ISDB-T pushes broadcasters off air

An independent frequency planning specialist has raised concerns that the ISDB-T field trial is interfering with other broadcasters' signals.

A field test of the Brazilian upgrade to the Japanese ISDB-T digital television standard has been on air since Tuesday, to prove the technology can work in SA.

The tests aim to back up the Brazilians' claims that ISDB-T trumps the European DVB-T standard, which SA initially elected to roll out in 2006, before suddenly deciding to investigate the Brazilian version earlier this year.

Communication ministers in the Southern African Development Community (SADC) are expected to announce, later this month, which standard the region will adopt. The ISDB-T trial has been seen as a last-ditch attempt by the Japanese and Brazilians to prove their technology works.

However, an independent expert says the ISDB-T trails are interfering with digital television testing that is being conducted by other broadcasters in SA. Etv and M-Net are testing the upgrade to DVB-T, DVB-T2, and are broadcasting 18 channels, including the three SABC stations, and etv and M-Net.

The tests are being run between towers in Pretoria, Johannesburg and Helderkruin, on Johannesburg's West Rand. The signal being carried includes all of the South African Broadcasting Corporation (SABC) channels, as well as 19 radio stations. The signal is being broadcast on channel 54, according to Sentech.

Koenie Schutte, MD of LS of SA Radio Communication Services, says the signal switched on at the Kameeldrift tower, in Pretoria, will interfere with transmission of M-Net signal in Rustenburg, as well as digital television trials being transmitted from Sentech's Hillbrow tower.

Although Schutte says he has not carried out field tests, based on previous experience, he says: “I know if I have predicted interference, there is a 100% chance of interference.”

The company is a local subsidiary of German frequency firm LS Telcom. It was tasked with investigating whether the ISDB-T tests would cause interference, although Schutte would not identify the parties that contracted the company.

Lara Kantor, etv's group executive for regulatory strategy, says the company's DVB-T decoders were not picking up any signal yesterday morning. She says the problem is intermittent and etv has written a letter of complaint to ICASA.

ICASA spokesman Jubie Matlou confirms there has been interference with signals sent out on the same channel. He says the licence was issued to Sentech subject to the entity entering into negotiations with MultiChoice, which transmits on channel 54.

Matlou adds that MultiChoice has complained about “some” interference, but after assessing the problem, it was not seen as severe and could be managed by coordination between Sentech and MultiChoice.

He says the test licence was issued despite the possibility of interference “in the spirit of innovation and cooperation”. MultiChoice referred questions to M-Net, which had not responded by time of publication.

Local industry commentators argue the Brazilian standard is not compatible with SA's frequency, which is on an 8MHz band, compared with Brazil's 6MHz band. They say switching standards now would result in existing investments being scrapped, and more money being spent.

However, the Japanese Embassy has hailed the transmission of ISDB-T as a success, saying the field test proved ISDB-T can work on an 8MHz spectrum.

Testuo Yamakawa, vice-minister for policy coordination in Japan's Ministry of Internal Affairs and Communications, says the “success of the trial opens the door for the ISDB-T system to the region with 8MHz channel space for the television broadcasting service”.

“I believe the SADC member states understand the superiority and advantages of ISDB-T for the benefit of Africans, and consider ISDB-T as a best option for the digital TV standards for the people of the SADC region."

Steven Ambrose, MD of WWW Strategy, says some of SA's viewing public have become casualties of the ongoing tussle over digital TV standards.

He says that, because SA's television spectrum is disorganised, any field test would have had to run on spectrum that is already in use, which would have resulted in interference.

However, Ambrose does not expect any further trials as he hopes sanity will prevail and SA will implement DVB-T.

Altech CEO Craig Venter previously threatened to sue government if it chooses ISDB-T, because the industry has spent about R700 million gearing up for switchover on DVB-T.

Ambrose says “little old ladies” will have had their viewing disrupted for nothing, although the trials will have resulted in foreign investment into SA, as the Japanese will have had to import equipment to make the tests work, because there is no ISDB-T technology in SA.

Sentech did not respond to requests for comment.