HAPS

High Altitude Platforms Systems (HAPS) : Wahana Terestrial Masa Depan
**Eddy Setiawan

Abstrak
The exponential growth of Internet and multimedia in big cities demand a high reliable and fast deployable infrastructure. These needs have been solved partly by the deployment of terestrial (wire, optical fiber and wireless) and satellite infrastructure. Anyhow each of the solution poses certain degrees of barier in term of cost, capacity and quality. The solution by applying a flying object flew closed enaough to the earth and high enough from ground could, in certain ways, solve the problems faced by the two previous infrastructure solutions. This solution is internationally named High Altitude Platform Systems (HAPS). This paper will highlight and summarize the idea, the technical and the applications issues of HAPS. This paper will be concluded by a summarized proposal of HAPS implementation in Indonesia.
Pendahuluan
Infrastruktur telekomunikasi dan broadcasting selama ini dibagi menjadi dua, pertama adalah infrastruktur terestrial dan kedua adalah infrastruktur extra-terestrial atau satelit. Infrastruktur terestrial terdiri dari terestrial darat dan laut, dimana untuk terestrial darat terdiri dari infrastruktur jaringan kabel (tembaga dan fiber optik) dan radio gelombang mikro. Sedangkan infrastruktur terestrial laut terdiri dari jaringan kabel tembaga dan fiber optik.
Setiap lapisan infrastruktur tersebut mempunyai kelebihan dan kekurangan. Infrastruktur terestrial meskipun mempunyai keunggulan di “unlimited bandwidth expansion” tapi kekurangannya adalah fleksibilitas dan mobilitas. Sedangkan infrastruktur satelit, kelebihannya adalah fleksibilitas dan mobilitas, tetapi resikonya tinggi, “limited bandwidth expansion”dan kelembaman waktu (time delay) tinggi khususnya untuk suara dan data interaktif. Sehingga penggunaan kedua infrastruktur tersebut mempunyai dua segment kebutuhan vertikal yang berbeda.
Di lain pihak, perkembangan dan konvergensi teknologi telekomunikasi, broadcasting dan informatika begitu cepat yang menghasilkan teknologi multimedia dengan berbagai macam aplikasi dan layana, berpita lebar dan berkecepatan tinggi. Kebutuhan akan jasa multimedia seperti ini disamping menuntut penambahan lebar pita frekuensi juga kecepatan implementasi. Sebagai solusi yang paling rasional adalah dengan pemanfaatan teknologi terestrial 'non-ground', alias wahana dirgantara super, pada ketinggian 20-50 km, dikenal dengan High Altitude Platform Systems (HAPS). Dalam perkembangannya ada beberapa solusi teknologi HAPS yang akan dijelaskan lebih lanjut.
Sejarah Singkat
Ketinggian 20 s/d 50 km dinamakan lapisan stratosfir. Penelitian terhadap lapisan tersebut sudah dilakukan lebih dari 40 tahun. Beberapa hal yang menarik adalah mengenai kestabilan perubahan angin pada ketinggian tersebut yang cenderung lamban dan konstan, 50 m/detik pada ketinggian 21 km [YCL-HYE].
Lapisan stratosfir berada diatas lapisan perubahan cuaca dengan suhu antara 0°C s/d -60°C dengan tekanan antara 90 mb s/d 0 mb[LC], serta jauh diatas jalur penerbangan sipil dan awan hujan (diatas kawasan turbulansi udara). Ditinjau dari aspek-aspek tersebut maka lapisan stratosfir dianggap layak untuk dimanfaatkan sebagai media observasi bumi dengan menggunakan wahana balon udara/gas atau pesawat terbang.
Dikaitkan dengan keperluan telekomunikasi maka lapisan stratosfir dapat dimanfaatkan untuk meletakan suatu wahana yang dapat memberikan layanan telekomunikasi dan broadcasting, atau multimedia, yang dapat memenuhi beberapa kriteria terbaik dari infrastruktur terestrial dan satelit, dinamakan High Altitude Platform System (HAPS).
Penelitian penggunaan HAPS sebagai wahana telekomunikasi dan broadcasting dilakukan oleh khusunya negara-negara maju, diantaranya Amerika Serikat, Eropa dan Jepang. Dalam hal ini, wahana HAPS dikembangkan dengan dua media yaitu : balon gas (gas yang lebih ringan daripada udara) dan pesawat terbang bermesin. Teknologi wahana balon gas dikembangkan oleh Amerika Serikat, oleh SkyStation dan SkySat, serta Jepang. Sementara teknologi pesawat terbang dikembangkan oleh Angel Technology (USA), dinamakan HALOTM (High Altitude Long Operation), dan oleh European Space Agency (ESA), dinamakan HALETM (High Altitude Long Endurance).
HAPS dibagi menjadi dua bagian utama, bagian pertama adalah platform (wahana) yang terdiri dari perangkat propulsi, bahan bakar, perangkat komunikasi pengendalian-pengukuran dan penyediaan energi. Bagian kedua adalah payload yang terdiri dari perangkat telekomunikasi atau broadcasting dalam bentuk semacam 'transponder'.
HAPS vs Terestrial dan Satelit
Seperti dijelaskan sebelumnya maka HAPS adalah solusi untuk mengatasi kekurangan yang ada pada infrastruktur terestrial dan satelit, untuk itu ada baiknya untuk membandingkan HAPS dengan teknologi terestrial bumi dan satelit.
Dari segi investasi, HAPS jauh lebih murah dibandingkan satelit GSO (36 transponder), sekitar 30% -nya saja, mengingat HAPS tidak memerlukan tempat, waktu peluncuran yang khusus dan tidak 'space standard'. Sementara itu payload dapat di upgrade sesuai kebutuhan atau dikembangkan secara mudah dan cepat. Dengan HAPS maka cakupan dapat digelar dengan cepat dan luas (radius sekitar 450 km s/d 500 km dari titik nadir). Biaya operasi HAPS relatif rendah, mengingat satu wahana HAPS dapat mencakup area yang luas, 637.000 km2 s/d 785.000 km2 dari ketinggian 21 km. Untuk SkyStation cakupan dibagi menjadi 2 : Urban Area Coverage (UAC) dan Suburban Area Coverage (SAC).[FRM]. HAPS beresiko rendah dibanding satelit, khsusunya dari segi teknis. Dengan HAPS, kecil kemungkinan wahana tersebut mengalami kecelakaan (meledak) atau hilang (miss-orbit). Penggelaran HAPS tidak memerlukan koordinasi global (konstalasi satelit LEO/NGSO) atau regional (satelit GEO/GSO). Dari sudut pandang aplikasi maka HAPS dapat diupgrade sesuai kebutuhan relatif jauh lebih murah dan mudah dibanding satelit, mengingat ketingginnya yang masih didalam atmosfir bumi.
Kapasitas HAPS, dengan payload seberat 1 ton (SkyStation) dapat memberikan output layanan sebesar 7 Gbps [YCL-HYE], sedangkan payload dapat berupa multi aplikasi. Sementara cakupan maksimal adalah antara 450 km s/d 500 km radius. Sebagai wahana pendukung aplikasi telekomunikasi, maka HAPS memiliki delay time (kelembaman waktu) yang jauh lebih kecil dibandingkan satelit yaitu sekitar 0,14 ms atau 140 ms. Dengan penerapan HAPS juga akan memperkecil faktor fading akibat tingginya sudut elevasi antara antena pengguna dengan wahana HAPS. Dimana untuk radius sampai dengan 150 km, dapat digunakan sudut elevasi antara 15° sampai dengan 30°. Resume perbandingan tersebut dirangkum dalam tabel 1.
Tabel 1. HAPS vs Terestrial dan Satelit

