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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
25
5 C
H C
OM
BIN
ER
BPF
8 C
H R
X M
UL
TIC
OU
PL
ER
4 C
H R
X
MU
LT
ICO
UP
LE
R
BPF
DPF
∆f=6.9 MHz
5 C
H C
OM
BIN
ER
5 C
H C
OM
BIN
ER
5 C
H C
OM
BIN
ER
BPF
BPF
BPF
DPF
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.
8. Q&A