EDCH UL OLPC_FNI_RNCLevel_West.ppt

Portfolio/Program Name Here 36/42pt with 12pt After Paragraph Subheadings 20ptFeature 121085
STC Deep Dive
Alcatel-Lucent PowerPoint Design Guidelines
When necessary Portfolio/Program Name can wrap to a second or third line to maintain consistent typographic spec
For title slide only, a 5% gray background has been added
General specifications
Page Setup set to “On Screen” format
Update footer to include appropriate “Portfolio/Program Name”
Ensure that only one font “Trebuchet” is used throughout. Following pages provide font sizes for text and graphic pages.
Ensure all text boxes sit in proper location. Sometimes the automatic PowerPoint settings are not exact
Titles on slides, Agenda and Division pages use “Title Case”
Text is set predominantly with regular weight. Bold Trebuchet is used to highlight key words or phases
When a slide has more text than comfortable fits on the page using standard font sizes, treat this instance as an exemption and reduce the font size of the entire block until it fits
For graphic only slides, use as much of the object area as possible to enhance legibility and emphasis
Slides with multiple logos should be adjusted so all logos appear visually equal in size and weight
Please remove any tinted or light color backgrounds from slides other than Agenda and Division slides
All Rights Reserved © Alcatel-Lucent 2013
* | EDCH UL OLPC | September 2013
Agenda
Introduction
Fast decrease mechanism
Agenda
Introduction
Introduction
PS traffic has increased over the past years. User need for high uplink throughput has pushed a lot of operators to request for HSUPA.
HSUPA uses an uplink enhanced dedicated channel (E-DCH) on which it employs link adaptation methods similar to those employed by High-Speed Downlink Packet Access HSDPA, namely:
shorter Transmission Time Interval enabling faster link adaptation;
HARQ (hybrid ARQ) with incremental redundancy making retransmissions more effective.
Similarly to HSDPA, HSUPA uses a packet scheduler, but it operates on a request-grant principle where the UEs request a permission to send data and the scheduler decides when and how many UEs will be allowed to do so.
A request for transmission contains data about the state of the transmission buffer and the queue at the UE and its available power margin. However, unlike HSDPA, uplink transmissions are not orthogonal to each other
Introduction
At the Physical Layer, HSUPA introduces new channels E-AGCH (Absolute Grant Channel), E-RGCH (Relative Grant Channel), F-DPCH (Fractional-DPCH), E-HICH (E-DCH Hybrid ARQ Indicator Channel), E-DPCCH (E-DCH Dedicated Physical Control Channel) and E-DPDCH (E-DCH Dedicated Physical Data Channel).
E-DPDCH is used to carry the E-DCH Transport Channel; and E-DPCCH is used to carry the control information associated with the E-DCH.
In order to maintain Ue call from being dropped, power control on channels is performed.
The objective of power control is to maintain service SIR almost equal to SIR target defined for each service.
The objective of the following feature is to decrease UL EDCH SIR for non active users, therefore enhancing Ue battery lifetime and enhancing a little UL RSSI.
Agenda
Introduction
Outer loop power control principle
The general principle of UL OLPC for E-DCH with Alcatel-Lucent implementation is summarized in the figure below.
The UL OLPC algorithm takes into account the link quality of each UL transport channel established (of DCH and/or E-DCH type) for the considered user, so that finally the link quality of each UL transport channel fulfills a target link quality specified separately for each channel. This algorithm is often referred to as “multiple reference transport Channel UL OLPC algorithm”.
Regarding the DCH transport channels, for each channel, a target BLER is set to a value tunable by the customer, and the BLER is monitored by an UL OLPC Machine dedicated to this channel. The BLER of each DCH is derived by the RNC based on the CRC Indicator (CRCI) of the selected UL DCH data frame (the NodeB computes a CRCI for each transport block it receives from the air interface and sends it to the RNC through Iub-FP. In addition, several data frames transporting the same user data can be sent by the different NodeBs having a link with the mobile; hence the CRCI retained by the RNC is the CRCI carried by the UL DCH data frame selected by the RNC).
A Partial UL SIR Target is derived each TTI (TTI period depends on the DCH channel considered) by the UL OLPC Machine of each DCH channel, so that BLER on a DCH channel would converge toward its target BLER if this Partial UL SIR Target were applied as the UL SIR Target.