No Aspek Terestrial HAPS Satelit
1 Investasi Sedang Kecil Besar
2 Biaya operasi Sedang Sedang Besar
3 Resiko Kecil Sedang Besar
4 Koordinasi Lokal Lokal Internasional
5 Biaya upgrade Besar Sedang Besar
6 Kapasitas sistem Besar Besar Kecil
7 Cakupan geografis Kecil Besar Sangat Besar
8 Delay time Kecil Kecil Besar
9 Fading Besar Kecil Kecil

Khusus untuk delay time HAPS (kondisi line of sight): pada titik nadir 1 hop = 70 m sec dan untuk 2 hop =140 m sec. Sementara untuk titik terjauh (500 km dari titik nadir) delay time 1 hop = 1.668 m sec dan untuk 2 hop = 3.336 m sec.

Wahana HAPS

Seperti dijelaskan sebelumnya maka wahana HAPS ada dua: 1) balon gas dan 2) pesawat terbang. Seperti dijelaskan sebelumnya Skystation dan Skysat (Amerika Serikat) mengembangkan dengan wahana balon gas menyerupai 'Zepplin'.

a)b)



Gambar 1. a) HALO (Angel Technology)[ATI]. b) STS (SkyStation Inc).[SSI]

Wahana STS SkyStation Inc seperti dijelaskan oleh [YCL-HYE] diresumekan dalam tabel 2.


Tabel 2. Data teknis platform balon gas Skystation
No Kriteria teknis Besaran Catatan
1 Platform weight 6.750 kg
2 Dimension at Ø max. (145 x 52) meter Diameter maksimum
3 Altitude 21 km 69.000 kaki
5 Masa operasional > 5 tahun
6 Electrical output max. 515 kW Pada saat siang hari
7 Load Power max. 135 kW 20 kW untuk payload
115 kW untuk platform
8 Top speed 107 knot
9 Cruising sbpeed 40 knot
10 Closed Loop Control GPS Window of : (400 x 700) meter


Sedangkan gambar 2 menunjukan karakter line of sight dari HALO serta pembagian area cakupan dan pelayanan.




Gambar 2.Karakter LOS dari HALO Angel Technology [JN]

Wahana HAPS STS SkyStation dapat beroperasi tanpa awak selama 5-6 tahun dengan station keeping atau stabilisasi ketinggian dan posisi menggunakan motor listrik. Sementara HALO beroperasi secara siklus setiap 5-7 jam sekali, sehingga dibutuhkan 1 armada pesawat HALO dan landasan pacu dibeberapa tempat.

