Internet Protocol Television

Transcription

1 METROPOLIA University of Applied Sciences Institute of Technology Degree Programme in Media Engineering Internet Protocol Television Seminar on Media Engineering Pertti Huuskonen

2 1. Introduction Definition History What is IPTV Live Television On Demand Content Time-Shifted Programming TV Distribution Methods Terrestrial Distribution Method Cable Distribution Method Satellite Distribution Method IPTV Distribution Method Comparison of Capacities IPTV Technology Case Study: Maxivision npvr Self Service Centre Set Top Box The Future of IPTV Conclusion REFERENCES

3 3 1. Introduction In the recent years Internet Protocol Television (IPTV) has become an addition to traditional TVdistribution methods. IPTV provides added value in many respect compared to the other television services. In the Internet protocol television service, the television signal is delivered using Internet protocol over packet-switched network infrastructure [1]. Similarly as cable, terrestrial or satellite operator distributes TV-channel using specific method, an IPTV operator delivers the channels over the Internet. The main services delivered by IPTV are live television, on demand content and time-shifted programming. IPTV is not widely spread yet, and logically is only offered in countries and areas where high-speed broadband connections are available. Fig. 1: List of countries where IPTV is available.[1]

4 4 2. Definition The definition of IPTV has been somewhat controversial in past years. Personally I consider IPTV merely as a way of distributing high quality and reliable TV-content via Internet. More importantly it should be distinguished from Internet television and such on-line television services. Easy way of distinguishing the two apart is to consider to following; IPTV is watched with television as the Internet TV is watched with a computer. Video is available all over the Internet. Some services such as YouTube or Ruutu.fi could be considered as an on-line video services or Internet TV services but not in my opinion as Internet protocol television. Internet TV is often referred as to Online-TV, which describes the concept more coherently. The basic idea is to browse archives of video material and either watch it on computer by streaming the content or by downloading the file in to the computer and watch locally. The official definition of IPTV by International Telecommunication Union: IPTV is defined as multimedia services such as television/video/audio/text/graphics/data delivered over IP based networks managed to provide the required level of quality of service and experience, security, interactivity and reliability. [2] 3. History The history of the Internet protocol television dates back to 1994 when ABC broadcasted their World News Now over the Internet using the CU-SeeMe videoconferencing software [1]. Since the late 90 s the concept has grown and demand has become wider. As the reliability, quality and speed have grown in broadband connections the IPTV has been able to provide TV solutions to growing number of subscribers. IPTV is usually provided as a triple-play system. That is, the IPTV, broadband connection and voice-over internet protocol (VoIP) are delivered as a package. It has been said that these triple-play

5 5 and IPTV services in closed network are slowing radically the growth of the Internet protocol television. In Finland the IPTV services has been available since 2003, but like in any other country the services are delivered using closed networks. In other words, the costumer can use the IPTV service only in the operators own broadband Internet connection. About a year ago, the first Finnish Internet protocol television operator launched the service in open network, that is, the service has no dependency to the broadband operator. In fact, that IPTV service is one of the first services in the world using the open network. [3] 4. What is IPTV Internet protocol television is what digital television claimed to be but proved out to be nothing of the kind. IPTV has the ability to true interaction between operator and the costumer. The two way communication allows IPTV to provide services unavailable in the traditional television distribution methods. 4.1 Live Television Before VHS- and BETA Video recorders the only way of watching TV was live television. It means that the program is watched in real time in respect to the broadcast. Live television is still by far the most common way of watching television. We are conditioned to watch specific programme at a specific time and day e.g. if Hill Street Blues is broadcasted on Mondays at 8 O clock the majority of its viewers will watch it then, instead of recording it or watching it as on demand. Actually the transformation of our viewing habits from live television to on demand television was one of the bigger objectives the digital television claimed to pursue but failed big time. 4.2 On Demand Content On Demand content is something that allows the user to view the specific content on demand. At a basic level and provided by most IPTV-operators is Video on Demand (VoD). Using the set-top-

6 6 box (STB) the costumer is able to browse through an archive of movies, select the movie and pay for the content demanded. It is much like a video rental place one has an access over the Internet using the digital receiver. Usually the rental time period is 24 hours, after which the access to the video expires [4]. Other on demand content could be digital music, data services, on demand games et cetera. Gaming on demand (GoD) is basically renting a game for some period of time as a movie is rented for using video on demand. Maybe in the future an IPTV set-top-box could be have a game console in it. 4.3 Time-Shifted Programming Time-shifted programming means recording television programmes and watching them later. Most of the IPTV-operators provides network Personal Video Recorder (npvr) as a part of the service for the customers. The hard drive space, where the content is recorded, is located in the operators head end. Basically it works like any other digital receiver with hard drive in it. Because the recording space is accessed using the Internet connection, the system allows flexible ways of handling the npvr. Instead of having to have the set-top-box as the only way of accessing the video recording IPTV clients are able to schedule, remove and to buy more capacity to the recorder using an Internet browser or even mobile device such as mobile phone or personal digital assistant (PDA). [5]. 5. TV Distribution Methods Traditionally television content is delivered to customers using terrestrial-, satellite- and cablenetworks. The latest addition to the distribution methods is Internet protocol television. There has to be some kind of demand for developing a new ways of distributing television content. And there is. Different distribution methods have different capacities, coverage s and restrictions. Considering the future of the television it seems as though the terrestrial network, at least, has reached its limits. The most beneficial feature of IPTV is its interactivity, something that the other methods lack.

