GSM 1800 having limited coverage area

[freakturd06]

Hi guys - Just want to asked what might be some factors for GSM sites (900/1800) to have limited/small coverage area. Is VSWR or transmission a factor for this. Of course, terrain type was already considered.

[haq_enam]

Hi guys - Just want to asked what might be some factors for GSM sites (900/1800) to have limited/small coverage area. Is VSWR or transmission a factor for this. Of course, terrain type was already considered.


Because of BW size , coverage area differ from 900 to 1800....CDMA has much high coverage area than 900 and 1800 because of low BW. 900 coverage area is around 6dBm higher than 1800. Propagation loss is higher in 1800. So, operator always want to build site with lower bad and therfore LTE 900 is getting popular...

[hari_2208]

Hope below helps!!!

As the freq increases the pathloss also increases..

[RF engineer]

Hi guys - Just want to asked what might be some factors for GSM sites (900/1800) to have limited/small coverage area. Is VSWR or transmission a factor for this. Of course, terrain type was already considered.

Due to path loss is 6 dB less+ 3dB MS TX power less+1 dB cable loss as compare with the 900 so total 10 dB difference .

Hope this help you

[qwertry]

Hi,
radio coverage do not depend from transmission lines, very important for good radio coverage are: antenna tilt (mechanical and electrical), good VSWR, low losses of feeder lines. Very good VSWR, not always means good feeder line, some time this mean high losses.
If you have problem with coverage is good to check:
- BTS output power, is same that you expect
- Antenna tilt for each band (Mech.&El.)
- pass through band of lightning protection, if you have
- pass through band of splitters, combiners, tma
- VSWR & cable loss

Generality check antenna feeder system

BR

[freakturd06]

Thanks for the inputs.

[prodigy]

Due to path loss is 6 dB less+ 3dB MS TX power less+1 dB cable loss as compare with the 900 so total 10 dB difference .

Hope this help you

Hi RF!, have you any tool or excel to calculate this?.
The pattloss difference we can calculate with ITU, Hata, Egli, etc., but the other two variables?.

Thanks!

[tremalnike]

Gyus , you forgot one more thing - TDMA limits GSM coverage also :p

[RF engineer]

Hi RF!, have you any tool or excel to calculate this?.
The pattloss difference we can calculate with ITU, Hata, Egli, etc., but the other two variables?.

Thanks!

Dear

Really i don't but this are general guidelines .

BR

[mica]

check first for the RxLev near the site (it must be very strong around -50 to -60dBm). Compare also your results to other site so that you have a basis.

If youre site now has low RxLev as compare to site w/ good coverage, then it must probably be VSWR.

If not, check for the tilting (MT and ET)..:) also check the TxPower!