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.
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.
- K
u 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.
- K
a band or “above K band” (26.5-40GHz). K
a-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 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
K
u 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.