Payload HAPS

Sementara itu tabel 3 merangkum aspek teknis payload berikut layanan yang diberikan dari wahana STS SkyStation.

Tabel 3. Aspek teknis payload STS SkyStation
No Kriteria Teknis Besaran Catatan
1 Berat 1.000 kg
2 Switch ATM onboard
3 Catu daya maksimum 20 kW
4 Antena Spot beam 1 spot = 150 km (diameter)
5 Connection E1 dan T1 - via LAN, PSTN, ISP
6 Rate services Fixed, Variable
7 Frekuensi 2 GHz - 50 GHz Tergantung aplikasi.


Sementara itu aplikasi yang dapat memanfaatkan HAPS adalah :

Internet : baik sebagai akses atau backbone.
Telekomunikasi: voice fixed dan cellular / wireless dan data.
Broadcasting : TV, Radio dan data (paging).
Video conference.
Tele-medecine.
Tele-education.
E-shopping dan E-commerce.
Remote sensing : monitor polusi, tata ruang daerah, kebakaran hutan dan potensi kelautan.
Civil service : keamanan, pemberi tahu dini (kebakaran hutan, bencana alam dll).
Komunikasi militer dan penginderaan militer.
Pengaturan lalulintas dan keperluan kepolisian.
Telecommuting.
Skenario Implementasi
HAPS dapat diimplementasikan secara stand alone, artinya sati HAPS untuk satu kota/aplikasi dan tidak terkait dengan HAPS yang lain, atau sebagai satu kesatuan jaringan (beberapa HAPS saling terhubung). Penggunaan HAPS jaringan biasanya untuk mencakup daerah yang sangat luas atau memanjang, seperti contohnya jalur pantai utara Jawa sebagai pendukung cellular atau remote sensing.


HAPS dapat diterapkan sebagai faktor komplemen dari jaringan terestrial atau satelit yang ada. Umumnya digunakan sebagai backup emergency atau pelimpahan beban traffic. HAPS dapat diimplementasikan sebagai wahana broadcasting TV, radio dan data baik secara individu (stand alone), network atau komplemen.


Untuk Indonesia, maka skenarionya adalah tahap 1 implementasi HAPS untuk Jakarta, Surabaya, Medan dan Bali. Untuk aplikasi internet, broadcasting, telekomunikasi (selular), pengendalian lalu lintas kendaraan dan monitoring polusi lingkungan hidup. Tahap 2, HAPS diimplementasikan untuk sub-urban dengan aplikasi internet, broadcast, telekomunikasi, tele-medecine, tele-education dan penginderaan jarak jauh. Sedangkan tahap 3 untuk daerah rural/remote (hutan dan laut) HAPS dapat digunakan untuk penginderaan jarak jauh dan telekomunikasi.


Perlu dicermati pula penggunaan spektrum frekuensi,mengingat HAPS payload dapat memanfaatkan pita frekuensi 2 GHz (L band) sampai dengan 50 GHz (V band). Hal ini mengingat di Indonesia khususnya dan di Asia Pasifik umumnya mempunyai curah hujan kumulatif rata-rata yang tinggi.


Tabel 4. Tingkat curah hujan di Indonesia dan Asia Pasifik. [ES]
Waktu (%/tahun) 1,0 0,3 0,1 0,03 0,01 0,003 0,001
Hujan (mm/jam) 12 34 65 105 145 200 250


Kesimpulan


HAPS merupakan teknologi baru dan teknologi masa depan meskipun sudah lama dikembangkan di negara-negara maju. Pengembangan HAPS dapat pula dilakukan di negara berkembang, karena teknologi HAPS tidak mempunyai kompleksitas etinggi satelit dan resiko yang rendah pula.


Namun demikian, pemahaman dan penelitian HAPS harus dilakukan secara sinergis dari berbagai disiplin ilmu dan ke-tehnikan. Penelitian terhadap karakter meteorologi-geofisika atmosfir dan karakter propagasi frekuensi (khususnya frekuensi EHF) merupakan hal-hal yang penting dilakukan didalam penguasaan dan penerapan HAPS di negara berkembang atau Indonesia. Disamping itu perlu pula dicermati pengaruh interferensi frekuensi uplink dengan satelit dan sistem terestrial (uplink dan down link).

Sebagai informasi maka bulan September 2000 akan diadakan seminar : the 1st Indonesia High Altitude Platform Systems (HAPS) 2000 di Jakarta dengan para pembicara dari pihak industri HAPS, regulator, penelitian dan ground equipments sebagai langkah awal pengenalan dan implementasi HAPS di Indonesia. Kegiatan ini di organisir oleh Asosiasi Satelit Indonesia (ASSI).

Referensi

[YCL-HYE] Yee Chun Lee & Huanchun YE, Skystation Stratospheric Telecommunication Systems, A High Speed Low Latency Switched Wireless Network; American Institute of Aeronautics and astronautics. Inc ; Document no A98-18885; AIAA-98-1394; 1998.

