Internet Protocol Television (IPTV) has become the most common name for subscription distribution systems for television or video signals using Broadband connections over the IP protocol. It is often supplied together with the Internet connection service, provided by a broadband operator on the same infrastructure but with a reserved bandwidth.
Definition of IPTV
IPTV is not a protocol in itself. IPTV or Television on the IP protocol, has been developed based on video-streaming]. This technology will evolve in the near future current television, although this requires much faster networks than the current ones, in order to guarantee quality of service.
Unlike the current situation, the provider will not broadcast its content waiting for the viewer to connect, but the content will arrive only when the client requests it. The key is in the personalization of the content for each client individually. This allows the development of Pay per view or pay per event or video on demand. The user will have a receiver device connected to his computer or to his television and through a guide he will be able to select the contents that he wishes to view or download to store in the receiver and thus be able to view them as many times as he wishes.
The programming that the companies will offer is based on both traditional channels and more specific channels on a certain topic, so that the customer can select the ones they like. In addition, sports events or premiere movies will be broadcast under pay per view, that is, paying an additional amount to the service fee to be able to see them. It is about buying the content you want to see to make a television on demand. Thanks to its characteristics, IPTV will allow you to store the contents to watch them as many times as you want, but it will also allow you to pause, advance, go back, etc. as if it were a videotape or DVD.
In the advertising sector, since it is information that arrives through the internet, they could personalize their ads, so that the user with just one click can access the purchase of their products.
Additionally, it is expected within the services, search methods and restrictions, that is, parents can block certain content on IPTV that can only be shown after verification of a parental key, likewise it can search for example all programs, series or movies in which this or that author acts or that they are of this or that gender.
For IPTV to be fully developed, it is necessary to increase the speed of current connections. We can differentiate two types of channel: standard definition SDTV or high definition HDTV. For a channel of the first type it would be necessary to have a connection of 1.5 Mbps and for a channel of the second type 8 Mbps. If we have several different channels simultaneously (by having several television receivers for example) we will need more bandwidth. To this bandwidth must be added that necessary for the internet connection. We are talking about 4.5 Mbps for three SDTV channels or 11 Mbps for one HDTV and two SDTV channels. These calculations are using MPEG-4 for video compression / encoding.
IPTV services like Nitro IPTV (https://iptvsubscription.site/nitro-iptv/) and USA Network (https://www.usanetwork.com/) needs technical values to be able to provide its content without problems, the values are the following:
Bandwidth: depending on the number of decoders, the speed of the internet or IP telephony (VoIP, must be higher in each case, the most common are: 4 Mbps, 7 Mbps, 8 Mbps, 10 Mbps, 12 Mbps, 14 Mbps, 16 Mbps and 18 Mbps). The fact that the bandwidth is higher, makes the ADSL line more sensitive to drops. That is, a line with a profile of 4 Mbps, if for example it has signal-to-noise values of 13dB and attenuation of 40, it does not support a profile of 10 Mbps, since it causes greater attenuation and less signal-to-noise.
Signal-to-noise: greater than 13dB to guarantee the stability of the service (the higher the value, the better the service quality)
Attenuation: less than 40dB, since if it is too high, the service can have constant drops….
The IP switching elements have grown in performance, and the conventional routers that made packet switching by software are giving way to the so-called level 3 switches, which are part of this switching by hardware.
Likewise, techniques have appeared commercially that allow to adjust and guarantee quality of services in IP networks, a very important factor, since video traffic is extremely sensitive to any degradation in network performance.
Likewise, by continuing to work with IP, the content encapsulation is done over RTP and UDP, using IP multicast technologies for distribution. These technologies have the advantage that each TV channel is transmitted only once and is replicated at all points of the network where the paths diverge to reach different users who have tuned in to this channel. This enables “one-to-many” communication on IP networks. Thus, each multicast channel is configured with a multicast IP address and to tune into any channel, our STB only has to subscribe (join) to the corresponding multicast group, sending an IGMP packet to the access router who finally serves the content. to the client. IP video transport is standardized in the DVB-IPI standard.
The advantages that IPTV brings are the following:
Interactivity – In IPTV, the possibility of new types of services that were previously not available in other networks opens. In this case, both video and interactive services are transmitted through the IP network, facilitating the overlapping of products, since everything is transmitted in IP packets. Furthermore, its bidirectional communication capacity allows providers to develop a large series of interactive applications in which no additional development is necessary to obtain the return channel, since the user has a modem. / router with the ability to communicate from home to the provider.
Time shifting – The combination of IPTv with video recorders, allows the scheduled recording of content for later playback.
Integration – Provides many companies / providers with the possibility of offering several services in a single integrated package, which reduces costs for the user.
Personalization – An end-to-end IPTV system allows two-way communication and allows the user to personalize their TV consumption habits by allowing them to decide what they want to watch and when.
Low bandwidth requirements – Instead of distributing all channels to each user, IPTV technology allows service providers to serve only the video stream that the user has requested. This feature is very attractive to operators as it saves bandwidth on their network.
