Trends in Digital Terrestrial Broadcasting

Countermeasures for analog channel adjustments that will be necessary to accommodate the upcoming launch of digital broadcasting began in the three largest metropolitan areas on February 9 of this year. The basic policy of the National Promotion Committee for Digital Terrestrial Broadcasting was determined in July for the other areas of the country, where work will advance on establishing a nationwide system. This article provides an overview of the schedule for analog channel adjustment countermeasures, broadcasts in //, digital broadcasting standardization, and work being conducted by related organizations toward digitalization of terrestrial broadcasts. It also explains broadcast-wave relay technology, which will play an important role in the future nationwide service.

1. Digital Terrestrial Television Broadcasting been covered in the initial plan, such as subscribers who Analog channel adjustment countermeasures receive broadcasts from transmitters other than the nearest The Joint Committee Concerning Digital Terrestrial ones (Table 1). Broadcasting, established in September 1999 by the The document detailing amendments to the basic plan Ministry of Public Management, Home Affairs, Posts and for promoting broadcasting and the frequency use plan Telecommunications (MPHPT), prepared the initial plan was released on September 27, 2002. It describes how the regarding the number of broadcasting stations and digitalization of terrestrial services would advance in households to be affected by the analog adjustment phases: first, the Tokyo / Osaka / Nagoya areas would be countermeasures and an estimate of the cost for the digitalized; then, other regions would be digitalized. It took changeover. Its report was released in April 2000. The into account that the survey had required a substantial ministry dissolved the Joint Committee, recently, and time and revealed a need to change the original plan. founded the National Promotion Committee for Digital Terrestrial Broadcasting. The MPHPT is charged with Analog Channel Adjustment Countermeasures revising the Radio Law, the basic plan for promoting Schedule broadcasting in , and the frequency use plan for The amended plan's schedule states that digital broadcasting. The new committee spent about a year broadcasting should start in the three major metropolitan conducting a nationwide survey on all aspects affecting the areas by the end of 2003 and in other areas by the end of planned countermeasures, including ones that haven't 2006 and that analog broadcasting service should be terminated in 2011. The Table 1: Cost of analog channel adjustment countermeasures countermeasures for the analog August 1, 2002 April 26, 2000 channel adjustment are to be (National Committee (initial estimate) Meeting) implemented as follows: Number of stations being affected 418 801 - Digitalization of the three major by analog channel adjustment metropolitan areas: to start in 2002, countermeasures) and be completed by 2006. Number of households requiring 2.46 million Approx. 4.26 million - Other areas: digitalization by region countermeasures to start no later than 2005. (of which households require cable (7000) (Approx. 0.13 million) TV countermeasures) - The entire cost will be covered by the Countermeasures cost Approx. 72.7 Approx. 180 government (financed by radio usage billion yen billion yen fees). - The details of the plan, such as 2002 2003 2004 2005 2006 2010 2015 specific countermeasures to be Three major metroplitan areas 2011: analog broadcast termination (based on a related announcement, "Basic Plan for implemented, have not been Analog channel adjustment Broadcasting Promotion") determined. Digital broadcasting in three major metropolitan areas In conjunction with the analog Preparation channel countermeasures, digital Analog channel adjustment terrestrial broadcasting will gradually countermeasures are to have been be started in areas outside the three Other areas completed within 5 years after a Analog channel adjustment new channel has been announced. major metropolitan areas (Figure 1).

