October 2018

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Q: I was reading your July edition & I have a doubt regarding the new TRAI tariff order.

Are "Basic Tier" and "Network Capacity Fee" different things ? Does the LCO get the network fees ? I am not sure if our customers will pay all these fees. Can we charge zero network fees?

We are MSO based out of Port Blair, Andaman Cable Network. We also operate an LCO network - Guru Enterprises.

Ashwin Dhinakaran, By E-mail.

ANS: Lovely to hear from you, from far away Andamans ! The 'BASIC TIER' is a Bouquet or group of channels, created by the cable operator for its Cable TV consumers.

The Network Capacity Fee is an additional fee that every consumer must pay for using the Cable TV network's bandwidth. This includes the Cable TV bandwidth used for transmitting the Basic Tier bouquet & any other SD and HD channels.

The cost of Pay Channels is extra.

The Tariff order does not specify the division of revenues between the MSO & LCO. The MSO provides 'capacity' from the headend to the LCO's unit. From there, the LCO provides 'capacity' for individual consumers. Hence, the MSO & LCO need to arrive at a mutually agreeable split of the network capacity fee.

Yes, if both - the MSO & LCO agree, they can reduce their Network Capacity Fee to zero. But it is important that this zero fee be extended uniformly to all consumers on their network.


Q: I am an LCO. Can I receive and re-transmit 2 separate signals from 2 different MSO's on my network, as shown in the block diagram (Figure-1).

I will allocate different frequencies for each MSO's signal.

My customers will be asked to choose either STB from MSO 1 or a different STB from MSO 2.

Please confirm if this will work.

Kesava Reddy, by WhatsApp

ANS: At first glance, your solution seems to be technically okay. However it will actually not work. Let me explain in detail.

The digital signals from each MSO contained various information as shown in Figure 1.

The SI (System Information) is basically a head under which various other information is transmitted. Broadly the various categories of information included in the SIR:

NIT: Network Information Table. This contains all information about the network such as network name, the frequency of each digital carrier, the modulation used eg. QAM64, QAM256 etc. and the symbol rate.

SDT : Service Descriptor Table contains information on the services available e.g. Discovery Channel on Channel no. 201, the multiple audio feeds which maybe stereo, different languages etc.

BAT: Bouquet Association Table. Some CAS Systems provide for a BAT. For e.g. an MSO may output 500 channels from their headend but permit certain LCO's to receive only 200 out of these 500 channels. This can be defined by the BAT thereby providing different LCO's different channel bouquets.

EIT: Event Information Table. An event information table (EIT) comprises data, which specifies the events or the programs, such as event name, start time and duration.


An STB is like a computer. When its starts (boots up) it check for certain information, which it needs to operate.

When an STB is switched on, it hunts all input frequencies for a SI stream. Once it finds this SI, it locks into the SI and then takes all the information such as the digital frequencies, modulation and all the other info listed above.

A single MSO can have 2 different CAS (Conditional Access Systems) at the same time and the SI will tell the STB full details of the single or multiple CAS systems available.

However, if when it boots up, the STB finds 2 different SI, (SI 1 from MSO 1 and SI 2 from MSO 2) it will not know which SI to lock into. The STB will not work.


Q: Is it true that the home stream frequency for Digital STBs is fixed at 306 MHz? Is it possible to use a different Home Stream frequency on our cable TV network? I am told that the STB will not work if any other home stream frequency is selected.

Mazher Jaffer, Mumbai.


The home stream frequency, in India, is very often set at 306 MHz. However, it is not compulsory or absolutely necessary for the home stream frequency to be set at 306 MHz. Let us look at the matter in detail.

The home stream on a digital cable TV network carries all the important information that a digital STB requires to receive all the channels. This includes the frequencies of the various digital streams as well as the type of modulation (e.g. QAM 64 or QAM 256), etc. Unless the home stream is received perfectly, other channels on the service may not be received or even detected. Hence it is essential to transmit the home stream at a frequency where there is minimal noise and interference (e.g. terrestrial interference, interference from VHF communications such as airports, police, VHF band, pagers etc.)

We spoke to Mr. Navroz Behramfram who is a technical stalwart for cable TV in India. He has been instrumental in setting up some of the first as well as largest cable TV systems when working with major MSO's such as Hathway and Den. Navroz spoke about the extensive all India trials that were conducted to find a frequency band that had minimal interfering signals. Also given the fact that Indian LCO networks a decade ago were of poor quality and used coaxial cable rather than optical fibre for distribution. It was decided to use the lowest possible frequency which had the least terrestrial interference.

The VHF band (below 300 MHz) simultaneously carried Analog Cable TV signals as well as suffered from terrestrial interference.

The beginning of the UHF band i.e. 300 MHz onwards was found to be ideal since it did not have terrestrial interference and the frequency was low enough to ensure adequate signal levels to STBs even in poor quality LCO networks. The first UHF channel in the PAL B/ G system used by India commences at 302 MHz and extends for 8 MHz i.e. Up to 3010 MHz. It was decided to place the home stream in this frequency band and the centre frequency of this frequency band is 306 MHz.

The first digital cable TV systems operated very successfully with their home stream at 306 MHz.

Typically, each STB carries certain preset information which includes for e.g. the network logo on boot-up etc. This initial information also includes the home stream frequency. If this is programmed at 206 MHz, the first time the STB boots up in the network it will first go to 306 MHz and try to obtain the home stream data. Once it finds this home stream data, it will get all the information required for it to receive all the other several 100 channels on the digital network.

If the STB does not find the home stream at the frequency information preinstalled into the STB, the STB will keep hunting the entire frequency spectrum to automatically find the home stream. This could take 20 to 30 minutes! However, this hunting will happen only once when the STB is first connected to the network and switched on. It is of course much better and faster if the STB is "told" the

correct home stream frequency in its preprogrammed data. Hence a network could decide on any other home stream frequency and have this data burnt into the STB ROM (Read Only Memory). The STB will then work perfectly, using whatever home stream frequency it has been pre-programmed with

Dish Doctor
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