iBet uBet web content aggregator. Adding the entire web to your favor.

The Wayback Machine - https://web.archive.org/web/20070311032635/http://web.ptc.org:80/library/ptr/june98/reinhart.html

This paper is the second in a three-part series on satellite broadcasting in the Pacific Hemisphere. Part 1, which was published in the December 1997 PTR, dealt with satellite television broadcasting in the Americas. This part covers satellite television broadcasting on the Asia-Pacific side of the Hemisphere. Part 3, to be published in the September 1998 PTR, will cover satellite sound broadcasting systems throughout the Hemisphere.

In the present paper, Section 2 summarizes the relevant background information from Part 1 on the evolution of the different generic types of satellite TV systems and describes their general technical characteristics.

Section 3 then describes the national, regional, and international satellite systems that carry the vast majority of satellite-delivered television programming to the countries of the Asia-Pacific region. Using the terminology introduced in Section 2, these are "DTH-C" and "DTH-K_u" systems; i.e.,satellite systems providing direct-to-home (DHT) transmission using frequency bands allocated to the fixed-satellite service (FSS) at C band (uplinks near 6 GHz and downlinks near 4 GHz) or K_u band (uplinks near 14 GHz and downlinks near 12 GHz).

Section 4 is devoted to "BSS" systems; i.e., the comparatively small number of satellite TV broadcasting systems that use frequency bands allocated to the broadcasting-satellite service (BSS). As explained in Section 2, a distinction must be made for the Asia-Pacific side of the Pacific Hemisphere between BSS systems with assignments in the BSS Plan for the 12 GHz band, and those that use one of three unplanned BSS frequency bands allocated to the BSS in Region 3.

To provide a framework for assessing the potential of the planned BSS band for future use by Asia-Pacific countries, Section 4 of the paper summarizes two aspects of the Plan for those countries: 1) The characteristics of the assignments to each country in the Plan, as just revised at the November 1997 ITU World Radiocommunication Conference (WRC-97), and 2) the large number of additions and modifications to the Plan that have been proposed for BSS systems serving the Asia-Pacific region.

The feasibility of using satellites for television broadcasting was recognized by the International Telecommunication Union (ITU) in 1971 when it allocated several frequency bands to the BSS. As defined in the international Radio Regulations, the BSS is "a radio-communication service in which signals transmitted or retransmitted by space stations [i.e., satellites] are intended for direct reception by the general public."

Use of one of these BSS bands (11.7-12.5 GHz) is governed by the WRC-97 revision of the frequency assignment Plan originally developed at the World Administration Radio Conference of 1977 (WARC-77). This Plan specifies the frequencies, orbital positions, beam coverages, polarization, and the maximum satellite equivalent isotopically radiated power (e.i.r.p.) that should be used by each country in ITU Regions 1 (Europe, Africa, Mongolia, and the former USSR) and 3 (the rest of Asia and Oceania). The details of the Plan for the Asia-Pacific side of the Pacific Hemisphere (Region 3 plus the Russian Federation) will be summarized in Section 4 of this paper.

The rest of the BSS bands available to Asia-Pacific countries are unplanned. Use of these bands for satellite TV is governed by regulatory procedures similar to those for the FSS; i.e. each proposed BSS system must "coordinate" with existing and previously proposed systems in all of the radiocommunication services to which the bands are allocated. The bands in question are 620-790 MHz, 2520-2670, and 12.5-12.75 GHz. Besides the need for coordination, each band is subject to constraints on coverage, type of reception (individual or community), and/or power flux density as specified in footnotes to the international allocation table. When it is necessary to distinguish BSS systems using the unplanned bands, they will be identified as "BSS-U," "BSS-S," and "BSS-K" systems, respectively. Those operating in the planned band will be referred to simply as "BSS" systems.

During the last twenty years, neither the planned 12 GHz band, nor any of the three unplanned bands have been heavily used by Asia-Pacific countries. There are several reasons for this. Initial deterrents included the high cost to develop and launch dedicated single-service satellites with e.i.r.p. high enough to be received by small consumer-grade receiving antennas feeding comparatively high-noise- temperature receivers.

Later (around 1980), it was recognized that the e.i.r.p. of transponders on satellites operating in the fixed-satellite service (FSS) allocations at C and K_u band had increased to a point where they could be used to support TV transmissions to practical home receiving installations as well as the point-to-point transmission of the telephone, data, and video traffic for which they were originally intended. This use of the FSS bands for such direct-to-home (DTH) service offered several advantages over the BSS bands,

As a result of these advantages, the number of FSS systems at both C and K_u bands that used analog frequency modulation (FM) to carry one or two television programs per transponder grew rapidly from the mid-1980's to the mid-1990's. Such systems now serve tens of millions of viewers throughout the world. With the development of higher-power transponders and lower-noise receivers, the effective diameter of the required home dish antenna has dropped to as low as 1.8m at C band and 60 cm at K_uband.