Digital broadcasting in other areas Preparation Figure 1: Analog channel adjustment countermeasures implementation schedule

Broadcast Technology no.16, Autumn 2003 C NHK STRL 7 Digital Terrestrial Television Digital Terrestrial Television Broadcasting Licensing Policy Broadcasting Licensing Form of Broadcasting Segments:12 1 X o'clock Figure 2 shows a general description HDTV/SDTV+supplemental broadcasts broadcast Supplemental

of the MPHPT's licensing policy and an (data broadcasting) HDTV(*) Supplemental broadcast HDTV programming ratio (Movie) broadcast Supplemental example of the broadcasting forms. broadcast Supplemental broadcast Supplemental 50% or higher (in one week) Applications for licenses were Simulcast ratio SDTV(*) SDTV SDTV (News) (Music) (Baseball submitted by NHK and 16 commercial Over 2/3 of programming is shared with relay) broadcasters, and preliminary radio analog broadcasting. broadcast Supplemental licenses with a December 1 start date HDTV(*) An example of a broadcast form is shown (Drama)

for the Kanto, Chukyo, and Kinki on right. broadcast Supplemental regions were granted on April 18. HDTV(*) (Information-related programs)

Broadcasting in the Three Major * Simulcast of analog service Metropolitan Areas Figure 2: Digital terrestrial television broadcasting licensing policy Table 2 lists the transmitting powers Table 2: Transmitting power for December-launch stations of each broadcasting station, whose Begin in End of End of Wide area Broadcasters signals will be progressively intensified 2003 2004 2005 until they are at full strength 300W 410W 10kW NHK General TV sometime between the end of 2004 15.5W 700W 10kW NHK Educational TV and Extended Kanto area extended area commercial and the end of 2005. The figures are Tokyo broadcasters based on the MPHPT press release 29W 700W 3kW Metropolitan "Report on Preliminary Radio Licenses 30W 3kW NHK GTV/ETV and extended Extended Chukyo area for Digital Terrestrial Television area commercial broadcasters Aichi pref. 30W 1kW TV Aichi Broadcasters," dated April 16, 2002. 10W 100W 3kW NHK GTV/ETV and extended The transmitters of the Kanto and Extended Kinki area area commercial broadcasters Osaka Kinki regions are to reach their 10W 100W 1kW TV Osaka maximum output in three phases, and the Chukyo area m steel tower and a broadcasting station will be opened in transmitters are to reach it in two phases. Hatanaka, Seto city and will broadcast the signals of NHK and other broadcasters. In the Osaka area, NHK has Tokyo/Nagoya/Osaka Digital Broadcast Transmitting installed an antenna for its exclusive use at the top of an Facilities Overview existing backup steel tower on Mt. Ikoma, which is In the Tokyo area, eight broadcasters have placed new approximately 690 m above sea level. Other broadcasters antennas at a height of 250 m on . A installed antennas on their own towers. An overview of transmitter room was built under the tower's large these facilities is shown in Figure 3. observatory. In the Nagoya area, a new facility with a 246- Tokyo Tower (Shiba) Osaka (Ikoma-yama) Nagoya (Hatanaka, Seto-city) 333.0m 68.5m Antenna for 246.3m digital signals (NHK) Antenna for digital signals (joint project) Antenna for digital signals 252.65m Backup (joint project) antenna MX-TV (existing)

Backup steel-tower Steel-tower (existing) (joint project) 3kW 10kW Digital Digital transmitter transmitter room room 3kW Analog 2F Digital Analog Station with transmitter broadcasting broadcasting transmitter room (5F) system system (joint project) 1F Power Fan system, system etc.

