INTRODUCTION OF VSAT

What is Toph, Inc?
Teleglobal of the Philippines (Toph Inc.) is a satellite Internet provider with a nationwide satellite coverage delivering high speed broadband Internet connection to private homes, small and medium enterprises and large scale businesses. Toph is part of the OCL of Korea a systems integrator with a high degree of expertise in satellite communications design, systems integration and commissioning using high-end technology solutions to provide reliable data communications solution and satellite services.

What is Gigapass?
Gigapass is the trademark/brand name of TOPH, Inc. It is a high speed internet VSAT network capable of delivering secure data connection for enterprises and organizations with remote offices. The network operates over the Hughes Networks high end satellite platform utilizing DVB-S2/ ACM satellite technology offering increased connectivity.

What is VSAT?
The VSAT technology is used for various types of communications, most especially internet in a very remote site where Landlines, Cable, Terrestrial, and Fiber optics is not possible.
VSAT is an abbreviation for a Very Small Aperture Terminal. It is basically a two-way satellite ground station with a less than 3 meters tall (most of them are about 0.75 m to 1.2 m tall) dish antenna stationed. The transmission rates of VSATs are usually from very low and up to 4 Mbit/s. These VSATs' primary job is accessing the satellites in the geosynchronous orbit and relaying data from terminals in earth to other terminals and hubs.

Equatorial Communications first used the spread spectrum technology to commercialize the VSATs, which were at the time C band (6 GHz) receive only systems. This commercialization led to over 30,000 sales of the 60 cm antenna systems in the early 1980s. Equatorial Communications sold about 10,000 more units from 1984 to 1985 by developing a C band (4 and 6 GHz) two way system with 1 m x 0.5 m dimensions.
In 1985, the current world's most used VSATs, the Ku band (12 to 14 GHz) was co-developed by Schlumberger Oilfield Research and Hughes Aerospace. It is primarily used to provide portable network connection for exploration units, particularly doing oil field drilling.

VSAT Configurations
Most of the current VSAT networks use a topology:

• Star topology: This topology uses a central uplink site (eg. Network operations center (NOC)), which transports the data to and from each of the VSAT terminals using satellites


• Mesh topology: In this configuration, each VSAT terminal will relay data over to another terminal through the satellite, acting as a hub, which also minimizes the need for an uplink site


• Star + Mesh topology: This combination can be achieved (as some VSAT networks do) by having multiple centralized uplink sites connected together in a multi-star topology which is in a bigger mesh topology. This topology does not cost so much in maintaining the network while also lessening the amount of data that needs to be relayed through one or more central uplink sites in the network.
  

VSAT's Strengths
VSAT technology has many advantages, which is the reason why it is used so widely today. One is availability. The service can basically be deployed anywhere around the world. Also, the VSAT is diverse in that it offers a completely independent wireless link from the local infrastructure, which is a good backup for potential disasters. Its deployability is also quite amazing as the VSAT services can be setup in a matter of minutes. The strength and the speed of the VSAT connection being homogenous anywhere within the boundaries is also a big plus. Not to forget, the connection is quite secure as they are private layer-2 networks over the air. The pricing is also affordable, as the networks themselves do not have to pay a lot, as the broadcast download scheme (eg. DVB-S2-ACM) allows them to serve the same content to thousands of locations at once without any additional costs. Last but not least, most of the VSAT systems today use onboard acceleration of protocols (eg. TCP, HTTP), which allows them to delivery high quality connections regardless of the latency.

VSAT Drawbacks
As with everything, VSAT also has its downsides. Firstly, because the VSAT technology utilizes the satellites in geosynchronous orbit, it takes a minimum latency of about 500 milliseconds every trip around. Therefore, it is not the ideal technology to use with protocols that require a constant back and forth transmission, such as online games. Also, surprisingly, the environment can play a role in slowing down the VSATs. Although not as bad as one way TV systems like DirecTV and DISH Network, the VSAT still can have a dim signal, as it still relies on the antenna size, the transmitter's power, and the frequency band. Last but not least, although not that big of a concern, installation can be a problem as VSAT services require an outdoor antenna that has a clear view of the sky. An awkward roof, such as with skyscraper designs, can become problematic.