The main difference with respect to UL OLPC for DCH transport channels is that, for the E-DCH channel, the quantity monitored is not the BLER but the number of HARQ retransmissions instead, and the link quality target is not a target BLER but a target average number of HARQ retransmissions. This is possible since the information concerning the number of HARQ retransmissions (for each MAC-e PDU correctly received or at HARQ failure detection) is sent by the NodeB to the RNC through Iub FP, via the N of HARQ Retransmissions IE enclosed in E-DCH UL Data Frames.
Agenda
Introduction
UA6 34249 introduces a “Fast Decrease” mechanism for Partial SIR Target(s) related to MAC-d flow(s) carried on E-DCH. This mechanism allows a faster convergence of the UL SIR Target when UE is in good radio conditions. The principle of this mechanism is as follows.
For the considered MAC-d flow carried on E-DCH, if more than edchNrOfConsecutiveZeroHarqReTxThreshold MAC-es PDUs are received at the RNC without any HARQ retransmission or HFI (HARQ Failure Indication), then the “Fast Decrease” mechanism is triggered, i.e. the Partial SIR Target related to this MAC-d flow is updated according to a specific formula
Once the triggering condition for “Fast Decrease” mechanism has been fulfilled, the Partial SIR Target of the considered MAC-d flow is updated according to above specific formula at each consecutive E-DCH Data Frame received without any HARQ retransmission or HFI.
“Fast Decrease” mechanism is cancelled as soon as an E-DCH Data Frame is received with at least one HARQ retransmission or with an HFI, and the Partial SIR Target is then updated according to the usual formula
Agenda
Introduction
Feature overview
The fast decrease mechanism didn’t take into account updating inactive users UL SIR.
The improvement introduced by this feature is to make UL SIR decrease rapidly also for non active users.
The introduction of a timer to manage the case where nothing is received by RNC was the solution encountered to enhance the “Fast Decrease” mechanism.
After expiring the above mentioned timer, a new “Fast Decrease” mechanism is triggered so the SIR target is reduced to the limit.
Feature overview
The UL SIR Target values of all existing MAC-d flows shall be preserved to their latest values from last activity period before triggering the new “Fast Decrease” process.
Traffic inactivity must persist for a configurable period of time before applying the fast decreased power.
This can be configured using the parameter eDCHOlpcInactivityTimeThreshold.
The decrease of UL SIR Target due to inactivity is limited to an optimum value so that it does not adversely impact the performance of UL physical control channels. This can be configured using the parameter eDCHOlpcInactivitySIRDecreaseLimit.
If Partial_UL_SIR_Target >eDCHOlpcInactivitySIRDecreaseLimit:
Finally, the preserved UL SIR Target values of all existing MAC-d flows shall berestored following detection of activity, i.e. receipt of MAC-d PDUs at RNC on any MAC-d flow. Initial power (saved right before fast decrease process) is reinstated as soon as traffic resumes, on any of the RAB.
Agenda
Introduction
Activation strategy
eDCHOlpcInactivitySIRDecreaseLimit set to 4 db
eDCHOlpcInactivityTimeThreshold set to 500ms
Agenda
Introduction
KPI results
No change in HARQ behavior was observed after feature activation
121085 has NO obvious impact on HARQ retransmission when eDCHOlpcInactivitySIRDecreaseLimit is 4 db.
KPI results
Uplink traffic didn’t affect after feature activation, and so is missing PDUs
KPI results
KPI results
Enhancement in SIR distribution, as number of samples with SIR distribution less than 7 has decreased on the other hand number of samples less than 5 has increased, so achieving 2 Db gain in UL SIR
KPI results
KPI results
Number of EDCH active users didn’t affect after feature activation
Agenda
Introduction
Conclusion
Feature has been tested successfully
Feature benefits has been proven.
Uplink SIR distribution has enhanced, saving 2 dB for Ues and therefore enhancing power saving for mobiles
Main KPIs didn’t affect after feature activation
Agenda
Introduction
Future steps
Roll out on the whole western region network is expected
Tuning for eDCHOlpcInactivitySIRDecreaseLimit and eDCHOlpcInactivityTimeThreshold in order to see impact on RNC level (mainly SIR distribution)
* | Advanced Location Services Overview | June 2008
At the speed of ideas
*
* | Advanced Location Services Overview | June 2008
www.alcatel-lucent.com

EDCH UL OLPC_FNI_RNCLevel_West.ppt

Documents

Transcript of EDCH UL OLPC_FNI_RNCLevel_West.ppt