ENHANCED PDCCH LINK ADAPTATION In legacy functionality, the PDCCH outer loop was really the outer loop for PDSCH plus fixed 10 dB margin Since PDCCH and PDSCH experience different interference and ha!e different target error rates, performing outer loop control for PDCCH "ased on PDSCH transmission success#failure was not optimal $he fixed 10 dB margin is too conser!ati!e in many cases, leading to PDCCH capacity degradation This feat featur ure e impr improv oves es the the PDCC PDCCH H oute outerr loop loop by adju adjust sti i! ! the the oute outerr loop loop base based d o PDCC PDCCH H trasmissio su""ess#failure su""ess#failure rather tha PD$CH su""ess # failures
PDCCH is many cases are not only traffic "ut health of %& 'uality as when PDCCH detection rate decrease, PDCCH load will increase as aggregation needs to use higher resource (hen PDCCH is o!er utili)ed this causes *!erload and $P%$ down to !ery low so this feature ad+usts PDCCH SI- "ased on PDCCH reception success#failure The umber of allo"ated CCEs %i&e& A!!re!atio level% o PDCCH are "al"ulated based o adjusted PDCCH $IN'
$pe"ial D'( "ofi!uratio is used for a %. with a /o&$. call $here is only a !ery short time period during which the %. will wae up to recei!e PDCCH If the D& assignment is not recei!ed in this period, %. will not wae up for potential H-2 retransmissions o H-2 mechanism for PDCCH transmission
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$his is what happens in D& 3left4 and %& 3right4 in case of PDCCH Decoding fail 3PDCCH .rror4
Impa"t of PDCCH de"odi! failure
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If D& assignment or %& grant transmitted on the PDCCH cannot "e recei!ed, !oice pacet might get lost or delayed
5 /oice pacet loss rate should "e less than 16 7 086 to a!oid impact on !oice 'uality 5 9outh5to5ear delay should "e around than :00ms
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D& radio lin failure is detected if PDCCH B&.- is greater than 106 for a certain period of time which may ha!e se!ere impact on !oice 'uality
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Currently there are many cells which ha!e a PDCCH error rate < 16 for /o&$. users
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PDCCH decoding failures might "e reduced "y selecting a higher CC. aggregation le!el $his can "e achie!ed "y further reducing the PDCCH target error rate for /o&$. users
1:>8 "ps 9-5(B codec generates 1:>8 "p1ms ? :8; "p:0ms fter protocol stacs added their headers we get ;00 "its of speech information e!ery :0ms s !oice samples are generated e!ery :0ms, :0 users can share same P-B sets So, after all headed are added to a /olte pacets which includes :0ms speech information, total si)e reaches to =: "ytes ? ;;> "its 3when 1:: "ps codec is considered, 1:: "ps means :== "p:0ms, :== # @ ? ;08 "ytes, when 1:>8 "ps codec is considered, 1:,>8 "ps means :8; "p:0ms, :8; # @ ? ;1>:8 "ytes4 which fits into one PDCP pacet It could "e said, PDCP Pacet &oss 6 ? /oice Pacet &oss 6
PDCCH Error 'ate Tui! A In general, a lower target for PDCCH .rror -ate will increase the pro"a"ility of allocating more CC.s 3more ro"ust transmission4 s most of the PDCCH error rate samples are within 065186 in &$. networs 3target is 1164, there is still a high pro"a"ility that the highest CC. aggregation le!el 3@ CC.s4 is not yet used
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By lowering the PDCCH error rate target 3pd""hTar!et)ler*olte+,, meas -&-. as the /ultipli"atio0a"tor is 1&124, a higher CC. utili)ation for /o&$. users is expected Since the total /olte contri"ution to o!erall traffic is !ery small, only a minor increase of total PDCCH utili)ation is expected
$tep si3e of Do4$tep If target B&.- 3pd""hTar!et)ler*olte4 is reduced to half , the DownStep is doubled eg target B&.- ? 116
0886, DownStep?08; dB
10@8 dB
o impact to %pStep 3set "y pd""hOuterLoop5p$tep*olte ? 000>dB default !alue,4 "ut as downstep is calculated "y DownStep ? %pStep 315 pdcchTargetBlerVolte4# pdcchTargetBlerVolte4 formula, a decrease on pdcchTargetBlerVolte will lead an increase in downstep si)e
Effe"t of parameter "ha!es to Eha"ed PDCCH Li6 Adaptatio In order to satisfy the re'uired B&.- for PDCCH, the estimated SI- must "e ad+usted to compensate for the C2I estimation errors on the PDCCH Both an upward step and a downward step are defined "ased on a target B&.- $he outer loop ad+ustment is increased "y an upward step or decreased "y a downward step $o determine the outer loop ad+ustment criteria, the .nhanced PDCCH &in daptation relies on the following elementsA 1
Success or failure of the PDCCH transmissionsA $he H-25C reports and the P%SCH detection results are used for this purpose If the -BS detects a user H-2 response, either negati!e or positi!e, the PDCCH transmission is considered successful If no response is detected, the PDCCH transmission is considered failed $he -BS considers the transmission on the P%SCH as failed if the Cyclic -edundancy Chec 3C-C4 fails and no !alid signal is recei!ed
