A Concept of Digital Television in Nepal

 

 

-By

Chinta Mani Baral

Chief Engineer, (NTV)

Background:

The history of Television Broadcasting in Nepal started when Nepal Television started its Broadcasting in 1985. Nepa Television started its broadcasting from VHS (Video Home System) video format to High Band and then BetaCam.  It has been few years; Nepal Television has been using DV formats for video recording. At the moment, Nepal Television is using DV and BetaCam format for video recording purpose. Nepal Television used its Repeater Relay Stations across the country to access the signal for wide geographical area of the country. But the signal quality degraded in a long distance. So, the alternate system was used to overcome the shortcomings of Repeaters using Satellite System for Television Broadcasting. Consequently, Nepal Television uplinked its signal to Satellite successfully in 2001 and used TVRO (Television Receive Only) to downlink the signal in different locations across the country and re-transmitted using LPT (Low Power transmitter) in the local area so that the common people accessed the NTV signal free of cost. In the mean time, several Private Television Stations are emerging in Kathmandu valley and around 10 Television Stations are broadcasting so far using Satellite System.

In course of time, the Television Broadcasting technology is changing rapidly and the one-way broadcasting system has been converted to Interactive and carrying so many additional facilities apart from audio and video. So, the World is moving forward towards Digital Television Broadcasting. The developed countries have already switched over Complete Digital System and developing countries are also trying to switch over to digital as soon as possible. Sooner or later, Nepal also should move forward towards complete digital system to keep up the latest technology developed in the World. If we try to carry on old technology even, we will be unable to get spare parts to rectify old system in the International market, so it

 

will be too late if we couldn’t plan now properly towards migration of digital World. We also need to hurry up for proper planning of Digital System to be compatible to International market and standard.

 

Terrestrial Television Broadcasting in Nepal:

Nepal Television is the oldest Television Station of the country doing terrestrial TV Broadcasting across the country. Nepal Television is using both VHF and UHF Bands for Terrestrial TV Transmission. But UHF band is on use for Terrestrial TV Transmission by Kantipur, Image and some TV Broadcasting stations outside the Kathmandu valley. But Nepal Television is using Terrestrial TV Broadcasting to fulfill the responsibility of Public Broadcasting Station to access signal to common people free of cost. NTV is the TV Broadcasting station to broadcast Terrestrial Transmission across the country in very effective way. So, it needs proper planning of frequency spectrum for Terrestrial TV Transmission so that Nepal Television could fulfill the public responsibility. So far, NTV is using VHF Band exclusively for Terrestrial TV Broadcasting.

 

Terrestrial Television Frequency Band Planning:

Television channels (frequencies) for digital television are the same as for analog television. This also means that the same antennas can be used to watch DVB-T signals. Of course, in some cases we will have to upgrade our antenna system in order to receive digital terrestrial television because DVB-T transmitters may transmit on a different channel which we may not receive with the existing installation. But in general the same VHF/UHF antennas are used. Below we can find TV channel frequencies as used in DVB-T Standard.

Both VHF and UHF Bands are used in Digital Terrestrial TV Transmission. Since Nepal Television is using both VHF and UHF Bands for Terrestrial TV Transmission and same band of frequency Spectrum can be used for Digital Terrestrial TV Transmission as well.

 

The following frequency system needs to be in planning for public and private sector for Digital Terrestrial TV Transmission.

 

 

VHF Channel frequencies (MHz)

CH Start Frequency Center Frequency End Frequency
5 174 177.5 181
6 181 184.5 188
7 188 191.5 195
8 195 198.5 202
9 202 205.5 209
10 209 212.5 216
11 216 219.5 223
12 223 226.5 230

UHF Channel frequencies (MHz)

