Olympic Spectrum Planning Mostafa Relmy & Nigel Gunn London 2012 Olympic Games & Paralympics 28 th 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 LOCOG OFCOM Stakeholder Management and Comms. Requirement Capture. Prioritisation. Management of order portal. Spectrum Acquisition. Spectrum Planning. Licensing and formal authorisation. Licensing management.
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). Regulatory Islands 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.
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 plan Band (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 nonguaranteed 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. UHF-2 CH21 CH22 CH23 CH24 CH25 CH26 CH27 450 460 470 470 478 478 486 494 494 502 502 510 518 518 526 Talkback Duplex Mobile DTT DTT DTT DTT Talkback Simplex PMR Handheld Talkback Duplex Base Telemetry Talkback Duplex Mobile Talkback Simplex Talkback Duplex Base Talkback Simplex PMR Handheld Crystal Palace Crystal Palace Crystal Palace Crystal Palace Wireless Mics DTT Guard Band Guard Band BaU User
Talkback Example 2 Host Broadcaster at Stadium 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). TX D1 415.275 MHz Raw Channels TX D2 415.800 MHz TX D3 416.100 MHz TX D4 416.425 MHz TX D5 416.650 MHz 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 8 CH RX MULTICOUPLER 5 CH COMBINER BPF 415.275-416.650 f=1.375 MHz BPF 406.350-408.575 MHz COUPLER f=2.225 MHz 3 db loss DPF f=6.9 MHz TX 415.475 416.650 MHz RX 406.350 408.575 MHz Once Channels Found IM free Candidates Identified RX A8 407.750 MHz RX A9 408.050 MHz RX A10 408.575 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 4 CH RX 5 CH COMBINER 5 CH COMBINER MULTICOUPLER BPF 414.225-414.600 MHz f=0.375 MHz BPF 418.425-419.275 MHz f=0.85 MHz DPF 5.05 MHz TX 414.225-414.600 MHz RX 418.425-419.275 MHz Equipment Schematic Developed & agreed With Stakeholder 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 5 CH COMBINER BPF 409.350-409.850 MHz f=0.500 MHz 25
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 xx xx Cleared spectrum - no DTT transmissions in London Interleaved spectrum - DTT relays in London 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 Configuration Unavailable: DTT Cleared spectrum available for WM/IEM assignments Provisioned for LMR or talkback assignments Provisioned for IEM assignments within the IBC Provisioned for roaming or newsgathering users 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. Interleaved spectrum available for WM/IEM assignments in the IBC Allocated to W-CATV 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)
29 Assignment Strategies 2: Detailed configuration 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.
30 Assignment Strategies 3: Channel Protection and Assignment Criteria 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 conflicting 1, 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 3 rd 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.
31 Assignment Strategies 4: Assignment Process Studio (IBC) and Venues ENG 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). 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 1GHz PMR, 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 Name Demand forecast Actual Demand/assignments Difference % increase for Olympic Park in the Olympic Park 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