[LC] Laurant Castanet, Propagation Terre-Espace, ONERA CERT France, 1999.
[JN] James Martin and Nicholas Collela, Broadband Services from High Altitude Long Operation (HALO) Aircraft, Angel Technologies Corporation, 1997-1998.
[SSI] SkyStation Inc., www.skystation.com
[ATI] Angel Technology Inc., www.angelhalo.com
[ES] Eddy Setiawan, Pengenalan Umum Frekuensi Kadan Industri Satelit Telekomunikasi Pita Lebar, Newsletter ASSI No 4 Vol 1, Elektro PII nomor 30 tahun VI, Maret 2000.
[FRM] Francesco Mini, Roberto Mizzoni and Mauro Piccinni, Skysation Stratospheric Telecommunication New Payload Description, American Institute of aeronautics and Astronautics, AIAA-98-1255, 1998.

L S C X Ku K Ka V W mm umm - Band

Quick-Reference
Satellite Frequency table
1–2 GHz L Band
2–4 GHz S Band
4–8 GHz C Band
8–12 GHz X Band
12–18 GHz Ku Band
18–27 GHz K Band
27–40 GHz Ka Band
40–75 GHz V Band
75–110 GHz W Band
110–300 GHz mm Band
300–3000 GHz u mm Band
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World Radiocommunication Conference-2000The Main Issues and Region 3 Cooperation in Preparation for the Conference
**www.elektroindonesia.com

1. Introduction
Recently, radiocommunications is the fastest growing segment of the international telecommunications market. With an ever-changing range of new applications, from mobile telephony and data messaging to wireless computer networking, global mobile personal communications by satellite (GMPCS), environmental monitoring systems and subscriber-based satellite television and broadcasting systems, the demand for radio frequency spectrum or ‘bands’ dedicated to these services is growing at an enormous rate.
However, the radio frequency spectrum, although reusable, is a finite natural resource which is already heavily used by some 40 services. In addition, some bands are unsuitable, for technical or economic reasons, for use by certain systems, and the problem of congestion becomes apparent.

From 8 May to 2 June 2000, ITU’s World Radiocommunication Conference (WRC 2000) will be convened in Istanbul Turkey. The conference is considered as an event which will play a key role in determining what kinds of wireless systems will be available at the start of the next millennium.

Until the close of the conference on Friday 2 June, the meeting rooms of the Istanbul Convention and Exhibition Centre (ICEC) will be the home of close to 2 000 participants representing both government and private interests. Delegations led by senior government officials and including executives from the corporate world will negotiate on how to make use of the radio-frequency spectrum – a finite resource – equitably and to improve ‘spectrum efficiency’ of radiocommunications services – that is, the ability to deliver the same service using less spectrum or to share spectrum with other services without causing harmful interference.

2. World Radio Communication
The four-week long conference, which is held every two to three years, is the forum where countries decide on the shared use of the frequency spectrum to allow the deployment or growth of all types of radiocommunication services, from television and radio broadcasting to mobile telephony, maritime and aeronautical navigation and safety systems, and science services.
One of the most important tasks of each World Radiocommunication Conference is to examine and decide on proposals for new or revised frequency allocations required for the introduction of new services or expansion of existing ones. As the usable portion of the frequency spectrum becomes ever-more heavily subscribed, and as more and more new services clamoring for the allocations needed to make their systems operational, the stakes at each conference are getting higher and higher.

3. WRC-2000 Agenda
The agenda for each WRC is prepared well in advance. The general scope of the program is determined four years before the conference itself, then fine-tuned by the WRC that precedes it and adopted by the ITU Council. The ITU Radiocommunication Study Groups and other components of the Radiocommunication Sector are then charged with preparing the groundwork for each issue under consideration by the conference. A Conference Preparatory Meeting (CPM) collects submissions from these groups and prepares a comprehensive report which outlines in detail the matters under consideration. The CPM-2000 concluded its work on 26 November 1999 with a 2.5 cm thick report which represents the best information on technical, operational and regulatory/procedural issues relevant to the topics of the WRC 2000 agenda to provide a basis for discussions.
The WRC-2000 agenda includes many difficult and important items. The Conference will consider possible frequency allocations and necessary regulatory modifications which will facilitate the use of frequency bands up to 275 GHz by practically all radiocommunication services. Some of the issues were pending topics in WRC-97 which were not concluded in 1997.

Among them will be:

a.Consideration of additional global spectrum identified for IMT-2000 which is foreseen for initial commercial deployment in 2001

International Mobile Telecommunications-2000 (IMT-2000) is the ITU vision of global mobile access in the 21st century. Scheduled to start service around the year 2000 subject to market and other considerations, IMT?2000 is an advanced mobile communications concept intended to provide telecommunications services on a worldwide scale regardless of location, network, or terminal used. Through integration of terrestrial mobile and mobile-satellite systems, different types of wireless access will be provided globally, including services available through the fixed telecommunication networks and those specific to mobile users. IMT-2000 proposes a range of mobile terminal types, linking to terrestrial and/or satellite-based networks, and the terminals may be designed for mobile or fixed use.

The IMT-2000 terrestrial standard consists of a set of radio interfaces which allow performance optimization in a wide range of radio operating environments. Satellite interfaces cover LEO, MEO and GEO orbits as well as those specifically aimed at maximizing the commonality between terrestrial and satellite interfaces.