: ggressi!e and conser!ati!e PDCCH allocationA $he PDCCH allocation is considered conser!ati!e if the num"er of allocated Control Channel .lements 3CC.4 exceeds, within a predefined range, the re'uired num"er, and it is considered aggressi!e in the opposite case $he outer loop eeps trac of ad+ustments made when allocation is aggressi!e or conser!ati!e, and it uses this information to decide how to mae the ad+ustment
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Effect of pdcchTargetBlerVolte (lower value means larger outer loop downstep adjustment. Higher PDCCH aggregation level is used most likely in lower values) Configured /alueA :: means ,,71&12+-&-. Tar!et PDCCH )LE'+891&2:;d) $IN' outer loop do4step adjustmet $est /alueA > means <71&12 + 1&:. Tar!et PDCCH )LE' +89-&;;=d) $IN' outer loop do4step adjustmet Eormula usedA DownStep Si)e ? %pStep Si)e 315 pdcchTargetBlerVolte4# pdcchTargetBlerVolte4
Effect of pdcchOuterLoopInitialAdjVolte (higher value means more compensation. Higher PDCCH aggregation level is used most likely in higher values) Configured /alueA 5F0 means 9>d) iitial $IN' adjustmet value $est /alueA 50 means 9;d) iitial $IN' adjustmet value
Note? .ach successful PDCCH detection 3ie H-2 response 3C or C4 sent "y %. is recei!ed "y eB4 increases SI- outer loop ad+ustment $his is added to estimated5SI- for compensation If PDCCH "locs are detected successfully, this maes estimated SI- closer to actual SI- and also
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leads to less compensation $he less the compensation, the less aggregation le!el on PDCCH 3less PDCCH CC. consumption4 $here is a trade5off "etween PDCCH ro"ustness and PDCCH capacity
E@pe"ted results after parameter "ha!es
9 PDCCH )LE' . redu"tio 9 CI- Pa"6et Loss . redu"tio yields lo4er jitter ad hi!her /O$ 9 PDCCH CCE 5tili3atio . i"rease 9 $li!ht improvemet o *olte retaiability mi!ht be e@pe"ted
'elated Couters i Eri"sso 5i"ast? to a spe"ifi" 5E% o broad"ast li6e $I)s Counter
Description
pmDlAssigsTrans
The total number of unicast DL assignments transmitted.
pmDlAssigsWithDetctedHarqAck
The total number of unicast DL assignments that are confirmed by detecting a corresponding HARQA!".
pmDlAssigsWith#nkno$nReception
The total number of unicast DL assignments for $hich the reception is unkno$n.
pm#l%rantsTrans
The total number of unicast #L grants transmitted.
pm#l%rantsWithDetected&usch
The total number of unicast grants that are confirmed by detecting a corresponding &#'!H transmission.
pm&dcchT(!onser)ati)e
The total number of conser)ati)e unicast &D!!H transmissions.
pm&dcchT(Aggressi)e
The total number of aggressi)e unicast &D!!H transmissions.
pmDlAssigsTrans*olte
The total number of unicast DL assignments transmitted to #+s that ha)e any bearer mapped to a Q!, $ith 'er)iceType of *-,&. The DL assignments are e(cluded if this cell is a secondary cell for those #+s.
pmDlAssigsWithDetectedHarqAck*olte
The total number of unicast DL assignments that are transmitted to #+s $ith any bearer mapped to a Q!, $ith 'er)iceType of *-,& for $hich the reception is confirmed by detecting a corresponding A!" or /A!" for any transport block. The DL assignments are e(cluded if this cell is a secondary cell for those #+s.
pmDlAssigsWith#nkno$nReception*olte The total number of unicast DL assignments that are transmitted to #+s $ith any bearer mapped to a Q!, $ith 'er)iceType of *-,& for $hich the reception is unkno$n. The DL assignments are e(cluded if this cell is a secondary cell for those #+s. pm#l%rantsTrans*olte
The total number of unicast #L grants transmitted to #+s that ha)e any bearer mapped to a Q!, $ith 'er)iceType of *-,&.
pm#l%rantsWithDetected&usch*olte
The total number of unicast #L grants that are transmitted to #+s $ith
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Counter
Description
any bearer mapped to a Q!, $ith 'er)iceType of *-,& for $hich the reception is confirmed by detecting a corresponding &#'!H transmission. pmDlAssigsTrans'!ell
The total number of unicast DL assignments transmitted to #+s that use this cell as a secondary cell.
pmDlAssigsWithDetectedHarqAck'!ell
The total number of unicast DL assignments that are transmitted to #+s using this cell as a secondary cell for $hich the reception is confirmed by detecting a corresponding A!" or /A!" for any transport block.
pmDlAssigsWith#nkno$nReception'!ell The total number of unicast DL assignments that are transmitted to #+s using this cell as a secondary cell for $hich the reception is unkno$n. pmDlAssigsTrans&!ell
The total number of unicast DL assignments transmitted to #+s that use this cell as the primary cell and do not ha)e any bearer mapped to a Q!, $ith 'er)iceType of *-,&.