The success of FSS DTH systems encouraged the countries of Regions 1 and 3 to take two significant actions in the period 1992-1997 that strongly affect the original WARC-77 Plan.

This renewed interest in the Regions 1 and 3 BSS Plan was concurrent with a technological development of enormous significance to both BSS and FSS DTH systems. Advances in digital video compression made it possible to transmit five or six digitally-encoded TV program channels in the radio-frequency bandwidth normally required for a single analog FN program. This development led a number of C and K_u band FSS DTH operators to convert their TV transmissions from analog to digital. It may also lead to a new appreciation of the utility of the four 27 MHz channels assigned to the typical Region 3 country in the planned BSS band now that they can support up to 24 TV program channels.

The current situation is that, on the Asia-Pacific side of the Pacific Hemisphere as on the America's side, satellite TV systems can be divided into three principal types:

As previously noted, the few systems using the unplanned Region 3 BSS allocations near 0.7, 2.5, and 12.7 GHz will be identified as BSS-U, BSS-S, and BSS-K, respectively. Typical characteristics of the three major types of systems are presented in Table 1 for both the Asia-Pacific side of the Pacific Hemisphere (labeled Region 3 in the Table) and the America's side (labeled as Region 2).

Besides the differences between Regions 2 and 3 in the frequency band limits corresponding to DTH-K_u and BSS systems, and in the number of BSS channel assignments per country provided in the Regional Plans, Table 1 displays important differences between the two types of system within the same Region. For example, BSS systems are guaranteed at least one orbital position per country and freedom from interference due both to other satellites and to terrestrial sources. Moreover, the higher e.i.r.p.s of the BSS assignments permit the use of much smaller receiving antennas compared with DTH-C, and somewhat smaller compared with DTH-K_u systems. On the other hand, these advantages for BSS systems come at the high cost of building and launching a dedicated BSS system compared with leasing or buying capacity on an existing FSS satellite.

It is not surprising that the Asia-Pacific side of the Pacific Hemisphere is a very attractive market for satellite TV broadcasting. The region has a population of over three billion distributed over a vast geographic area that includes many rural areas and isolated islands as well as densely-populated, low-rise, often un-cabled urban and suburban areas. Moreover, the necessary satellite resource is in place.

The number of FSS satellites offering C- and K_u band transponders suitable for DTH transmission (as well as for distribution to cable TV systems) in the Asia-Pacific region is rivaled only by the number available to North America. And this satellite resource is growing more rapidly than anywhere else in the world. Indeed, some market researchers predict an excess of transponder capacity within the next few years.

There are also factors that constrain the Asia-Pacific market for satellite TV. Although the per-capita income and number of households with television sets is high in countries like Japan and Australia, it is comparatively low in many other countries such as India, Bangladesh and Vietnam. In addition, a number of Asia-Pacific countries currently impose severe restrictions on the ownership and use of satellite dishes. These include China, India, Iran, Myanmar, and Vietnam. TV programs for these countries are still distributed by satellite, but the homeowner or apartment dweller is expected to receive them through cable TV systems.

There are at least 73 operational satellites using the FSS allocations at C- and K_u band to transmit signals receivable within the Asia-Pacific region. These satellites are identified in Table 2 together with some of the technical characteristics of interest to possible DTH use. They are listed in the sequence of their current orbital position in degrees East longitude as given in Column 1 of the Table. Note that, in common with FSS satellites serving North America, the orbital separation between adjacent satellites is typically 2 degrees or 3 degrees.

Table 1. Typical characteristics of satellite TV
broadcasting systems

view table

The name assigned to each satellite by its operator is shown in Column 2. With two exceptions, the country responsible for intersystem coordination and registration of the satellite in compliance with ITU procedures is identified in Column 3 using the ITU symbol of the country. The exceptions are the satellites operated by two multi-national organizations, The Arab League (AL), and Intelsat (IS). Relations with the ITU for these satellites are handled by Saudi Arabia and the USA, respectively, as notifying administrations.

Column 4 indicates the year that the satellite was launched; i.e., the beginning of its operational life (BOL). This is of interest because many of the satellites in the Statsionar series and a number of the older Intelsat satellites have gone beyond their design lifetime and, for lack of station-keeping fuel, are operating in increasingly inclined orbits.

