In Broadcast - March 2015 - 53

53

www.inbroadcast.com | Vol: 5 - Issue 3 | March 2015

InMedia

Contribution Infrastructures
Are Being Transformed By IP
Nevion CEO Geir Bryn-Jensen discusses how
IP connectivity has the power to transform
broadcast contribution...

C

ontribution has always been a
challenge for broadcasters. In the
early days the majority of engineering
efforts in a remote broadcast went
toward creating wireless links back to
the studio.
While the introduction of satellites
solved some of these technical issues,
they led to additional vehicles and
equipment being needed on location.
Permanent solutions for video and
audio circuits proved limiting as the
nature of broadcasting changed - and
continues to do so.
As broadcasters were deciding how
best to solve this issue, telcos were
installing high-capacity IP networks.
While this appeared to be the perfect
solution to these technical issues,
scepticism remained around using IP
for mission-critical contribution.
The best-effort principle that sat
behind IP was in direct contrast to
the
fail-safe,
immediate-delivery
expectations of broadcasters. If
broadcasters can't deliver a new
picture every 40 milliseconds without
fail, everyone notices - and that's not
good for business.
Far-reaching bandwidth is now
readily available and at an attractive
price. This has led to IP contribution
being a much more viable option.
Furthermore, companies like Nevion
are providing technology which brings
a broadcast-level of reliability to IP,
manages the network and enables
simple set-up and management of adhoc circuits and deﬁned networks over
IP.

IP connectivity can transform the way
broadcasters work

IP Management Layer
It requires extensive knowledge
to properly build and manage an IP
contribution network. This makes IPbased transport's inherent ﬂexibility
its primary challenge. Technological
overlays can overcome the difﬁculties
posed by IP-based media transport
and bring simplicity to something
inherently complex.
We're in the midst of convergence
between the broadcast and IT
industries for real-time broadcast
applications. We can now maximise
the efﬁciencies of IP and off-the-shelf
components to build highly-effective
IP-based broadcast networks. An
overarching media management layer
is the most important element that
ties this all together. Software Deﬁned
Networking's philosophy of centralised
control of all parts of a network is
the key ingredient that anchors any
IP-based media network. With this,
all systems are constantly monitored
and controlled to ensure end-to-end
managed services. Network users can
identify faults before they happen and
quickly resolve them if they do.
Protecting IP-Transported Media
Delivering content quickly and
without disruption means it has to
be protected. Protection against
random and short burst packet losses
comes in the form of Forward Error
Correction (FEC). This is deﬁned by
SMPTE as ST2022-1 for transport
and J2K streams and ST2022-5
for uncompressed SDI. Additional
technologies should be
deployed in tandem with
FEC for more severe faults.
This will help avoid outages
that would impact the
streams.
Mechanisms like Nevion's
Streaming
Intelligent
Packet Switching (SIPS)
can
increase
network
performance and increase
resiliency.
Codecs & Encapsulation
In the digital age, there

Cost-effective IP contribution is a viable option

is no single deﬁnition of a "broadcast
quality" contribution link and the
availability of bandwidth is usually
the determining factor. At the most
prestigious events, uncompressed HD
is expected and requires the strongest
signal. Nevion can provide this as well
as any other signal strengths.
While dark ﬁbre can be used to
transport multiple uncompressed
HD feeds - it isn't always available.
Because of IP's versatility, it can
carry uncompressed HD as well as
varying degrees of compression.
This means IP networks are ideally
suited to occasional-use or temporary
connections.
The choice of codec will depend upon
bandwidth availability and the number
of signals to be transported. JPEG2000
is often the best choice for very high
quality media. If the contribution
circuit comes under pressure, a slight
softening of the image would occur.
H.264/AVC compression provides
the right balance between quality,
bitrate and latency. High quality H.264
encoders/decoders
are
available
including the Nevion NX4600 media
gateway.
Service Provisioning & SLAs
The IP network provides anywhereto-anywhere
connectivity.
While
setting up connections is theoretically
simple, technical expertise has
historically been needed to navigate
telco networks. Broadcast engineers
should be able to establish circuits
themselves to use IP effectively. A
simple, open interface that allows
routings to be set up easily must be
provided.
This can be achieved with Nevion's
VideoIPath management platform.
While edge hardware devices provide
encoding/decoding
and
network

interfacing, VideoIPath provides a
network abstraction layer for the
engineer to establish and monitor
services without having to consider
detailed conﬁguration settings in each
network element.
The system is also capable of
performing network provisioning and
using the optimal media transport path
through the network infrastructure
from source to destination(s). The
path-ﬁnding algorithm is technology
agnostic, allowing the system to
support path ﬁnding at different layers
in the network stack, at the baseband,
Ethernet or MPLS layers.
The level of automation and easy
provisioning, inventory management
and system monitoring enables nonspecialists to manage their media
transport services on their own,
removing traditional user/supplier
boundaries.
While broadcasters can trust IP
circuits and control their set-up and
management, appropriate Service
Level Agreements (SLAs) should be
agreed upon. SLAs should guarantee
bandwidth
when
needed
and
broadcasters need to understand the
nature of the telco's business. A telco
will ﬁnd trafﬁc from elsewhere when a
network's not being used.
When
properly
implemented
and managed, IP connectivity can
transform the way broadcasters work.
Highly sophisticated two-way links
can be established to and from any
location. The combination of powerful
hardware from market leaders like
Nevion and good SLAs can deliver
networks that provide low latency and
high resilience. These circuits are cost
effective, quick to set up and more
practical than previous options. IP
seems certain to become the dominant
connection for contribution circuits.
http://www.inbroadcast.com http://nevion.com/
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