CH Start Frequency Center Frequency End Frequency
21 470 474 478
22 478 482 486
23 486 490 494
24 494 498 502
25 502 506 510
26 510 514 518
27 518 522 526
28 526 530 534
29 534 538 542
30 542 546 550
31 550 554 558
32 558 562 566
33 566 570 574
34 574 578 582
35 582 586 590
36 590 594 598
37 598 602 606
38 606 610 614
39 614 618 622
40 622 626 630
41 630 634 638
42 638 642 646
43 646 650 654
44 654 658 662
45 662 666 670
46 670 674 678
47 678 682 686
48 686 690 694
49 694 698 702
50 702 706 710
51 710 714 718
52 718 722 726
53 726 730 734
54 734 738 742
55 742 746 750
56 750 754 758
57 758 762 766
58 766 770 774
59 774 778 782
60 782 786 790
61 790 794 798
62 798 802 806
63 806 810 814
64 814 818 822
65 822 826 830
66 830 834 838
67 838 842 846
68 846 850 854
69 854 858 862

 

 

Worldwide Scenario of DTV: The trend of Television Technology is in transition from analog to digital all over the World. Some of the countries have already switched over to digital completely and most of the countries have fixed the Analog switch off deadline. The World is now in the transition of Analog to Digital migration. So, it is essential to determine the fix date of digital switch over.

 

 

Courtesy: Elettronika

Some Countries with complete Analog Switch-Off:

S.N. Name of the countries Analog Switched off date
1. Luxembourg 1st SEPT, 2006
2. Finland FEB, 2008
3. Sweden 29th OCT, 2007
4. Switzerland 26th NOV, 2007
5. USA 12th June, 2009
6. Denmark 1st November, 2009
7. Norway 1st DEC, 2009
8. Belgium 1st March, 2010
9. Spain 3rd April, 2010
10. Slovenia 1st DEC, 2010

 

Some Countries targeted to Complete Analog Switch-Off:

S.N. Name of the Countries Analog Switch-Off Targeted
1. Australia 31st DEC, 2013
2. Bolivia 2012
3. Canada 31st August, 2011
4. Colombia 1st January, 2017
5. Hong Kong 2012
6. Japan 24th July, 2011
7. France 30th NOV, 2011
8. Italy 12th DEC, 2012
9. United Kingdom 2012
10. Malaysia 2012

 

Why Digital Television?

  1. Due to efficient encoding and modulation techniques used in Digital Television broadcasting; Band Width (BW) is saved.

 

  1. Digital Terrestrial Transmission is used in SFN (Single Frequency Network) and MFN (Multi Frequency Network) mode, so that there is significant Spectrum Efficiency. The single frequency can be used all over the country with the same content transmitted in the same time/frequency synchronization connected with GPS (Global Positioning System). Multi Frequency Network (MFN) can be used for different content in different frequencies.

 

 

 

Courtesy: Elettronika

  1. Digital Terrestrial Television Signal can be received by not only Television Receiver but also by hand-held devices like cellular phone.

 

 

Courtesy: Elettronika

Courtesy: Elettronika

Commercial Advantages of Digital Television System:

A Digital Television Broadcasting is not only a simple Television Broadcasting System; it also carries out several other facilities and interactive activities with viewers. The following points are the additional facilities which are carried out by Digital Television System so that we can generate additional revenue from those facilities and services.

  1. PPV (Pay Per View): Digital Television System can be used for PPV (Pay Per View) service to the viewers so that additional revenue can be generated from on-screen pre-scheduled programs.

 

  1. VOD (Video on Demand): Viewers can demand their interesting programs with the CAS (Conditional Access Server) by network and they pay the additional charge for it.

 

  1. Internet Connection: An IP Packet can be encapsulated in the Digital Television Network so that Internet Service can be provided in the rural area where cable is not available. So that the common people can access Internet service in addition to Television Channels.

 

  1. EPG (Electronic Program Guide): Digital Television System provides complete scheduling of the programs which are to be broadcast during a week or a month or more duration.

 

  1. Encryption: A Scrambler can be used in CAS (Conditional Access System) to encrypt the signal to protect from unauthorized access.

