Transcript
8/10/2019 Ran15.0 Umts-To-lte Fast Return
1/16
www.huawei.com
Security Level:
HUAWEI TECHNOLOGIES CO., LTD.
RAN15.0 UMTS-to-LTE
Fast Return
Author/Email: zhangdaliang 00164806
Version:V1.0(20121221)
8/10/2019 Ran15.0 Umts-To-lte Fast Return
2/16
HUAWEI TECHNOLOGIES CO., LTD. Page 3HUAWEI Confidential
Background
Introduction
Deployment
Performance Monitoring
Acronyms and Abbreviations
Contents
8/10/2019 Ran15.0 Umts-To-lte Fast Return
3/16
HUAWEI TECHNOLOGIES CO., LTD. Page 4HUAWEI Confidential
Background
The circuit switched fallback (CSFB) applies to scenarios where UMTS and LTE are
deployed together. The LTE network does not support voice services. Therefore, when a
UE initiates a voice service on the LTE network, it will fall back to the UMTS network.
When the voice service is complete, the UE can fast return to the LTE network from the
serving UMTS network, improving user experience.
LTE UMTS
CS call
8/10/2019 Ran15.0 Umts-To-lte Fast Return
4/16
HUAWEI TECHNOLOGIES CO., LTD. Page 5HUAWEI Confidential
Background
Introduction
Deployment
Performance Monitoring
Acronyms and Abbreviations
Contents
8/10/2019 Ran15.0 Umts-To-lte Fast Return
5/16
HUAWEI TECHNOLOGIES CO., LTD. Page 6HUAWEI Confidential
Introductionprinciple
Fast Return (RRC
connection releasewith LTE
frequency)
UMTS
LTE
When the voice call is complete in UMTS, the RNC sendsfrequencies for neighboring LTE cells to the UE so that the UEcan fast camp on a suitable LTE cell.
Without fast return (8s)
With fast return (400 ms)
CSFB to
UMTS
CS call is
complete.
Cellreselection
Camp on
LTE
Fast return
CSFB
The time required for the UE to return from the serving UMTS
network to the LTE network decreases from 8s to 400 ms.
When the UE's voice service is complete, RRC Connection Release
message is sent to UE containing frequencies for neighboring LTE
cells whose priorities are higher than the priority of the serving UMTScell.
Frequency source: LTE frequencies carried in system information
block 19 (SIB19)
UE: Huawei E392 (a data card)
8/10/2019 Ran15.0 Umts-To-lte Fast Return
6/16
HUAWEI TECHNOLOGIES CO., LTD. Page 7HUAWEI Confidential
Introductionspecify a CSFB user
Satisfy one of the conditions below
1. The cause value inthe RELOCATION RQEUSET message is CSFallback triggered
2. The information element (IE) CSFB Informationcarried in RELOCATION
REQUEST message is set to CSFBor CSFB High Priority
3. Meets all the conditions below RRC CONNECTION REQUEST message does not carry the IE pre-
redirection.
UE supports E-UTRA TDD or E-UTRA FDD.
A CS call is successfully setup within 10s after RRC connection setup
complete.
4. The IE CSFB Indicationis carried in RRC CONNECTION REQUEST
message
5. The IE End of CSFB is carried in IU RELEASE COMMAND message.
8/10/2019 Ran15.0 Umts-To-lte Fast Return
7/16
HUAWEI TECHNOLOGIES CO., LTD. Page 8HUAWEI Confidential
Background
Introduction
Deployment
Performance Monitoring Acronyms and Abbreviations
Contents
8/10/2019 Ran15.0 Umts-To-lte Fast Return
8/16
HUAWEI TECHNOLOGIES CO., LTD. Page 9HUAWEI Confidential
Prerequisite Features The LOFD-001033 CS Fallback to UTRAN feature has been enabled on the LTE network.
Mutually Exclusive Features None
Impacted Features None
Hardware
None NEs
When UEs are redirected to UMTS due to CSFB, UEs must comply with 3GPP Release
9.4.0, or MSC can sent IU RELEASE COMMAND with IE End Of CSFB.
When a UE in LTE is handed over to UMTS due to CSFB, the cause value in the
RELOCATION RQEUSET message sent to the RNC is CS Fallback triggered (268), or
the IE CSFB information carried in the message is set to CSFBor CSFB High Priority, orMSC can sent IU RELEASE COMMAND with IE End Of CSFB .