IMT-2000 will provide wireless multimedia service capabilities, harnessing the power of the Internet for e-commerce while on the move, instant access to personal or business information and for entertainment. The economic benefits of this new global standard will be felt by all ITU Member States as wireless access provides a cost-effective solution to the "telecommunications gap" between developing and developed countries.

At WARC?92, 230 MHz of spectrum was identified for IMT-2000/FPLMTS via a provision (No. S5.388) in the Radio Regulations (RR). However, due to the tremendous growth in mobile communications since then, and the demand for wideband multimedia capability, the expected demand for additional IMT-2000 spectrum after the initial deployment must be considered.

b.Review the power limits for the sharing of bands currently allocated exclusively for aeronautical and maritime navigation systems, with the Mobile Satellite Service.

These bands are currently used by Global Navigation Satellite Systems (GNSS) such as GPS and GLONASS. This issue caused considerable debate over the suitability of these bands for the MSS in 1997 and discussions on the possible sharing of the band was postponed until WRC 2000 to allow for technical studies to be carried out.

c.The protection of radioastronomy services which are not easily able to share with other services and which are prone to interference with mobile services (terrestrial and satellites).

With the explosion in the use of mobile services, the problem of interference with radioastronomy has triggered concerns among radioastronomers. They are now seeking a "quiet zone" where they could have their antennas and telescopes and where any other radio transmissions would be banned. That would however not solve the problem of possible interference from non-geostationary satellites. Moreover, to study the expansion of the Universe, astronomers claim to need to use the entire frequency spectrum at specific times and places and not the part of the spectrum they have been allocated.

d.The review of the power limits which were provisionally agreed in 1997 for the sharing conditions in the band 10-18 GHz between the non-geostationary satellites and existing geostationary satellite and terrestrial networks including television broadcasting.

The sharing conditions were particularly important for ‘broadband’ global satellite systems which have the potential to deliver Internet and multimedia applications to homes and businesses anywhere in the world. This new breed of system, the best-known of which are currently the Bill Gates/Craig McCaw-backed Teledesic project, Alcatel’s SkyBridge and Galileo.

This was one of the most controversial issues of the 1997 conference. In defining the regulations needed to prevent such a scenario, proponents of non-GSO FSS systems attempted to push for provisions that would not unduly hamper their plans. Some took the view that more spectrums for these kinds of broadband systems would mean a better chance of fair competition between systems. The WRC-97 tried to achieve a balance between clearing the path for healthy, equitable growth of these systems and protecting geostationary systems. One proposed way of achieving this was to limit the emission power of LEO satellites. And now, the power limits which were provisionally agreed in 1997 are to be reviewed.

While CPM brought parties close together on those limits, it is up to WRC 2000 to decide on the basis of proposals by countries and negotiations to take place in Istanbul.

e.To determine a technical basis for re-planning the broadcasting satellite service which delivers direct-to-home television services.

These technical bases are to provide each country an amount of spectrum that permits the development of an enhanced broadcasting satellite system. The issue of capacity for future additional requirements such as sub-regional systems is also to be taken up. This was also a difficult topic at WRC 97 as well as the issue of defining the conditions under which countries could broadcast outside their national territory.

f.To decide on sharing criteria between stations in the High Density Fixed Service (HDFS) and stations in other services to which the frequency bands above 30GHz are allocated.

High-density applications in the fixed service applications are being used increasingly to provide significant number of point-to-point (P-P) and/or point-to-multipoint (P-MP) services in the bands above 30 GHz. These new types of services are starting to be used by service industries to optimize their business operations. For example, with HDFS, multiple links to commercial offices such as banks in city business districts can replace a "spaghetti" of hard wires to provide the links. With HDFS, the links are wireless. Further, for applications previously not done through central polling, (for example water or gas meters that are currently read one by one by people sent to the premises where they are located), HFDS will make it possible to automate the tasks. Availability of small, light-weight components and a high degree of frequency re-use are key factors in enabling the deployment of a large population of fixed service systems.

g.To identify the extent to which sharing of the bands designated for High Altitude Platform Stations (HAPS) in the fixed service is feasible with systems in the other services using the same bands.

A new telecommunication concept using High Altitude Platform Stations (HAPS) for providing fixed service operations such as SkyStation was officially recognized by WRC 97 which made provisions for operation in the 47.2-47.5 GHz and 47.9-48.2 GHz bands.

h.Frequency allocation for Little LEO

For GMPCS systems operating below 1GHz (in many cases, so-called ‘Little LEO’ systems), delegates will be required to examine different ways of alleviating spectrum overcrowding, including complex frequency-sharing scenarios that would see new systems sharing the airwaves with existing terrestrial and fixed-satellite services. The sharing difficulties with terrestrial services are compounded in many systems by the high number of satellites many of these systems comprise, and the high number of zones over which they operate. Studies already undertaken have shown that interference to conventional systems could mean occasional disruption of service ranging from every 10 hours to every 21 months. The conference will have to decide whether to delay further allocations pending more extensive studies – which would hamper operators and delay the launch of these non-GSO services – or whether the level or possibility of interference would be low enough to allow for simple fine-tuning once systems have been launched.

i.Satellite Network Co-ordination, Including the Problem of ‘Paper Satellites’

For satellite systems to operate effectively, they need to be ‘coordinated’ – that is, their operating frequencies and orbital positions need to be checked before they can be put into service, to ensure that they are not going to cause interference to other satellites already in place. This co-ordination is the responsibility of the ITU, which receives all requests for new satellite systems, and performs the checking of operational parameters and publishes a Master International Frequency Register of all satellites currently in place.

