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Formation Telecom: Radio

Formation Telecom: Radio. Telecom type sum-up (early 2016). 70 bases in total: 31% Vsat => 22 bases in 9 countries ( 32% in 2013… ) 36% DSL or Fiber optic => 25 bases including 11 capitales ( 33% in 2013… 14 capitales )

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Formation Telecom: Radio

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  1. Formation Telecom: Radio

  2. Telecom type sum-up (early 2016) 70 bases in total: • 31% Vsat => 22 bases in 9 countries (32% in 2013…) • 36% DSL or Fiber optic => 25 bases including 11 capitales (33% in 2013… 14 capitales) • 27% Radio internet(Wifi/Wimax/WLL) => 16 bases including 9 capitales (20% in 2013…Radio becomes better than DSL…) • 50% Radio HF/VHF => 10 missions (mainly africa) • 6% 3G keys => 3 bases (8% in 2013, but explode for backup use…) • 0% still with BGAN => 0 bases… (7% in 2013)

  3. Electromagnetic wave • Photon • Caracteristics of a wave: • Amplitude • Frequency (Hz) • Lenght (m) • Speed (light speed) :

  4. Radio Frequencies

  5. Waves transmission trough antennas The perfect antenna has the same physical length than the frequency we want to use (reception or transmission). In this case almost all the power of the transceiver is tranmited into electromagnetic wave. Electromagnetic wave Transmission Reflected power If the antenna is not well choose of if there is to many obstacles, the power of the transmission is dangerously reflected into the transceiver. Electromagnetic wave Electromagnetic wave Tranmission Reflected power

  6. DANGEROUS ! GOOD PERFECT Radio material Managing the relfected power The only feed back you have : SWR meter

  7. Storm Lightning protection So we need to protect the radio antennas Lightnings can go up to 300 000 volts And radio antennas are a important target.

  8. To optimize the Radio transmission Technicaly speaking : • NEVER TOUCH THE radio ANTENNA WHILE TRANSMITING ! • Position your radio antennas as hight as possible (6 meters) except for NVIS, far from any obstacle. • Take great care of the connections (grease and silicone). • Take great care of the cables (respect lenght, do not bend). • Respect the earth connection.

  9. HF radios

  10. Connecting HF Radios (ACF Doc…) : Do not forget the earth connection (half the antenna ! Double the performance... (see annexe)

  11. Connecting HF Radios (ACF Doc…) : Do not forget the earth connection (half the antenna ! Double the performance... (see annexe)

  12. To optimize the HF transmission Antenna position Topview Sideview

  13. VHF radios

  14. VHF material GP340 16 channels 136 – 174 MHz 5 watts (Tx) 8 to 14 hours autonomy Computer programming 265 euros GM340 6 channels 136 – 174 MHz 25 Watts (Tx) Computer programming About 300 euros Antenna: As high as possible

  15. VHF repeater In duplex mode : one frequency to transmit, another one to receive. Duplex TX:155 725 KHz RX: 155 775 Khz • VHF contact is similar to visual contact • VHF reapeater can overcome the obstacles. Duplex TX: 155 775 Khz RX: 155 725 KHz Duplex TX: 155 775 Khz RX: 155 725 KHz In simplex mode : the same frequency to tranmit and to receive. Simplex TX-RX:155 250 KHz Simplex TX-RX:155 250 KHz

  16. VHF RADIOTESTS • If the coverage is not sufficient (< green zone for ex), => IMPROVE THE COVERAGE Material Power Altitude Range VHF Handset VHF Mobile VHF Base VHF Repeater 5 watts 25 Watts 25 Watts 25 Watts About 2 meters About 3 meters About 6 meters About 20 meters - + ++ +++

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