pmDlAssigsWithDetectedHarqAck&!ell
The total number of unicast DL assignments transmitted to #+s that use this cell as the primary cell and do not ha)e any bearer mapped to a Q!, $ith 'er)iceType of *-,& for $hich the reception is confirmed by detecting a corresponding A!" or /A!" for any transport block.
pmDlAssigsWith#nkno$nReception&!ell The total number of unicast DL assignments transmitted to #+s that use this cell as the primary cell and do not ha)e any bearer mapped to a Q!, $ith 'er)iceType of *-,& for $hich the reception is unkno$n. pm#l%rantsTrans&!ell
The total number of unicast #L grants transmitted to #+s that use this cell as the primary cell and do not ha)e any bearer mapped to a Q!, $ith 'er)iceType of *-,&.
pm#l%rantsWithDetected&usch&!ell
The total number of unicast #L grants transmitted to #+s that use this cell as the primary cell and do not ha)e any bearer mapped to a Q!, $ith 'er)iceType of *-,& for $hich the reception is confirmed by detecting a corresponding &#'!H transmission.
pm#l%rantsTrans/oAck
The total number of transmitted unicast #L grants not designated for &#'!H data transmissions.
pm#l%rantsTrans*olte/oAck
The total number of unicast #L grants not designated for &#'!H data transmissions. The grants are transmitted to #+s that ha)e any bearer mapped to a Q!, $ith ser)iceType of *o,&.
pm#l%rantsTrans&!ell/oAck
The total number of unicast #L grants not designated for &#'!H data transmissions. The grants are transmitted to #+s that use this cell as the primary cell and that ha)e no bearer mapped to a Q!, $ith *o,& ser)iceType
NOTE? /olte pacets uses lower S length than the other "earer pacets 3lower "it rate re'uirement, lower pacet si)e4 rl"$Le!th? 8 for 'ci1 and 10 for the rest
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pd"p$Le!th? F for 'ci1 and 1: for the rest
/olte icin, ePDCCH &in daptation parametreleri ayarlanara !olte PI !e metrilerinde iyilesme elde ede"iliri) sagida a"aca, featureGin calisma mantigini toparlamaya calistim Her "ir "asarili PDCCH detectionda 3yani eBGnin %.Gden, C ya da C olmasindan "agimsi) olara H-2 responseGunu almasi4, toplam SI- compensation, upstep si)e adar a)altilir Her "asarisi)lita ise, SI- compensation, downstep si)e adar arttirilir 3i "i)imde parametri degisilile amacladigimi), "u mitari arttirara %.Gye, daha yuse PDCCH aggregation le!el ullandirma4 Daha yuse compensation, daha yuse PDCCH aggregation le!el ullanilmasini saglayaca anca PDCCH CC. %tili)ationGin artmasina neden olaca Boylece, PDCCH decodingtei "asari ile PDCCH apasitesi arasindai trade5offGu /olte ser!isi icin degistirip, /olte ullanicilarinin performansi arttira"iliri) tif 2CI1 .-BGina sahip ullanicilar icin, PDCCH lin adaptationGi seillendiren ii ana parametreyi asagida "ula"ilirsini) pd""hTar!et)ler*olteA Default deger ? :: 3ie $arget PDCCH B&.- 6 ? 116 4, "u deger 08; dBGli "ir SI- outer loop downstep ad+ustmentGa arsili geliyor Bu deger 3SI- outer loop downstep4 ne adar yuse olursa, o adar fa)la SI- ad+ustment yapilir dolayisiyla daha yuse PDCCH aggregation le!el ullanilip, daha saglam "ir PDCCH decode performansi elde edilere, /olte paetlerinin ay"olmasi ya da gecimesi engellene"ilir
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Do4$tep $i3e + 5p$tep $i3e7 B-9 pd""hTar!et)ler*olte# pd""hTar!et)ler*olte 5p$tep $i3e, pd""hOuterLoop5p$tep*olte parametresi ile ayarlanir 3default deger? >4
pd""hOuterLoopIitialAdj*olte A Default deger ? 5F0 35FdB4 Bu, SI- outer loop downstep ad+ustmentGin initial ismini 5FdB olara set ediyor Bu deger ne adar dusu olursa, o adar fa)la SIcompensation yapilir
/O
Parameter
EUtranCellFDD pdcchTargetBlerVolte pdcchOuterLoopInitial EUtranCellFDD AdjVolte
Tur6"ell
P&I&or6s
*alue
'e"ommedatio
22
16
-70
-80
Degisikliklerden sonra beklenen etkiler: - PDCC !"E# $ %te a&al'a - (C)1 Pa*ket "oss $ %te a&al'a +b,n,n son,*,nda itter.da a&al'a /e artisi - PDCC CCE Utili&ation $ artisi +o&ellikle aggregation le/el 8.de olte tragi tola' tragin *ok k,*,k bir 'iktarini ol,st,rd,g, i*in b, artisin genel er9or'ansi etkile'esi beklen'e& ine de 'onitor edil'esi i;i ol,r
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