder.

32

Conclusions

Our priority was to create a robust plan which assumed a reasonable, but not

exceptional, standard of radio deployment. In this respect, the plan was a success – no

interference cases were reported as a result of over-aggressive assignments.

It is possible that greater packing density could have been achieved within studios had

we been able to access detailed deployment plans early in the planning process.

Spectrum partitioning of major services worked well. Since IEM transmitters are often

sited close to WM receivers, it is important that the close physical separation is

mitigated by spectrum partitioning.

It is difficult to assess actual spectrum utilisation due to the likely “padding” of

requirements to include stakeholder-specific contingency. However, across the IBC as a

whole, we made a number of assignments in a congested environment.

Need to capture business need rather than RF requirements. As an example is the

requirement for a Broadcast need or ENG.

5. SEMI COORDINATED

SPECTRUM

Semi coordinated Spectrum – Approach

Users required access to spectrum that could not be fully coordinated – SOAP: Sub

Optimal Assignment Process.

Shared spectrum.

Light licensed.

Licence exempt devices.

A known risk of interference in the band.

Ofcom and LOCOG agreed that SOAP should not be suitable for Games Critical

Applications and the process was:

The applicants were briefed on the condition of the spectrum, possible alternatives,

and the implications for interference resolution of operating a sub-optimal

assignment.

Ofcom/LOCOG spectrum wrote directly to the applicant setting out the risks

associated with the spectrum and the resulting implications for interference

resolution.

Interference to any system authorised on this basis was not subject to agreed

incident resolution targets for the Games and were dealt with on a best endeavours

basis.

Licence/Authorisation was issued with a SOAP clause.

Semi coordinated Spectrum – use

Timing/scoring systems.

PMR applications.

Light licence products.

PMR/DMR 446.

Wireless Microphones.

Fixed and Video links.

Telemetry/camera control.

WIFI – this was coordinated and managed by LOCOG.

Timing/scoring systems

Games critical applications. These were either developed for the purpose of the Olympics or were

based on existing systems commonly in use for each particular sport.

There were often different sub-contractors used by the timing provider Omega for different sports.

Many of the systems were utilising licence exempt spectrum - often harmonised either worldwide or

across large geographical regions. Re-used for events held across other countries.

Over 2 years prior to the Games, Ofcom/LOCOG/Stakeholders worked together to understand the

requirements, discussing the risk of timing/scoring systems proposed within SOAP and finalising the

assignments plan. Some example were:

A telemetry link holding all the key sailing information was changed from UHF frequencies (shared

with amateur – max 400W ERP).

Ofcom proposed frequencies in two other frequency bands using clear UHF borrowed from

other third parties.

Monitored the quality of the spectrum.

Stakeholder agree to use the alternative frequency.

We offered some 915-921MHz spectrum, as an alternative for scoring system based on Zigbee

protocols in the 2.4GHz wifi band. However stakeholder could not accept the alternative frequency

and was willing to accept the risk. Also as a precaution, LOCOG limited the use of one of the wifi

carriers in their venue to give additional protection to this scoring system.

Letters were sent advising that a number of systems were within SOAP.

6. ASSIGNMENT STATS AND

USAGE

Licences issued and assignments made to Games users

Spectrum Utilisation/Usage – Above 1GHz

Spectrum Utilisation/Usage – Above 1GHz – Video Link

Spectrum Utilisation/Usage – below 1GHzPMR, Talkback, ADS, Mass Cast and Telemetry

Spectrum Utilisation/Usage – below 1GHz

PMR, Talkback, ADS, Mass Cast and Telemetry

Games time use of DTT Spectrum within LONDON

Games time use of DTT Spectrum within the Olympic Park

Games time use of DTT Spectrum within the IBC

Actual demand was significantly greater than estimated

Product NameDemand forecast

for Olympic Park

Actual Demand/assignments

in the Olympic ParkDifference % increase

Land Mobile Radio (PMR) 845 970 -125 14.80%

Talkback 410 772 -362 88.30%

In Ear Monitor 100 343 -243 243.00%

Wireless Microphones 350 1564 -1214 346.80%

Wireless Camera 75 185 -110 147%

Telemetry and Telecommand 50 84 -34 68%

Wireless CATV 1 4 -3 300%

Estimation made by LOCOG and Ofcom based on stakeholder feedback early 2011

Actual demand and user behaviour Summary

The key areas of excess demand were:

Talkback and telemetry (esp 450-470 MHz).

