Xpicimplementationxpdalignmentinterferencetest-170528140911.pdf

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ML-TN Xpic implementation and xpd Optimization Khalil Al-Alami

Agenda ›Dual Polarization MW. ›XPIC Technology. ›XPD Test and Optimization. ›Interferences and its impact. ›Interference Test for ML-TN MW.

Khalil Al-Alami | 2017-05-23 |

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Dual pollarization › Is the MW radio link combination where we creates two links through one path with different polarization and via one dual polarization antenna at each terminal. › Here we use such technology to duplicate the capacity. And in the same time it’s a hardware protection, in case one polarization has hardware problem one polarization will carry the traffic but with the half capacity. › In each radio terminal there will be two MMU’s which supports XPIC and two similar band and sub-band RAUs. › The two RAUs at each radio Terminal will be integrated to one dual polarization antenna via a hardware structure called “integration kit” or “Assembled OMT”.

Khalil Al-Alami | 2017-05-23 |

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Mini-link tn instalation › f1

Packet link V

RAU

RAU

V H

f1 RAU

V H Packet link H

RAU

Dual Pol.

Dual Pol.

MMU2 K

MMU2 K XPIC

XPIC

MMU2 K

Khalil Al-Alami | 2017-05-23 |

MMU2 K

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f1 f1

Dual polarization installation ›

Integration Kit Feed

Khalil Al-Alami | 2017-05-23 |

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Dual polarization installation

Khalil Al-Alami | 2017-05-23 |

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Mini-link tn installation › For protected (1+1) radio terminals, two MMUs must be placed in a pair successively, starting with an even Slot. › Each pair of MMUs placed in adjacent slots (2 and 3, 4 and 5, and so on) is related to the same polarization. The XPIC cable to be connected between the 2 MMUs which will build XPIC. Therefore, the front panel XPIC cross-cable connects modems in alternate slots (2 and 4, 3 and 5, and so on).

Khalil Al-Alami | 2017-05-23 |

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Mini-link tn Configuration › It is better to enable the XPIC during Configure Radio Link. › When you configure the Modulation capacity for each radio link of the 2+0 links the value will be half of that in the FSC then the total capacity of the 2+0 will be as the FSC. For example the below FSC the Modulation Capacity will be 204 and 46

Khalil Al-Alami | 2017-05-23 |

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XPIC signal cable › XPIC cable: RJ45-RJ45 screened 100 Ω pair cable (4x2x0.25) cable with the below Pin layout.

Khalil Al-Alami | 2017-05-23 |

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Mini-link tn Configuration › It is better to enable the XPIC during Configure Radio Link. slot 2 config. (Vertical)

Khalil Al-Alami | 2017-05-23 |

slot 4 config. (Horizontal)

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Mini-link tn Configuration › WAN Creation: go RL-IME and select Radio Link Bonding Mode, and Assigned the 2 Packet Links. › Note: (For 6P, NPU3D only RL-IME 1/7/100 and RL-IME 1/7/101 can do the bonding configure, 20P NPU1C RL-IME 1/11/100 ~RL-IME 1/11/107 can do the Bonding) › Right Click RL-IME then Configure :

Khalil Al-Alami | 2017-05-23 |

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Mini-link tn Configuration

Khalil Al-Alami | 2017-05-23 |

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2+0 alignment. › Turn off the transmitters for H pol and do the Alignment for V polarization as normal 1+0 until get the max RSL. › Loosen the 4 screws on the OMT Assembly with the Reflector Support Bracket. Rotate until the max value is found. The rotation range is ±5°. Do the same procedures in both Sites. › Turn the H Pol on and check the RSL at both Pol. Dual Pol Antenna

Integration kit

RAU

Khalil Al-Alami | 2017-05-23 |

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Cross Polarization Discrimination Optimization (XPD):  The Min XPD value for bands (15 – 38 GHz )= 27dB  1st do the XPD test (see XPD Test Slides), if value is >= 27dB then done, else you need to do XPD optimization by the below steps: 1. Turn on the Tx on far end of V pol and turn off The Tx of H. 2. Check with a voltmeter at near end on the RAU of H pol and Rotate +/until the worst voltage value found. (The rotation is performed to minimize the leakage between the two polarizations, that is, to maximize the XPD). 3. Verify the RX Level at near end in H pol and record the value.

4. Verify the RX level at near end in V pol and record the value.

Khalil Al-Alami | 2017-05-23 |

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XPD Optimization : › A cross polarization discrimination (XPD) of at least 27dB must be reached. The value is the difference between the signals measured on the two radios (H & V). › If the reached value is less than 27 dB, perform steps (1,4) again. › If the reached value is less than 27 dB, after repeating steps (1,4) verify again the hardware installation.

Khalil Al-Alami | 2017-05-23 |

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XPD Test screen shots This screen shots to show how to check the XPD value by MINI-LINK Craft. • Vertical & Horizontal TX ON • Polarization: Vertical

Khalil Al-Alami | 2017-05-23 |

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XPD Test screen shots • Polarization: Horizontal

Khalil Al-Alami | 2017-05-23 |

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XPD Test screen shots before XPD alignment

• Vertical TX ON & Horizontal OFF • Polarization: Vertical RSL.

• Polarization: Horizontal Off . XPD=27.0dB (different between Horizontal and Vertical) and its critical.

Khalil Al-Alami | 2017-05-23 |

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XPD Test screen shots After XPD alignment

• Start the Test. • Vertical TX ON & Horizontal OFF • Polarization: Vertical RSL.

Khalil Al-Alami | 2017-05-23 |

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XPD Test screen shots After XPD alignment

• Polarization: Horizontal RSL. • XPD= 33.0dB (different between Horizontal and Vertical). Which is better than before.

Khalil Al-Alami | 2017-05-23 |

Page 20

Interference Test › Interference is one of the challenges which is facing the MW Radio systems. It can degrade the performance or even stop the transmission. › During the alignment when we face difficulty to achieve the desired RSL, the interference is one of the issues we expect. › Also during the link life when we get E1 BER or Ethernet PER we put the interference in our considerations. › Here we will take the interference test by using our ML Craft:  Access the far-end terminal through ML Craft and switch the far-end transmitter off. Note: In a 1+1 system both transmitters must be switched off.  Check RSL level at near end, If the level exceeds -90dBm, there could be a such interference. Like in the following screen shots. Khalil Al-Alami | 2017-05-23 |

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Interference Test Scr. shots › We off Transmitter power from Far end at RSL view by tick Transmitter on Ra1 box and save.

Khalil Al-Alami | 2017-05-23 |

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Interference Test Scr. shots › Check the RSL at near End terminal. In this below screen Shot means there is an interference.

Khalil Al-Alami | 2017-05-23 |

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Interference Test Scr. shots › In this screen shot its normal RSL as no signal coming from The far end terminal.

Khalil Al-Alami | 2017-05-23 |

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Interference Test Scr. shots › After you finish the test don’t forget to turn the far end transmitter to restore back the traffic.

Khalil Al-Alami | 2017-05-23 |

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Khalil Al-Alami | 2017-05-23 |

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