Download - Vsat(very small aperture terminals(
VSAT(VERY SMALL APERTURE TERMINALS(
Prepared by/fata el hoorVSAT ((very small aperture terminal))
VSAT
In this powerpoint we aim to
• Describe the technology of VSAT
• Planning process and its topology
• BANDS OF VSAT
WHAT IS VSAT!
VSAT is micro_earth station that uses the latest innovations in the field of satellite communication to allow user’s access to reliable satellite communication .
It is provide users with simple equipment that required minimal installation and repair easy to repair and simple to troubleshoot.
VSAT STATION IN DETAILS
OVERALL VIEW ON VSAT STATION
ODU&antenna provide RF conversion and amplification for the satellite downlink &uplink
ODU called transceiver In up link we use(up converter + SSPA) In down link we use (LNA & down converter) IDU provide modulation & demodulation From IDU we can obtain service we need (data-
telephone-fax)
ODU UNITAs depicted in figure We can see ODU unit !!
IDU UNIT
IDU FRONT VIEW IDU BACKWARD VIEW
LOW POWER CONSUMING
it is excited that you know we need low power in some cases solar cellProviding power,
Simplicity in VSAT installation It takes only few hours
VSAT terminal is apart of network with LARGER earth station that serves as network The hub contain the intelligence to control network operation configuration and traffic each VSAT terminal .Database generated by the hub are else used for billing purpose
HUB IN DETAIL
VSAT RELIABLE SERVICE
VSAT technology often high availability & reliability it is accuracy reaches to 99.6 to 99.7percentage For the total VSAT network. BER(bit error rate) is better than 1error in 10 million transmitted bits
RELATION BETWEEN VSAT&HUB
TWO TYPES IN COMPARISON!
TERRESTRIAL VSAT
TWO TYPES IN COMPARISON!
TERRESTRIAL VSAT
The cost per lease line increase with distance between headquarter
It exposed to cable connection break
Installation fee is related to the required data rate
Long distance not apply to VSAT
VSAT can be managed independently of terrestrial network
The equipment and installation costs VSAT higher than terrestrial alternatives
COST OF EACH OTHER
TERRESTRIALVSAT
Cost of dedicated lines Monthly
maintenance=……$ Installation fee(non
recurring)=………$ Equipment
charges=……$ Service charges=…..$
Cost of VSAT service Service charges=….$ VSAT equipment
cost=….$ Installation fee(non
recurring)=……$
COST OF TERRESTRIAL & VSAT IN PLOT
VSAT ADVANTAGES MORE AND MORE! In addition to low
cost Full control over the
entire communication network
In sensivity to distance between nodes
High grade of service and flexibility
VSAT TOPOLOGY NETWORK
We commonly use mesh &star topology in VSAT network in star topology each VSAT transceiver only to the hub . This isn't preclude VSAT terminals from communication
among themselves as vsat communication is routing through hub by using two satellite hop.
Majority of VSAT use star topology because the large antenna gain at the hub optimizes the use of space segment and minimize the size of the VSAT terminal.
The drawback of star topology is the delay for VSAT to VSAT communication as we take two hops
STAR &MESH TOPOLOGY
MESH TOPOLOGY
In mesh topology allow terminals to communicate each other directly ,hub controlled communication and tears down processes ,hub not involved it in carrying traffic it said operate hublessly it suited for voice that cannot tolerate delay.
VSAT terminals is equipped with the network management and control equipment each VSAT must have sufficient power and receive sensivity (G/T) to communicate with every other VSAT .
Mesh topology requires larger antennas and SSPAs than star topology
VSAT BANDS
Currently we use two frequency bandsC-band and Ku-Band.
For C-band operations, the antennas transmit at 6 GHz and receive at 4 GHz.
Ku-band requires transmission at 14 GHz and reception at 11-12 GHz
WHICH FREQUENCY BAND IS BETTER!
TABLE 1-1. KU-BAND VS. C-BAND
There is no direct answer to this question. The VSAT operator mustdecide the frequency band based on each band’s different aspectslisted in Table 1-1
Proper network engineering can minimize the effects of Ku-band signalfading during rain. High network availability is available at both Ku- and Cband.VSAT operators prefer Ku-band to C-band because it allows them toreduce the capital investment by using smaller antennas