Many see IPTV as the “next big thing”. However, often both providers and users are unclear on one of the most basic tenants of IPTV quality functionality. The required bandwidth. So… just what is the minimum bandwidth which will give a “good” movie experience?
Actually, the question posed in those terms does not make a lot of sense.
As a matter of fact you must take into consideration the resolution in pixels of the video. Example, for a 16:9 broadcast the numbers are as follows:
The frame rate will be 24, to match the cameras used to film movies.
Then you should consider the codec in use to compress the image ….. and the bitrate you want to use.
Then you must move on to the audio part. Again you should use an appropriate codec and bitrate.
The TV set used plays an important role as well. For example, a 52 inch 16:9 LCD/plasma flat panel will show more artifacts than a 32 inch analogue 16:9 CRT TV.
Also the media could be a notebook or a mobile phone instead of a TV…
As stated earlier, this is a difficult question to answer and it all depends on your network design to be honest. Some providers have done HD quality streams at a constant 1Mbps and viewed it on a 50+ inch plasma …. which wow’d clients. One sample provider streamed a maximum 8 sessions on a demo from 8 different countries via MPLS ….. and has a multicast stream of about 2.5Mbps in HD.
MPLS helps ….. but you have to keep in mind that your network engineers should know multicasting extremely well, as well as QoS. Plus your equipment should not slack. MPLS means nothing if your network is engineered improperly. It also means nothing if your MPLS provider is clueless ….. and or peering with someone else who is not honoring packet coloring.
Generally speaking, there are quite a few variables as to how much bandwidth is required. On ITVN and Fios systems, 1.2Mbps seems to deliver 480 equivalent video and 5.1 audio. HD content usually requires at least 5 Mbps. The biggest issue normally seen is the consistent availability of bandwidth. If there are multiple users in a household or in the same area, the bandwidth fluctuations can cause buffering and degrade the picture quality. You may also see latency issues running ping tests or excessive pings.
To be able to truly predict (IPTV) Bandwidth Requirements on equipment selection and deployment it is useful to have a base starting point for simultaneous Multi – Play Service Delivery to the Digital Home.That makes sense as a Portofolio offering and not separating the streams vs. the whole package when predicting capacity.
The initial assumption would include 2 x Standard Definition (SD) and one High Definition (HD) TV streams ….. and let’s say three Voice over IP (VoIP) phones along with some streaming digital audio/music.
Using H.264 this B2C basic scenario suggests a minimum bandwidth requirement of 15 megabits (not 6 Mbps) .
This most probably will increase as HD content is becoming more ubiquitous and HD-capable displays are appearing more and more in every home.
The planning folks within your orginization have to bear in mind that there’ll be about three simultaneous HD streams – usually and nowadays the average number of streams per household. This means about 24 megabits give or take… without even considering the potential future applications (e.g. video telephony , personal broadcast).
With potential future applications ….. the bandwidth required to the Digital Home may go up to 50Mbps!
As for planning from an Operator’s point of view – understand that IPTV is a major investment critical to the success for your orginization. Not to be confused with WebTV which is a step before (full) IPTV.
With this in mind choose your Bandwidth Service Providers (BSP) carefully. There’s more to consider than just cost. A stable Tier 1 provider with a solid SLA (Service Level Agreement) and QoS (Quality of Service standard) is a MUST.
Try to work with your chosen BSP on Capacity Planning and Backhaul. Validate 4 major critical investments: 1 to 6 months , 6 months to 1 yr. , 1 yr. to 3 yrs. and 3 yrs. to 5 yrs. Try to use a MPLS backbone to the full extent that you can. (Note: you may get lot of potential applications on top of it later on as likely move to “Intelligent” BackHaul.)
Again ….. make sure you take into consideration the HD implications as mentioned above which will double your bandwidth requirements per household served.
You’ll incur significant investment if you plan to provide IPTV. It is not only about Fiber Optics to the Premises/Homes ….. but also the whole backhaul design plus the transport and enablement of such capacity. Thus my suggestion(s) to approach your BSP with some type of partnering arrangement (at least in the early stages) to share the Business Case in a fairly win-win proposition (keeping your initial costs lower).