Technological developments and enhancements in terrestrial TV broadcasting with the advent of DVB-T2, has introduced numerous advantages in terms of high quality content, interactivity, integration capability, signal robustness and more available bandwidth into the sector.
The DVB T2 technology is an extension of the existing DVB-T standard, in order to allow for a better use of the spectral resources by integrating cutting-edge signal processing technologies. In the same frequency bandwidth, the expected gains yield up to 50% additional bitrates.
The migration to digital terrestrial television (DTT) will guarantee multiple TV channels, clearer pictures, better sound quality and offer more opportunities for advertisers and broadcasters in Ghana.
The K-NET future-proof and energy efficient DVBT-T2 turnkey solution covers critically every aspect of the infrastructure workflow both physically and logically with quality control and assurance indicators for business and administrative purposes. The solution is configured to a high availability of all active content and data processing components from the supply of power, AV sources, AV processing and distribution, inter-regional AV feed uplinks, local remixing mechanism, service transmission, etc.
The Government of Ghana plans to migrate from Analogue Terrestrial Television transmission to Digital Terrestrial Television in conformity with the International Telecommunications Union (ITU) requirements. DVB-T2 with MPEG-4 compression has been adopted as the terrestrial transmission standard for Ghana. The Government is expecting to undertake the analogue to digital migration in conformity with the International Telecommunications Union deadlines to switch over from analogue to digital.
K-NET has been awarded the contract, based on a competitive bid by over 7 (mainly) international companies. KNET’s proposal carefully provides solutions designed to meet Ghana’s DTV broadcasting requirements.
The TV channel broadcast requirement is for the provision of at least 40 standard definition (SD) channels, with capacity to provide HD channels when needed. We are therefore proposing a Head-end with capability to support this immediate channel requirement, and highly scalable to accommodate future channel additions.
We are also proposing a completely new Head-end infrastructure, and not an upgrade because of the following reasons:-
- The existing Head-end is an older generation DTT and its major components are not upward compatible with our proposed DTT-2 Head-end.
- Moreover, the DTT-2 Head-end has several advantages over its older generation counterpart, and more cost-effective to go for a complete newer generation head-end than to upgrade.
The proposed Head-end to be installed at the central location shall have a 1+1 redundancy configuration. Additionally we are proposing to supply a second Head-end, with 1+0 redundancy to be installed at a different location to provide back up for the main one. This will ensure that we attain the almost 100% system availability that we envisage for the network.
A business and operations sub-system, comprising of Subscriber Management System (SMS), Electronic Programme Guide (EPG), Conditional Access System (CAS), and Multimedia Information System (MIS), shall be incorporated in the Head-end sub-system.
Our proposal considers four (4) classes of DVB-T2 transmitter equipment to be deployed for the transmitter sites. The classification is based solely on transmit power requirements per site. The four transmitter classes are: (a) 5-Kilowatt, (b) 2-Kiliwatt, (c) 1-Kilowatt, and (d) 600-watt transmitters. In effect, depending on coverage prediction studies that have been conducted by our team, the requisite category of transmitter has been proposed for each site, complete with associated RF Antenna systems and other accessories. All the transmitters have 1+1 redundancy in their sub-components, such as exciters, power amp modules, etc.
A Ku-band Satellite Uplink shall be supplied, installed and commissioned at the Head-End location to distribute content from the Head-end to the transmitter sites. Satellite link budget considerations will ensure that there is adequate capacity to uplink a minimum of 40 SD channels at the uplink station, with good margins at the receiver stations. At the satellite receive stations, link budget predictions indicate that the transport streams will be received with minimum 99.7% availability.
K-NET proposes to use its existing satellite uplink infrastructure, comprising of an 11-meter ku-band antenna, as back-up for the DTT Satellite Uplink Distribution network. This is to strive to attain 100% system availability at all times.
DTT/DTH Hybrid Concept
The Satellite Uplink Distribution network shall also be used to provide DTH services to cater for locations that are not covered adequately by the DTT network. This will ensure that there is 100% DTV coverage in Ghana.
Additionally, this hybrid concept will allow for “national” programming as well as “regional” programming. This feature enables the drop and/or insertion of content at the regional (or transmission station) locations. This also allows the use of the available satellite transponder resources for Out-station Broadcast (OB) from any part of country.
Site Infrastructure and Power Requirement
K-Net proposes to build support infrastructure including towers and equipment shelters to the highest possible standards. Sites that already have these support infrastructure will be upgraded to meet the proposed standards.
A completely redundant and uninterruptible power system, comprising of Steam Turbine Generators (STG), Uninterruptible Power System (UPS), Isolation Transformers, and Automatic Voltage Regulators (AVR) is proposed for each transmitter site. This will ensure reliable and uninterruptible power supply on all transmitter sites.
DTT Network Design
A total of 42 DTT transmitter sites have been selected to meet the Ghana DTT coverage requirement of more than 90% population coverage.
K-NET has used a highly reliable Coverage Prediction Methodology to arrive at the transmission parameters for all the sites in the proposed roll out; hence a scalable, fully redundant, and very reliable design is envisaged for the roll out.
see current coverage data