Ikoma-yama GL=621.8m

Figure 3: Tokyo/Nagoya/Osaka digital transmitting facility overview

8 Broadcast Technology no.16, Autumn 2003 C NHK STRL Feature

Analog Channel Adjustment Countermeasures in Other October 2003. Table 3 gives an overview of the Areas preliminary licenses issued in September 2001. The The National Promotion Committee for Digital frequency bandwidth to be used for broadcasting is 4 MHz, Terrestrial Broadcasting announced its basic policy in July which is common to Kanto and Kansai and corresponds to 2003. The policy calls for implementation of analog part of VHF Channel 7. Eight densely packed segments channel adjustment countermeasures throughout the will be transmitted in the 4-MHz bandwidth by connecting country in fiscal 2004, with broadcasting to have begun by together the segments that have the same structure as ones the end of 2006 (Figure 4). Areas needing more involved used for digital terrestrial television broadcasting. countermeasures will follow an accelerated schedule. The The plan is to divide broadcasters into groups that will release of master station frequencies for each region is develop their own multimedia services for these segments. scheduled for September, except in areas that require There will be five one-segment groups and one three- further studies on interference, for which the release date is segment group in Tokyo, and eight one-segment groups in December. These exceptional areas are the Ariake region Osaka. of , , , and , and the San- in region of , Shimane, and . As in 3. Standardization Trends in Digital Terrestrial Tokyo/Osaka/Nagoya, the transmitting power of the Broadcasting and Other Services master stations in each region will gradually increase as Operational Guidelines for Digital Terrestrial Television analog channel conversion progresses. Broadcasting: ARIB TR14 Coinciding with this process, the MPHPT amended its The Digital Terrestrial Television Broadcasting frequency use plan for allocating frequencies to the master Standardization Panel comprises NHK and five stations that will be established outside the three commercial broadcasters in Tokyo. It was inaugurated in metropolitan areas and setting up the analog channel October 2000 and is working to establish or revise the adjustment countermeasure stations. This is in line with operational guidelines for broadcasters. To provide digital the amendment to the frequency use plan for terrestrial television broadcasting based on ARIB standards, broadcasting. these guidelines should specify the areas of services, data broadcasting, conditional access systems (CAS), receiver 2. Digital Terrestrial Sound Broadcasting specifications, and rights management and protection. The The Digital Radio Promotion Association (DRP) first version, ARIB TR-B14, was completed in January 2002, comprises 81 organizations and companies, including and several modifications have been made to it. The NHK, commercial sound broadcasters, new broadcasters, current version, 1.4, was issued in June 2003. and manufacturers. Its members will begin digital Examples of the operational guidelines' contents are terrestrial sound trial broadcasts in Osaka and Tokyo in shown in Tables 4 to 6).

2003 2004 2005 2006 Standards for Broadcasting Based Preparing implementation environment on Home Servers: ARIB STD-B38 for master station analog channel adjustment Broadcasting based on home servers Implementation in areas with September uses a receiver equipped with a complex countermeasures , Kagawa, , Ehime communications function and large- December capacity storage equipment such as a Nagasaki, Kumamoto, hard disk. The server will record and replay program contents according to Announcement of master station September frequencies Areas requiring no analog-adjustment and metadata giving the description and analog-adjustment completed areas characteristics of the contents and December rights related information. This lets 7 prefectures in Ariake, San-in programs be tailored to the individual regions viewer's preferences. In September Master station transmitting power Gradual increase during analog adjustment 2002, the Telecommunications Figure 4: Analog channel adjustment countermeasures in areas other than the three Council released a report titled, major metropolitan areas "Coding, Transmission, and Storage Table 3: Digital terrestrial sound broadcasting preliminary license overview Specifications for Broadcasting System Licensee Digital Radio Promotion Association Based on Home Servers," and drafted Station name Osaka experimental station Tokyo experimental station ARIB STD-B38 in February 2003. Frequency 190.214286MHz (Channel 7 on television) The standard defines two types of Transmitting power 240W 800W transmission system: a streaming type (per 1 segment) (30W) (100W) Transmitting location Ikoma-yama Tokyo Tower (I), and a filing type (II). The fact that Broadcasting area Parts of Osaka, , , Parts of Tokyo, Kanagawa, Type I is the same scheme as the and Hyogo prefectures , and prefectures current digital broadcasting makes

