Why use VSATs?
VSAT networks provide rapid, reliable satellite transmission of data, voice, and video to an unlimited number of geographically dispersed sites or from these sites to headquarters. With a satellite network, there are no routers and no switches - nothing between the user and the source of the information, except the sky. There are no physical limitations in terms of geography or distance to make deployment difficult or too expensive. And since VSAT (Very Small Aperture Terminal) satellite communication systems often provide a complete end-to-end infrastructure, they can be completely independent from Telcos. Furthermore, VSATs have a reliability rate and a network availability that is significantly higher than terrestrial systems. Particularly effective for broadband applications, the high throughput VSATs offer - of 40 Mbps downstream and 76.8 Kbps upstream - means that rich-content material can be delivered live and on-line, or downloaded for later viewing.
VSAT networks offer value-added satellite-based services capable of supporting the Internet, Data, LAN, Voice/Fax communications, Video Conferencing, Distance Learning, and can provide powerful, dependable private and public network communications solutions.

The key advantage of a VSAT earth station, versus a typical terrestrial network connection, is that VSATs are not limited by the reach of buried cable. A VSAT earth station can be placed anywhere - as long as it has an unobstructed view of the satellite. VSATs are capable of sending and receiving all sorts of video, data and audio content at the same high speed regardless of their distance from terrestrial switching offices and infrastructure.

How does a VSAT network work?
A VSAT network has three components:

• A central hub (also called a master earth station)
• The satellite
• A virtually unlimited number of VSAT earth stations in various locations - across a country or continent

Content originates at the hub, which features a very large -15 to 36-foot (4,5 -11m)- antenna. The hub controls the network through a network management system (NMS) server, which allows a network operator to monitor and control all components of the network. The NMS operator can view, modify and download individual configuration information to the individual VSATs.

Outbound information (from the hub to the VSATs) is sent up to the communications satellite's transponder, which receives it, amplifies it and beams it back to earth for reception by the remote VSATs. The VSATs at the remote locations send information inbound (from the VSATs to the hub) via the same satellite transponder to the hub station.

This arrangement, where all network communication passes through the network's hub processor, is called a "star" configuration, with the hub station at the center of the star. One major advantage of this configuration is that there is virtually no limit on the number of remote VSATs that can be connected the hub. "Mesh" configurations also allow for direct communication between VSATs.

Simply Higher Technology

When and Why VSAT network is better
From major telecommunications providers to the United States Postal Service, businesses and governments around the globe have chosen to implement enterprise networks, telephony systems and broadband solutions based on Satellite's very small aperture terminal (VSAT) satellite technology.

Small businesses, schools, remote farms, Internet Service Providers, air traffic controllers, financial services, banks, restaurants, retailers and other enterprises worldwide choose Satellite VSAT satellite networks for a number of key reasons:
> Ubiquitous availability
> Superior economics
> Reliability
> Timely deployment and installation
> Multicast content distribution
> Site relocation and addition
> Flexibility and expandability

Ubiquitous Availability

Satellite is the only telephony and broadband wide-area network technology that is available everywhere - in even the most remote urban and rural areas, rain forests or concrete jungles, anywhere in the world. All that's needed is a clear view of the sky.

By contrast, other telephony and broadband technologies are strikingly limited in their coverage area. Terrestrial broadband technologies, such as DSL, Frame Relay, ISDN and cable reach only a small percentage of homes and businesses. For example, it is currently estimated that DSL service is available to less than 25% of the continental U.S.

Telephony infrastructure - terrestrial copper and fiber optics, microwave, radio, wireless and underground cable - is also extremely restricted when compared to the virtually limitless reach of satellite technology. Satellite overcomes terrestrial limitations to provide these essential services to remote communities and businesses around the globe.
Superior Economics

Satellite networks are much less costly to deploy, maintain and operate than terrestrial network technologies. Terrestrial networks require heavy infrastructure, whether they are telephony networks (based on copper wiring, fiber optic cables, radio or microwave towers), or broadband data networks (such as Frame Relay, DSL, ISDN and cable). High overhead costs for these infrastructures are passed on to the customer. In remote areas where such infrastructure does not exist, the expense of building such networks is often prohibitive, in developing and developed countries alike.

The economics of a satellite network are much simpler. The individual VSAT units are relatively inexpensive (about the same cost as a router in a Frame Relay network) and can be quickly and easily installed by a field technician. Hub and satellite costs are shared among thousands of customer sites, so the per-site cost of equipment, maintenance and management is low - and gets lower as more sites are added to the network.

