By Raymond Miklius
Vice-President and General Manager
Television Product Group
GatesAir has supported the over-the-air industry from its inception nearly 100 years ago, and has lived through every significant game-changing development. Over the past two decades, the company has managed digital transitions of varying scale throughout the world.
Every continent and region has its unique need and challenges. However, the Asia-Pacific market stands apart due to its embrace of different standards. Today’s digital television landscape demonstrates extraordinary diversity: while DVB-T and increasingly DVB-T2 remain the most widely adopted, we see ISDB-T (Japan, the Philippines), DTMB (China) and even ATSC 3.0 (South Korea) supporting DTV initiatives.
All of these standards will provide broadcasters with the DTV benefits they seek:
- The delivery of more programmes and media services
- Improved reception, with perfect picture and sound
- The same coverage as analogue, at less power
Let’s explore each of these in more detail.
More choices, new services
First, the delivery of more programmes and services is made possible through the far more efficient bandwidth of digital streams. Where broadcasters traditionally could count one analogue programme through a single RF channel, multiple digital programmes can now be delivered using the same spectrum.
Digital encoding and multiplexing technologies in the headend play a significant role in compressing signals ahead of the RF architecture, while today’s advanced digital modulation techniques provide integrity through the transmitter. At this stage, a GatesAir transmission system provides the headroom, signal correction and other capabilities required to prepare the signals for over-the-air delivery.
Improved reception is no mystery with digital TV — the days of fuzzy analogue pictures on the edges of the coverage area are gone forever. However, the perfect picture and sound immediately drops at the edge of the coverage area. Today’s leading-edge standards — notably, DVB-T, DVB-T2, ISDB-T and ATSC 3.0 — allow broadcasters to adopt single-frequency network (SFN) architectures that are designed primarily to solve this problem.
SFNs deploy multiple, overlapping transmitters of low-to-medium power levels, with very low power gap fillers to fill in the most difficult-to-reach areas. This is especially important in countries of challenging terrain or multiple islands, with Indonesia being an excellent example.
Lower operating costs
GatesAir’s Maxiva transmitters currently provide up to 45% efficiency — a staggering increase from previous generations of digital transmitters. The higher efficiency is a substantial driver in cost savings in many ways; chief among them is that broadcasters cover the same ground with less power. This is particularly important in SFN architectures with multiple transmitters on the same frequency, sending out multiple programmes with less electrical energy consumption.
Broadcasters transitioning to current-generation transmitters will cut power usage by at least 40%, in most cases. Meanwhile, the continued migration from tube to solid-state transmitters is further lowering costs through streamlined maintenance, improved redundancy and diagnostics, and less expensive spare parts with greater availability.
With experience in digital transmissions worldwide, GatesAir is currently working with broadcasters in Vietnam, Thailand and India, among other countries, to help establish the right transmission system for their choice of standard and coverage requirements. Often, this requires software modelling to pinpoint power level needs that maximise coverage and reception. GatesAir is particularly skilled in this area, paying close attention to regions of dense population (such as identifying terrain shielding, optimum tower heights and ERP).
Elsewhere, from optimising antenna radiation patterns all the way through working with regional partners to design, install and commission the infrastructure, GatesAir is well prepared to help broadcasters manage the most challenging DTV transitions imaginable.