IPTV/OTT guide¶
IPTV/OTT architecture¶
Over-the-top (OTT) is a means of providing television and film content over the internet at the request. It should be pointed out that it is not the internet provider, who provides the IPTV/OTT service and supervises it, unlike IPTV.
For example, capturing channels in Argentina, user himself can be in Germany and watch native channels, whereas his provider in Germany will not even know the list of provided channels.
This technology of TV signal transmission appeared about 10 years ago. At the moment, main providers and operators switch to IPTV/OTT due to its flexibility of convenience. However, the traditional IPTV model is still used, but mainly in the hotel and restaurant business.
One of IPTV/OTT's main features is that it provides the content to the viewer directly via data network, in contrast with the traditional IPTV that provides the content through a private network managed by the provider.
Classic IPTV/OTT architecture looks like following (see diagram 1.2):
Diagram 1.2. IPTV/OTT architecture
This is how the signal transmission is performed in IPTV/OTT:
The first stage is the same as in IPTV: headend captures TV signal from a source or several different sources. Further stages of signal transmission will differ. Through the IP protocol it is then delivered to the ingest server. The output of the ingest becomes the input for the transcoder (see Transcoding), where the video stream breaks into 3 or more formats (depending on the quality of the input signal): Full HD (1920×1080 pixels), HD (1280×720 pixels), SD (720x576 pixels). The next step is to send this stream to DVR. DVR is a storage or an archive, where video content is recorded and stored. Right from the DVR the signal is transported to the restreamer, where the stream is encrypted to protect it from third-party users.
It should be kept in mind that before the stream reaches the Internet, it is transmitted over the private network*.
Before playing video content on any device (smartphone, PC, TV), passing authentication and getting an access to it is required. The video content is protected by the Digital rights management (DRM) system, so to get the access the viewer needs a decryption key (URL). After passing all the decryption and authentication stages, the viewer can enjoy the content.
IPTV/OTT model provides the following services:
- Video on Demand (VOD). Individual delivery of video content to a subscriber or a viewer. It allows to watch any movie from the VoD server’s media library.
- Near Video on Demand (nVoD). A pay-per-view video service intended for multiple users subscribed to nVoD service. The content broadcasting schedule is compiled beforehand and subscribers can look at the schedule and watch content of their interest.
- Time-shifted TV. Lets subscribers view live broadcasts later so they can playback and resume at their convenience. Rewind option is also provided for TV programs.
- Transactional Video On Demand (TVoD). Selected TV channels are recorded so they can be viewed whenever desired, but for a limited period of time (for example, a week).
Netflix, Hulu and Disney + are the examples of IPTV/OTT.
Transition from traditional IPTV to IPTV/OTT¶
It should be emphasized that IPTV and IPTV/OTT are two types of content delivery to the end-user. IPTV/OTT is considered to be a part of IPTV or, as to say, its new version. Roughly speaking this transmission path can be represented as follows (see diagram 2.):
Diagram 2. IPTV/OTT data delivery
For more information about IPTV, see IPTV.
In IPTV model the stream is transmitted via a closed network, while in IPTV/OTT model it is transmitted via an open-access network. Hence, the first difference is access to the network. In the first case (IPTV) — closed, in the second (IPTV/OTT) — open. The content in IPTV is almost impossible to intercept, so the level of piracy there is much lower than in the case of IPTV/OTT. Since this is an open network, it is much easier to intercept the content.
Next is supervision of the signal transmission channel. In IPTV the owner of the network is the same as the internet provider. This operator manages the entire process, i.e. knows how many users there are and what content they consume. Thus, there is a feedback. In IPTV/OTT there is no supervision and control over the signal transmission channel, it is not clear who is watching and what. So there is no feedback.
In IPTV the content consumer interacts directly with the operator, while in IPTV/OTT the consumer interacts directly with the content producer.
The next difference is the quality of the transmitted material. In the IPTV model the stream is passed on almost continuously and it is quite stable, which guarantees excellent quality, whereas the signal transferred in IPTV/OTT model is unstable and affects the quality of the content. Here we should mention adaptive bitrate or ABR. The aim of IPTV and IPTV/OTT is to deliver the content without visible failures and delays for the viewer. Thus, given the fact that in the IPTV/OTT model the signal may be unstable (due to the speed and the quality of the internet connection), IPTV/OTT technology adjusts to the current network performance, so that the video and audio are delivered without pauses.
IPTV is characterized by georeferencing. The delivered content is specific for the place where it is distributed. IPTV/OTT provides all kinds of content to the viewer despite his location.
Considering the price, it is necessary to bear in mind the following: the cost of services and how it is formed. Let's start with the cost: IPTV is more expensive than IPTV/OTT. The cost of IPTV is usually formed by the cost of the following package: internet access + the service itself IPTV (i.e. connecting the STB and its maintenance). The cost of IPTV/OTT is equal to the cost of the internet access service. IPTV/OTT is cheaper than IPTV because it uses free content from public channels.
It should also be noted that new content release is quicker in IPTV/OTT than in IPTV.
To sum up, all the main points are tabulated (see table 1):
Table 1. IPTV and IPTV/OTT
Features | IPTV | IPTV/OTT |
---|---|---|
Transmitted content quality | + (high) |
+/- (depends on the network performance) |
Transmission channel supervision | + | - |
New content release | - | + |
Price | - | + |
Price components | internet (IPTV included)/internet + IPTV | internet + subscription |
Connection reliability | + | - |
Network access | - (closed) |
+ (open) |
In conclusion, classic architectures of IPTV and IPTV/OTT were reviewed. Nowadays IPTV and IPTV/OTT technologies have become less distinguishable and there is no clear line between the two. Although the main difference remains the same: the way of delivering the stream to the end-user (the last stage). IPTV model uses private network and IPTV/OTT — open network, i.e. internet.