7 7 5.1 Terrestrial Distribution Method In terrestrial distribution of television content the signal is transmitted over the air using radio frequencies. In order to receive such a signal the consumer has to have a television antenna. In the era of digital television the terrestrial method of distribution is referred as Digital Video Broadcasting, Terrestrial (DVB-T). The benefit of terrestrial transmission is the coverage, which is in Finland over 99 percent of the country. Because the signal is travelling through the air the method does not require any fixed network. Because the reserved radio frequencies are limited, the capacity in terms of the bandwidth available for television signals, the amount of channels provided are very few compared to all the other distribution methods [6]. At the moment there are about 30 television channels available in the terrestrial network, including both the free channels and the pay-tv channels [7]. 5.2 Cable Distribution Method The majority of Finnish television households receive the content of their TV-service using the method of distribution via fixed coaxial cable or optic fibre. Cable network is operated by local cable company. Most of Finnish cities have a fixed cable for TV content and broadband connections. The capacity of cable is multiple times the capacity of terrestrial network. The capacity allows huge amount of television channels in standard or even high definition format. The channel selection varies according to the operator, but all of them deliver larger selection than terrestrial network. In metropolitan area of Helsinki the cable operator is Welho. Welho has probably the best television content in the country of Finland. There are over one hundred television channels all together including all high definition channels available in Finland [8].

8 8 5.3 Satellite Distribution Method In satellite television distribution the signal is reflected over communication satellite to the users satellite dish. The initial investment is considerably higher than in any other distribution method. Also the law prohibits the instalment of satellite dish in apartment buildings with only few exceptions. The satellite is an option for detached house in the area where cable is not available. The satellite has the required capacity to provide all the channels available in Finland but could present a lack of capacity in the future when all the channels are in high definition. The biggest satellite operators provide almost hundred channels in Finland at the moment [9]. 5.4 IPTV Distribution Method In IPTV distribution the television signal is transmitted over the Internet to the users set-top-box. Before IPTV was mostly available for households in city areas because of the bandwidth required to receive good quality television. Also the distribution of IPTV in closed networks has limited its status as an alternative for TV-service. At the moment, though, it is strengthening its position with availability, lower bandwidth requirements and better Internet connections. Internet protocol television has the capacity to broadcast all of the channels in Finland at the moment and undoubtedly in the future, even when high definition television obsoletes the standard definition television. 5.5 Comparison of Capacities In capacity wise IPTV benefits from its technology. Unlike any other distribution method, where all the channels are being received simultaneously, in Internet protocol television system the user receives only one stream at a time, corresponding the chosen channel. Since the bandwidth of the receiving end is according to the quality of the video, not the amount of channels, it is fair to consider the backbone capacity of the operators distribution channel to be the bottleneck of the system. Operators backbones today can be 10Gbps and more, thus capable of broadcasting over five thousand standard definition channels simultaneously. [6]

9 9 Service Coding Capacity Mbps Note HDTV MPEG i HDTV MPEG p SDTV MPEG2 5 VoD MPEG2 5 HDTV MPEG i HDTV MPEG p SDTV MPEG4 2 VoD MPEG4 2 Figure 2 Capacity requirements according to service and coding. [6] DVB-C DVB-T DVB-S IPTV Max capacity 4 Gbps 154 Mbps 4,5 Gbps 10 Gbps -> SDTV (MPEG2) no. of channels > HDTV (MPEG2) > no. of channels SDTV (MPEG4) no. of channels > HDTV (MPEG4) > no. of channels VoD Ok Difficult Difficult Good Interactivity Ok Difficult Difficult Good Figure 3 Comparison of different distribution methods. [6]

10 10 6. IPTV Technology Internet protocol television distribution is operated in a physical faculty called the head-end. The principle of its functions is quite simple; the television signals are received from terrestrial network distribution and satellite transmissions and converted for Internet distribution. The signal received from other distribution methods are presently coded in MPEG2, a format used in DVD s and other media for video and movie distribution. MPEG2 has been the choice of a format for IPTV distributors widely, but as the significantly higher compression codec MPEG 4 H.264 provides decent quality of video stream, operators have begun to take an interest in the option. The method of distributing live television signal is multicasting. Multicasting simplified means that each video stream is broadcasted once through the head-end backbone and then duplicated for each receiver. For on demand content multicasting is not an option, because e.g. video on demand content is delivered to designated receiver only. This applies to network personal video recorder content also where the method of distribution is unicast. [10]. Multicast requires only certain amount of bandwidth for each channel that is independent of the number of receivers where as in unicast the required bandwidth is directly proportional to the number of destinations. Figure 4 Multicast (upper) duplicates the signal, unicast provides own signal for each destinations [10].