For some time, the coordination of satellite networks has been problematic, due to the rapidly growing demand for satellite-based services. There is strong competition in the marketplace between operators, who are keen to move quickly to get a foothold in emerging new markets, and who are pushing for faster co-ordination procedures and notification of satellite positional allocations. In regions with a high concentration of planned and existing satellites, the congestion and difficulties in obtaining coordination agreements are such that some operators are bringing systems into use, or repositioning existing satellites, without proper co-ordination. In the regions with highly ‘valuable’ orbital positions – such as those covering lucrative markets – real conflicts are beginning to emerge. At present, there is no formal means of resolving such disputes.

Resolution 86 (PP-98) resolves to request WRC-2000 and subsequent WRC’s to continually review and update the advance publication, coordination and notification procedures, including the associated technical characteristics, and the related Appendices of the Radio Regulations, so as to ensure that they reflect the latest technologies, as well as to achieve additional simplification and cost savings for the Radiocommunication Bureau and administrations. Some administrations suggest the use of coordination arc concept, decoupling of the uplink and downlink filings, multilateral coordination meeting, et cetera.

Paper Satellites
Another consequence of this problem of co-ordination is the issue of so-called ‘paper satellites’. These are satellites systems which have been notified to the ITU and coordinated, but which in reality have never been launched. Paper satellites have largely come about because of desire to ‘hoard’ satellite slots for future use.
WRC-97 produced Resolution 49, which contains provision about ‘administrative due diligence’. Under the principle of due diligence, the ITU would require satellite operators to regularly provide information on the implementation status of any planned system, with failure to comply resulting in loss of the priority rights of that system to certain frequencies and orbital positions. The general secretary of ITU will report at the WRC-2000 the effectiveness of the procedure.

Resolution 88 (PP-98) instructs WRC-2000 to consider whether, in the light of the Council decisions, any relevant amendments to the Radio Regulations may be necessary for the implementation of processing charges for satellite network filings. The Council Decision recommends that operators be required to pay a filing fee for initial applications, a registration fee covering any system recorded in the Master International Frequency Register.

4.Region 3 Cooperation

To help ensure good preparations, BR has worked very closely with regional entities, inter alia, the Asia-Pacific Broadcasting Union (ABU), the Asia-Pacific Telecommunity (APT), the Arab States Broadcasting Union (ASBU), the respective units of the European Conference of Postal and Telecommunications Administrations (CEPT), the Inter-American Telecommunications Commission (CITEL), the European Broadcasting Union (EBU), the Pan African Telecommunication Union (PATU) and the Union of National Radio and Television Organizations of Africa (URTNA).

In WRC-97, it was the first time that agreed regional proposals have been developed for Region 3, which was represented by the Asia-Pacific Telecommunity (APT). It was a significant step forward in terms of cohesion in the region as well as providing considerable assistance for successful completion of the WRC itself. The main advantage to the ITU-WRC process is the combining of various countries’ individual proposals into a set of regional proposals. The APT meeting enabled various differences between country proposals to be resolved through a regional discussion process. Such a process tends to remove proposals which receive no support, to improve the quality of proposals and generates a better and wider understanding of the issues. These factors contribute directly to the reduction of the total volume of proposals to be considered by the WRC, facilitate the efficient handling of less controversial matters and achieve a clearer focus on the more difficult issues.


Figure 1. Region 3

In preparation for the WRC-2000, APT held four meetings. The first meeting in preparation for WRC-2000 was held in Bangkok on 6-8 May 1998 discussed about HF Interference and BSS Replanning Meeting (APG2000-1). The second meeting was held in 11-16 April 1999 Bangkok. The 2nd APT Conference Preparatory Group Meeting for WRC-2000 (APG2000-2) and the 3rd APT Conference Preparatory Group Meeting for WRC-2000, in 4-8 October 1999 in Australia which produced the APT provisional views which were submitted to the CPM-2000.

On 31 January – 4 February, 2000, APT held The 4th APT Conference Preparatory Group Meeting for WRC-2000 (APG2000-4) produced the APT provisional views and proposals whish were submitted to the WRC-2000 and were also distributed to all Region 3 countries and to Members of the Informal Group for WRC-2000 preparations for the information of countries in Regions 1 and 2.

The APT common proposals cover the whole range of WRC-2000 agenda items, including regulatory and procedural matters, HF aeronautical and maritime mobile bands, broadcasting-satellite, mobile-satellite and fixed-satellite services, space science services, fixed services, PP 98 and the agenda for WRC-2003. While nearly all of the proposals were agreed unanimously, a few were strongly supported, but not agreed by all and these form separate parts of the documents.

