Hem, Manager – CAS, DEN Networks
When we talk of current digital TV broadcasting, channels/services can be received by connecting a set top box (STB) to the TV or sometimes the STB is in-built in the TV itself. With this model there is the limitation that the STB of one service provider cannot be used for another service provider.
This limitation gave rise to many disadvantages like:
- One service provider STBs cannot be used with another service provider signal and hence when the user wants to switch to another service provider he has to re-invest in another STB
- Since every time customer has to replace the STB it results in wastage or we can say increase in e-waste
- It gave rise to monopoly
India is a hot market these days for all STB manufacturers with large number of MSOs and DTH operators. STBs are in huge demand in India as we have huge number of subscribers using digital TV.
Looking into the disadvantages of noninteroperable STBs, interoperable STBs are in news these days.
Interoperable STBs shall be used to receive and display signals from multiple operators. Hence every time the user will not have to invest in a new STB when switching the service provider and also the user will be free to choose any service provider any time as per his taste. These STBs will be independent of any specific operator and CAS (conditional access system).
There are many challenges in front of interoperable STBs like CAS and EPG.
When we talk of STBs hardware configuration is the same for all STBs except for the demodulator, which is different for different DVB receivers since transmission schemes are different.
The Demodulator is used to demodulate the signal which is then descrambled using similar CW (control word) which is used at the time of scrambling. The descrambled signal is then decompressed which is again different.
Scrambling is done according to DVB standards called DVB-CSA (common scrambling algorithm) and during this process ECMs (entitlement control messages) and EMMs (entitlement management messages) are added to the TS (transport stream). ECMs are channel/service specific and contain CW which is used to scramble the program.
EMMs (entitlement management messages) are unique for each subscriber. These encrypted EMMs and ECMs are the main challenge.
Interoperability is in great news in India where we have huge number of Pay TV subscribers and various types of delivery models like DTH (direct to home), cable, hits (head-end in the sky), IPTV (Internet protocol TV).
Also when we talk of noninteroperability, STB of a subscriber changes when the service provider is changed and the STB which is technically good (nonfaulty STB) becomes useless and adds to garbage/e-waste. Till date millions of STBs are lying as waste in a developing country like India.
With interoperable STBs customers can use the STBs just the way mobile phones and computers are used. Also interoperable STBs will increase competition in the Pay TV market and where competition arises innovation starts with great speed; hence, customers shall start receiving new/improved services. It shall also give rise to improvement in service quality.
Thus with interoperability we shall have freedom to choose the service provider and change according to taste, new innovative services, improved service quality, less e-waste, and STBs available in the open market.
Let us watch how interoperable STBs move and how they change the Pay TV market in India.