Cover Story
With networks under
increasing pressure, Test
and Monitoring is in the
frontline of preserving
consumer QoE and
shielding the provider
from avoidable Opex and
Capex. Euromedia spoke
to a range of players to
find out how they enable
their broadcaster and
service provider clients
to maintain market share
and protect revenue in
an age where the Cloud is
playing a growing role and
consumers are looking to
access their content across
a range of unmanaged
devices.
W
hat are the main challenges
in maintaining QoE as
networks transition video
distribution from DVB to IP? Do hybrid
networks
demand hybrid
monitoring
solutions?
Accenture
Digital Video:
By design, IP
networks are
a shared medium offering an assembly of
services with a number of touchpoints. This
changes the game in terms of bandwidth. With
DVB, the distribution was fixed unlike IP, so
there are significant differences when it comes
to testing. As operators are transitioning, most
networks today are hybrid so there is a need
for hybrid monitoring.
In order to systematically measure
performance and availability there are aspects
of a testing and monitoring environment that
need to be aware of the hybrid infrastructure
underneath. However, the consumer watching
the video is unaware of how the data is
travelling and they are purely concerned
about the experience. As such, there is a
fundamental need to do some testing through
the users’ eyes, taking into account the actual
end user QoE independently of the underlying
architecture.
Agama: Yes, definitely. Your monitoring
solution must be able to follow the service
delivery throughout the delivery chain,
regardless of the mix of technologies used. The
ability to understand end-to-end perspectives
and not just details in any single point of
the distribution is key. In addition, as more
and more operators provide secondary
services, for example an OTT companion
service complementing their cable offering,
understanding the experience delivered to
the customer across all services becomes ever
more important.
Bridge Technologies: Hybrid networks
have always existed, as has the need for
hybrid monitoring solutions – from that point
of view, nothing changes. As an industry, we
have long dealt with RF and DVB side-byside, for example. In our probes, ETSI TR
101 290 (commonly abbreviated to ETR290)
functionality is included as standard,
enabling analysis of Ethernet, ASI, COFDM,
QAM and DVB-S/S2 QPSK. Yes, metrics
for IP networks will be required – but not
only are these already in place, they are well
characterised and well understood in the
wider networking community. The challenge
is for engineers in the broadcast industry to
“The Cloud is the future,
and T&M should share
the same home as the
network.” – Bridge
Technologies
the legacy signals. This often results in very
complex monitoring installations with a mix
of systems from different vendors. As it is
hard to keep the complete operational team
trained on each system, a hybrid and unified
monitoring solution supporting everything
from video baseband to OTT, from SD to UHD
resolutions, is definitely desirable.
Tektronix: Yes, the challenges of monitoring
QoE for a DVB-based linear distribution
platform are different to monitoring an IP
delivery platform. With DVB, it is normal
to monitor at ingest (for video and audio
QoE issues such as blockiness and for any
associated QoS transport stream (TS) issues),
post multiplexer (it would also be typical to
monitor for compression artefacts introduced
by the in-plant encoders), in the core network
(for QoS issues such as dropped packets), and
post RF (for RF performance as well as TS QoS
issues).
In an ABR IP distribution network, in
addition to monitoring at ingest, it is vital
to monitor the output of the transcoders for
all profiles of all channels to ensure that the
Test and Monitor
“Your monitoring solution
must be able to follow
the service delivery
throughout the delivery
chain.” – Agama
14 EUROMEDIA
get equally up to speed.
Qligent: Stations transitioning to IP usually
face multiple problems that include fluctuating
jitter, reordering of packets, burst losses,
and insufficient bandwidth due to improper
network QoS settings, among many other
performance issues. The problems are
becoming fuzzy and soft; it might be slightly
too much jitter meeting bandwidth limitations,
causing short receiving buffer underrun, which
than disappears leaving some blocky or frozen
video. Traditional monitoring solutions are not
designed to register and troubleshoot those
soft problems, so there is a demand for IT-toTV monitoring solutions for hybrid networks
built on IP infrastructure.
Rohde & Schwarz: The ongoing
fragmentation of video distribution networks
increases the complexity of monitoring. Most
new video formats or distribution protocols
bring along new monitoring equipment,
while the old equipment remains to support
video quality is acceptable for all the available
bitrates. It is also important to check that
the content is encoded correctly in such a
way that it can be packaged correctly. This is
done by checking that the IDR frames occur
at the correct period for each profile on each
channel. The next challenge is to validate
that the delivery platform (origin or caching
server) is capable of delivering the content to
the consumer. This is achieved by subscribing
to the content and validating the manifest
files, checking that the bitrates are correct and
that each of the profiles is delivered with an
acceptable load time.
Torque Video Systems: It will also be a
case of the right tool for the right problem. So,
hybrid monitoring? Yes, of course, in the same
way we have always had ‘hybrid’ monitoring of
RF and Transport Stream.
But the transition to IP transport of content
does