It is apparent that the satellites listed in Table 2 fall into a number of families, or series, corresponding to a particular administration and/or operating agency, and often, a similar spacecraft design. For example, the Australian Optus series includes Optus A3 at 152 degrees E, Optus B1 at 160 degrees E, and Optus B3 at 156 degrees E, all with similar specifications. Other countries are responsible for more than one series. For example, in Japan, separate companies operate three different families of satellites: JC Sat 2, 3, 4, and 5 at 154 degrees E, 128 degrees E, 124 degrees E and 150 degrees E, respectively; Superbird A, B, and C at 158 degrees E, 162 degrees E, and 144 degrees E, respectively; and N-Star A and B at 132 degrees E and 136 degrees E, respectively. Altogether Table 2 contains about 25 such families including four series of Intelsat spacecraft.

Columns 5, 6 and 7, respectively show the number of C-band transponders, the type of polarization used (C for circular, L for linear), and an indication of the geographic coverage provided by the satellite beam(s) (N for national, R for regional). Columns 10, 11, and 12 provide corresponding data for the K_u band transponders carried by most of the satellites.

It will be noted that, of the 73 satellites listed, 19 carry only C-band transponders and 12 carry only K_u band transponders, but each of the remaining 42 satellites operate in both bands. A slight majority of the C-band transponders transmit on circular, rather than linear, polarization, but the K_u band transponders on nearly every satellite launched since 1990 use linear polarization.

The geographic coverages are rather more difficult to describe. Comparatively few satellites provide purely national coverage to the country identified in Column 2. Most of them provide coverage of multiple countries either in one large beam or through a series of separate "spot" or "zone" beams. The details of the resultant coverage areas are only hinted at in Columns 7 and 12.

As an example of the variety of regional coverages that are offered, Figure 1 displays the e.i.r.p. contours for two C band beams and three K_u band beams provided from a single satellite, PAS2 at 169 degrees E. Coverage maps for most of the other satellites in Table 2 are readily available in the "1997 Asia-Pacific Satellite Industry Directory" (Phillips Business Information Inc., Potomac, MD 20854, USA) or the "Asia-Pacific Satellites on Disk Library" (Mark Long Enterprises, Inc., P.O. Box 159, Winter Beach, FL 32971, USA).

Not included in the table are three other satellite parameters which affect their suitability for DTH service: transponder bandwidth, transponder output power, and the e.i.r.p. levels in the direction of the satellite coverage areas. Nearly all of the transponder bandwidths lie in the range 36 to 77 MHz. This is more than adequate to support from 1 to 3 analog TV channels or up to six times this number of digital channels. For the satellites listed in Table 2, transponder output powers range from 5W to 75W at C-band and from 10W to 120W at K_u band. The transponder power and bandwidth then combine with the gain of the satellite transmitting antenna towards the beam coverage area to determine the e.i.r.p. per rf channel. It is this quantity and the rain attenuation statistics in the coverage area that determine the size of receiving dish required for reliable reception.

Table 2. Operational FSS Satellitesand DTH use in
the Asia-Pacific broadcasting systems

view table

Table 1 includes typical e.i.r.p. ranges for DTH transmission at C- and K_u band and the corresponding receiving antenna diameters. For countries with heavy rainfall, the indicated antenna sizes, especially at K_u band, will not be large enough to yield the 99 percent-of-the-worst-month level of signal availability considered as the performance objective for most satellite TV broadcasting.

It should also be emphasized that not all of the satellites listed in Table 2 will produce e.i.r.p. levels high enough to support high-availability DTH service. However, the entries in Columns 8 and 9 for C band and in Columns 13 and 14 for K_u band will identify most of the satellites currently being used for this application. These data will be discussed further in the next sub-section.

As just noted, an indication of the extent to which the FSS satellites listed in Table 2 are currently being used for DTH service in the Asia-Pacific Region is provided in Columns 8 and 9 for C-band transponders, and in Columns 13 and 14 for K_u band transponders.

Table 2a. Operational FSS Satellitesand DTH use in
the Asia-Pacific broadcasting systems (cont.)

view table

Columns 8 and 13 indicate the number of TV programs being transmitted using analog modulation. Normally, this number is equal to the number of transponders required. Similarly, Columns 9 and 14 indicate the number of TV programs being transmitted using digital video compression and digital modulation. In this case, however, the number of transponders required is normally only one-quarter or one-fifth the indicated number of program channels. However, in a few cases, it is known only that a transponder is carrying TV programs in digital form; here, the number in columns 9 or 14 is followed by a "Tr" to indicate that it refers only to the number of transponders carrying digital TV programs, and not the number of individual digital program channels.

The data on the numbers of TV programs presented in Table 2 are based on a combination of information from three sources.

The data in the first of these publications were based on monitoring of signals received in Japan. That contained in the second publication presumably represents only the TV channels receivable in India. The third reference is probably more inclusive, but it is possible that some TV transmissions were not taken into account. Therefore, the total level of transponder usage for DTH service may be somewhat higher than the total implied by Table 2.

