Webcasting the G20 London Summit

Due to the lack of space surrounding ExCel, and partly as security measure, an SNG park for all OB facilities was established on waste ground on the other side of the river Thames with transmission services supplier Arqiva tasked with taking the SDI broadcast signal from ExCel into its vehicle for satellite uplink.

“Since ExCel is located adjacent to London City Airport there are limitations on where we could transmit from without interfering with flights,” says Arqiva’s ad-hoc sales manager Nigel Crow. “The biggest challenge lay in making sure we could set up a 100% resilient transmission hub from the field opposite, over 2km of fibre, and within civil aviation rules.”

Arqiva encoded the core feed into MPEG-2, modulated as a DVBS signal and transmitted on 9MHz of capacity on satellite Intelsat 12 @ 45°W, which is in geostationary orbit 23,000 miles above the equator. This was received back at Arqiva’s west London earth station and routed by fibre to BT Tower (the capital’s main distribution hub). From here any organisation could access the feed to enhance its own newscasts.

The signal was simultaneously received at FlyOnTheWall’s London HQ on the KU band frequency in the range of 11-12 GHz using broadcast standard 1.8m redundant receive dishes and Tandberg Receivers, then converted back to SDI and analogue video and audio.

For the live stream the audio and video feeds were balanced/enhanced and then distributed utilising a Kramer VM-10YCxl distribution amplifier. The feeds were captured using Videum Duo multi-channel capture cards and encoded as a Windows Media multi-bitrate live stream with a resolution of up to 400x224 pixels and bitrates up to 350 kilobits. The raw pool feed, which included ‘record’ signals to broadcasters warning of upcoming events, was smoothed out at FlyOnTheWall with additional vision mixing and graphics.

“It’s hard to predict audience volumes for this kind of event partly because there have been few previous examples to draw on but we were anticipating anywhere from 100 – 400,000 total and believed that a multi-rate feed capped at 350 kilobits was the right balance between quality of delivery and cost,” explains Jason Gleave, FlyOnTheWall’s CEO. “My chief concern is planning for the number of concurrent users so we had to be prepared for audiences of ranging from 50,000 to 250,000 or more.”

During the event, 200,000 streams were delivered globally, distributed using the Akamai EdgePlatform and presented via Windows Media and Silverlight players across www.londonsummit.gov.uk, www.number10.gov.uk and the other FCO country sites. Financial sites and national newspapers including leading Spanish publication El Mundo also took the webcast.

“Live events only happen once, so it’s critical to get it right,” says Tim Napoleon Akamai’s media and entertainment product line director. “It’s always extremely challenging to negotiate all the different backbones and ISPs for a project as global as this but that’s where Akamai excels. We have the edge delivery capacity to play in Asia-Pacific, North America and Europe whereas a CDN based out of Amsterdam with a purely European footprint would not work so effectively.”

Akamai builds on FlyOnTheWall’s five-year relationship with the CDN. “Certainly they are at the high end in terms of cost but they are also at the high end in terms of scalability and reliability,” notes Gleave. “In the live arena the only thing that’s important is getting it there and in this instance in distributing to as wide a public group as possible.”

A live webcast ran continuously from March 25 through to the afternoon of April 1 showing a 20-minute looped intro video, so that any viewer could check that the settings were enabled but also to allow the internal IT teams to ensure they were linking to the feed correctly.

The live coverage of the London Summit and associated activity began from the afternoon of April 1 tracking arrivals at airports and a special reception at Buckingham Palace. The schedule included an evening dinner at Number 10 Downing Street followed by the day-long conference at ExCel, much of which occurred behind closed doors. Press conferences were also covered by Feltech’s production.

A full ‘as live’ video-on-demand feed, compiled from audio/visual files captured to hard disk and digital tape, was updated continuously throughout and following the event. The VoD was cut into 10-minute ‘chapters’, encoded and uploaded with links provided to the client for incorporation on the main site, all country sites and a YouTube channel (www.youtube.com/londonsummit).

The FCO’s webcast wasn’t the only online video coverage of the event but it was the most comprehensive and intentionally the most impartial.

“My biggest challenge was to reassure both our partners upstream and our clients and their stakeholders that a webcast is a reliable part of the broadcast equation,” says Gleave. “In meetings for this or any project I often get asked ‘is this going to work?’ There’s a doubt about delivery, because unfortunately webcasting, in some quarters, has a bad reputation. That’s something we’ve carried for a while as an industry and there are still operators out there who are not delivering effectively for major events.

In the event the webcast proved flawless. “Although only a two-day event this was the most high profile we have achieved requiring considerable planning and coordination of multiple teams,” says Gleave. “The execution was robust on all levels.”