Accessible by Multiple Devices – Viewing IPTV is not limited to TV use. Consumers can access the service through PC or mobile.
Video on Demand – VoD is an interactive element but with such an entity that it is worth mentioning it separately. It allows us to purchase content (movies, documentaries, series …) at our convenience, view it when it suits us best and perform the classic functions of a video player on it, such as pause, forward, rewind.
Although it is true that IPTV has all the above advantages, making it a very attractive product, we cannot forget about some disadvantages that it is necessary to know:
Packet loss – IPTV uses the same technology as web page access, data transmission, for its purpose. Since this protocol is not connection-oriented, packet loss or delays may be experienced from time to time, preventing correct viewing and listening to TV, in those cases where packet loss is high enough.
Coverage – The possibility of offering IPTV services to subscribers is inversely proportional to the distance that this subscriber is with the central. While countries like Italy the average distance does not exceed 800 m. In other countries such as France or Spain, this average distance exceeds 2.5 km, which is a limitation for the signal to arrive without packet loss and IPTV to be a reality.
In short, the services that are traditionally offered through IPTV are two:
Broadcast Channels – Where the customer has a wide set of high quality digital television / radio channels that are offered by the operator in the form of packages, subscriptions, etc.In this sense, the IPTV operator is it behaves like any satellite or cable TV operator.
Content on demand (VoD) – This is the differentiating service with satellite or cable operators. It allows access to a catalog of audiovisual content with the same features as if the content were available on DVD. In this case and given that the user has complete control over the reproduction of the program (stop, forward, backward …) it is not possible to share the same flow among multiple users, so the usual unicast techniques (RTP) are used. This forces to a certain extent to place the VoD servers in points relatively close to the users to achieve adequate scalability of the system.
The transmission of video services can be done through different types of telecommunication networks such as cable, wireless, satellite networks, although telephone companies and Internet access companies were the first to develop this type of service, thanks to technology ADSL2 +. For this reason we are going to focus on the typical architecture of this type of provider.
Video signal contribution – It is in charge of receiving all the video signals, which will make up the TV offer of said operator. This is commonly known as Video Header (Video Headend) and it does not differ at all from the equipment of any other traditional TV content operator such as Cable Operators, Satellite Operators, etc. It consists of a reception stage (reception of channels through cable satellite, reception of content by IP, etc.) where a Line-Up is defined with the offer’s broascast TV services.
A second encoding stage in which the video signal is encoded and compressed in the established standard (generally MPEG-4, H264 that achieves a decrease in bandwidth in some cases to levels as low as 1.5 Mbit / s per channel). The choice of the codec is vital since it is decisive when establishing a good balance between the video quality, the necessary bit rate, the complexity of the encoding / decoding algorithm, the robustness against data loss and errors and another large number of factors. In this stage, in addition, the video signal is usually adapted, encapsulating it in IP so that it can be transported and later delivered to the multiplexer where the Transport Stream of the total TV offer will be formed, and thus the subscriber can receive the flow properly.
VoD servers – This stage is responsible for receiving content in different formats, either through the Internet, transferring files to a central server (FTP), etc. It is at this stage and normally in a module apart from the header where these contents are encoded and stored on servers, ready for users to access them. These servers can be centralized or distributed in local nodes where users can access specific content in their area. Normally these servers are based on IP server platforms with Linux or Windows operating systems that are capable of delivering multiple video streams simultaneously, although to avoid possible saturation due to increased demand, load balancing is used, so video delivery sessions are shared.
Distribution network – The distribution network refers to a high capacity transport network that allows the unidirectional transmission of content, where each of the channels is made up of an MPEG-2 transport frame encapsulated over IP and using the protocol UD / multicast. The availability of high transfer capacity is very important as this guarantees us to have stable transmission rates in order to offer sufficient quality to subscribers. The transport network is always responsible for guaranteeing the transport service and is the workhorse of the large telephony / Internet access operators as they are continually improving it and introducing new equipment to ensure this quality of service.
Customer Access Network- The Access network is the point where the operator’s transportation network ends and the customer part begins, although it remains the property of the company. Generally it is on ADSL2 + or VDSL, thanks to which customers can receive TV content over the copper lines of their homes (traditionally telephone lines).
CPE – In addition to the subscriber pair the customer needs the equipment of a normal ADSL connection. Provides network termination, and allows you to separate voice connections from data connections. Generally, connected to the ADSL modem is the decoder, the PC and usually also the telephone.
IPTV Client- It is the end client equipment where the IPTV traffic ends, generally it is a single device, known as STB, which allows establishing the connection, establishing the quality of service with the central node, decoding the video and displaying the specific content to the client. Generally, this client or STB has software capable of presenting the functionalities of the service to the end user, as well as interactive applications. Normally, the client interacts with all the services through the remote control of this STB, becoming the gateway to the services that the provider is offering. This equipment is one of the most important in the entire system, which is within reach of the subscriber. Considering all these points and due to the cost of said equipment, the objective when selecting one equipment or another by the provider will be to ensure compliance with all the software and hardware requirements of the service.