And no terrestrial infrastructure development is ever needed. In fact, VSATs - which are built for low power consumption - can even run without electricity, using simple solar panels.
Reliability
Satellite networks provide unmatched reliability, with far fewer potential points of failure than terrestrial solutions and built-in redundancy at almost every level to limit service interruptions when problems do occur.

Terrestrial networks have Multiple potential points of failure where outages can occur: construction projects digging up streets; falling trees taking down telephone poles; equipment failures at the local telephone central office, to name a few. And many times, terrestrial network providers may not be able to fix these outages without third-party carriers.

Satellite networks have just three potential points of failure, each with built-in redundancy and back-ups: the satellite, the hub and the VSAT. Satellite outages are exceedingly rare but, should one occur, it is usually possible to automatically reroute traffic to back-up transponders without impacting service.

In the even more remote case of total satellite failure - which has occurred just twice in the 30-plus years that satellites have been in commercial use - back-up capacity is available on dozens of satellites. At the hub, online redundant equipment is used to provide immediate switching for uninterrupted service in the event of equipment failure. And VSAT equipment has the longest mean-time-between-failure in the industry: about 10 years.
Timely Deployment and Installation
Satellite networks can be rolled out to hundreds or thousands of locations in a fraction of the time required for a comparable terrestrial network.

With a terrestrial network, deployment and installation of new systems or even single locations is complicated, often involving Multiple vendors who have no incentive to work with or assist each other. But VSAT technology is almost completely free of terrestrial infrastructure, so there is no need for coordination with any third party. With a satellite network, installation and deployment are quick and simple.

A Satellite installation team can usually complete a site install in a matter of hours, no matter where the site is located, meaning that complete network deployment to hundreds of sites can be accomplished in a matter of weeks, rather than months.
Multicast Content Distribution
Satellite's inherent strengths as a broadcast medium makes VSAT networks ideal for the distribution of bandwidth-intensive information - data, video or audio - to large numbers of remote locations.

To send a file to 1,000 recepients over a terrestrial network requires sending 1,000 separate and identical messages, each of which consumes valuable bandwidth and server resources. They are also likely to arrive at different locations at different times.

Satellite multicasting; on the other hand, can simultaneously deliver content to a virtually unlimited number of end-user locations - at speeds up to 40 Mbps. By eliminating duplicate transmissions, Satellite's multicast technology maximizes the efficiency of existing servers and networks, and frees up valuable bandwidth.
Site Relocation and Addition
Relocating and adding network sites is significantly less complicated and less expensive with a satellite network than with most terrestrial technologies.

In the terrestrial world, vendors require advance notice to move a site; they may be unwilling or unable to fulfill requests for quick relocations, or charge significant extra fees. Adding a new location can be similarly complex and costly, in addition to incurring increased monthly bandwidth fees and other charges. In either case, the time and expense required increases significantly if infrastructure is not already in place - which is very often the case in remote and rural areas.

With a satellite network, installation of new sites takes just a few hours. Relocation can occur on the same day, in most cases, if the sites are close to one another. And no additional terrestrial infrastructure is ever required.
Network Capacity Expansion
Satellite technology provides a uniquely convenient environment for accommodating network and bandwidth expansion.

Indeed, one of the biggest wide-area network challenges is the ever-increasing need for additional bandwidth to support new applications. In a terrestrial environment this is especially challenging since, if a new application is large enough, new terminal components (routers, cards, etc.) have to be ordered - and increased bandwidth has to be commissioned - separately at each site, in conjunction with local third-party vendors. In many cases, the cost of expanding network capacity on a terrestrial network can actually exceed the original cost of deploying the network. Plus, such an upgrade, if economically feasible, can take months, since new circuits have to be ordered and a field technician must visit every site.
With a satellite network, network expansion is extremely easy and comparatively inexpensive. First, all bandwidth allocation is controlled at the hub, so increasing network capacity is as simple as increasing the amount of bandwidth allocated to the network. And, while in some cases additional equipment may be required at the hub to support the increased capacity, this hardware can most often be installed in a matter of days. More importantly, no hardware changes or field technician visits are required at the remote sites, since Satellite's VSAT equipment is designed out of the box to handle maximum bandwidth requirements.

Flexibility and Expandability
Satellite's VSAT technology has an unmatched ability to support a wide range of devices and applications. Single platforms can provide voice, fax, data and Internet connectivity; data networks can support advanced functions including multicasting.

Satellite's modular product design also allows for maximum scalability and fast upgrades - with an ease and simplicity not possible with terrestrial networks.

And satellite technology - with its unique broadcast and multicast capabilities - is the only choice for companies planning video and high-bandwidth content distribution as part of their wide-area network future.
See our Satellite Telephony and Internet Network Diagram