The Gurara Dam and hydroelectric power station is currently under construction in Nigeria, around 120km northeast of the country’s capital city, Abuja.

The project encompasses the building of the new dam and reservoir and a pipeline that will take water from the reservoir to provide drinking water for the population in Abuja. The reservoir also provides water for local irrigation projects, and the power plant generates 37.5MW of power, providing electricity for the local population. Both the irrigation and the power generation are contributing significantly to the economic prosperity of the region and the quality of life of the local population.

alstom Hydro has supplied and installed the water turbines and generators for the project and is equipping the power station. The generators were built in the company’s factory in Bilbao in Spain and transported to the construction site.

At the start of the project in July 2008 the communications in this remote part of Nigeria were almost non-existent. An old antenna was available for mobile telephony but this provided a weak and sporadic signal with very patchy coverage, meaning that project staff could only make calls from certain locations.

Decisions often have to be made quickly on such complex projects, and this requires the availability of key staff and managers and also immediate access to business-critical information and documentation. The lack of a reliable communications infrastructure in such major projects can lead to critical delays in project implementation. Data communications are as important as voice telephony, since the project management often depends on the fast and reliable delivery of data, including reports, drawings, images and plans.

The success of such projects, often in remote locations, therefore depends on the availability of high quality, effective and reliable communications. alstom-hydro considers the communications infrastructure to be an essential element for its overseas power plant construction and project business, placing great emphasis on the importance of being universally available, with a reliable, uninterrupted and secure telecommunications infrastructure.

The solution

alstom decided to complement the existing telecommunications infrastructure with a VSAT satellite connection to West Africa and a communications link to the construction site in Nigeria. This communications solution was designed, delivered and implemented by atrexx Ltd. & Co. KG Remagen.

atrexx created a customized communications infrastructure to provide the high quality of voice and data communications that was important for the success of the project. The solution comprised a 2way2sat Ku-band satellite communications system providing an IP-based infrastructure, combined with fon4all Voice over IP (VoIP) for cost-effective telephony.

Advanced 2way2sat satellite technology provides high availability in difficult tropical conditions

One of the problems in tropical regions is that heavy rain can cause a weakening of the signal for satellite communications users. In Nigeria, for example, such situations cause problems for VSAT IP connections. Alstom, however, needed to be sure of a high availability of its communications links even in the rain. C-band is more robust in rainy periods because of its lower frequency transmission, but it requires large antennae. Local site conditions and the problems of transportation, however, meant that smaller antennae were needed. These provide an adequate service in drier regions but generally lead to restricted availability in tropical environments.

atrexx therefore implemented its 2way2sat Ku-band satellite communications, based on the recently launched iDirect Evolution Series. These services have adaptive coding and modulation (ACM) and provide stable Ku-band communications – even in tropical regions.

The atrexx 2way2sat satellite communications infrastructure provides Alstom with a high performance satellite link via the Ku-band satellite Telstar 11N. This allows the satellite signal to be sent directly from the European Teleport to the construction site in Nigeria. The site network and the local telephone switchboard are connected directly using a satellite modem. Since the atrexx solution is a two-way link, it is completely independent of the existing infrastructure and the entire telecommunications process is IP-based.

fon4all VoIP via satellite link delivers increased efficiency and reduces costs

One of the most important benefits of the IP-based satellite solution is that of VoIP telephony on the site. This provides greater functionality and reduces telephone operating costs. The implementation of a system of IP telephony over satellite eliminates the cost of installation, operation and maintenance of a separate voice network. In fact, this would not have been possible given the lack of local infrastructure and GSM availability at the construction site.

atrexx implemented its fon4all VoIP solution via the satellite channel in order to meet Alstom Hydro’s requirement for reliable, effective telephone services. A flexible billing system means that staff can make calls globally at local rates with full cost control. The integration of an international direct dialling system allowed atrexx to make Swiss phone numbers available to staff in Nigeria. The Swiss office is therefore able to contact the construction site via the Swiss telephone network, saving several hundred Euros per month.

alstom Hydro now has a satellite IP connection (VSAT IP infrastructure) for its essential data communications as well as an independent telephony solution that brings significant advantages in terms of availability and cost.

“This is an extremely flexible system that can be fully centrally managed and easily expanded to meet changing requirements,” said Jean-Claude Bisenius, CEO of atrexx.

According to attrexx, the customer benefits of this system included:

• High availability of reliable, robust communications in a remote and difficult location.

• Excellent reliability, even under tropical rainforest conditions.

• Improved efficiency through high speed data transmission – high performance data communications allow the rapid, easy transmission of data, including technical reports, drawings, images and other documentation.

• High quality voice communications – the new VoIP system, independent of the local network, allows better, more reliable voice communications.

• Lower set-up costs – the use of IP telephony over satellite eliminates the need for a separate network for voice communications.

• Cost-effective communications – the IP telephony solution allows staff to make calls globally at local rates through the company’s Swiss office network, significantly reducing the operating costs .

• Expert knowledge – atrexx’s team understood the Alstom Hydro business imperatives, the importance of the communications infrastructure and the impact that its operations have.

• Quality of service – atrexx provided skilled and experienced personnel, including local engineers to implement the system.

“[atrexx] have delivered an excellent solution and implemented the whole project from the specification to the transportation of materials and equipment to this remote location, plus the on-site implementation,” said Thomas Lüscher, Project Manager Site / HEPCHI, Alstom Hydro. “The atrexx local engineers have also been extremely supportive and have always reacted immediately to deal with any issues that arise.

“The 2way2sat solution implemented by atrexx has provided a very high performance communications environment for our voice, data and video needs, with excellent quality, high availability and good transmission speeds. We are able to send drawings, images and documents easily and reliably, vastly improving the efficiency of our project management – and the VoIP has greatly reduced our costs.”

For further information, please visit