Key features of the IPTV service implementation¶
Providers of the IPTV/OTT services face challenges that were not present 5 or 10 years ago. Let's have a look at them and define the aspects of the IPTV/OTT service implementation.
Capturing and transcoding¶
Satellite equipment is notoriously resistant to technology updates. Historically, satellite TV uses the MPEG-2 video and, so to speak, MPEG-2 audio codecs. The implementation of the H.264 codec to satellite broadcasting has been going for years and has not finished yet.
However, neither of those are supported by modern devices like iPhone and others. Moreover, the H.264 signal sent from satellite today cannot be processed by the iPhone due to the intra-refresh technology.
The MPEG-2 codec can be safely replaced with H.264 to achieve 3-4 times more bitrate efficiency and, consequently, traffic economy.
When HD signal is captured from the satellite and delivered to viewers over a non-local network, bandwidth limitations can prevent most users from consuming the content, so the signal should be encoded in different bitrates to enable adaptive quality switching.
Accordingly, video and audio coming from satellite needs to be transcoded to H.264/AAC, since iPhone doesn't support it. HD signal needs multi-bitrate conversion.
How the issues of capturing and transcoding are solved by Flussonic Media Server?
Flussonic Media Server can receive video over IP protocols not only from any IRD (Integrated Receiver-Decoder) devices or systems, but also directly from DVB-S and some other cards.
Flussonic Media Server can also decode video from UDP/HTTP, MPEG-TS, RTMP sources and encode it in multiple formats, that allows to play videos not only on set-top boxes, but on tablets and iPhones as well.
For more information, see Capturing and Transcoding)
From catch up (programs archive) to Interactive TV¶
As previously mentioned, historically, set-top boxes have a feature of recording just one TV channel's broadcast on demand. This approach doesn't work well, since people often forget to set the recording timer and then get frustrated: what is the reason to buy this expensive STB if it's no better than any old VCR?
The modern approach to providing access to the archive of TV shows is as follows: record the entire TV broadcast on the provider's side and give the viewer permission to manage the watching itself, namely: * watching the programs from the archive using the TV schedule or EPG (Electronic Program Guide), * rewind, * pause.
To provide the Interactive TV service, following steps should be : * implement archive on the provider's side * configure the players on the viewer's side.
Flussonic Media Server provides a wide functionality range to work with the archive, using DVR (Digital Video Recording) technology. Such as: user-friendly navigation and access to the archive, unlimited recording space, quick preview of individual thumbnails without a need for rewinding and etc.
For more information, see DVR
Linear TV broadcasting over Wi-Fi¶
The conventional way of multicast delivery has to deal with interference caused by Wi-Fi. HD signal (6-15 Mbit/s, compared to the old SD's 1-3 Mbit/s) and home Wi-Fi become a challenge for multicast: an expensive TV set shows the tell-tale green squares (pixels) instead of a crystal clear picture. It happens due to considerable packet loss on the way from the headend system to the set-top box.
Flussonic Media Server can function as a restreamer and perform multi-stream broadcasting, allowing to configure several signal sources and set up a fail- safe configuration.
For more information, see Cluster restreaming
Geo-distributed delivery¶
As the number of the IPTV service's subscribers increases, sooner or later the provider faces a challenging situation when delivering content from one central server becomes tricky or almost impossible.
Typical examples are: - provider opening a branch office in another city - a massive influx of new subscribers in another country as a result of an ad campaign.
In situations like these delivering video content from one central server becomes impractical, especially if there appear to be clusters of viewers located close to one another watching the same TV channel.
In order to save traffic, local retranslator servers are used: the channel's content is transmitted from the central repository to the local retranslator and then sent to the end-users located nearby.
This architecture may become far more complex with the increasing number of retranslators and channels. Since every channel must be set up manually, the administrator has to deal with a vast number of channels manually.
Also, geo-distributed video delivery sets its own limitations to archiving. It is not feasible to store the past content of all channels on each local server. In fact, the content of channels with narrow audience should be stored on one central server. And yet, every subscriber must be able to access this archive.
Taking geo-distributed video delivery into account, the question of access to the archive arises: does it make sense to store all recorded TV broadcasting channels on all servers? Of course not. It is easier to store rarely watched channels in central archive, but the access to this archive has to be provided for the viewer.
Flussonic Media Server offers a number of tools to solve those problems.
For more information, see DVR and Cluster restreaming
IPTV/OTT solution based on Flussonic Media Server¶
So, we have examined what IPTV/OTT is, its way of content delivery to viewers as well as the transition from IPTV to IPTV/OTT. Furthermore, we have also covered key features in this area. What part does Flussonic Media Server plays in this system and how can it be used to implement such technology?
Flussonic Media Server may be used in different stages of content delivery from capturing the signal from the satellite dish and/or TV tower by the headend to its playback by the end-user. Thus, this entire segment of the path can be implemented with Flussonic Media Server (see diagram 3.1).
Diagram 3.1. Flussonic Media Server in IPTV/OTT
In the case of IPTV/OTT, each individual component (headend, capture server, transcoder, DVR, and restrimer with DVR function) can be implemented with Flussonic. Our product allows you to deliver the content the most efficient way possible and with minimal loss of quality for viewer. So that you can focus on the content maker's and veiwer's experiences, while Flussonic will take care of the rest.
If you have any questions about implementing IPTV/OTT with Flussonic Media Server or you are willing to try out out product, please fill out the form to receive a free Flussonic Media Server trial key.
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