IPTV 2.0 Is Coming – It’s Time to Get Prepared! (Part 1)
At TV Connect 2014, Harmonic predicted the arrival of IPTV 2.0, and it’s becoming true. During this two-part series, I’m going to take you on an IPTV 2.0 journey. The first part will focus on defining IPTV and the typical challenges encountered for IPTV 1.0.
So what is IPTV? IPTV is a switched IP technology that only sends content to the home that is requested. As a consequence, IPTV is bounded by the number of channels that can be consumed at the same time inside the home, compared with a broadcast mechanism that is constrained by the number of channels available on the transmission link.
IPTV 1.0 consists of an IP multicast infrastructure that delivers multiple channels to the home to serve various TVs and PVR recording. For this discussion, let’s assume video content is being transmitted via MPEG-4 AVC, encoded in HD at 5 Mbps and in SD at 2 Mbps. HEVC could change the economics, but due to the limited installed base of HEVC STBs and difficulties in HEVC licensing, this discussion will focus on AVC for IPTV, with HEVC being an option for OTT.
The number of simultaneous channels received over IPTV is mostly dictated by the networking technology deployed. For example, ADSL can receive one SD channel on a 5 Mbps link and VDLS2+ can receive up to three HD and two SD at 25 Mbps.
The first hurdle operators typically encounter with IPTV 1.0 is PVR recording, where a minimum of three “virtual tuners” are needed to compete with cable and satellite offerings, which sometimes support additional tuners. This scenario does not incur any extra transmission cost, as all channels are transmitted. However, it requires three channels to be sent to the home under the assumption that two HD and one SD channels are being recorded at 12 Mbps.
Many homes today have multiple TV sets. When a second or third TV is involved, it requires carrying additional channels to the home. To serve two HD and one SD screens, an operator needs 7Mbps on bandwidth for one SD and one HD channel, in addition to 12 Mbps for the PVR channels. Adding 5 Mbps internet access on top of this, you end up with 24 Mbps. Today AT&T offers an IPTV package with a minimum eligibility of 25 Mbps for three HD and two SD sets. This plan was designed back in the 2000s, and it reflects the needs back then.
Of course, access technology has evolved. Lately, pair bonding, vectored technology and the G.fast standard have been implemented to increase the initially deployed access bandwidth by a factor of four. In addition, new codecs such as HEVC have arrived to reduce the bandwidth by up to 50 percent. Does this solve IPTV operators’ issues?
It is not as simple as that. Upgrading an entire network is very expensive, and today the focus for telcos is improving the broadband side of the business. Any additional bandwidth first goes to traditional internet services, which is by far the most profitable part of the business compared with video offerings. Moreover, not all devices support HEVC, and the patent situation isn’t fully settled. Although HEVC may someday resolve bandwidth issues, it will take time.
Fast-forward in 2016. Today, we have much higher broadband speed expectations than we did when IPTV first surfaced. The U.S. FCC mandates that broadband speeds should be at a minimum of 25 Mbps. In Europe, some countries will start enforcing broadband speeds of 20 Mbps in 2020. In essence, broadband is going to use up a lot of the bits coming to the home, especially for delivery of OTT service such as Netflix. For UHD services, 15 Mbps is recommended. Adding HDR to the equation requires 25 Mbps.
We also need to take into account the increasing consumption of TV on connected devices, such as smartphones, tablets, PCs, media players like Roku, and connected TVs. To serve those devices, adaptive bitrate streaming (i.e., Apple HLS, Microsoft Smooth Streaming, Adobe HDS, MPEG-DASH) is being used. The second part of this blog series will focus on ABR streaming and its benefits for the IPTV world.
– Thierry Fautier, Vice President of Video Strategy at Harmonic and President of the Ultra HD Forum