1 system structure
VSAT satellite communication consists of HVB, communication satellite repeater and small station. The detailed is as follows：

1.1 HVB
HVB, also known as center station, is equipped with aperture to reduce transmission power of far-end small station and satellite transmission power. Besides, HVB which manages, monitors and controls the overall network, also has VSAT primary station terminal device and network control center. Data port of primary station generally extends to the user for ground interrupted line and connects with computer and the information rate of primary station port is higher.

1.2 Communication satellite
Communication satellite is transfer station of signal in space. For example, public VSAT system adopts Asian 1 geostationary satellite, which locates at east longitude 82° and has 24 repeaters. Our country adopts partial band of 8th repeater. Repeater operating at C-band, adopts satellite northern hemisphere beam with linear polarization mode which can cover the whole country.

1.3 VSAT or PES
VSAT can be assembled at user’s communication site, which is divided into indoor and outdoor parts. Outdoor device can be set up at the top of buildings and the antenna is offset modified parabolic one with 1.8m aperture. Indoor device can be directly connected with user communication device. And indoor device is connected with outdoor device by coaxial cable. VSAT small station can offer communication function and have voice port itself. It enters telephone switched network after satellite repeater and main control station is made proper technical treatment. Thus, user of small station can communicate by telephone with any user on telephone website. Similarly, any user on telephone network can communicate by telephone with users of small station through main control station.