- This topic has 4 replies, 1 voice, and was last updated 14 years, 2 months ago by Lucka.
20th September 2006 at 15:06 #45764LuckaGuest
I´m a junior RF Optimizer. I am wonder about the high BER% that we are having in our cells. We have SFH and a reuse of 1/1. Thank you in advance22nd September 2006 at 18:20 #45765yogesh_rfGuest
BER is basically no. of bits nt transmitted/total bits sent*100.Now BER has 2 values BER Sub and BER Full,Full values are calculated for 1 SACCH frame(26 Multiframe) consisting of 24 TCH TDMA frames,1SACCH frame and 1 idle frame used for measurement purposes.On the other hand Sub values are calculated by only 2 mandatory frames transmitted -1 SACCH and 1SID(SILENCE INDICATOR),
for instance if DTX DL is used (which is calculated on basis of 24 TCH blocks),so when no speech is transmitted (or we can say no Bits are transmitted during silent periods) Full values will count bits transmitted on SILENT+SPEECH so Full values will come BAD,but as Sub values only counts 1SACCH and 1SID which ar mandatory(assuming GOOD RF conditions) so they will not deteriorate, and also note that in Hoppping Specially 1/1 U MUST BE GETTING high interference and due to this BER will go down.so its should nt be a pblm ,but kindly check for MAIO,HSN,Frequencies positively and call on BCCH should also be checked for.
yogesh_rf23rd September 2006 at 19:13 #45766LuckaGuest
Thanks Yogesh_rf !
could you explain me what should i check concretly.We have Ericsson BSS. We have also experience an increment in the Interference in Uplink in the band3 and band2 and in the CHGR1 where are the TRX with hopping, the RxQUAL is bad (in some cases 6 and 7).
We have the same HSN for all sectors and diferents for each BTS and MAIO are also well separately. We have for SFH just 18 freq. Could you recomend me a well distribution of maio for a site configuration 4-4-4 .Thank you very much .Lucka24th September 2006 at 07:34 #45767yogesh_rfGuest
you should go either for odd MAIO planning OR even MAIO planning means that 4/4/4 then 1/3/5,7/9/11,13/15/17,19/21/23 like wise for sectors TRXs if ur frequencies are continous and u can use continous MAIO if ur frequencies are ALTERNATE like 31,33,35…….,like that.MAIO is basically a counter to ensure same frequency not to be emitted from any TRX at same time.26th September 2006 at 15:53 #45768LuckaGuest
OK. Thanks very much yogesh_rf
I´ll do that and give you some feedback.