antenna rooftop effect

[rimoucha]

please, can you help me to determinate the distance required between two antenna when the site is in the roof , and the impact of rooftop effect?

[aubidamax]

please, can you help me to determinate the distance required between two antenna when the site is in the roof , and the impact of rooftop effect?

hi rimoucha

Figure in below illustrates the principle of shadowing from a roof-top and suggests a range of heights which could be used to avoid shadowing[1].

27404

If the antennas have a vertical separation then there should be at least 0.2 m between the base of one antenna and the top of the other antenna. If the antennas have a horizontal physical separation and a horizontal beamwidth of 65° then there should be at least 0.5 m between them. Figure below illustrates these physical separation requirements[1].

27405

27406

GSM to UMTS:


For UMTS, NodeB acceptable noise is less than -115 dBm/3.84MHz. According to table
2, the worst case of GSM spurious emission leaked in UMTS band is -30dBm/3MHz
(-29dBm/3.84MHz). Thus the isolation between GSM transmitting antenna and UMTS
receiving antenna is: -29dBm – (-115dBm) = 86dB. Assume both antennas are
directional antenna and have same azimuth (see Figure below)[2].

27407



References :

[1] NSN
[2] Huawei

[labviewlover]

@aubidamax

thanks alot for the nice post. would u please send the link for the original documents ?...

[Stantheman]

Hi aubidamax, do you have a higher resolution copy of the third diagram, with the graphs in it?

BR's, Stan.

[aubidamax]

Hi aubidamax, do you have a higher resolution copy of the third diagram, with the graphs in it?

BR's, Stan.

hi Stantheman

here is the 3rd figure.............http://www.4shared.com/photo/gTGMK9-d/antenna.html

BRs

[aubidamax]

@aubidamax

thanks alot for the nice post. would u please send the link for the original documents ?...

hi labviewlove

here is one of two docs....the other doc i can't share it here in public...plz check your PM (@labviewlover & @Stantheman)

thanks

BRs

[peanut]

hi rimoucha Figure in below illustrates the principle of shadowing from a roof-top and suggests a range of heights which could be used to avoid shadowing[1].27404If the antennas have a vertical separation then there should be at least 0.2 m between the base of one antenna and the top of the other antenna. If the antennas have a horizontal physical separation and a horizontal beamwidth of 65° then there should be at least 0.5 m between them. Figure below illustrates these physical separation requirements[1].2740527406GSM to UMTS:For UMTS, NodeB acceptable noise is less than -115 dBm/3.84MHz. According to table2, the worst case of GSM spurious emission leaked in UMTS band is -30dBm/3MHz(-29dBm/3.84MHz). Thus the isolation between GSM transmitting antenna and UMTSreceiving antenna is: -29dBm – (-115dBm) = 86dB. Assume both antennas aredirectional antenna and have same azimuth (see Figure below)[2].27407References :[1] NSN [2] HuaweiDear,do you have an explanation for the general rules in the first image to avoid shadowing from roofTop,


regards,