The shutting down of analogue television platforms in favor of the digital is set to begin in December according to Communications Commission of Kenya {CCK}.

 

At the 2006 International telecommunications union Regional Radio communication Conference, European, African and Middle Eastern nations agreed to phase-out analogue broadcasting embracing digital platforms.
The effort did commence in June 17, 2006 with analogue broadcasting set to end in 2015.
The different countries set about achieving these goals through various initiatives and at different dates. CCK set varied deadlines for different parts of the country to achieve a progressive transition. The digital transition process has been marred by controversies and postponed severally due to a low level of preparedness among crucial players as well as claims of limited consumer awareness. The commission had threatened to switch-off the analogue signals currently in use in July 2012 but changed to September and then December of the same year. This however did not take place, the major obstacle being a legal case filed at the High Court where the court stopped the switch-off process on the grounds that it was going to banish most Kenyans to darkness at an election time which was in March, making them miss timely and crucial information that the television gives.
CCK is again threatening to shut down all analogue transmission in the country since the elections are long gone. This is to start from Nairobi on December 13. It poses the potential of over half a million households losing access to television services. The switch-off dates for Mombasa, Malindi, Nyeri, Meru, Kisumu, Webuye, Kisii, Nakuru and Eldoret are set for March 2014. The remaining parts of the country have until June 30, 2014 to conform.
Elsewhere in Africa only 2.5 million homes have acquired the set-top boxes two years to the analogue broadcast switch-off deadline. To deal with the lack of awareness CCK Director General Francis Wangusi said the commission would start a consumer awareness campaign to get about 500,000 households to purchase the set top boxes before the deadline.
There had been confusion before on whether people who had pay TV decoders had to upgrade to use the digital platform. This was settled with the recommendation that the pay television providers offer at least five free-to-air channels such as NTV, KTN, K24 and Citizen and make them available even when the subscriber is in default.
There are two licensed digital terrestrial signal distributors in Kenya. They use the Digital Video Broadcast Technology 2 (DVB-T2). Digital migrations will increase the spectrum for use in deployment of other ICT services including mobile broadband.  It will also facilitate a wider choice of programs, and allow for plurality of content.
On migration individuals without pay TV will be required to have set to boxes. Set top boxes are gadgets that decode digital signals that are broadcast on digital platforms for viewing on ordinary television sets. There are two types of set top boxes in the market – pay TV and free to air set top boxes.

Technical aspects as provided by DVB consortium.
The Digital Video Broadcasting Project (DVB) is an industry-led consortium of over 200 broadcasters, manufacturers, network operators, software developers, regulators and others from around the world committed to designing open interoperable technical standards for the global delivery of digital media and broadcast services.
The DVB-T2 system transmits compressed digital audio, video, and other data in “physical layer pipes” (PLPs), using OFDM modulation with concatenated channel coding and interleaving.
DVB-T2 is the world’s most advanced digital terrestrial television (DTT) system, offering more robustness, flexibility and at least 50% more efficiency than any other DTT system. It supports SD, HD, UHD, mobile TV, or any combination of them.
DVB-T is the most widely adopted and deployed DTT standard. 70 countries have deployed DVB-T services and 45 more have adopted but not yet deployed DVB-T. This well-established standard benefits from massive economies of scale and very low receiver prices. DVB-T2, an improvement of DVB-T easily fulfils commercial requirements, including increased capacity, robustness and the ability to reuse existing reception antennas.
Like its predecessor, DVB-T2 uses OFDM (orthogonal frequency division multiplex) modulation with a large number of sub-carriers delivering a robust signal, and offers a range of different modes, making it a very flexible standard. DVB-T2 uses the same error correction coding as used in DVB-S2 and DVB-C2: LDPC (Low Density Parity Check) coding combined with BCH (Bose-Chaudhuri-Hocquengham) coding, offering a very robust signal. The number of carriers, guard interval sizes and pilot signals can be adjusted, so that the overheads can be optimized for any target transmission channel.

Other technologies applied include;

-Multiple Physical Layer Pipes allow separate adjustment of the robustness of each delivered service within a channel to meet the required reception conditions. It also allows receivers to save power by decoding only a single service rather than the whole multiplex of services.

-Alamouti coding is a transmitter diversity method that improves coverage in small-scale single-frequency networks.

-Constellation Rotation provides additional robustness for low order constellations.

-Extended interleaving, including bit, cell, time and frequency interleaving.

-Future Extension Frames (FEF) allow the standard to be compatibly enhanced in the future.

The first country that deployed DVB-T2 is the UK in March 2010. 2010 and 2011 also saw the launch of DVB-T2 services in Italy, Sweden, and Finland. Outside of Europe DVB-T2 pay-TV services were launched in Zambia, Namibia, Nigeria, Kenya and Uganda and many more are expected to follow soon.

Refrences

1. DVB Project fact sheet August 2013

2. CCK

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