On the other hand, the listings do not distinguish between program transmissions intended for community reception or cable headends and those intended for direct-to-home use. Nor do they give any indication of the number of households equipped for DTH reception in various countries and the number of TV programs receivable by those so equipped. These questions are addressed in the next subsection.

The data in Table 2 on the use of transponders for TV transmission show that nearly 40 out of the 73 satellites listed carry at least a few program channels. However, in order to receive and view any of these TV programs, a household must first have a TV set. It is then of interest to know, for each Asia-Pacific country, how many TV households are, in fact, equipped for DTH reception, and to compare this number with that for cable TV reception. The ratio of DTH-equipped households to total TV households is the "DTH penetration," and the corresponding ratio for cable subscribers is the "cable penetration."

Figure 2 presents 1997 estimates of all five of these quantities for 21 Asia-Pacific countries. Not surprisingly, DTH penetration is highest (over 20%) in countries such as Japan, New Zealand, and Pakistan with few government restrictions on the use of DTH, low cable penetration, and/or high per-capita income. Conversely, low DTH penetration (less than 3%) is expected, and generally observed where the reverse of one or more of these conditions exist such as Iran, China, Russia, Myanmar, and Vietnam.

For reasons that will be suggested in the next Subsection, it is expected that DTH penetration will increase substantially during the next few years. Some analysts predict a growth rate on the order of ten per cent per year.

With regard to the specific satellite TV programs receivable by DTH-equipped households in individual Asia-Pacific countries, no comprehensive country-by-country breakdown was available. However, the channel guides for India cited in Subsection 3.2 above are probably representative of the number of satellites and program channels potentially receivable at C band in many Asia-Pacific countries. Specifically, in India 19 different satellites collectively transmit a total of 130 analog TV channels at C band. Eight of these satellites also provide a total of 53 digital channels at C band. Presumably, K_u band TV transmissions are also receivable.

In practice, the number of TV channels viewable in an average DTH household will be much smaller. To view all the of the programs listed in a channel guide for a particular country would require a very sophisticated DTH receiving installation.

Antennas would have to be steerable and equipped to handle C and K_u band signals on both senses of linear and circular polarization. Receivers would have to be able to demodulate and decode both analog and digital signals using a variety of conditional access coding methods.

For this reason most DTH households are limited to the channels available in a single band from a particular satellite using one type of polarization and the same type of modulation and coding.

There are several reasons that DTH penetration is likely to grow in the future. One of the most fundamental is that before the current economic downturn in Southeast-Asia, at least fifteen additional satellites were scheduled for launch. They included the addition of one or two satellites to each of several existing series, and the launch of the first satellite in at least four new series, as follows:

Asiasat: 3R at 105.5 degrees E and 4 at 122 degrees
E Chinastar: 1at 87.5 degrees E
Insat: 2 E at 83 degrees
E Intelsat: 901at 62 degrees E, 902 at 50 degrees E, & K-TV at 95 degrees E
Measat: 3 at 91.5 degrees E
Orion: 3 at 139 degrees E
PAS: 7 at 68.5 degrees E and 8 at 166 degrees E
Sinosat: 1 at 110.5 degrees E
Superbird: 4 at 162 degrees E
ST: 1 at 88 degrees E
Telkom: 1 at 108 degrees E
Thaicom: 4 at 120 degrees E

One of the most interesting of these new satellites, and to some extent representative of their capabilities, is listed here as "K-TV" in the Intelsat family. Now under construction in France, it was designed specifically for the DTH market in Asia. Unlike most other members of the Intelsat family, all of its transponders operate at K_u band. Coverage will be provided in two fixed, shaped beams over India and China, and two steerable spot beams with nominal pointing towards the Far East and Malaysia. Transponder output power will be sufficient to yield e.i.r.p.s of 50 to 55 dBW in these beams, making reception possible with dishes as small as 45 cm.

It is also of interest that this satellite will not be operated by Intelsat. Along with five other Intelsat satellites already in operation, including Intelsat 513 at 183 degrees E and Intelsat 703 at 57 degrees E, ownership of K-TV will be transferred to an independent new venture called New Skies Satellite, N.V., whose creation was approved by the Intelsat Assembly of Parties in March 1998.

If all of the new satellites were to be launched, they would add over 300 new C band transponders and about 280 new K_u band transponders. However, even in this optimistic scenario, the present operational capacity of about 750 C band transponders and 360 K_u band transponders would not increase by these amounts. Some of the older satellites, already in inclined orbits, will be retired and some of the new satellites would replace existing members of their series.

Nonetheless, any significant increase in the number of available transponders should lead to lower transponder leasing costs and an increase in the number of transponders leased for DTH transmission. With the continuing trend from analog to digital TV, the number of program channels will increase even more rapidly than the use of additional transponders. This large increase in TV program channels will, in turn, permit system operators to increase the diversity of their TV programming so as to better target local viewing preferences in different countries and thus stimulate the demand for DTH service.