Wireless cameras at 2 GHz.

Wireless mics for roaming ENG crews (600-800 MHz).

PMR (380-420 MHz).

Strategies for dealing with excess demand:

Encouraging users to alternative bands (e.g. 7GHz for wireless cameras).

Use of licence-exempt or sub-optimal spectrum (e.g. PMR 446 – which was heavily

loaded).

Shared/bookable solutions (e.g. ENG wireless mics managed from the Spectrum Help

Desk).

Rationing and prioritising.

Users tend to ask for more than they need.

Example: major broadcaster requested 128 duplex pairs for ENG and agreed to use 23.

Some users (especially NOCs) were late in providing requirements and have limited technical

capability.

Need to reserve some frequencies for late applications.

Hire solutions available in case we can’t meet their needs when they arrive.

We continued to support normal business

Volumetric Number

Applications booked within OLY Zones 1443

Frequencies booked within OLY Zones 13,237 (10% increase from 2011)

Audio Link and ADS frequencies booked 120

Data Channels booked 63

Wireless Camera Channels booked 363

Talkback booked 3754

Wireless Mic/IEMs booked 7882

Protected bookings via transfer list (annuals) 1975

Frequencies requiring clearance with Ofcom 2401 (18% of overall)

• Assignments made by JFMG and co-ordinated with Ofcom

• Torch Relay is in addition to these numbers – some 2,500 assignments

7. INTERFERENCE

MANAGEMENT

Interference Management and the use of field

engineering resources

Careful planning and licensing minimises the number of problems for spectrum users.

Some field engineering resources were still required. Our approach was:

Aim to minimise the number of interference incidents, using:

Stakeholder communications including site engineering best practice.

Testing and tagging of portable equipment.

Commissioning of fixed equipment in advance of Games time.

Detailed technical understanding of the characteristics of the spectrum.

Use technology to make the engineers on the ground as efficient as possible:

a network of sensors to locate interference.

handheld spectrum analysers to pinpoint sources of interference.

Deployment

Ofcom deployed 145 field engineering colleagues.

Eight venue clusters of 4 engineers: venues staffed two hours before events start to

one hour after.

Team of 4 in the TOC 24x7 (manager, engineer, 2 x case administrators).

Interference cases

None of the “interference cases” raised were as a result of

bad frequency planning.

Some cases were not followed/investigated, so in some

cases we offered an alternative frequency or allowed a

higher power.

The following are examples of interference cases raised:

The mobile phone base station deployed adjacent to

the broadcaster satellite link. The day of the Opening

Ceremony.

Interference from USA DECT to the Mobile base

station.

Interference to a video down link.

Inside and outside the venues

Licensing and interference management covered both inside and outside venues:

Many customers need authorisation inside and outside venues (e.g. wireless

microphones for news-gathering crews).

Interference from outside may impact in venues and vice versa.

Accreditation issues can slow down engineers moving between inside and outside.

Associated cultural events and BAU activities outside venues must be protected.

We implemented a “One stop shop” for customers:

Olympic Family apply through the LOCOG Portal for authorisations inside and outside

venues.

Non-rights holders apply through the normal Ofcom process for their out-of-venue

authorisations.

Most users needed different frequencies at different locations (e.g. because of local

TV transmitters).

A bookable solution for wireless cameras at 2 GHz was offered (but not much used).

Interference management needed a team of field engineers to handle outside-venue

issues.

The finish line.....not quite

53

8. Q&A