11 11 7. Case Study: Maxivision Maxisat is an IPTV-operator in Finland. It is a pioneer it the field of Internet protocol television for its open network Maxivision-service. As stated earlier the vast majority of IPTV-services are delivered in closed network, thus demanding the dependency on the operator s broadband connection. Apparently the ideology behind Maxivision is to provide decent quality television service to as many as possible. Maxivision-service requires the minimum of 2Mbps broadband connection for standard definition channels, yet another feature still uncommon among IPTVservices. Though, lower bandwidth requirement is at the expense of poorer quality as the method of coding is MPEG4. Since last month Maxivision has offered the possibility for MPEG2 stream of the channels where bandwidth of 8Mbps is available. The choice of video quality is an example of Internet protocol television s flexibility. There are other features unique to interactive television services. Other feature worth of mentioning is the lack for the need of pay-tv cards with their monthly feeds. STB is identified by its Media Access Control address (MAC address). 7.1 npvr Network Personal Video Recorder (npvr) is comparable to hard drive in traditional digital receiver. Its sole purpose is to record programs for later use. In npvr the hard drive space is physically located in the operator head-end instead of the set-top-box itself. This setup allows flexibility for the customer. The capacity can be modified according to the needs of the user. Also user has the access to the npvr over the Internet, the management of the scheduling and recorded programs can be handled using web browser or mobile device. Simultaneous recording of channels is not restricted as it is in a conventional recordable set-top-box. 7.2 Self Service Centre Maxivision has an Internet based customer portal where the service is handled. Actually the self service centre makes the Maxivision IPTV very up-to-date service. All the subscriptions, recordings

12 12 and settings are handled over the customer portal. No paper invoices are even available since subscriptions are prepaid using credit card or Internet banks. Once a subscription is paid over the Internet the acquired TV channel is viewable in 10 seconds. These features will provide a new way of watching TV in the near future. For example if there is a football match coming on some pay-tv channel the user could subscribe to the channel for the duration of the game i.e. costumers would be able to purchase just a game instead of committing to the channel for longer time for higher price. 7.3 Set Top Box The most important and the only physical apparatus in the Maxivision service is the Set-Top-Box (STB). STB is simply connected to ADSL or Cable modem and to the television. In addition it has the DVB-T tuner for receiving signal from terrestrial network. It is basically a computer with optimized operating system for decoding the IPTV-video signal for the TV. Because of the Internet connection and therefore the real interactivity of the system the STB can process other software also. In Maxivision service there is at the moment a weather forecast service provided by Foreca, with some functionality. Other software under development is a web browser for the television. Even though most digital receivers claim to have the ability to have automatic software updates, in most cases it is not the truth except for IPTV receivers. 8. The Future of IPTV The capacity, interactivity and increasing supply of open network IPTV services will most like grow IPTV s share as a television distributor in near future. Even now applications are available for STB s with connection to Internet. More on demand content is already coming and other services such as digital music or data services will soon become part of the whole IPTV concept. When considering the future of IPTV I would say the sky is the limit. It could be compared to mobile phones; few years back they were actually used for making phone calls but what about the current situation.

13 13 9. Conclusion Internet protocol claims what digitalization of television promised. It provides a huge improvement for those living in peripheral areas. As the costs are coming down and more content is being provided, let alone interactive content, IPTV will probably reveal its potential. There is no doubt IPTV is here to stay and compared to other distribution methods, it certainly has a big role in tomorrow s television services. On the downside the mobile Internet connections cannot provide sufficient quality of service, therefore IPTV as an alternative is not yet possible for everyone.

14 14 REFERENCES 1 Wikipedia IPTV[online]. URL: Accessed 6 December International Telecommunication Union[online]. URL: Accessed 6 December Maxisat [online]. URL: http// Accessed 1 November Elisa Viihde [online] URL: Accessed 5 December Maxivision [online]. URL: Accessed 8 December Internet-pohjainen televisio (IPTV): Nykytila ja lähivuosien kehity 2006 [online]. Liikenne- ja viestintäministeriö. UIL: Accessed 6 December Plus TV [online]. URL: Accessed 21 November Welho [online]. URL: Accessed 21 November Canal Digital [online]. URL: Accessed 21 November Wikipedia Multicast [online]. URL: Accessed 8 December 2009.