In addition to these factors, expected reductions in the cost of DTH receiving equipment, the availability of new standards for integrated receiver-decoders (IRDs) for digital multi-program TV, and the probable easing of government restrictions on home dish use in some countries should also lead to higher DTH penetration.

A final observation is that, when compared with the Americas side of the Pacific Hemisphere, the satellite TV market on the Asia-Pacific side is more like that of Latin America than that of the US and Canada. That is to say, there probably will not be a rapid transition from DTH-C and DTH-K_u systems to BSS systems in the planned band such as has occurred in North America over the last few years. Some of the reasons for this will be discussed in the next (and last) Section below.

For reasons discussed in Section 2 above, none of the bands allocated to the BSS for use in the Asia-Pacific region, planned or unplanned, has been heavily used. However, the BSS bands, and especially the planned bands (11.7-12.2 GHz in Region 3, and 11.7-12.5 GHz in Region 1) are very important to the future of satellite broadcasting in this part of the Pacific Hemisphere. In this Section, each of the BSS bands will be examined in turn to identify the other radiocommunication services with which the band must be shared, the constraints on BSS use, and the characteristics of systems that have been, or are planned to be, implemented.

Terrestrial TV broadcasting systems operate in bands allocated to the broadcasting service (BS) in the VHF and UHF parts of the spectrum. The 1971 World Administrative Radio Conference decided that the 620-790 MHz part of the UHF broadcasting band could also be used for assignments to satellite television stations in the BSS, subject to certain conditions. These conditions are specified in footnote S5.311 to the allocation table and include the use of frequency modulation, securing the agreement of "affected" administrations, and limiting to -129 dBW/m2 the power flux diversity incident at elevation angles below 20 degrees on other countries (unless they consent to higher values).

In 1976, the Soviet Union used this band to establish the first geostationary BSS system, Ekran. Each satellite in the Ekran series was designed to provide one TV and 2 radio program channels to cable TV systems throughout the USSR and to individual home receivers in northern Siberia. Early Ekran satellites used orbital positions in the range from 48 degrees E to 95 degrees E, but recent Ekrans, including the current Ekran 20, have been stationed at 99 degrees E.

These 3-axis stabilized satellites carry a single 24 MHz, 200 W transponder, feeding a 28 dB gain antenna transmitting on right-hand circular polarization to produce e.i.r.p.s in Siberia in the range 50 to 55 dBW at 714 MHz. The corresponding feeder link uses left-hand circular polarization at 6200 MHz.

The second unplanned BSS band is at 2520-2670 MHz in the frequency range commonly known as "S band." Footnote S5.416 limits the use of this band to national and sub-regional systems designed for community reception subject to agreement with affected administrations and to a specific limit on power flux density. In addition to sharing the entire band with the FSS and the terrestrial fixed and mobile services, the sub-band 2535-2655 MHz is allocated in a number of Region 3 countries to the BSS (sound) and the BS (sound) for digital audio broadcasting (DAB) systems. Satellite DAB use of the band will be discussed in Part 3 of the present series.

To date, satellite television broadcasting in the 2520-2670 MHz BSS band in Asia-Pacific countries is limited to India's INSAT series of domestic coverage, multi-service satellites and the INDOSTAR series recently launched for Indonesia.

Figure 2. Figure 2. Penetration of DTH services in
Asia-Pacific Countries. (reprinted with permission
from the November 1997 issue of Sky Report,
published by Media Business Corp., Golden Colorado,
USA. the Asia-Pacific broadcasting systems

view map

Each of the INSAT series, from INSAT 1A in 1982 to INSAT 2D in 1996, carry two S band transponders in addition to the complement of C band transponders described in Section 3 above. The S band subsystem is used primarily to broadcast educational TV programming to community receivers in thousands of villages throughout India. This application is a direct outgrowth of India's Satellite Instructional Television Experiment (SITE) carried out at principally at UHF (790 MHz), but with some S band receivers, in the mid-1970s using NASA's Applications Technology Satellite, ATS-6.

The INSAT S band transponders have an rf bandwidth of 40 MHz, an output power of 50 W, a beam-center e.i.r.p. of 42 dBW, and transmit on left-hand circular polarization. Active satellites in the INSAT series include: ID at 83 degrees E, 2A at 74 degrees E, and 2B and 2C co-located at 93.5 degrees E. To replace the transponder capacity lost with the failure of INSAT 2D last year, the Indian Government recently purchased ARABSAT 1C, renamed it INSAT 2DT, and stationed it at 55 degrees E. As with the original INSAT series, INSAT 2 DT carries two 50 W S band transponders producing a beam center e.i.r.p. of 41 dBW.

