- This topic has 5 replies, 1 voice, and was last updated 5 years, 1 month ago by Junaid Ahmed.
13th July 2009 at 08:22 #57888Ashok DasGuest
I am involved in installation and comissioning of GSM IBS using Ericssom Indoor micro bts. Can anybody tel me how to measure the VSWR of distributed antenna system used in IBS. I am using passive splitters for antenna branching.
Ashok13th July 2009 at 10:54 #57889DavidGuest
I hope you are having a VSWR meter. Keep the range in 900 band. Then disconnect your cable at the cabinet end n connect VSWR meter.
Normal values has to be 1.4 for VSWR and 1.04 for DTF. If u get a value say 64.5 VSWR it means that the port is opened somewhere. u can also say that the signal which was sent by VSWR meter has not all returned back. Ultimately the job of a VSWR meter is to send a signal n check the value of signal returned and if not, the measure of signal loss, n also the distance where the signal is lost.
if u get a a very high level VSWR, then check the DTF. it will give you the dictance where u have got th problem, u can approximately calculate the distance of cable check at the nearest junction again. this way u can find exactly wher the issue is.
hope u r atleast a bit clear.16th July 2009 at 14:08 #57890Ashok DasGuest
but is it possible to measure the vswr in presence of passive RF splitters? I am having high vswr in multiple sites which having no installation problems and newly installed sites.
Ashok17th July 2009 at 09:45 #57891AyeGuest
There is no problem measuring VSWR inclusive of all these passive components.Make sure that your site master is calibrated to the Frequency band used by the RBS before performing the measurements.
Try to consider the DTF function of the Site Master/VSWR meter as suggested by David, from here you will have a better reference on which part of the DAS segment is causing the high VSWR.
Keep in mind also the bending of your feeder cables, different size of cables has their own bending radius which could contribute to high VSWR measurement if not followed.7th January 2013 at 06:29 #57892ShyamGuest
How many types of antenna used in IBS. Please give details with Gain.1st December 2015 at 07:02 #57893Junaid AhmedGuest
I need IBS calculator. Any Link or information?