 

  1. Mobile TV: The Digital Television can be used in mobile systems in handheld devices like cell phones.

 

  1. Doctors’ Prescription: Digital Television Network is useful to provide experienced doctor’s access in remote area to common people who can not afford to visit in city area.

 

 

Courtesy: Elettronika

 

  1. Banking Transaction: Digital TV Network will be useful in Banking Transaction like account information, managing account, using credit card via Network etc.

 

  1. E-Commerce: Online buying and selling is emerging market called E-Commerce in modern World which can be carried out from Digital TV Network.

 

  1. Distance Education: Distance Education will be very effective from Digital TV Network because Digital TV Network is interactive. So, remote people can access proper education from Digital TV Network.

 

Similarly, the Digital Television network can be used to send Telegram, subscribing music and songs, demanding movie for tonight, latest news etc.

Digital Television Standards:

After the successful attempt of Digital Television Broadcasting; several standards have been developed. Those standards are being used on the basis of regions and technical convenience. Some countries have adopted the digital standards on the basis of foreign assistance in technology. It is the right time of us to choose the suitable digital standard for our country.

 

The different Digital Television standards are as given below:

S.N. Digital Standard Adopted Countries
1. DVB European Countries, Russia, Australia, India, North African Countries, Middle East Countries.
2. ATSC US and Canada
3. ISDB Japan, South America
4. DMB (CMMB) China

Abbreviations and full forms:

DVB: Digital Video Broadcasting

ATSC: American Television Standard Committee

ISDB: Integrated System Digital Broadcasting

CMMB: China Multimedia Mobile Broadcasting

 

The above mentioned standards are further divided into sub-standards according to the transmission media used for Digital Television Broadcasting as below:

DVB-T/T2: DVB- Terrestrial (To broadcast Digital Terrestrial Television)

DVB-S/S2: DVB-Satellite (To broadcast Digital Satellite Television)

DVB-C/C2: DVB-Cable (For Digital Cable TV)

 

DVB-T/H: DVB- Terrestrial-Hand Held (For receive Digital Television in mobile hand-held devices like cell phones)

Above mentioned T2, S2 and C2 are the latest technical standards.

 

Digital Standard Recommendation for Nepal:

Since DVB standard has been adopted in European Countries, Russia, Australia, India, North African Countries, Russia, and Australia and in Middle East Countries. We have already adopted DVB-S standard in Satellite System and we are updating to DVB-S2 shortly. India and Australia are also adopting the DVB standard. In this regard, DVB could be the first selection in context of our country.

ATSC used in US is too expensive and ISDB of Japan is also difficult to afford. Chinese standard (DMB) is another option but the technology is limited to a particular country. We need to depend on in a single country if we adopt DMB.

For Digital Terrestrial TV Transmission, there are two standards T and T2. Terrestrial Standard (T) has been used commercially and T2 standard is still under documentation. But Terrestrial (T) can be updated to T2 easily. So, we can start from Standard T and update to T2 whenever required. In addition to this, T2 is more expensive and technically complicated.  So, it will be prudent to start up form T and update to T2 later on.

 

Courtesy: Elettronika

Digital TV Receiver:

The Digital Television is received either by Digital Receiver which viewer should buy new receiver with integrated Set-top Box or by old analog receiver with additional device. Those viewers who wish to use old analog TV receiver need to buy additional set-top Box to watch the Digital Television. The cost of set-top Box is not significantly expensive which viewers can afford easily.

 

Conclusion:

Adopting Digital Television System is the demand of time and we need to migrate towards digital system as soon as possible. We have to take advantage of digital television broadcasting to generate additional revenue by providing additional services and facilities to viewers.

 

 

 

 

References:

  1. Broadcast Engineers Seminar, Tokyo Japan (2002)
  2. Digital Mobile Television Seminar, Kuala Lumpur (2004)
  3. Low Cost Digital Studio Workshop, Colombo (2006)
  4. Digital TV in your Pocket by Marco Fiore, Elettronika (Italy),2010

 

 

 

 

 

 

 

 

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