Broad way

Digital technology moves fast. From being a rather geeky, niche service fawned over by videogamers just a few years ago, broadband internet is now the standard system of choice for the online world. Increasing use of the multimedia capability of the World Wide Web — audio, video, voice-over internet protocol (VoIP) telephone — means that if you do not have a broadband connection, you’re missing out on a great deal of useful functionality.

However, broadband internet requires infrastructure and while city dwellers take it for granted, until it breaks down, it can be a different story in the countryside. Running fibre-optic cabling to remote villages and isolated housing is no small task and nor is uprating local exchanges. According to the Office of National Statistics, more than 85 per cent of UK internet access was via broadband in 2008, but only 56 per cent of households had broadband coverage, which was an eight per cent increase on the previous year. Clearly, there is still a gap. Outside the UK, coverage is even more patchy. Internet service providers (ISPs) estimate that large parts of rural Western and Eastern Europe are unlikely to be connected to broadband services for 10 years. This leaves significant population areas without access to the broadband services most of us take for granted.

The answer to the problem is in the skies, according to Avanti Communications, a UK company specialising in providing alternative sources of internet coverage. A large part of Avanti’s business comes from using satellite transmission to provide back-up broadband services to large businesses in case their landlines fail. The company is now preparing to launch its first purpose-built satellite, called HylasOne, which will use microwave technology to beam both broadband and high-definition television services across Europe to any location, no matter how isolated or small.

HylasOne (Hylas is an acronym for ‘highly adaptable satellite’) will be the first British-owned communications satellite for 15 years. Funded privately by both the British National Space Centre (BNSC) and the European Space Agency (ESA), the satellite is a private-sector response to a problem that ESA tried — and failed — to tackle. Although the agency had originally proposed to launch two large satellites to beam microwave broadband, it was unable to secure enough support from member states and the European Commission. Avanti stepped into the gap.

‘We knew we could help,’ said David Bestwick, chief technology officer. ‘We suggested building a smaller satellite to prove the worth of the investment and then go on to build a bigger one with more capacity once the market was proven.’

The project, which began in 2006, is the first public-private pan-European satellite programme. Of the total £80m of funding, £23m has come from the BNSC through ESA’s ARTES 3 programme — part of the agency’s communications activities. The company also raised £50m via City of London investors, before the recent financial chaos.

HylasOne is a relatively small satellite. The basic platform is, in fact, an Indian design, the Indian Space Research Organisation (ISRO) I-2K, which is tried and tested, having been in use for around 22 years.

The satellite payload, which was made by Astrium, is what provides its highly adaptable character. HylasOne is capable of automatically allocating different amounts of power and bandwidth to the regions within its footprint, which ranges from Ireland to Greece from east to west and Denmark to Spain and Italy from north to south. This means that, at any one time, up to 320,000 users can access Hylas.

The satellite will use two microwave bands: Ka and Ku. The former will provide the broadband functionality, while the latter will provide about 250 HDTV channels. The Ka-band transmitter is two to three times as powerful as any other satellite over Europe, according to Avanti, and will be broadcast in eight overlapping ‘spots’. This, claims ESA, is a capacity equivalent to 40 of the conventional 33MHz transponders used to provide coverage.

The variable-power application is provided by one of two new satellite technologies on board: Astrium’s General Flexible Payload. At the heart of this is a module made using a technique called highly integrated modular microwave hybrids. According to Paul Gidney, broadband manager in Astrium’s telecom business development division, this packages different microwave units together within layers of ceramic and gives satellite payload builders a number of advantages.

Hylas’s ability to work in the Ka and Ku band is unusual, Gidney said. ‘The Ku band is full and operators are looking to move over to the Ka band as that has more capacity and that means more space for more services and TV channels.’ The hardware within the satellite allows it to receive and transmit signals across these ranges. ‘We offer the ability to route as much or as little capacity to those spot beams as is required and also the ability to take different uplink frequencies and link them to different downlink frequencies,’ he added.

Hylas also uses advanced routing and switching equipment (RACE) to connect the incoming signals to outgoing ones. ‘It allows you to connect any input to any output, using a solid-state multi-switch microwave matrix,’ said Gidney. ‘In a more conventional satellite, that would require lots of mechanical switching, which adds mass and degrades reliability.’

The integrated solid-state modular approach allows complex payloads to be built up from standardised modules in a very small space, while also minimising the number of connections that have to be made between the various components using wires, making the system more robust and reliable. The use of standard modules is expected to reduce the cost and complexity of satellite payloads. Hylas represents a pilot project for this system.

The other technology is the Next Generation Antenna, which again uses innovative manufacturing techniques to boost its performance. Its innovation lies in a rapid production process called direct metal laser sintering, where a laser is used to melt together a nickel-bronze powder to build up the complex geometry of the antenna in 20-micron-thick layers.

This allows the antenna to be made as a single part, whereas spark erosion, a conventional method, would make four to five pieces that would then have to be assembled. This, claims Astrium, makes the component far faster to create directly from computer-aided design models, reducing test and production costs and speeding up the design process; it will also make it easier to produce bespoke or modified designs.

Bringing in another partner to the project, Avanti formed a partnership with Inmarsat to provide satellite control for Hylas. Inmarsat is currently operating a fleet of 10 communications satellites and will use the same systems to run Hylas. Andrew Sukataway, chairman, said: ‘Avanti is implementing one of the UK’s most innovative space projects and we intend to work closely with them.’

The launch method for Hylas also represents a first: the company has bought a space on a Falcon 9 rocket, which is being developed by SpaceX, a commercial space transportation company. Falcon 9, a reusable multi-stage launcher, is currently awaiting its first demonstration launch from Cape Canaveral; the Hylas launch will be its first commercial outing. The launch is currently unscheduled, but Avanti and SpaceX expect it to be within the next few months.