Digital Migration: Analogue Switching Off (ASO): 28 Oct

18 October 2016

South Africa will on 28 October 2016 hold an event in the Northern Cape to mark the first phase of television broadcasting analogue switch off (ASO). The ASO is one of the critical milestones of the Broadcasting Digital Migration process.

1.1 On the 1st of October 2015, the South African Post Office (SAPO) - commenced with the registration process for government subsidized STBs in the Northern Cape.

1.2 On the 17th of December 2015, following the availability of the Set-Top-Boxes (STB) and accessories, the DTT Project was launched live by the Minister. This saw the distribution and installations of STBs to qualifying households in Keimoes, Kakamas and other towns in the Northern Cape Province

1.3 In April 2016, the DTT PMO engaged into and finalised a door-to-door registration campaign plan for the four core SKA towns, namely, Brandvlei Williston, Carnavon (including Vosburg) and Vanwyksvlei. This was a direct intervention aimed at fast tracking the uptake and usage of STBs and therefore facilitate analogue switch off in the SKA area.

1.4 The campaigns continued to cover the entire SKA towns including those towns in the borderlines of the SKA polygon.  All in all, a total 18 SKA towns were targeted with the door-to-door intervention.

1.5 The campaigns were supported by local municipalities through providing community volunteers. Carnarvon, as the area with the highest estimated TV households was considered a key pilot site for the door-to-door registration, distribution and installation process, due to its closest proximity to the SKA telescope sites.

1.6 The Square Kilometre Array (SKA) in the Northern Cape is protected under the Astronomy Geographic Advantage (AGA) Act of 2007 from harmful frequency interference. The existence of analogue television transmissions in the area presents the biggest source of the unwanted radio noise. The situation is made more serious by the fact that analogue television transmissions are no longer protected under the statutes of the International Telecommunications Union (ITU), which lapsed on 17 June 2015. It is therefore imperative upon government to comply with the requirements of the SKA project by, among other things, switching off all existing analogue services in the area.

1.7 There is a total of approximately 178 high power analogue TV transmitters across South Africa. An estimated 18 of these are situated in the SKA area of the Northern Cape. Among these 18 transmitter sites, 4 (four) are located in the core of the SKA telescope sites around the towns of Carnarvon, Williston, Vosburg and Vanwyksvlei. The entire SKA area has been demarcated by means of a polygon inhabited by an estimated 25,000 households.

1.8 Against this background and other related work in the Digital Migration Project, the Department of Communications embarked on a focussed door-to-door registration and installation of decoders or STBs necessary to migrate households from analogue to digital TV reception in the SKA region.

1.9 The households in the four towns in the core of the SKA area, namely Carnarvon, Williston, Vosburg and Vanwyksvlei were successfully migrated to digital. Approximately 91% of the households were migrated as per the table below, an achievement which surpasses the 85% nominal threshold for households to migrate before analogue switch off can be effected.

Core SKA Towns

Actual Door-to-Door Registrations

Installations completed


% Installations completed


1 658
















3 575

3 244


1.10 The Analogue Switch Off (ASO) event being undertaken is therefore a demonstration of the first major national milestone in the quest for complete analogue switch off in the country. Although the event will be focussing at the Carnarvon transmitter switch off, there are other three transmitters in the core of the SKA that will also be decommissioned as part of the first switch off phase.

1.11 The ASO process is undertaken in phases across the nine provinces, the Northern Cape being the first in line. The switch off in the SKA and the rest of the Northern Cape will be followed by Free State, Limpopo, Mpumalanga, North West, Eastern Cape, KwaZulu-Natal, Western Cape and finally Gauteng.

This symbolizes capabilities of Broadcasting Digital Migration stakeholders who made it possible to reach this stage, and marks the beginning of the long-awaited process of vacating the spectrum needed for mobile telecommunications and other applications that will add considerable value to the county’s economy.

The Northern Cape, which hosts the international radio telescope Square Kilometer Array (SKA) project, will become the first province in the country to switch off its analogue television signal. Analogue transmitters will be switched off in the SKA towns Vanwyksvlei, Brandvlei, Williston, Vosburg and Carnarvon.

Registration for government subsidized STB decoders is currently underway in Limpopo, Mpumalanga and Free State and will be rolled out to the rest of the country in phases.

The main event in the Northern Cape is expected to be attended by senior government officials including the Minister of Communications and Presidency, BDM stakeholders together with representatives from ICT International bodies such as International Telecommunication Union (ITU) and SADC.

The main reason for the world’s migration to digital is to release valuable spectrum which can be used for mobile telecommunications and other services. Spectrum is scarce, therefore more efficient use of the spectrum is necessary if more terrestrial telecommunications and broadcasting services are to be made available.

With digital broadcasting, sound, video, text and still images can be transmitted using a technology that allows for information to be compressed, thus using frequency spectrum efficiently.

More information on Broadcasting Digital Migration

Artwork for download: