Edinburgh
Glasgow
DL
Belfast
Newcastle
Manchester
Oxford
Cardiff
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RL
London
Hinxton
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GridCast
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GridCast
Using the Grid in Broadcast
Infrastructures
Ron Perrott
Queen’s University,
Belfast
{r.perrott@qub.ac.uk}
BBC
GridCast
Belfast e-Science British Telecom
Centre
UK-Japan N+N October 2003
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The Grid Scenario: The BBC Nations
BBC NI, BBC Scotland and BBC Wales
• BBC Nations provide
customised services
in each nation
• Television
programmes are
distributed to BBC
Nations from BBC
Network (London)
using dedicated
leased ATM circuits.
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Grid Infrastructure
• Technical
– High-bandwidth
network
connections interconnect broadcast
locations.
– Network bandwidth
means geography is
less of an issue.
• Organisational
– Less centralised
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Overview
• To develop a baseline media grid to
support a broadcaster
–
–
–
–
Manage distributed collections of stored media
Prototype security and access mechanisms
Integrate processing and technical resources
Integrate with media standards and hardware
• To analyse Quality of Service issues
– Analyse remote content distribution infrastructures
– Analyse remote service provision
– To analyse reactivity, reliability and resilience issues
in a grid-based broadcast infrastructure
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Characteristics
• Stored media files are Gbytes and increasing
– 1 hour ~ 200 Gbytes; distributes 1 petabyte /year
• Management and distribution is significant
technically
• Metadata – location, timings, artists, storage
formats etc. is an integral part of broadcast
structure
• Content is a valuable commodity – access,
modification, copying must be controlled
• High levels of quality required
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High level view of the Infrastructure
Live Content
Transmitter
Cable, Satellite, internet
Broadcast
Output
Controller
Scotland Glasgow
Glasgow
BBC Scotland
BBC
Scotland
Schedule
Controller
Network
Schedule
BBC NI Belfast
BBC NI
Schedule
Live Content
Controller
Controller
BBC
Wales
Schedule
Broadcast
Output
BBC Network London
BBC Wales Cardiff
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Broadcasting Grid Services
Each Broadcast site is defined
by its collection of available services
BBC Northern
Ireland
BBC Scotland
•Control services
•Content services
Local Content
Controller
Live
Output
High
Bandwidth
IP Network
Live
Output
BBC Wales
Network Content
Controller
BBC Network
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A Virtualised Infrastructure
BBC Scotland
Sound Improvement
Image Rendering Cluster
BBC NI
Video Editing Suite
High Bandwidth
IP Network
Subtitling Engine
BBC Network
BBC Wales
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Scenario
• A Network Schedule is defined
– This schedule is the framework for Nation
schedules
• Network Schedules are distributed to BBC
Nations
– Usually via email
• BBC Nations formulate their schedule
• A Schedule is Broadcast
– By programming local network and content
control automation
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Model of Broadcast
• Automatic distribution of broadcast
schedules
– Management of schedule archives
– Automatic notification
• Content is copied from archives to local
content storage
– Content distribution defined by schedule
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Broadcast grid issues
• Business change
– A revised organisational model. Services and resources
– Each broadcast location gains control….no network schedule.
• Resilience
– Resource sharing and no single programme repository
– A BBC Nation can be anywhere!
• Reliability
– Use resources available in other BBC sites or from 3rd party suppliers
• Cost
– Better use of resources and less need for backup resources
– Less dependence on particular vendors or suppliers
• Customisation
– Schedule, local resources, local capabilities
• Interoperability
– Business model facilitates sharing with other broadcasters
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Broadcast Schedule Services
• Services to control the exchange and
modification of schedules
• Management of a distributed collections of
broadcast schedules
• Services to deliver stored media to local sites
• Services to plan transport of content between sites
• Services to manage collections of stored media
• Services to distributed content to facilitate
resilience
• Services to prepare content for broadcasting
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Progress Assessment
• Software Development
• Good experience of GT3
• Understanding of grid service model
• GT3 shifting sands has been good and bad
• Network Infrastructure
– Essential network infrastructure in place
• BBCNI---BeSC link in place
• Janet link complete soon
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Model: Grid Service Operation
• A schedule is registered with schedule (network)
management service
• Schedule is automatically distributed to (nation)
schedule management
– Local controller receives notification of schedule
availability
• Nation Controller registers (nation) schedule
with local schedule management
• Transport services develop a transport plan for
content movement
• Scheduled transport service moves content as
defined in transport plan
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Grid Service Operation
• Index services track grid sites and available services
• Discovery services locate available copies of broadcast
content
– Services for nearest, or least busy or …
• Discovery services identify best transport service to use
– Cross mounted file systems, 3rd party or ftp-type
transport.
• Transport services move work flows associated with
content
– The necessary operation(s) when content is delivered
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Grid Service Operation
• Transport planner incorporates a model of network load
– High cost at peak times and low cost at off-peak
– Other models in development
• Content archives are managed as replica archives
– Content locations are tracked….content can be withdrawn
• Content archives permit automatic replication
– For resilience and/or QoS
• Public and private services facilitate operation with
public and private networks
– Co-ordinating security policies with internal BBC policies
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