The first of a projected series of four BSS-S satellites, INDOSTAR 1, was placed in orbit at 107.7 degrees E last year. It is designed to broadcast up to 40 TV program channels throughout Indonesia using five 70 W transponders. In addition, it is planned to provide a digital audio broadcasting (DAB) service to Indonesia using the L band worldwide allocation to BSS (Sound) at 1452-1492 MHz.

The unplanned BSS allocations at UHF and S band are worldwide - i.e., available in all three ITU Regions. The third unplanned BSS, allocation, 12.5-12.75 GHz, is unique to Region 3. Like the other bands, however, it must be shared with other services and is subject to conditions intended to facilitate sharing with systems in those services; in this case the FSS (space-to-Earth) and the terrestrial fixed and mobile services. In particular, footnote S5.491 limits BSS-K systems to community reception and subjects them to a power flux density limit of -111 dBW/m²/27 MHz.

The existence of the BSS allocation at 12.5 - 12.75 GHz presents Region 3 countries with a choice if they wish to utilize about 500 MHz of K_u band spectrum for satellite TV broadcasting. They can use the FSS space-to-Earth band, 12.2-12.75 GHz, for DTH and/or distribution to cable head ends and broadcast stations, or they can use the lower 300 MHz of this frequency range for such DTH transmissions and the upper 250 MHz for BSS transmissions to community receivers.

Australia has made the latter choice. Each of its OPTUS satellites, A3 at 152 degrees E, B1 at 160 degrees E, and B3 at 156 degrees E, uses part of the BSS band to support the "homestead and community broadcasting satellite service" (HACBSS) to deliver one TV channel using B-MAC analog encoding, six 15k Hz digital sound channels, and auxiliary data and telex services for reception by 1.5m dishes.

As explained earlier, the BSS allocations at 11.7 - 12.2 GHz for Region 3 countries, and 11.7 - 12.5 GHz for Region 1 countries are governed by a frequency assignment Plan. For each specified BSS service area (mostly national or sub-national), the Plan lists the channel frequencies, orbital positions, satellite beam characteristics, polarization, and maximum satellite e.i.r.p. that should be used.

The original Regions 1 and The original Regions 1 and 3 BSS Plan was developed in 1977. It was revised at WRC-97 to reflect not only current BSS technology, but also the changes in the geographic and political situation of Regions 1 and 3 countries and territories that have taken place since 1977. All aspects of the WRC-97 BSS Plan, including the regulatory procedures for its implementation and modification, are given in Appendix 30 of the ITU Radio Regulations, as amended by the Final Acts of WRC-97. The FSS (Earth-to-space) allocations at 14.5 - 14.8 GHz, and 17.3 - 18.1 GHz are also governed by an assignment Plan providing feeder links (uplinks) for the 12 GHz BSS assignments. This Plan is given in Appendix 30A of the Radio Regulations subject to the modifications adopted at WRC-97.

Since the WRC-97 BSS Plan for Regions 1 and 3 was adopted only 6 months ago and the definitive version of the WRC-97 Final Acts has not yet been published, a summary description of the assignments to countries in the Asia-Pacific part of the Pacific Hemisphere is provided in Table 3.

Referring to this table, column 1 lists alphabetically the total of 37 independent countries and 12 territories with assignments in the Plan, together with the ITU symbol used to identify them. Column 2 gives the symbol of the responsible ITU administration in each case. For example, assignments to the Cook Islands, Nauru, Niue, and Tokelau are all administered by New Zealand.

Column 3 in Table 3 indicates the orbital position(s) assigned to each country or territory. Note that several large countries, such as Australia, China, India, Indonesia, New Zealand, Papua New Guinea, and the Russian Federation have two or more orbital positions. In certain other cases, such as Japan and South Korea, a second position was added as a result of a modification to the original 1977 BSS Plan. Apart from these additions and a major shift in the orbital positions assigned to countries whose geographic and/or political situation had changed, such as Australia and the Russian Federation, the orbital positions in the WRC-97 Plan are identical to those provided in the original WARC-77 Plan.

Column 4 shows the number of beams assigned to a country at each of its orbital positions. All beams in the Plan are assumed to be of elliptical or circular cross section although shaped beams are normally used in the practical implementation of Plan assignments. In most cases, there will be a separate beam for each of the BSS service areas covered from a given orbital position. However, as explained in the Notes for column 4, there are cases in the Plan where more than one beam is assigned to the same service area, either from a single orbital position or from separate positions.

For countries with only a single beam from a single orbital position, the beam coverage, or "footprint" is simple to describe. It is the intersection with the Earth of a beam of elliptical cross-section so sized and oriented that it just encompasses the national service area of the country.

