[OMStar Cases] Interference Due to Out-Of-Sync of Frame Offset in Single-Mode and Dual-Mode RRUs at Site H by z00135560

Interference Due to Out-of-Synchronization of Frame Offset in Single-Mode and DualMode RRUs at Site H

Interference Due to Out-of-Synchronization of Frame Offset inRRUs Single-Mode at Site Hand Dual-Mode

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Contents ! "ac#ground$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$% & nalysis 'rocedure$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$% #,% Spectrum *nalysis,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,& #,# Interference Source P/I /hec0,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,& #,' 1ngineering Parameters /hec0,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,2 #,& Pro3lem Resol(ing,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,.

( 'rinciple nalysis$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ ) ',% Principle,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,. ',# Solution,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,. ',' Suggestion,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,.

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! "ac#ground *t site H4 the single-mode RRU'%2#e and dual-mode RRU'%2% uses ad5acent-fre6uency co-co(erage on the 1 fre6uency 3and in the indoor distri3uted scenario, In this scenario4 the frame offsets configured on the single-mode RRU'%2#e and dual-mode RRU'%2% are not synchronized, 7his 3rings intra-system interference and affects access 8PIs,

& nalysis 'rocedure &$! Spectrum nalysis /ollect the re(erse spectrum /HRs of the pro3lem site 9using RRU'%2#e at fre6uency ':#2$; and import them into the <71 uplin0 interference su35ect on the OMStar =2R:, *nalysis on /HRs sho)s o3(ious sym3ols of /RS interference time domain, 7he interference source should come from the <71 system, In addition4 the timeslot out-of-synchronization e>ists, 7he follo)ing figure sho)s sym3ols of reser(e spectrum in the time domain, Figure 1.17ime domain spectrum

&$& Interference Source 'CI Chec# Start the interference source P/I chec0 on the OMStar, o interference source P/I is found, Further o3ser(e the spectrum during interference period and find that the spectrum of one site has an o3(ious incline,

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Figure 1.2Fre6uency domain spectrum

&$( *ngineering 'arameters Chec# /hec0 the engineering parameters4 and find that the pro3lem site and another ad5acent-fre6uency indoor distri3uted site on the 1 fre6uency 3and 9RRU'%2%efae at fre6uency '?:2$; are co-site, 7he follo)ing ta3le lists the RRU information and frame offsets of the t)o sites, 7he fre6uency inter(al 3et)een the t)o sites is %$ MHz,

According to the timeslot configuration principles in co-coverage scenarios of singlemode RRU3152e and dual-mode RRU3151/RRU3161, you need to configure the frame offset on the single-mode RRU to eep the frame offset consistent !ith that on the dual-mode RRU "on the # fre$uency %and&' (he pro%lem site "using RRU3152e& is not configured a non-) frame offset, resulting in timeslot out-of-synchroni*ation %et!een t!o sites' +ased on the adacent fre$uency relationship %et!een the t!o sites and the o%served inclined spectrum sym%ols, it is suspected that a %loc eists'

Cell +ame

@ushan 3uilding-@ushan 3usiness hall

RRU ,ype

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Freuency "and

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Ratio Special Su/frame Ratio

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&$% 'ro/lem Resol0ing Pro(ide the feed3ac0 to frontline engineers, *ccording to the recommended (alue of 7DDframeoffset for the pro3lem site 9RRU'%2#e; pro(ided in O&M Documentation-SingleRAN TDS-LTE Workaround Guide of Live Netork !ro"lem#-$%'%$$$-A-()*4 the frontline engineers change the (alue of 7DDframeoffset, 7hen4 the interference is cleared and the access 8PIs meet the re6uirements,

( 'rinciple nalysis ($! 'rinciple In ad5acent-fre6uency co-co(erage scenario of the single-mode RRU'%2#e and dual-mode RRU'%2%A'%.% 9on the 1 fre6uency 3and;4 the frame offsets configured on the single-mode RRU'%2#e and dual-mode RRU'%2% are not synchronized, 7his 3rings intra-system interference and affects access 8PIs,

($& Solution /hange the frame offset for cells ser(ed 3y the single-mode RRU,

($( Suggestion Impro(e the parameter chec0 su35ect and pay attention to parameters in co-co(erage scenarios of singlemode and dual-mode RRUs on the 1 fre6uency 3and, 7he pro3lem can 3e identified through the parameter chec04 )hich impro(ing the trou3leshooting efficiency, In addition4 pay attention to the follo)ing aspectsB 



7imeslot out-of-synchronization in the ad5acent-fre6uency <71 system may 3ring interference, Pay attention to the parameter configurations, @hen there is 3loc0 or spurious interference caused 3y time out-of-synchronization4 the tool cannot calculate the interference source P/I,

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[OMStar Cases] Interference Due to Out-Of-Sync of Frame Offset in Single-Mode and Dual-Mode RRUs at Site H by z00135560

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