Interference Analyzes

Classical problem in wireless network is interference. that problem are commonly faced when we investigated and get the data flicker or Low BER.
so the procedure to analize can be describes:

Procedure of Interference Investigation
Interference is an unwanted energy, which enter to our radio system. There are many kind of interference will occur on Microwave Radio System.
1. Adjacent channel (same hop)
2. Cross Polarization (same hop)
3. Front to back radiation
4. Opposite hop front to back reception
5. Co-channel or adjacent channel from different hop directional

Consider there is one hop A to B direction and we suspect that there is interference on site A.
In order to check if interference affected to our system there are some procedure that we have to conduct.
1. Adjacent channel (same hop)

Interference signal is shown by dashed arrow.
Procedure to determine interference:
– Turn off transmit power on Site B which system is interference on Site A
– Measure receive level on Site A which system is suspected interference, that is interference level.
– Turn off transmit power on site B at another system which channel is near to suspected interference channel
– Measure receive level on Site A, if there is receive level, interference is not coming from adjacent channel (same hop) interference, but if there is no receive level, interference is coming from adjacent channel (same hop)
2. Cross Polarization (same hop)

Interference signal is shown by dashed arrow.
Procedure to determine interference:
– Turn off transmit power on Site B which system is interference on Site A
– Measure receive level on Site A which system is suspected interference
– Turn off transmit power on site B at another system which channel frequency is same but different polarization from suspected interference channel
– Measure receive level on Site A, if there is receive level, interference is not coming from Cross Polarization (same hop).interference, but if there is no receive level, interference is coming from Cross Polarization (same hop).
3. Front to back radiation

Interference signal is shown by dashed arrow.
Procedure to determine interference:
– Turn off transmit power on Site B (opposite system) which system is interference on Site A
– Measure receive level on Site A which system is suspected interference
– Turn off transmit power on site B (back to back with opposite of site A)
– Measure receive level on Site A, if there is receive level, interference is not coming from Front to back radiation interference, but if there is no receive level, interference is coming from Front to back radiation.
4. Opposite hop front to back reception

Interference signal is shown by dashed arrow.
Procedure to determine interference:
– Turn off transmit power on Site B (opposite system) which system is interference on Site A
– Measure receive level on Site A which system is suspected interference
– Turn off transmit power on Site C (opposite of Back to Back site A which is suspected interference).
– Measure receive level on Site A, if there is receive level, interference is not coming from Opposite hop front to back reception interference, but if there is no receive level, interference is coming from Opposite hop front to back reception.
5. Co-channel or adjacent channel from different hop directional

Interference signal is shown by dashed arrow.
Procedure to determine interference:
– Turn off transmit power on Site B (opposite system) which system is interference on Site A
– Measure receive level on Site A which system is suspected interference
– Turn off transmit power on Site C (opposite of different hop directional site A which is suspected interference).
– Measure receive level on Site A, if there is receive level, interference is not coming from Opposite hop front to back reception interference, but if there is no receive level, interference is coming from Opposite hop front to back reception.

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