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GridCast
UK-Japan N+N October 2003
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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
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Broadcasting Grid Services
Each Broadcast site is defined
by its collection of available services
•Control services
•Content services
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A Virtualised Infrastructure
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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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