Standardization of Cable TV Network A Review

Harchran Singh and Reema Garg Bureau of Indian Standards New Delhi

Introduction

A large number of Cable TV Networks presently exist in various parts of the country. The growth of such networks has been phenomenal and haphazard. The vigorous growth and acceptance of Cable TV Network has also attracted the attention of regulators and legislators. Government of India had passed ‘Cable TV Network (Regulation) Act’ in 1995. Under this Act, among other things, all Cable TV Network equipment are required to conform to the relevant Indian Standards brought out by BIS, within a period of 3 years from the date of establishment and publication of the relevant Indian Standards. Urgent need was therefore felt to identify areas where standardization was required and also to expeditiously evolve national standards for the same.

Standardization Efforts - At National Level Bureau of Indian Standards.

The National Standards Body has been successfully promoting and nurturing the standardization movement within the country since 1947. The technical work is done through a number of Technical Committees represented by reputed manufacturers, users, technologists and consultants; and standards are formulated by consensus. The general philosophy is to recognize apex status of international standards and adopt them as national standards as far as possible and compliment that further with suitable national standards to cater to our environmental needs and application areas. 

The national standards in the field of electronics and telecommunication are the responsibility of the Electronics and Telecommunication Division Council (LTDC) of BIS. BIS has so far brought out more than 1400 standards in this field covering diverse areas such as Consumer Electronics, Electronic Components, Computers, Radio Communications, Electronic Measuring Equipment, EMI/EMC and Information Technology. 

Standardization in the field of Cabled Distribution System is the responsibility of Radio Communication Sectional Committee, LTD 20. In this work LTD 20 is assisted by an expert Panel, namely, ‘Panel for cabled Distribution System’. LTD 20/P7. This committee had taken up the task of identification and preparation of standards in the cable TV areas on priority basis. Lt. Col. K.K. Sharma is a member of the Cable Operators Federation of India in this committee. 

This committee has finalized 14 standards for Cable TV Network so far. Most of these standards are largely based on corresponding International Standards brought out by International Electrotechnical Commission (IEC). These standards pertain to Cabled Distribution Systems’ requirement and Cable TV Equipment relating to dish antenna, headend equipment (satellite receivers, antenna amplifiers, frequency converters, combiners, separators and generators), active wideband coaxial components (modulators, amplifiers, etc.), passive wideband coaxial components (system outlets, splitters, subscribers’ taps, filters, attenuators and isolators) and RF coaxial cables, etc. All these standards which cover optimum level of performance requirements, safety requirements and uniform testing methods will ensure certain minimum level of quality of indigenously manufactured Cable TV Equipment and improve the quality of services rendered in the field of cable TV Network. A list of Cable TV standards so far brought out is given in Annex below. 

1. Cabled Distribution Systems Requirements (IS 13420)

IS 13420 is the basic standard for Cabled Distribution System. Among other things, the standard covers terminology, performance requirements and safety requirements for the system. It also includes the basic methods of measurement of operational characteristics to assess the performance of the systems. Beside? The minimum and maximum carrier signal levels at system outlets have also been specified.

2. Dish antenna [IS 14320, IS 13987 (Part 1 Part 2)]

The standards in this area specify performance requirements of C-Band Dish Antenna, conditions and methods of measurement for electrical. mechanical and environmental characteristics for the antenna. 

3. Headend Equipment [(IS 14231 (Part 5)]

The standard covers performance specification and methods of test for the equipment used in the headends of terrestrial broadcast and satellite receiving systems. It mainly includes antenna amplifiers, frequency converters, combiners, separators and generators. 

4. Distribution components [IS 14231 (Part 3 and Part 4)]

The distribution components are classified into two groups. Active coaxial wide band distribution components and passive coaxial wide band distribution components. The standard pertaining to active components includes all broadband amplifiers. The standard for passive components includes receiver leads, system outlets, splitters, subscribers’ taps, filters, attenuators, equalizers, isolators, etc. The standards cover the frequency range of 5 MHz to 1 750 MHz. The basic methods of measurement of operational characteristics of these components to assess their performance are also described in the standard. 

5. RF Co-axial Cable [IS 14131 (Part 1 and Part 2)]

The standards specify the general requirements and tests applicable to single unit coaxial cable for use in the Cabled Distribution System. The particular requirements of solid polyethylene and cellular polyethylene coaxial cables which include their dimensional details, constructional details and performance requirements are specified in the standard. 

Standardization -At international Level

At the international level, International Electrotechnical commission (IEC) is responsible for preparation of international standards in the field of electro-technology including electronics. The Subcommittee SC 100 D Cabled Distribution System functioning under Technical Committee TC 100 Audio, Video and Multimedia Systems and Equipment of the IEC is responsible for laying down international standards in this area. The work done by this committee forms the basis of national standards. India is a member of this committee and actively participates in its work. 

Indian Standards on Cable TV Network

a. IS 13420 (Part 1): 1994, Cabled distribution system: Part 1 Systems primarily intended for sound and television signals operating between 30 MHz and 1 GHz. 

b. IS 13986 (Part 1): 1994, Methods of measurement on receivers for satellite broadcast transmission in 12 GHz band : Part 1 Radio frequency measurements on outdoor units. 

c. IS 13986 (Part 2): 1994, Methods of measurement on receivers for satellite broadcast transmission in 12 GHz band: Part 2 Electrical measurements on DBS tuner units

d. IS 13987 (Part 1): 1994 Method of measurement on receiving antennas for satellite broadcast transmission: Part 1 Electrical measurement on DBS receiving antennas. 

e. IS 13987 (Part 2): 1995 Method of measurement on receiving antennas for satellite broadcast transmissions: Part 2 Mechanical and environmental measurement on DBS receiving antennas. 

f. IS 14131 (Part 1): Radio frequency cables Part 2 Particular requirements and tests for single unit coaxial cable for use in cabled distribution systems. 

g. IS 14131 (Part 2): 1995 Radio frequency cables Part 2 Particular requirements and tests for single unit coaxial cable for use in cabled distribution systems. 

h. IS 14230 : 1995 C-Band parabolic dish antenna – Specification. 

i. IS 14231 (Part 1): 1995 Cabled distribution system for television and sound signals Part 1 Safety requirements. 

j. IS 14231 (Part 3): 1995 Cabled distribution system for television and sound signals Parts Active co-axial wideband distribution components. 

k. IS 14231 (Part 4): 1995 Cabled distribution system for television and sound signals: Part 4 Passive co-axial wide band distribution components. 

l. IS 14231 (Part 5): 1995 Cabled distribution systems for television and sound signals: Part 5 Headend. 

m. IS 14264 : 1995 Satellite signal distribution on cabled distribution systems. 

n. IS 14265 1995 Satellite receivers- Specifications.

Source: http://cablequest.org/articles/cable-tv/item/1308-standardization-of-cable-tv-network-a-review.htmlSource: http://cablequest.org/articles/cable-tv/item/1308-standardization-of-cable-tv-network-a-review.html