A Guide to Testing IPTV: Technologies and Challenges Part 4


Testing IPTV Networks

The Technology Lifecycle
The deployment of new technologies tends to follow a similar lifecycle that begins with early research, development and standardisation and ends with full deployment and service management.

The lifecycle diagram illustrated in Figure 5 shows a number of different technologies moving through the design and deployment stages to a point where the services are fully operational and managed. The lifecycle itself consists of four distinct rings and it is important to note that any one technology may go round each ring a number of times as the technology advances and matures (or in some cases fails). As the technology progresses, the type of customer (e.g. Network Equipment Manufacturers (NEM)) and location (e.g. telecom Carrier Lab) tends to change.

As the technologies progress through the lifecycle there is a transition in the quality expectations delivered (shown on the right of the diagram). In the early stages, QoS parameters are significant as early researchers strive to get the base technologies to work (either standalone or interoperating with other equipment) and deliver the service. As the technology matures, and many of the QoS issues are resolved, the focus switches to optimising the QoE delivered to the subscriber, since it is this that will provide a differentiator between service providers.

In order to move efficiently and cost effectively through each stage of the lifecycle the need for testing and the selection of the right test equipment is essential. As illustrated, the test tools required through the lifecycle go from those that provide deep diagnostic capabilities (particularly in the early stages) to those capable of monitoring national and even global networks. Consistency of measurement becomes an important factor throughout the process if operators are to develop and deploy services quickly.


IPTV Test Methodology
Figure 6 shows an IPTV network reduced to its simplest form. In effect these systems consist of two key subsystems: the video headend, where video is ingested and made ready for transmission, and the IP network which is used to distribute the video along with voice and data services.

Design requires in-depth tests for standards compliance and interoperability of video and network infrastructure equipment. Manufacturing requires consistent, rapid and repeatable functional test and results logging. Early deployment and trialling requires tools that provide rapid fault identification and diagnosis of IP, video and voice faults.

For full deployment and ongoing system management the emphasis will shift from monitoring and testing parts of the network to 24/7 real-time monitoring of the whole network (which could be global).

Today total IPTV subscriber numbers remain low, and although IPTV networks have been in operation for a while, most are still in their early stages. The key objective during this phase is for operators to “get it working”.

There are three key steps that need to occur during this phase of deployment:

1. Can the “IP Pathway” be reliably set up and torn down? A triple play network needs to assure availability of network resources and bandwidth to deliver video services; however, as video is bandwidth intensive, it is equally important to ensure that pathways that are no longer needed can be torn down successfully. This requires test equipment capable of establishing and testing the IP pathway and providing statistics on network jitter and packet loss.

2. Is the video correct at the source and destination? Once the IP pathway is established it is then essential that the video data pushed into and received from the pathway is correct. This requires the monitoring and analysis of the Transport Streams at the output of encoders and multiplexers at the Headend. At the receiver end, similar monitoring and analysis is required to ensure there has been no degradation of the video as it passes through the system.
When discussing IPTV, it is also important to consider the ingest and storage facilities within the Headend (these are often overlooked). Significant amounts of content to be distributed through the system are ingested over RF, and the integrity of these links is as important as any other in the chain. Being at the front end of the transmission chain, any errors introduced at this stage will be propagated throughout the system. Similarly, much of the video content is stored on servers prior to playout into the system; corruption of the stored video can also lead to the propagation of poor video through the system.

3. Is it a great subscriber experience? The final stage of the early deployment phase is to configure the system to deliver a high QoE. This requires the optimisation of Control Plane (IGMP and RTSP) parameters. Engineers are required to ensure that the requested channels are actually delivered and there is access to the Electronic Programme Guide, etc. This can be an iterative process and will have to be repeated as new services are added, and the system scales up to cater for larger numbers of subscribers.

Throughout these stages engineers require test equipment that brings the broadcast and telecom’s worlds together. The equipment is required to perform comprehensive QoS (e.g. network jitter, lost packets), and QoE (e.g. IGMP response, PCR jitter) measurements. To aid rapid fault isolation and diagnosis, the ability to see and correlate errors across the different layers of the network is essential. Not all errors that occur on the IP layer cause video errors. It is important to understand which do, and which do not.
Multi-layer Monitoring
In a monitoring system, each monitoring device can be considered a probe, monitoring quality at a particular point and layer in the distribution and transmission chain, however probing at only one layer can give a misleading picture of system health.

To be confident that their facilities are performing correctly and efficiently, operators will generally need to probe at multiple layers in their systems. This type of test methodology is known as “multi-layer” monitoring, and allows operators to gain a complete picture of system quality, and to quickly detect and isolate quality problems. Figure 7 shows a small sample of multi-layer test/monitoring points.

This type of multi-layer testing will become more important as IPTV deployments mature and move into the Operate and Manage phase of the lifecycle, and the test emphasis shifts from deep analysis and diagnostics to one of 24/7 monitoring.



****

Throughout this article series we have uncovered a myriad of technological challenges faced by IPTV engineers and operators, and have highlighted the importance of effective test and measurement for the successful deployment of IPTV networks. In the final part of this series, we will provide some examples of specific test and measurement technologies which can be used to help engineers and operators to successfully design, build, monitor and expand these networks.

Tags: iptv | tektronix | iss034 | iptv network | test and measurement | ip pathway | multi-layer monitoring | N/A
Contributing Author N/A

Article Copyright tv-bay limited. All trademarks recognised.
Reproduction of the content strictly prohibited without written consent.

