satellite can plug broadband gap

Access to high-speed communications has become a prerequisite for any company hoping to do business internationally. For enterprises located in the more remote parts of the globe where conventional terrestrial-based infrastructure is not viable, satellite broadband services provide a vital link with the wider world.

The absence of reliable terrestrial communications infrastructure presents an obstacle to economic development; and connecting under-developed regions has been described as one of the biggest challenges facing the global communications industry. Broadband IP services over satellite fill this gap and provide worldwide connectivity to enterprises, while extending enterprise applications globally enables companies to successfully pursue their business anywhere.

The continuous growth of the satellite broadband market has prompted satellite operators to launch new satellites at an accelerated rate to increase capacity for growing regions like Africa.

Satellite operators in Europe believe they can play a vital role in bringing broadband to areas not covered by fixed-line services. According to the European Satellite Operators Association, some parts of Europe will probably remain unconnected to terrestrial broadband and European Commissioner for Information Society and Media, Viviane Reding, has stated that satellite broadband can provide a medium term solution in areas where terrestrial roll out is uncertain.

taking advantage of satellite broadband

Satellite is an attractive option for businesses that cannot access other communications services, normally due to their remote location. Compared with terrestrial installations, remote sites can be deployed very quickly with satellite access and are independent of any terrestrial infrastructure. Satellite broadband services allow organizations to extend their enterprise VPNs, but also facilitate highly secure, private networks where the satellite network is dedicated to a single enterprise customer.

Satellite broadband enables new applications, such as communications-on-the-move (COTM), which provides services to mobile sites - for example, ships, trains, planes and vehicles - for both commercial and military applications.

Satellite broadband also introduces a new level of availability and reliability, providing business continuity to terrestrial IP VPN services. Diverse technologies and infrastructure protect against natural disasters and man-made outages and provide always-on enterprise connectivity.

satellite transmission bands

Satellite communications uses microwave frequencies, which require direct line of sight between the receiving and transmission equipment. The following frequency ranges are commonly used:

• C Band (4-8GHz). These lower frequencies have longer wavelengths and require larger dishes (1.8-2.4m, 6-8 feet) for reception, but are not affected by "rain fade."
• X band (8-12GHz) is largely reserved for military purposes.
• Ku band or "under K band" (12-18GHz). A shorter wavelength permits smaller dishes. Precipitation causes "rain fade," which reduces signal levels, especially at higher frequencies. Most domestic satellite systems use this waveband, including television and broadband.
• K band (18-26.5GHz) is entirely absorbed by water in the atmosphere, making it unsuitable for long-range communications.
• Ka band or "above K band" (26.5-40GHz).  Ka-Band is a relatively new frequency band for satellite broadband and will provide additional transmission capacity. Its sensitivity to rain fade makes it particularly interesting for dry regions and will support the use of small antennas (<1.2m).

technology advances

Early satellite links were dedicated SCPC (single circuit per channel), point-to-point links similar to leased lines. Now the satellite industry uses a more efficient, shared broadband IP architecture to minimize satellite space segment cost. Most enterprise networks are therefore built using a shared, hub-based infrastructure that can be centrally managed and controlled.

Advanced bandwidth, traffic and congestion management technologies allow sharing of bandwidth across multiple customer networks, remotes sites, applications and time zones.

The satellite broadband infrastructure supports all IP-based voice, data, video or audio enterprise applications efficiently. Data broadcasts and video multicasts are transported reliably and can be delivered simultaneously to an unlimited number of remote sites.Time-sensitive and mission-critical applications are prioritized for predictable service levels.

Latency (the time it takes to send and receive a message) is higher with satellite than on terrestrial networks. However, data and web-based applications can be delivered with fast response times through technological advances such as TCP acceleration.

Satellite broadband services are available from traditional telecoms providers which obtain their capacity from network operators that own and operate the satellites, ground stations and network operations centers. Enterprises typically subscribe to services using geostationary satellites, rather than the low-earth-orbit (LEO) satellites used for consumer applications such as satellite television.

Among the major sources of demand for satellite broadband are businesses looking to integrate their remote global sites with the corporate IP VPN so these sites have access to email, supply chain management, enterprise resource planning applications and other internal applications, like the rest of the corporate sites connected via terrestrial infrastructure.

To overcome issues of bandwidth contention, service providers use a technique known as class of service to distinguish between information that has to be sent immediately; critical information that is not time sensitive; and non-essential communication such as personal email.

VSAT increasing in popularity

Increasingly, two-way satellite broadband systems are based on very small aperture terminals (VSATs), which consist of a small dish - typically between 60 and 240cm - outdoor electronics mounted on the dish and an indoor satellite router. Signals from the satellite can be concentrated into "spot beams," permitting re-use of the same frequency over the satellite's broadcast area and return transmissions combine multiple channels to maximize the number of simultaneous users.

Advances in antenna technology and satellite coverage have combined to make VSAT Ku Band satellite services a practical option for international maritime companies. Previously, C Band and Inmarsat were the only options for deep ocean routes, but the size of the antenna was prohibitive for many vessels. According to telecommunications consultancy Comsys, there are already thousands of vessels using VSAT and tens of thousands of potential customers.

With VSAT, bandwidth is shared among vessels at rates up to 256 kbps with bandwidth busting at higher speeds when required. Maritime satellite broadband service providers can integrate the various vessels in a fleet to the corporate IP VPN, which enables no-cost communication between vessels and terrestrial sites and between different ships.

No market is immune from the effects of the wider economy, but the satellite broadband market has proved more resilient than most. Northern Sky Research suggests that broadband satellite market revenues could more than double from USD 3.3 billion in 2008 to USD $7.6 billion by 2018.

Continual research is undertaken into new technologies that will improve the satellite broadband experience for users. For example, the new DVB-S2 standard introduces more efficient and flexible coding and modulation technologies through its adaptive coding and modulation (ACM) specifications. ACM can dynamically maximize the IP throughput of the satellite broadband network taking into account changeable link attenuation based on weather conditions. This breaks ground for new, innovative and cost-effective broadband services and service level agreements between the network operator and enterprise customer.