Table 3. The WRC-97 plan for the Asia-Pacific
side of the Pacific Hemisphere

view table

The multiple beams assigned to cover larger countries are best described by maps. Figures 3, 4, and 5 provide such maps for three of the several countries in the plan whose longitudinal extent and/or geographic distribution of language or ethnic groups require multiple beams from two orbital positions; specifically Australia, India, and Indonesia. The labels for each beam indicate the ITU beam number, the number of assigned channels and the orbital position from which the beam originates.

Returning to Table 3, the interpretation of the total number of channels in column 5 and the breakdown of channels per beam in column 6 is explained in the notes to the table for these columns.

Examples of other BSS system technical characteristics typically used in implementing the Plan assignments, e.g., transponder bandwidth, satellite e.i.r.p., and receiver antenna size, were given in Table 1.

Among Asia-Pacific countries, only Japan, South Korea, and Russia have implemented assignments in the Regions 1 and 3 BSS Plan. Indeed, Japan was one of the first countries in the world to do so, having launched the BSE, or "Yuri," satellite into its assigned orbital position at 110 degrees E in April, 1978. This was followed by BS-2A in January 1984, and BS-2B in February, 1986, both at 110 degrees E, each carrying two active 100W transponders to provide e.i.r.p.s of 45-54 dBW over the Japanese mainland, and 45 dBW over Okinawa and other offshore islands. Subsequent launches into the 110 degrees E slot include BS3 Yuri A, BS3 Yuri B, and BS 3N in 1990, 1991, and 1994, respectively, each carrying three 120W transponders.

Figure 3. Beam Coverage Areas for Australia
(152.0 E & 164.0 E) in the WRC-97 BSS Plan

view diagram

Today, regular service from 110 degrees E is provided on BS4A using channels 5, 7, 9, and 11 in the Plan. Channels 7 and 11 are used by NHK to provide standard-definition analog 525-line NTSC programming in the clear to about 11 million viewers using 45 to 50 cm parabolic dishes or equivalent flat-plate array antennas. Channel 5 is encoded for a subscription audience of about 3 million, and channel 9 carries 1125-line, MUSE-encoded high definition TV. The expected launch of BS4B in the year 2000 will enable the use of the remaining four Japanese assignments in the WRC97 Plan, channels: 1, 3, 13, and 15. They will be used to broadcast digital TV signals, but the detailed signal characteristics remain to be decided.

South Korea is providing national BSS coverage with a beam-center e.i.r.p. of 59.4 dBW using three 120 W transponders on Koreasat 1 and Koreasat 2, launched in 1995 and 1996, respectively, and co-located at 116 degrees E.

It is understood that the Gals 1 and Gals 2 satellites launched by Intersputnik in 1994 and 1995 into the slot at 36 degrees E provide three transponders each with an e.i.r.p. of 57 dBW towards the Western part of the Russian Federation.

As may be confirmed by an inspection of column 6 in Table 3, the vast majority of assignments to Asia-Pacific countries in the WRC-97 BSS Plan provide either four or five 27 MHz-bandwidth channels on beams that cover a service area of only national or sub-national extent. Just four countries have more channels per beam; Japan, 8; Australia and South Korea, 6; and Russia, 16.

Figure 4. Beam Coverage Areas for India
(56.0 E & 68.0 E) in the WRC-97 BSS Plan

view diagram

By contrast, the commercially-successful DTH-C and DTH-K_u systems serving Latin America, Europe and the Asia-Pacific region use satellites that provide many times more transponders in beams of multi-national extent, often at both C and K_u band. With such systems as a model, many nations began in the early 1990s to apply the plan modification procedures of Appendices 30 and 30A of the Radio Regulations to seek additional assignments in the original 1977 BSS Plan.

In order for a proposed modification to be incorporated into the Plan, the procedures require that the proposing administration secure the agreement of all administrations whose plan assignments or existing systems would be affected - i.e., receive interference from the proposed modifications in excess of levels specified in Appendices 30 and 30A. The agreement-seeking process normally entails bilateral coordination between the proposing and each of the affected administrations.

A few of the modifications and additions proposed by Asia-Pacific countries were successfully coordinated with existing Plan assignments and were incorporated into the revised Plan adopted at WRC-97 and summarized for Asia-Pacific countries in Table 3. However, the majority of them are still pending as summarized in Table 4.

As indicated in the first column of Table 4, proposed modifications for service to Asia-Pacific countries were received by the ITU from some 16 administrations and from Intelsat. Altogether these additions would increase the channel assignments at orbital positions in the existing Plan (or would add assignments at new orbital positions) to accommodate the 75 satellites named in Column 2 of the Table. Coincidentally, this is close to the number of FSS satellites already serving Asia-Pacific countries at C and/or K_u band.