Related Interviews
  • IPTV Digital Signage from VITEC at NAB 2017

    IPTV Digital Signage from VITEC at NAB 2017

  • Elemental Technologies news at IBC 2015

    Elemental Technologies news at IBC 2015

  • Thomson Video Networks at IBC 2014

    Thomson Video Networks at IBC 2014

  • BBright at IBC 2014

    BBright at IBC 2014

  • Viaccess-Orca at IBC 2014

    Viaccess-Orca at IBC 2014

  • Perception at NAB 2014

    Perception at NAB 2014

  • Elemental Technologies Software-Defined Video at NAB 2014

    Elemental Technologies Software-Defined Video at NAB 2014

  • Elemental Technologies HEVC solutions at NAB 2014

    Elemental Technologies HEVC solutions at NAB 2014

  • Elemental Technologies Multiscreen Solutions at NAB 2014

    Elemental Technologies Multiscreen Solutions at NAB 2014

  • Haivision on BroadcastShow LIVE at IBC 2013

    Haivision on BroadcastShow LIVE at IBC 2013

  • Albis Technologies celebrating ten years at IBC 2013

    Albis Technologies celebrating ten years at IBC 2013

  • Bridge Technologies QoE Monitoring with Mobile Videowall Display at IBC 2013

    Bridge Technologies QoE Monitoring with Mobile Videowall Display at IBC 2013

  • Visionary Solutions at NAB 2013

    Visionary Solutions at NAB 2013

  • Telestream Vantage v5 at NAB 2013

    Telestream Vantage v5 at NAB 2013

  • Visionary Solutions at NAB 2012

    Visionary Solutions at NAB 2012

  • Tektronix at IBC2011

    Tektronix at IBC2011

  • Tektronix at IBC 2016

    Tektronix at IBC 2016

  • Tektronix at IBC 2015

    Tektronix at IBC 2015

  • Tektronix at IBC 2014

    Tektronix at IBC 2014

  • Tektronix at IBC 2013

    Tektronix at IBC 2013

  • Phabrix RX2000 at NAB 2013

    Phabrix RX2000 at NAB 2013

  • Phabrix at BVE 2012

    Phabrix at BVE 2012

  • Sencore at IBC2011

    Sencore at IBC2011

  • Leader at IBC2011

    Leader at IBC2011

  • Murraypro at IBC2011

    Murraypro at IBC2011

  • Hamlet at IBC2011

    Hamlet at IBC2011

  • Phabrix at IBC2011

    Phabrix at IBC2011


Related Shows
  • Content you want, when you want it: Recommendation Engines

    Content you want, when you want it: Recommendation Engines


Articles
Using Wireless Transmission
Jeremy Benning Wireless acquisition is a staple of live sports, entertainment and reality shows where cable free capture permits shots not previously possible, for health and safety reasons, and gives the camera-operator greater artistic licence to roam. The same is increasingly true of narrative drama where cinematographers are keen to work handheld or Steadicam where that helps tell the story. Any equipment which frees their movement and time by being lighter, easier to use and reliable in performance is going to tick a lot of boxes.
Tags: iss134 | wireless | 4k | transmission | Jeremy Benning
Contributing Author Jeremy Benning Click to read or download PDF
An Epiphany Moment
Peter Savage 2 I had been negotiating the sale of my company and had reached the really hard end of the bargain. We were close to agreeing the final sum after a lot of too-much-give-and-not-enough-take negotiation. The solicitors were calling me, keen for a deal. It had come down to one sticking point and, in my hard ball “I am the Wolf of Wall Street” guise, I wasn’t going to let it go. It would make a value difference of 1.5% on the total outcome. Not much, you might think, but I had already nearly fallen out with the solicitors over their fees and I was giving my advisors an extremely hard time because the corporate adviser couldn’t see how I had already given more than an inch and the buyers were taking more than a mile. I was not going to let them win.
Tags: iss134 | azule | finance | Peter Savage 2
Contributing Author Peter Savage 2 Click to read or download PDF
Accelerated Workflows with eGPU
Mike Griggs From the UK’s National Trust to magazine publishers to manufacturers, digital content creator Mike Griggs has a wide and varied portfolio of clients for whom he creates 3D art, motion graphics and multimedia exhibits. A typical day might involve sampling birdsong near Virginia Woolf’s country estate or creating 3D animations for VR. To keep on top of these demands, Griggs wanted to take the full power of the GPU computing revolution on the road.
Tags: iss134 | sonnet | egpu | amd | post production | editing | Mike Griggs
Contributing Author Mike Griggs Click to read or download PDF
University and Mental Health
Rhiannon Jenkins University study and mental health has been in the media quite a bit over the last year, and I’m sure there are many people wondering what is going on? The issues are complex, and I suppose the focus of employability off the back of a degree course has raised the stress stakes for a lot of young people. I’m only qualified to talk about this from my perspective, and my story began when I joined a course not knowing I had a mental health condition.
Tags: iss134 | portsmouth uni | mental health | student | tvfutures | Rhiannon Jenkins
Contributing Author Rhiannon Jenkins Click to read or download PDF
Protecting the continuity of transmission
Lorna Garrett Your viewers love you. You consistently bring them their preferred channels 24/7. They’ve come to rely on you for their viewing pleasure. They never miss cheering on their beloved sports teams. They’re the envy of their friends as they watch live concerts of their favourite bands. They gather the family around and catch up on their must-see shows. They don’t have a bad word to say about you.
Tags: iss134 | garland | gpl | streaming | artel | disaster recovery | Lorna Garrett
Contributing Author Lorna Garrett Click to read or download PDF