Broadcast Technology no.16, Autumn 2003 C NHK STRL 9 Table 4: Digital terrestrial television broadcasting service pattern Application Execution Environment Service Segment Transmission EPG Standard for Digital Broadcasting: TV system pattern number parameter Basic Extension ARIB STD-B23 (1) 13 64QAM HDTV, SDTV Home - This standard defines the procedural (2) 13 16QAM, QPSK HDTV, SDTV Mobile Home (execution-type) application execution (3) 1 16QAM, QPSK LDTV Portable Home/Mobile environment, in addition to 12 64QAM HDTV, SDTV Home - (4) 8-2 16QAM, QPSK SDTV Mobile Home conventional declarative 5-11 64QAM HDTV, SDTV Home - (presentation-type) data broadcasting (5) 1 16QAM, QPSK LDTV Portable Home/Mobile standards. With regard to monomedia 12 16QAM, QPSK HDTV, SDTV Mobile Home coding schemes, it considers (6) 1 16QAM, QPSK LDTV Portable Home/Mobile compliance with the digital BS and CS 7-1 16QAM, QPSK SDTV Mobile Home 5-11 64QAM HDTV, SDTV Home - broadcasting systems that are already Note 1 LDTV(Low Difinition TV) will be implemented for data broadcasting. in use, and includes schemes required Note 2 The basic EPG transmits data to a hierarchy that is the same as that of the service hierarchy. by DVB/MHP (Multimedia Home The extension indicates a data transmission that differs from the basic EPG and can be made regardless of service hierarchy whenever the broadcaster chooses to do so. Platform). The application execution environment has the necessary Table 5: Data broadcasting profile standards for domestic broadcasting, Profile Description such as an extension for Japanese A Basic operation profile for data broadcasting services designed language fonts, and it conforms with mainly for home receivers (fixed, STB, portable, etc.). B Basic operation profile for data broadcasting services designed network applications and DVB/MHP (T.B.D) mainly for portable receivers (car TV, portable TV, PDA, etc.). standards, including the GEM C Basic operation profile for data broadcasting services designed (Globally Executable MHP) standard. mainly for portable receivers (cellular phone, etc.).

Table 6: EPG operation H.264 Added to ARIB STD-B24 MPEG-4 data broadcasting coding is Digital terrestrial television broadcasting Digital BS broadcasting the coding scheme assumed for digital EPG type H-EIT (EPG for home receivers) 1 type terrestrial broadcasting's one-segment M-EIT (EPG for mobile receivers) L-EIT (EPG for portable receivers) service. However, MPEG-4 rights Transmitted Transmits only own-station data Transmits all-station holders are demanding use-based data data royalties, and whether to accede to this Receiver - Receivers capable of nighttime power Presents received data demand has become an issue among operation control; e.g., fixed receivers collect data without any processing. broadcasters. Consequently, the for all stations in standby mode. - Portable receivers can also receive commencement of services employing own-station data. MPEG-4 is not presently within sight. ARIB is discussing a proposal from feasible real-time viewing using a conventional receiver. broadcasters aiming at an early start of services. Increased Along with regular program contents, Type II transmits system options would offer alternative standards to MPEG- characteristics about the contents' file format, such as its 4; In fact, H.264 has already been selected as an pixel number and coding scheme, by using a data carousel alternative in the ARIB STD-B24 standard. scheme compliant with MPEG-2 system multiplexing. The This concludes our overview of the main standardization standard also specifies schemes for metadata, rights trends related to digital terrestrial broadcasting. Nearly all management and protection, and CAS. An of the ARIB digital broadcasting standard systems are listed unconventional charging-at-replay fee mechanism will be in Figure 5. introduced. It does not charge for stored contents until they are played. The broadcasters' operational guidelines for 4. Related Organizations broadcasting based on home servers are being compiled, National Promotion Committee for Digital Terrestrial including details about receivers and their standard Broadcasting (National Committee) operation. This private organization was established in July, 2002 and is chaired by Makoto Kitagawa, President of the Access Control System Standard for Digital Broadcasting System of Inc. It consists of the Broadcasting: ARIB STD-B25 MPHPT, NHK, and 127 commercial television broadcasters, The previous standard, "Conditional Access System and it discusses with regional councils analog channel Specifications for Digital Broadcasting: ARIB-STD-B25," was adjustment countermeasures and related publicity renamed after the replay control scheme for broadcasting activities. based on home servers was added to Section 2, in February 2003.

