Hello, The SCaT Diary section of the magazine's January 2017 issue indicates that the CCBN 2017 show in Beijing China, will be held from 23-25 March, 2017.

However, the CCBN ad in the same magazine indicates the CCBN dates as 24-26 March, 2017.

Please clarify the correct dates for the CCBN-2017 show.

Thanks and Best Wishes.

Anil Katara, Mumbai.

We have checked with CCBN. The correct CCBN 2017 dates are as mentioned in the January SCaT diary viz 23-25 March, 2017.

The dates indicated on the CCBN January ad are incorrect.

The correct dates are mentioned in the CCBN ad this month. - Ed


Dear Sir,

Has the government declared any restrictions on frequency usage by cable TV networks?

In its 2010 recommendations for "Implementation of Digital addressable cable TV systems in India" the TRAI has mentioned a frequency band of 47 MHz to 860 MHz.

We are often told by mobile phone companies in Chennai that we are not permitted to use certain frequencies, and that Cable networks are causing interference.

Please advise.

SK Bhaskar, Chennai

To the best of our knowledge, currently, there is no government notification instructing Cable TV networks to not use any frequencies that fall within the band 47 MHz. to 860 MHz frequency band which is as per BIS standards, and has been mentioned by the TRAI in its recommendations (indicated by you).

In the past, there has been some talk of disallowing the use of 700 MHz by cable TV networks to avoid interference with mobile phone companies. However, there has been no notification or any restriction on use of cable TV frequencies. As of today, the 700 MHz band has not yet been auctioned for mobile telephony and hence it is irrelevant.

It must be noted that cable TV signals are carried within a closed environment i.e. within the fibre optic cable and inside RF coaxial cables. Of course, there is no electrical interference whatsoever from optical fibre.

As long as the coaxial cable meets BIS specifications, along with the rest of the distribution equipment such as connectors, RF amplifiers and nodes also meet BIS specifications, there will be not be excessive RF radiation outside the cable TV network that will cause interference. The Cable Act, clearly specifies that all equipment used in a Cable TV network must meet BIS specifications.

Besides Doordarshan's terrestrial TV signals there are several other VHF transmissions from aircraft, airports and defence radar etc. that are known to cause interfere with communication. As indicated in the magazine this month, Doordarshan plans to commence DTT (Digital Terrestrial Transmissions). These will also add to terrestrial interference.

It therefore seems unreasonable for telephone companies to conclude that the interference that they are facing is due to cable TV networks.- Ed