The final step will be the coordination of the efforts of APT and ITU Region 3 Member countries to promote the APT proposals during the Conference, and to work together to achieve the best possible results. This will necessarily require negotiation of compromises where there are contentious issues and proposals from other regions. This process will be helped considerably by the success of the APT regional meeting which has established good working relationships, and a better understanding of the issues and the needs of different countries in all three ITU regions.

Indonesia Preparation
As a member of ITU and APT, Indonesia has intensely involved in the preparation of the WRC not only in the ITU forums but also in the APT forums. Under the coordination of Department of Communication, all interested party, including frequency users and operators have been preparing for Indonesia views in the WRC. Indonesia is supporting a number of APT common proposals. Those proposals that are not supported, are submitted directly to the WRC’2000 as separate proposals. Some issues being concerned are especially related with regulatory procedures and frequency allocation, for example allocation for Little LEO, Mobile Satellite Services, Maritime services and IMT-2000.
5. Conclusion
The array of issues facing WRC-2000 is formidable. The Conference has many very substantial issues to address concerning the HF aeronautical and maritime mobile bands, broadcasting-satellite, mobile-satellite and fixed-satellite services, space science services, fixed services, as well as setting the agenda for WRC-2003.
Despite a very good working atmosphere in the preparation of the technical basis for WRC 2000 carried by CPM, the competing interests and approaches to make use of spectrum for systems deployment and growth are likely to give rise to tough negotiations in Istanbul. Nevertheless, the extensive preparatory work and coordination within and between regions has paved the way for early decisions on many matters, and this should enable the conference to focus its major efforts on the more difficult issues.

Achieving a successful outcome will depend more than ever on good management and a high degree of cooperation among the numerous countries and delegates expected to participate in WRC-2000.

Reference:
“Turkish government and ITU sign agreement to host WRC 2000”, ITU Press Release ITU/99-25 16 December 1999
ITU-R Report of the CPM to the WRC-2000
“Major Agreements Reached at WRC 97”, ITU Press Release ITU ITU/97-20
21 November 1997 David Hartley, “Region 3* and worldwide cooperation in preparation for WRC-97”, ITU News Room CMR 1997
Asia-Pacific Telecommunity (APT) Conference Preparatory Group (APG) Common Proposals for the Work of the Conference
http://www.itu.int
http://www.aptsec.org/radio/apt-wrc.htm
Note :
For the purpose of radio conferences, the world is divided into three regions:
Region 1: Europe (including the whole territory of the Community of Independent States) and Africa
Region 2: the Americas
Region 3: Asia and Australasia

Quick-Reference Frequency table 1–2 GHz L Band
2–4 GHz S Band
4–8 GHz C Band
8–12 GHz X Band
12–18 GHz Ku Band
18–27 GHz K Band
27–40 GHz Ka Band
40–75 GHz V Band
75–110 GHz W Band
110–300 GHz mm Band
300–3000 GHz u mm Band


Cessy Karina

Syariah Vs Konvensional

Bank syariah tidak memberikan pinjaman dalam bentuk uang tunai, tetapi bekerja sama atas dasar kemitraan, seperti prinsip bagi hasil, prinsip penyertaan modal, prinsip jual beli, dan prinsip sewa.
be well,
Dwika



Perbankan syariah Vs Konvensional
**ariesyevo.blogspot.com

Perbankan Syariah waktu beberapa tahun belakangan ini sedang naik daun, dipicu dengan besarnya keinginan masyarakat untuk mendapatkan kehalalan dalam berbenturan dengan perbankan. Sedikitnya ada beberapa faktor yang menjadi pemicu perkembangan Perbankan Syariah sekaligus menjadi pembeda antara perbankan syariah dan perbankan konvensional, yaitu:
1. Pasar ( Market )
Tidak ditetapkannya Nasabah hanya dari golongan orang muslim, dibeberapa bank Syariah banyak nasabahnya yang non muslim.
2.bagi hasil
sistem bagi hasil terbukti lebih menguntungkan dibandingkan dengan sistem bunga yang dianut bank konvensional (bagi bersarkan besasr kecilnya pendapatan lembaga),
3 Pinjaman
bank syariah tidak memberikan pinjaman dalam bentuk uang tunai, tetapi bekerja sama atas dasar kemitraan, seperti prinsip bagi hasil (mudharabah), prinsip penyertaan modal (musyarakah), prinsip jual beli (murabahah), dan prinsip sewa (ijarah).
4 prinsiplaba
Laba bagi bank syariah bukan satu-satunya tujuan karena bank syariah mengupayakan bagaimana memanfaatkan sumber dana yang ada untuk membangun kesejahteraan masyarakat (lagi pula, bank syariah bekerja di bawah pengawasan Dewan Pengawas Syariah).
Mengapa Bank Syariah dirasakan lebih adil dan lebih memberikan kenyamanan kepada nasabahnya? Hal ini disebabkan karena prinsip-prinsip dasar yang berjalan di bank-bank syariah yang menjadikan sebuah perbedaan mendasar dengan bank Konvensional banyak terletak pada pelayanan nasabah diantaranya :
1. prinsip keadilan, yakni imbalan atas dasar bagi hasil dan margin keuntungan ditetapkan atas kesepakatan bersama antara bank dan nasabah,
2. Prinsip kesetaraan, yakni nasabah penyimpan dana, pengguna dana dan bank memiliki hak, kewajiban, beban terhadap resiko dan keuntungan yang berimbang, dan
3. prinsip ketenteraman, bahwa produk bank syariah mengikuti prinsip dan kaidah muamalah Islam (bebas riba dan menerapkan zakat harta).
2.BANK SYRIAH
Syariah merupakan hukum, yaitu hukum yang diterapkan dari, oleh, dan untuk islam. Syariat menjadi satu dalam Al Quran dan As Sunnah Rasulullah saw. Masa sebelum ada bank syariah kata syariah sudah dikenal dalam konteks bernegara di NKRI.
Pada awal pembuatan UUD 1945 kata syariah menjadi salah satu kata dalam sila Pancasila yang berbunyi Sila 1. Ketuhanan Yang Maha Esa Dengan Menjalankan Syariat Islam Bagi Pemeluk – Pemeluknya. Kata syariah setelah kejadian itu kemudian artinya menjadi ibadah, yaitu sahadat, sholat, zakat, puasa dan haji. Kelima rukun islam itu kemudian dijalankan sebenar-benarnya sesuai syariah, sehingga yang tidak sesuai syariah batal.