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As of June 5, 2003 Digital television broadcasting Digital sound broadcasting BS/wide-area Terrestrial television Terrestrial sound 2.6-GHz-band CS broadcasting broadcasting broadcasting satellite sound (enacted or revised (enacted in May 2001) (enacted in May 2001) broadcasting in Nov. 1998/ (enacted in June 2003) Dec. 2000) Transmission scheme Transmission Transmission Transmission Transmission System for System for System for System for Digital Satellite Digital Terrestrial Digital Terrestrial Digital Satellite Broadcasting Television Sound Sound ARIB STD-B20 Broadcasting Broadcasting Broadcasting ARIB STD-B31 ARIB STD-B29 ARIB STD-B41 Coding scheme, Video Coding, Audio Coding and Multiplexing Specifications for Digital Broadcasting multiplexing scheme ARIB STD-B32M Service Information for Digital Broadcasting System ARIB STD-B10 Data Contents- Data Coding and Transmission Specification for Digital Broadcasting broadcasting presentation ARIB STD-B24 scheme type Program- Application Execution Engine Platform for Digital Broadcasting execution ARIB STD-B23 type Conditional access system Conditional Access System Specification for Digital Broadcasting ARIB STD-B25 Broadcasting based on Coding, Transmission and Storage Specification for Broadcasting System Based on Home Servers home servers ARIB STD-B38 Receiver Receiver for Digital broadcasting Receiver for Digital Receiver for Digital ARIB STD-B21 Terrestrial Satellite Sound Sound Broadcasting Broadcasting ARIB STD-B30 ARIB STD-B42 Operational guideline Operational Operational Operational Operational (technical report) Guidelines for Guidelines for Guidelines for Guidelines for BS/wide-area CS Digital Terrestrial Digital Terrestrial Digital Satellite Digital Broadcasting Television Sound Sound ARIB TR-B15 Broadcasting Broadcasting Broadcasting (enacted/revised in ARIB TR-B14 ARIB TR-B13 (pending) Oct. 1999/July 2001) (enacted in Jan. 2002) (enacted in May 2002)

Note 1: "ARIB STD-BXX" and "ARIB TR-BXX" indicates ARIB "Standard" and "Technical Report", respectively. Note 2: Standards related to digital CS broadcasting have been omitted. Figure 5: ARIB Standards on digital broadcasting

Digital Terrestrial Television Receiver Test Center The Association for the Promotion of Digital Council Broadcasting (D-PA) This council's aim is to support the development and test This association was incorporated in August 2003. Its manufacture of receivers and the smooth diffusion of president is Mr. Makoto Kitagawa. It is made up of NHK, digital terrestrial broadcasting equipment. It was founded 127 commercial broadcasters, and receiver manufacturers. in April, 2002 and 93 companies, including broadcasters Its purpose is to promote a smooth, prompt transition to and manufacturers, participate in it. Its work ranges from digital terrestrial television broadcasting, and ensure stable creating standard test streams and conducting high operations. Its specific activities include promoting receiver frequency tests to conducting receiver interference diffusion, as well as the standardization of experiments. It is also preparing the experimental transmission/reception technologies by continuing the broadcasts that will be made prior to the actual service functions of the Digital Terrestrial Television Broadcasting commencement in December. Standardization Panel and the Test Center. It provides engineering services for reception function version Digital Terrestrial Broadcasting Promotion National upgrades and error removal using broadcast-waves, as well Conference as contents protection for broadcasting programs. This private organization was established in May, 2003. It is chaired by Mr. Nobuo Yamaguchi, Chairman of the 5. Nationwide Development after 2006 Japan Chamber of Commerce and Industry. It consists of The digitalization of terrestrial service covering the representatives from the MPHPT, NHK, 127 commercial nation will have started by 2006, and it will include a television broadcasters, broadcasting related organizations, partially accelerated program for analog channel manufacturers, distributors, and consumer organizations. adjustment countermeasures in "frequency congested" It works to promote various approaches toward the steady areas, as previously noted. The biggest challenge will be implementation of digital terrestrial broadcasting. the digitalization of the many small-scale relay broadcasting stations throughout the country, including those in mountainous areas. In the case of NHK, in

