8/10/2019 Analysis Report for Occasional Low DC Throughput

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Analysis Report for

DC-HSDPA occasional low

throughput issue

2014-10-17 Huawei Confidential

8/10/2019 Analysis Report for Occasional Low DC Throughput

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1.Problem description

We have noticed that during the Auto Ping function from RNC to !" thethroughput changed occasionally after disconnecting and connectingagain with the S# datacard$ Without changing the radio conditions at all"the CD% throughput could &e either '()&ps or *()&ps +,igure .$

Figure 1: Occasional ping throughput reduction after VMC re-connections

%he pause period &etween the connections was only a few seconds andthe ! position remained e/actly the same$

2.Problem Analsis

!very time a ! is connected to the networ0" RNC allocates a Chip 12setto this !$ ,or DC service" the Chip 12set has an optimal value which canensure the highest performance of the DC user$ %he optimal value for theChip 12set in Huawei RNC is 3('4$ When the Chip 12set assigned to theDC-! is 3('4 the ma/imum performance is guaranteed$ %he optimal Chip

12set is directly connected to the ! response performance$

,rom the collected traces of RNC and Node# CD% during the tests" wehave found that sometimes RNC did not allocate the optimal Chip 12set tothe user +,igure '.$

Figure 2: Chip o!set is not the optimal

5n these cases the Node# would not receive AC67NAC6 info on time fromthe ! +,igure *.$

%herefore" the DC user schedule rate was reduced" and the DC user4s

throughput was less than its ma/imum capa&ility$

10/17/2014Huawei Technologies Co., Ltd.

8/10/2019 Analysis Report for Occasional Low DC Throughput

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Figure ": #ode$ does not recei%e &C-AC' in time

)ore speci8cally" in ,igure * the red mar0ed trace records show that manytimes the Node# does not receive the DC-AC6 over the HSDPCH in timeduring the 8rst 'ms frame" and waits for the ne/t 'ms$ %his issue causesthe DC ser4s throughput to drop$

".(olution5n the current RNC software version +SPC'99." a Chip 12set optimi:ationalgorithm is included which can &e activated using the following two ));commands$

SET URRMCDLCFG: INNERSWITCH3=RESERVED_SWITCH_BIT_0-1;

MOD UCELLALGOSWITCH: CellId=! R"#d$%&%3='; (()*& +*, .%&&/e&"

%he 8rst command opens the algorithm switch in RNC level" &ut it will not&e e2ective unless the second command is e/ecuted in cell level$

5n order for this function to &e e2ective" Node# RAN' SPC''9patch or later is also needed$

When this algorithm is activated" RNC will guarantee the optimalChip 12set for the DC-users in order to achieve the highest DCperformance$ %his change can &e implemented in live networ0 without anyris0s$ %his function is used only for optimi:ation of DC and )5)1 users4performance +

8/10/2019 Analysis Report for Occasional Low DC Throughput

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$ode) patch is needed, as alread* mentioned.

).Function &eacti%ation

5n case we want to deactivate the optimi:ation algorithm we need to

e/ecute the &elow commands=

SET URRMCDLCFG: INNERSWITCH3=RESERVED_SWITCH_BIT_0-0;

MOD UCELLALGOSWITCH: CellId=! R"#d$%&%3=0; (()*& +*, .%&&/e&"

10/17/2014Huawei Technologies Co., Ltd.