Pada era reformasi kata syariah kembali dipentas bernegara baik dalam ibadah, politik, ekonomi, bahkan sampai dasar negara. Sehingga pada tahun 1999 M asas tunggal Pancasila dihapuskan, sehingga tidak ada lagi asas tunggal pancasila dalam berpolitik, ekonomi dan lain-lain. Orde sebelum reformasi perbankkan adalah konvensional semua yang memiliki bunga dan dihukumi sebagai riba. Riba dalam syariah dilarang karena menambahkan takaran atau terjadi ketidakadilan. Selain dalam bentuk bunga, riba juga dikenal dalam jual beli, seperti menaikkan timbangan, menambahkan uang kembalian, atau menambahkan uang yang diniatkan untuk mendapatkan keuntungan. Sehingga jajanan atau jualannya jadi ramai karena pengembaliannya dilebihkan atau timbangannya dilebihkan dari harga sesungguhnya.

MUI mengharamkan riba namun MUI bukan wakil pemerintah yang bisa menghentikan riba, sehingga bermunculan bank-bank syariah atas dorongan dari MUI. Dengan jalan mendirikan bank syariah ini ternyata mampu menjadi pioner terbebas dari kendala moneter dunia pada era 2000-an M. Sekarang hampir bank-bank konvensional mendidikan cabang atau merchandish bank syariah.

Campuran hitam dan putih ini menjadi abu-abu, bank di Indonesia hampir semuanya abu-abu. Karena mereka sudah saling bekerjasama antar bank. Bank konvensional dan bank Syariah mendirikan ATM bersama, membuat pelayanan bersama. Dalam perbankkan abu-abu ini tindak kriminal yang menggunakan uang dan disimpan diperbankkan menjadi tidak bisa diketahui. Peledakan JW Marriot dan Rich Carlton di Jakarta belum bisa diungkap, bank mana yang menjadi sumbernya? Dalam arti bank abu-abu ini tidak memiliki kekuatan dan keberanian untuk menolak nasabah yang berusaha haram, baik perseorangan ataupun perusahaan.

Jadi dalam keabu-abuan ini perbankkan Indonesia harus lebih berani untuk mengambil sikap ada dijalan haram atau halal, dengan proaktif menyebarkan informasi kepada masyarakat akan hala dan haram. Semoga pada saatnya nanti yang abu-abu akan menjadi putih karena seringnya disiram dengan air jernih Ramadhan 1430 H dan ramadhan-ramadhan selanjutnya. Siraman ramadhan dapat diartikan sebagai pencerahan sebulan yang sudah dilakukan beberapa awal tahun 2008 M. Pada saat bulan ramadhan Metro TV menyiarkan acara saur dengan tema bank syariah. Begitu seterusnya, pada setiap ramadhan. Sayangnya, usaha ini seperti halnya acara sinetron, diputar berulang-ulang menjadikan tidak menarik. Apalagi tidak ditindak lanjuti dengan sosialisasi offline, dengan sosialisasi perdusunan atau pedesaan yang kontinyu.

Usaha-usaha offline untuk menjelaskan bagaimana perbankkan syariah yang putih, tidak abu-abu sangat dinantikan, meskipun tidak harus mengatakan sebagai bank syariah. Misalnya, semua persyaratan dan ketentuan sudah terpenuhi, semisal meninggalkan riba atau bunga bank. Maka bank tersebut tanpa mengatakan dan menambah nama syariah masyarakat sudah mengetahuinya. Model seperti ini yang kemudian dikenalkan, bahwa bank di Indonesia adalah syariah, bank adalah syariah, bank adalah tidak berbunga, bank adalah anti riba, bank adalah bagi hasil usaha dari investasi nasabah, bank adalah tempat pinjam-meminjamkan uang yang halal. Sehingga syariah itu akan berguna untuk semua segmen masyarakat tanpa embel-embel syariah dibelakangnya.
Diposkan oleh aris.yevo