Slide title In CAPITALS 50 pt Slide subtitle 32 pt XPD measurement & Alignment

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal  Cross Polarization Interference Cancellation (XPIC  How does Microwave having XPIC capabilities effectively double the potential capacity of a Microwave Path.  It allows the assignment of the same frequency to both the vertical & horizontal Polarization on a Path.  Where available frequencies are limited then it is possible to assign the same frequency twice on the same path using both Polarizations. XPIC

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal XPIC  Using standard Microwave equipment from any of the major manufacturers, if a full block of eight frequencies were available for a 6 GHz Lower band path then eight frequencies could be assigned in each direction on the path, four per polarization.  Using equipment with XPIC capability, sixteen frequencies may be assigned each way on the same path (eight per polarization).

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal XPD - Cross Polarization Discrimination Meaning of XPD - "Cross-Polarization Discrimination", is defined as the ratio of the co-polarized average received power to the cross-polarized average received power. XPD quantifies the separation between two transmission channels that use different polarization orientations. The larger the XPD, the less energy is coupled between the cross-polarized channels. The XPD values were found to decrease with increasing distance.

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal XPD - Cross Polarization Discrimination Polarization can be used as a tool to reduce co- channel interference due to a property of polarized transmissions known as Cross Polarization Discrimination or XPD. Due to XPD, when a horizontally polarized antenna receives a co-channel signal sent from a vertically polarized antenna (and vice versa), the effective signal strength is reduced by several dB.

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal XPD - Cross Polarization Discrimination  In a Cross-polar discrimination, the difference in dB between the peak of the co-polarized main beam and the maximum cross-polarized signal over an angle is measured within a defined region. The ratio of the radiation intensity, in a given direction, to the radiation intensity that would be obtained if the power accepted by the antenna was radiated isotropic ally. The four transmitters on the Horizontal polarity are separated from the four transmitters on the Vertical polarity by the XPD value of the antenna feed horn. Typical XPD values range from 30 DB for standard antennas to 40 DB for Ultra High Performance antennas.

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal XPD - Cross Polarization Discrimination  The cross-polarization discrimination (XPD) for a location is calculated as the ratio of the sum of the powers from the same slant Tx/Rx antenna pairs to sum of the powers from the opposite slant Tx/Rx antenna pairs. This can be done using the total power from each PDP or for a particular delay (path) common to all the PDPs. The main path is at the delay of the CPDP maximum power in the first cluster. The second path is at the delay of the CPDP maximum power in the second cluster. Not all locations have a second path

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal What XPD test ?  in order to test XPIC functionality, we need to do the XPD ( crosspolar Decoupling ) measurement.  Measurment of polarization isolation :  Decoupling Vertical => Horizontal X dbm >= 30 dbm.  Decoupling Horizontal => Vertical X dbm >= 30 dbm.

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal Procedure for XPD Measurement  Connect the PC in the near end site, Disable ATPC for both sites near end and far end  Check the receive level both sites ; RX initial  Switch off the transmitter for the Vertical in the near end, now only the Horizontal is transmitting  Next Check the receive level in the far end ; Rx  Decoupling Horizontal => Vertical [ Rx initial – Rx ] dbm >= 30 dbm ……….X1

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal Procedure for XPD Measurement  Next, Switch on the Vertical and Switch off the transmitter for the Horizontal in the near end, now only the Vertical is transmitting  Next Check the receive level in the far end ; Rx  Decoupling Vertical => Horizontal [ Rx initial – Rx ] dbm >= 30 dbm………….X2

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal Procedure for XPD Measurement  Next, Switch on the Transmitter for the vertical.  You should find approximately the same value X1 and X2  Next, Switch on the Transmitter for the vertical.  Repeat this procedure from the far end to the near end ; you ll get the XPD for the far end  Enable the ATPC for both sites before you leave the site.

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal XPD Alignment Antenna alignment:  Alignment with spirit level on feed horn ( all antenna )  Align antennas according to commissioning document  XPD Alignment :  Align with vertical polarization is the best way as Horizontal polarization is more prone to fading effect than V Mechanical Alignment: ( Should be done before any antenna alignment )-adjust the feed horn measureing with high precision spirit level until correct level.

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal Electrical Optimization  Disable ATPC in the Link  Far end, switch off the power at e.g. polarization  Measure the discrimination on the RSL level V- H=/>30dB  If=/of 30dB is not reached, Then:  Adjust the feed horn until the minimum level at V is reached. And the discrimination is =/>30 but not more than 38dB.  At the same time make sure that the eye –opening is kept at 90% or higher

Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level pt Ericsson Internal Electrical Optimization  This should be done in the order:  A-side measurement & possible feed horn adjustment for 1 st main and then diversity antenna.  B-side measurement & possible feed horn adjustment of diversity antenna only  Once the alignment is done switch on ATPC for all channels again if needed.

Slide title In CAPITALS 50 pt Slide subtitle 32 pt Thank You..