The date that each of the proposed Plan modifications was received at the ITU is shown in Column 3 of Table 4. This date is important because, before being accepted into the Plan, each proposed modification must coordinate, not only with affected assignments in the existing Plan and with affected systems in other services, but also with all previously submitted modifications that they affect - i.e., potentially interfere with.

The main reason that the modification listed in Table 4 are still pending is that they embody technical system characteristics that cause them to affect a large number of the other systems, which leads to a large number of often very lengthy bilateral coordination actions.

Figure 5. Beam Coverage Areas for Indonesia
(80.2 E & 104.0 E) in the WRC-97 BSS Plan

view diagram

The remaining columns in the table describe some of the technical characteristics of the systems for which the Plan modifications are being sought. Comparing the orbital position in Column 4 of Table 4 with those of the existing Plan shown in Column 3 of Table 3, it will be seen that many of the proposed positions are exactly half-way between existing positions - i.e. 3 degrees from each of two adjacent Plan positions. On the other hand, many other proposed new positions are separated by only 1.5 degrees or less both from existing positions, and from other proposed new positions. To the extent that such closely-spaced satellites serve geographically adjacent or overlapping service areas on the same or adjacent channels, they are almost certain to affect existing Plan assignments and other proposed modifications.

It will be noted that, in nearly every case, the proposed number of channels shown in Column 6 is the maximum available at a single orbital position in the Plan: 24 or 25 for Region 3 service and 40 for those modifications which would offer beams into Region 1 countries such as Russia. This choice maximizes the capacity of the system for which the Plan modification is intended. But it also means that all existing and proposed assignments at neighboring orbital positions are potentially affected by co-channel and adjacent channel interference.

Other features that will make it difficult to coordinate the proposed modifications are reflected in the choices for channel bandwidth and polarization indicated in Columns 7 and 9 respectively. Both the original 1977 BSS Plan and its WRC-97 revision are based on dividing the BSS band into partially-overlapping channels with a bandwidth of 27 MHz and a particular channel separation and using circular polarization for emissions. But, following the example of European DTH-K_u band systems, at least half of the proposed systems would either use, or seek the option of using, 32, 33, or 36 MHz channels, possibly with a different channel separation from that used in the Plan. And, also in imitation of DTH-K_u systems, more than half of the modifications seek to use, or preserve the option of using, linear polarization.

The use of a frequency plan, channel bandwidth, and type of polarization different from those incorporated into the Plan is technically sound in and of itself. However, it sacrifices the possibility of using either polarization isolation or frequency inter-leaving that otherwise would mitigate interference into existing assignments and into those proposed Plan modifications that incorporate the same technical choices as the existing Plan assignments.

For all of the reasons just described, as well as delays at the ITU in processing the large number of proposed modifications that were received, progress towards obtaining the bilateral agreements necessary for incorporating them into the BSS Plan has been very slow.

Table 4. Proposed modifications to the WRC-97
BSS Plan for Asia-Pacific countires

view table

Adding to the uncertainty as to whether and when the proposed additions can be incorporated into the BSS Plan for implementation by Asia-Pacific countries is an action taken at WRC-97. In response to proposals from developing countries in Region 1, WRC-97 adopted Resolution 532 which established a multi-national Group of Technical Experts (GTE) to study the feasibility of increasing the minimum number of channels assigned to Regions 1 and 3 countries from 4 or 5 to 10.

Working under guidance from an Inter-conference Representative Group (IRG), the GTE has held the first in a series of meetings and is considering at least three technical approaches to achieving the proposed increase in channel capacity. To the extent that any such approach is successful in doubling the minimum number of channels assigned to each country in the Plan, it must necessarily reduce the orbit-spectrum capacity available for accommodating the proposed Plan modifications.

Despite the foregoing description of the difficulties surrounding the incorporation into the plan of the modifications listed in Table 4, the prospects for obtaining the necessary agreements and/or implementing some of the Plan modifications are not entirely bleak for the following reasons.

On balance, however, it may still be concluded that it is unlikely that very many of the DTH-like modifications listed in Table 4 will become available for implementation in the next few years. Therefore, the present dominance of DTH-C and DTH-K_u systems on the Asia-Pacific side of the Pacific Hemisphere can be expected to continue through at least the end of the century.

The author acknowledges with gratitude the contractual support of NASA in the preparation of this paper. He also extends special thanks to Mr. Sharad Sadhu of the Asia-Pacific Broadcasting Union for providing many valuable inputs to the paper, and to the several delegates from Asia Pacific countries who shared their knowledge of satellite broadcasting during ITU meetings and conferences.

Nov	MAR	Aug
	11
2004	2007	2008

Satellite Broadcasting in the Pacific Hemisphere Part 2- Satellite TV in the Asia-Pacific Region

Satellite Broadcasting in the Pacific Hemisphere
Part 2- Satellite TV in the Asia-Pacific Region