Broadcast Technology no.16, Autumn 2003 C NHK STRL 11 comparison with the over 90% of the nation's households interference from other sources, sometimes from ones in that can be covered by the 550 main stations, the other countries. A co-channel interference elimination remaining 10% require nearly 2,000 small-scale relay system employs an adaptive array technology that stations for coverage. Issues of deficiencies in exclusive suppresses interference waves by identifying the angle of frequencies and related costs make it difficult to deliver arrival. services via microwave network to these relay stations; the - The last countermeasure listed in the Table 7 is equipped remaining option is networking as many relay stations as with a function to cancel the coupling loop interference possible via broadcast-wave relay. from its own waves in an environment where co-channel Because the broadcasting frequencies allotted for relay interference occurs. To expand the range of an SFN stations are inadequate, it is essential to employ broadcast- broadcast-wave relay, work is underway on new wave relays in which the received radio waves are algorithms to respond to two mixed-interferences retransmitted over the same frequency, in addition to the simultaneously. conventional methods of retransmission after frequency Determining which countermeasure technologies to conversion at a relay station. The realization of such a apply in SFN or MFN broadcast-wave relay stations will be technology will make feasible the construction of a done based on a network design that considers both the network that is both frequency and cost efficient, through reception environment and future station construction the incorporation of broadcast-wave relay stations into a plans. The most important issue, regardless of the type of single frequency network (SFN). This, however, will only be countermeasure technology used, is to prevent digital possible if one can suppress coupling loop interference signal transmission disruption, the so-called cliff effect. (CLI) caused by relayed waves feeding back to a receiving Broadcast-wave relay transmission of digital broadcasting antenna. The countermeasure technologies for broadcast- in an extremely congested frequency environment like wave relay operations, including a CLI canceller, are Japan's is unprecedented, intensifying the need for us to described in Table 7. thoroughly understand all issues affecting transmission - Since 1995, efforts have been made to develop a CLI and reception, especially those related to station countermeasure technology for digital terrestrial construction. For example, prior to the construction of a broadcasting networks. The specifications for the CLI national network of stations, a long-term trial using a pilot canceller are based on field trials conducted using 13 station and a backup exclusive network could be TAO digital experimental stations located from conducted. Digitalization would then advance in stages, to Okinawa and the analysis of a full-year's with the reliability of broadcast-wave relay transmissions worth of analog station data collected at satellite stations being verified in the field at each stage. in Tomakomai and Kamioka. - While an ordinary broadcast-wave relay converts the (Makoto SASAKI, Director, Digital Broadcasting Networks) frequency at relay stations, to avoid disruptions in digital broadcasting transmissions, there must be a large enough margin against severe multi-path fading with a large fluctuation of amplitude. Two types of diversity reception system, which differ in their equalization processing, have been fabricated for this purpose. A frequency domain processing scheme is also an effective technology for Hi-Vision (HDTV) mobile reception. Processing to determine signal points improves the CN ratio, making feasible multi-stage relay broadcasting. - The above technologies are equalization technologies for the identical channel fluctuations. A relay station is almost always installed on high ground, where besides receiving the desired waves, it is exposed to co-channel Table 7: Interference countermeasures technology for broadcast-wave relay Interference type Target relay Countermeasure Transmitting In-band Multi-path Fading station type wave coupling interference CLI canceller SFN Diversity reception Time domain processing SFN system Frequency domain processing MFN Co-channel interference elimination system MFN CLI canceller with co-channel interference SFN elimination function

Excellent Good Adequate Ineffective

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