- This topic has 6 replies, 1 voice, and was last updated 12 years, 6 months ago by pix.
27th August 2008 at 10:55 #53662MKTGuest
Consider that we have following constraints:-
1.) You can neither increase or decrease the HEIGHT(also azimuth cannot be changed) of antenna.
2)You can neither increase or decrease the TILT of antenna.
3)BTS is transmitting at its maximum BTS_TX_PWR_MAX.( so there is also no scope of increasing the power further)
4)VSWR is nominal
5)You have the choice to play with TRX.
6) You have to choice to play with BSS parameters.
HOW CAN WE IMPROVE THE INDOOR COVERAGE IN A PARTICULAR LOCALITY?
Regards.27th August 2008 at 12:52 #53663pixGuest
do drive tests, and check what is the actual rxlev measured indoor. if you see -110dBm, then you must install an indoor site (no amount of optimization can provide coverage in such a “hole”…)
if it’s about -95dBm, then you can do some optimization.
– install high power TRX (that will enhance only DL) + a TMA (to balance the UL signal too)
– install a signal booster at the bottom of the antenna (it enhances UL and DL signals)
– install a repeater with donor antenna located outdoor, and serving antenna located indoor (antenna or radiating cable).
with parameters, you could try to set rxlev access min = -110dBm, and slow down handovers and power control. Problem is, it will affect the whole coverage of the cell, not only the indoor subscribers.
you can also implement lower frequencies and frequency hopping (SFH ?) in order to provide better wall penetration.
the general rule is : you CANNOT increase coverage with parameters. Coverage is physical, parameters are logical. It’s just not working this way at all.27th August 2008 at 12:53 #53664pixGuest
you can also increase the radio link timeout (DL and UL), just to avoid dropping the call too early. i don’t recommend this solution though… but that’s a possibility.
you can also try to use AMR, with robust codecs…28th August 2008 at 04:16 #53665MKTGuest
Thanks for suggestions.
“install high power TRX (that will enhance only DL) + a TMA (to balance the UL signal too)”.
Does it means that TMA works only in UL direction?
Will disabling the downlink power control will do some relief to improve indoor coverage?
Regards28th August 2008 at 04:30 #53666MKTGuest
i forgot that BCCH TRX doesn’t have PC on it.
Regards28th August 2008 at 06:25 #53667BilalGuest
TMA amplifies the signal received at BTS antenna .i.e Uplink.
Power control even if it is enabled wont have any impact in low coverage scenario. Commonly used threshold for DL PC is around -90dBm that means no power down regulation if SS is below -90dBm.28th August 2008 at 08:22 #53668pixGuest
ok, nothing more to add 🙂
my choice would be : repeater