HSDPA Throughput very low

[dah.]

hi all,
description of the problem: I have a new Huawei 3G network and "HSDPA.MeanChThroughput" per cell is very low (200-500kbs). can you help me to identify the cause off this loss.
note: the IUB interface is not congested
HSDPA Cell configuration:
technologie: Huawei
Code Max Number for HS-PDSCH:15
Code Min Number for HS-PDSCH:1
Code Number for HS-SCCH:4
HS-PDSCH MPO Constant:2.5db
Code Adjust Switch for HSDPA :ON
User Number for Code Adjust: 3

[dadiono]

hi all,
description of the problem: I have a new Huawei 3G network and "HSDPA.MeanChThroughput" per cell is very low (200-500kbs). can you help me to identify the cause off this loss.
note: the IUB interface is not congested
HSDPA Cell configuration:
technologie: Huawei
Code Max Number for HS-PDSCH:15
Code Min Number for HS-PDSCH:1
Code Number for HS-SCCH:4
HS-PDSCH MPO Constant:2.5db
Code Adjust Switch for HSDPA :ON
User Number for Code Adjust: 3

What about setup 16QAM/QPSK.
Is it node B wih IP or IMA/ATM.

[dah.]

the problem occurs in all nodeB ( IP and ATM)

[auto_art]

hi all,
description of the problem: I have a new Huawei 3G network and "HSDPA.MeanChThroughput" per cell is very low (200-500kbs). can you help me to identify the cause off this loss.
note: the IUB interface is not congested
HSDPA Cell configuration:
technologie: Huawei
Code Max Number for HS-PDSCH:15
Code Min Number for HS-PDSCH:1
Code Number for HS-SCCH:4
HS-PDSCH MPO Constant:2.5db
Code Adjust Switch for HSDPA :ON
User Number for Code Adjust: 3

at which layer you are checking.?

try checking at throughput MAChs layer. verify your counters details to get info about it.

[elkador]

Do you have HSUPA enabled?
If no, check your setting for the HSDPA return channel. R99 return channel of 16kbps can severely limit your actual downlink throughput...

[gprastomo]

Cek by conducting drivetest, maybe its the provile

Do you have HSUPA enabled?
If no, check your setting for the HSDPA return channel. R99 return channel of 16kbps can severely limit your actual downlink throughput...

[ritgail]

Fetch the CQI report, moreover as said check the counters because you have 15 codes available, throughput must be high. also application throughput and overall throughput are different. There is near matching value of these, if :

1.radio condition is very fine( will go for 16QAM rather than QPSK, will effect coding)
2.scheduling algo Max CQI(for maximum cell throughput which will pull up both the figure)
3.coding near to one.

From you figures:
1. 4 users are there in per 2ms TTI
2. Maximum codes in one TTI is 15
So taking worst case scenario radio(check for hardware alarms also), Modulation is QPSK and coding is 1/3 turbo coding then:

Symbol rate with one SF 16 code is 240 x 1000 /sec then 480symbol/2ms TTI or 960bits/2ms TTI. For 1/3 turbo coding effective application bit rate is 320bit/2ms TTI

So if 1 user is given only 1 code and is scheduled every 2ms TTI(500 times in 1 sec) then speed comes 160 kbps(application througput). Here your counter may be different
Your overall throughput will be then 160 x 3 = 480 kbps. Here your counter may be different.

So minimum cell throughput should be near to 480 kbps.(without re-transmission). if 4 ue scheduled per tti then it should be high.

Please correct me if i am wrong.

[boring]

in addition to the previous. this is a new cell or it was working ok and suddenly it started having this issue?

also, are you sure the HS-PDSCH MPO Constant is only 2.5 dB?