License An RNC-level license control item has been introduced on the RNC side to accommodate
the UMTS-to-LTE Fast Return feature. Note that the feature is optional.
Prerequisites
8/10/2019 Ran15.0 Umts-To-lte Fast Return
9/16
HUAWEI TECHNOLOGIES CO., LTD. Page 10HUAWEI Confidential
Activation
Switches in RNC Select HO_UMTS_TO_LTE_FAST_RETURN_SWITCHunder the HandOver Switchparameter in RNC
MML command SET UCORRMALGOSWITCH.
Select PERFENH_PS_FAST_RETURN_LTE_SWITCHunder the Performance Enhancement Switch 3
parameter in RNC MML command SET UCORRMPARA.
Switches in cell(if they are configured, switches in RNC are out of service)
Select PERFENH_PS_FAST_RETURN_LTE_SWITCH andHO_UMTS_TO_LTE_FAST_RETURN_SWITCH under the Fast Return To LTE Switch parameter in CELL
MML command MOD UCELLHOCOMM.
If the feature has been activated, the RNC
sends the UE an RRC Connection Release
message carrying the IE Redirection info, which
contains frequencies for neighboring LTE cells
after the UE's RRC connection is released in
UMTS.
8/10/2019 Ran15.0 Umts-To-lte Fast Return
10/16
HUAWEI TECHNOLOGIES CO., LTD. Page 11HUAWEI Confidential
Deactivation
Switches in RNC(they are effective only when cell MML commandADD UCELLHOCOMM
is not configured)
Deselect HO_UMTS_TO_LTE_FAST_RETURN_SWITCH under the HandOver Switch
parameter in RNC MML command SET UCORRMALGOSWITCH.
Deselect PERFENH_PS_FAST_RETURN_LTE_SWITCH under the Performance
Enhancement Switch 3parameter in RNC MML command SET UCORRMPARA.
Switches in cell(if they are configured, switches in RNC are out of service)
Deselect PERFENH_PS_FAST_RETURN_LTE_SWITCH and
HO_UMTS_TO_LTE_FAST_RETURN_SWITCH under the Fast Return To LTE Switch
parameter in CELL MML command MOD UCELLHOCOMM.
8/10/2019 Ran15.0 Umts-To-lte Fast Return
11/16
HUAWEI TECHNOLOGIES CO., LTD. Page 12HUAWEI Confidential
Background
Introduction
Deployment
Performance Monitoring Acronyms and Abbreviations
Contents
8/10/2019 Ran15.0 Umts-To-lte Fast Return
12/16
HUAWEI TECHNOLOGIES CO., LTD. Page 13HUAWEI Confidential
Gains
Query the time required for UEs to return from UMTS to LTE from UE logs.
The time is the interval at which the UE receives the RRC CONNECTION
RELEASE message and sends the RRC CONNECTION REQUEST message.
If the time is shorter than that before the UMTS-to-LTE Fast Return feature is
enabled, this feature yields positive gains.
Time required
for UEs toreturn from
UMTS to LTE
8/10/2019 Ran15.0 Umts-To-lte Fast Return
13/16
HUAWEI TECHNOLOGIES CO., LTD. Page 14HUAWEI Confidential
New Counters
None
8/10/2019 Ran15.0 Umts-To-lte Fast Return
14/16
HUAWEI TECHNOLOGIES CO., LTD. Page 15HUAWEI Confidential
Background
Introduction
Deployment
Performance Monitoring Acronyms and Abbreviations
Contents
8/10/2019 Ran15.0 Umts-To-lte Fast Return
15/16
HUAWEI TECHNOLOGIES CO., LTD. Page 16HUAWEI Confidential
Acronyms and Abbreviations
CSFB: CS fallback
PS HO: packet service handover
8/10/2019 Ran15.0 Umts-To-lte Fast Return
16/16
Copyright 2013 Huawei Technologies Co., Ltd. All Rights Reserved.
The information in this document may contain predictive statements including, without limitation, statementsregarding the future financial and operating results, future product portfolio, new technology, etc. There are a
number of factors that could cause actual results and developments to differ materially from those expressed
or implied in the predictive statements. Therefore, such information is provided for reference purpose only and
constitutes neither an offer nor an acceptance. Huawei may change the information at any time without notice.
Thank youwww.huawei.com
top related