Technical Blog
IPTV Instant Expert Part 1: IPTV Challenges
4th October 2011
In a climate where Triple and Quadruple play is being billed by some as the magic bullet for rescuing Service Providers from the depths of financial disaster, vendors and standards bodies are desperately seeking to push their ideas, visions and solutions in a fiercely competitive market.
Coupled with voice and broadband, delivering video is a key facet of the Triple Play concept. Triple play itself is nothing new; cable providers have been offering it for decades. However, it is only fairly recently that service providers without access to a HFC (Hybrid Fibre Coax) distribution network have had the opportunity to enter into this market. This is largely due to the video component of the Triple Play trinity; in essence, video has some very exacting demands on the network, from heavy bandwidth requirements to service aware intelligence needed at the network edge. So, if a service provider chooses to venture into the video distribution market, what are the challenges they can expect to face? Listed below is a brief synopsis of these challenges:
- Content Acquisition - there is little point in deploying a content distribution network if you don't have any content to push across it! The service provider needs to acquire the right content at the right cost to make sure the service is financially viable.
- Video Processing - it's unlikely that the service provider will be pushing raw content to the customer. Encoding, re-encoding, ad-insertion and Trick Play services are but three video processing considerations that the service provider will need to handle.
- Content Distribution - IP packet transport networks are used by service providers to deliver content, but this is not as simple as it sounds. Efficient content distribution in a broadcast environment means IP Multicasting, and this can add complexity.
- Upholding SLAs - when a customer signs up for a service, they expect a good "Quality of Experience". How does the service provider ensure this? Very tight monitoring and troubleshooting capabilities are required, adding more complexity to the distribution network.
- Being Creative - in a challenging market, you have to differentiate yourself from the competition. As such, providing a TV service that simply emulates a regular terrestrial broadcast is not enough; consumers want more for their money. Tackling the Customer Premises - from bandwidth bottlenecks to choosing the right STB (Set Top Box) vendor, service providers have a key challenge in this area.
IPTV Terminology
The term IPTV is used extensively across the industry to describe the high level concept of delivering video services across an IP transport network. As such, YouTube could be considered a form of IPTV but in the context of this article, the focus is on carrier grade TV services. That is, a feature rich, quality ensured service which at the very minimum, provides a similar grade of TV services to current satellite, cable and terrestrial offerings.
If we do take YouTube as an IPTV example, this would be described as an "Over the Top" video service. The concept of OTT video essentially involves using a service provider's IP network as the transport pipe ie. the video runs over the top of the service provider's network down to the customer premises. However, there is potentially a fundamental problem with OTT video - by virtue of the fact that the service is "over the top", the service provider has no awareness of the traffic, other than the fact that it is packet data of some description. Consequently, over the top video tends to be distributed in an inefficient manner (unicast instead of multicast) and QoS is essentially none existent. Unless of course the service provider and the content provider come to some agreement with regard to policy enforcement, but it is early days with regard to solutions such as this.
Consequently, carrier grade IPTV, often termed "Telco TV", demands the deployment of a dedicated, end to end architecture. This is often termed a "Content Delivery Network" and is set up in a way that ensures TV services can be delivered efficiently (multicast and unicast) and in a scalable fashion. Although it will be an IP based transport network, it will be managed with respect to QoS, unlike an Internet based TV service. It is also useful to bear in mind that it does not really matter if we are talking about fixed or mobile TV - both require dedicated content distribution networks.
In summary, you can loosely catagorize IPTV into 3 different areas:
- OTT (Over the Top) - whereby content is delivered over the top of the Internet service provicer's network and is typically sourced from the Internet.
- VoD (Video on Demand) - operating in a similar vain to OTT content, with the key difference being content is hosted by an IPTV service provider and delivered across a managed IP transport network. Video content is fed to the customer premises as unicast traffic and as such, the subscriber has full control over that content (play, pause, picture search - termed "Trick Play").
- Broadcast - this is the emulation of regular terrestrial broadcast services, delivering video content to the masses. For optimal delivery, content is multicasted and as such, subscribers have no Trick Play functionality, unless they use a PVR (Personal Video Recorder). Crucially, the key difference between IPTV broadcast and the more traditional broadcast techniques (Cable, DVB-T) is that customers only receive the content they ask for (typically one or two services). They do not receive all of the content all of the time.
Finally, it is important to understand that these 3 areas of IPTV are not mutually exclusive. A typical service provider will offer all 3 of these solutions in order provide a comprehensive service offering.
Next Month we will be exploring the CDN (Content Distribution Network)