Delegates to the World Radiocommunication Conference (WRC) in Geneva, which begins Oct. 22, will spend hours pouring over technical data assessing whether terrestrial broadband wireless technologies should be permitted to share radio spectrum currently used for satellite telecommunications.
But listening to Chevron Corp. describe its attempts to install a satellite network to link its service stations and corporate offices in 10 African nations might be just as useful as the technical data presented to WRC delegations.
For Warren Myburgh, project manager for Chevron’s Africa VSAT Project, a network installation that should have taken six months took the better part of three years and was far more costly than foreseen in part because terrestrial wireless links made satellite operations impossible.
Ironically, Chevron leased much of its VSAT, or Very Small Aperture Terminal, network equipment from Orange, the France Telecom unit that is now among the companies urging WRC to permit broadband-wireless systems into the radio frequencies that are reserved for satellites.
In a presentation Sept. 26 at the VSAT 2007 conference in London organized by the Comsys consultancy of Britain, Myburgh said Chevron duly obtained the VSAT operating licenses required by each of the 10 African governments. But even then, the company on several occasions had to dismantle its satellite transmissions gear because of interference that knocked out the satellite link. While t
he interference came from terrestrial broadband wireless sources whose operations were apparently legal, the various licensing authorities involved did not make Chevron aware of the potential conflicts.
“We have had relations in these countries for 30 years,” Myburgh said. “We thought we could do this fairly quickly and easily. It didn’t turn out that way.”
Delays caused by civil war (Ivory Coast), the shutdown of the telecommunications ministry before an election (Benin) and the dismissal of the telecommunications minister which froze license requests (Zambia), had already put the project behind schedule.
In the case of Zimbabwe, the government issued the VSAT license only to insist that the annual fee be raised to $75,000 per year. Chevron agreed to pay.
But the terrestrial wireless links, which had not been identified by VSAT installation crews in advance of installation, were an even bigger challenge, Myburgh said.
In Lagos, Nigeria, weeks of negotiations regarding a site that was acceptable to local authorities were lost when Chevron’s VSAT network encountered interference and had to be dismantled.
In Brazzaville, Republic of Congo, implementation was delayed, and then canceled when similar interference was discovered.
In Douala, Cameroon, an installed VSAT operation ceased functioning because of interference. Its antenna was moved to another location.
In Kampala, Uganda, a VSAT link suddenly stopped operating because of interference. In this case, the source of the interference was located and forced to stop transmitting, Myburgh said.
“Our impression in almost all of these cases was that the sources of interference were operating legally,” Myburgh said, adding that both the VSATs in question and the broadband terrestrial wireless sources were operating in the 3.4-3.6 GHz portion of the radio spectrum. “The problem was we did not know of their existence.”
Myburgh said Chevron’s need for reliable, high-speed links was so great that it completed its project – 36 sites in the 10 nations – despite the delays and interference issues. “We felt we could not do without satellite,” he said.