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HSDPA 7.2 Mbps Bitrate Requirement

Some people need the actual throughput to define the real network speed. Most of them dontknow the requirement to get the real throughput from the network, they just need the salespromises. On marketing media, people read "internet access up to 7.2Mbps", but in fact itneeds some conditions to achieved 7.2 Mbps.So, to achieve 7.2 Mbps HSDPA bitrate on 3G network, there are a lot of requirement thatneeds to be met.

Item DescriptionRAN configuration(RNC, NodeB, and IuBinterface)

Cells HSDPA status and configuration and HSDPA_CellMaximum Tx power should have equal values.

The number for HS-PDSCH codes: at least 10 codes shouldbe configured for 7.2M HSDPA.

The number fo UEs camped on the cell: not more than oneUE should be camped on the cell used for tests, so that the

HS-SCCH success rate can reach more than 90% Mac-hs Scheduling Parameters in the NodeB, for example

SET MACHSPARA: LOCELL=0, SM=EPF, SCCHPWRCM=CQI,SCCHFER=3, IBLER=0, RSCLMSW=CLOSE, 16QAMSW=OPEN;

Iub available bandwidth and configuration: for 7.2M HSDPAin ATM transmission mode, at least 5 E1s are needed, whilein IP transmission, the available bandwidth must be morethan 9Mbps.

In IP transmission mode, check whether the Ethernet portwork mode both in RNC and Node B is configured toSPEED=100M, Duplex=Full. The same condition refers to theports of the LAN switches, if such are used.

The UL and DL BLER is more than 10%. RNC and NodeB licenses do not have limitations that might

influence the downloading speed such as HSDPA Support,Maximum Cell Power, CE resource/consumption, Number ofHSDPA users, HSDPA RRM1 package, etc.

Transmission or congestion alarms exist in the RNC andNodeB used for the tests

The cells PCPICH power is reasonable: it should be lessthan the maximal Tx power with about 10dB.

NodeB flow control configuration through NodeB transfer resource management mapping through RNC LMT

and ensure that HSDPA is mapped on NRT PATH NodeB Protocol version configured in RNC

UE (smartphone,handphone) andcomputer capacity andconfiguration

UE version and category Computer TCP Windows Size configuration: TCP windows

size should be 102400, MTU should be 1460 (can beconfigured with Dr.TCP).

Computer RAM memory should be more than 1G During downloading tests you should avoid high CPU

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consumption caused by other applications, as it may impactdownloading speed.

Shutdown computer firewall, if any.UE profile orsubscription and Core

Network configuration

Operator offers some option to use data packet depend onuser, likes speed, volume base, or time base.

Iu Interfaceconfiguration RNC IuPS interface bandwidth configuration. SGSN IuPS interface bandwidth configuration.FTP Serverconfiguration FTP servers configuration: TCP Window Size should be102400, MTU should be 1460 (can be configured with

Dr.TCP). During downloading tests you should monitor the FTP

server CPU consumption, as high CPU consumption of theFTP server may impact the subscriber downloading speed

Others conditions suchas radio environment,

download managerusage

Radio environment is important , likes signal(RSCP,RSSI,Ec/No) effect the modulation and bitrate each

symbol, Download manager like IDM have a good effect tomaximize the resource. Signal quality during downloading: Channel Quality Index

(CQI) should be more than 23. Multiple session download is recommended to avoid

limitations of TCP protocol implementation in Windows OS,FTP server or SGSN.