SL OPTIMIZE DM MELA
Knowledge Sharing Session
5G Optimization
Session#3
2022 – Q2
Rinja Sinha | Nazdeep Behl | Tanumoy Sett
BMAS SA NDO SL OPT DM MELA
2022-05-20
Timeline
NR Optimization principles
NSA (Competitor system)
NR Features & Radio DOT
Solution for NR
(Ericsson system)
Integrity & Mobility NSA
(Ericsson system)
NR Retainability NSA
(Ericsson system)
NR Overview and NR
Accessibility
NSA (Ericsson system)
WK18
WK19
th
May 6
May 13th
75 mins
75 min
SME Forum:
❖ Balkaran Singh
❖ Nandan Thakur
❖ Ruchika Singh
❖ Siddharth Pathak
❖ Tanumoy Sett
❖ Rinja Sinha
❖ Nazdeep Behl
❖ Ashok Cheerla
❖ Peeyoosh Mailapravan
❖ Dhiraj Sharma
❖ Vijay Kumar D
WK20
May 20th
WK21
May 27th
WK22
June 3rd
WK23
June 10th
WK24
June 17th
WK25
June 24th
WK26
July 1st
WK27
July 8th
75 mins
75 mins
75 mins
75 mins
75 mins
75 mins
75 mins
75 mins
✓ 5G Knowledge sharing sessions will be delivered over a span of 10 weeks
✓ Sessions will be repeated twice on the training day to accommodate NDO colleagues supporting different
time zones within MELA.
✓ Subtopics will be distributed over 2 weeks for detailed explanation of concepts and case studies.
Agenda
➢ Recap from the previous session.
➢ NSA Call flow and Retainability KPI.
➢ MOs/counter/parameters.
➢ Case studies related to Retainability.
➢ Test your knowledge
➢ Q&A
What is ENDC??
NR Retainability
REFERANCE MATERIAL
Non-Standalone Retainability Overview
In NR NSA scenario:
— Control plane is established in LTE cell / eNodeB
while user plane is established in gNodeB
— The loss of the NR link does not imply the loss of
the control plane one
If both LTE and NR branches are dropped:
— The user will perceive it as a drop
If only NR branch is lost:
— The time to re-establish the RAB either in LTE or
NR will be perceived as a degradation in
integrity KPIs (lower throughput or higher delay)
Non-Standalone Retainability KPIs
In providing wireless end-user services, services must not be interrupted or ended prematurely
Retainability in EN-DC is measured by:
Differentiated E-RAB Retainability - Percentage Lost
Captured in eNodeB (EN-DC)
SCG Radio Resource Retainability Captured in
gNodeB
Bearer Type Transitions (EN-DC connection release)
SN Release Overview (EN-DC)
MeNB initiated SN Release triggered at:
— UE detected RLF
— Failed random access
— RLC UL delivery failure
— Out of synchronization
— LTE handover
SgNB initiated SN Release triggered at:
— gNB detected RLF
— RLC DL delivery failure
— NR cell lock
UE release into Idle mode in eNB & gNB
UE release into Idle mode in eNB & gNB
— UE release decision due to inactivity is always taken by the MN (eNodeB)
— If the UE has only MN terminated bearers, then the inactivity release is identical to that for legacy
LTE
— If the UE has SN terminated bearer(s), then both the MN (eNodeB) and the SN (gNodeB) monitor
UE activity
— The SN notifies the MN of the UE inactivity by sending the SGNB Activity Notification (inactive)
message over the X2-AP interface
NR Radio Link Failure (in EN-DC)
1. When a UE configured with EN-DC with SCG
moves out of NR coverage, a NR Radio Link
Failure will eventually be triggered
— Detected by the en-gNB
or
— Detected by the UE and reported to the MeNB
via RRC: SCGFailureInformationNR message
2. The Radio Link Failure triggers a SN release.
B1 measurements are configured upon SN
release
MeNB Initiated SN Release
Secondary Node Release, keeping the Master Node, can be initiated either by the Master Node or the
Secondary Node.When the SN is released, any SN terminated bearers are transitioned to MN Terminated
MCG Bearers.
Reason for Abnormal release:
• Bad NR radio conditions
• UE detected RLF
• gNB Cell not Available
• Connection gNB to eNodeB is lost
• T310
MeNB Initiated SN Release
SgNB Initiated SN Release
In SgNB initiated SN Release, any SN terminated bearers are transitioned to MN Terminated MCG Bearers..
The Secondary Node initiates a Secondary Node release in the following cases:
Reason for Abnormal release:
• Internal cause (considered abnormal)
• RACH procedure problems (expiry of the Random Access Supervision Timer)
• Bad NR radio conditions (RLC exceeds its maximum downlink retransmission)
• NR cell lock
SgNB Initiated SN Release
EN-DC Bearer Type Transition (Retainability Counters)
NR Radio Link Failure (in EN-DC)
— UE detected NR RLF:
— Not possible to synch to NR cell (sync reconfig Failure)
— T304 is started at reception of SCG configuration at EN-DC Setup
— T304 is stopped at successful random access.
— T304 expiry -> radio link failure
— RLC UL delivery failure (RLC-MaxNumRetx)
— Number of UL RLC retransmissions in NR leg exceeds a threshold
(ulMaxRetxThreshold)
— Out of synchronization (t310-Expiry)
— UE monitors SSB (TRS in High-Band) and counts “in-synch” and
“out-ofsynch”indications.
— N310 consecutive “out-of-synch” indications starts timer T310
— N311 consecutive “in-synch” indication stops timer T310
— T310 expiry -> radio link failure
— Network detected NR RLF
— RLC DL delivery failure
— Number of DL RLC retransmissions in NR leg exceeds a threshold
(dlMaxRetxThreshold)
Network RLF detection (DL)
Important Questions
1. Which Timer starts for the SCG configuration ?
T304
2. What are the two major type of SN Release
MeNB Intiatited and SgNB initiated SN Release
3. When is T310 Timer starts?
Once there are N310 consecutive “out-of-synch” indications
4. Main Counter in NR NSA available for Drops
pmEndcRelUeAbnormalMenb & pmEndcRelUeAbnormalSgnb
5. NR NSA RLF mechanism is based on which measurement
SSB/CSI-RS Link Monitoring
6. When NR RACH takes Place
Randome Access happened after NR Leg setup
Q&A
Upcoming Sessions
Session#1
Session#2
Session#3
Session#4
Session#5
Session#6
Session#7
Session#8
Session#9
Session#10
SOID
CW18
May 6th
CW19
May 13th
CW20
May 20th
CW21
May 27th
CW22
June 3rd
CW23
June 10th
CW24
June 17th
CW25
June 24th
CW26
July 1st
CW27
July 8th
12:00 to
13:30hrs
NA
502222
502225
502191
502193
502195
502197
18:00 to
19:30hrs
NA
502224
502226
502192
502194
502196
502198
Registration closes 6days prior to the training.
For e.g. 27th May training session SOID 502191 & 502192, registrations close on May 19th
Hence, we encourage all participant to register themselves for the session well in advance.
Training Evaluation_Slot1_SOID 502225
—Kindly have your mobile connected to internet.
—Scan the QR Code shown on screen from your mobile camera and slightly tilt the phone to read the code,
if QR code is not being read.
—In case your mobile camera is not able to access the QR code at all, advise is to download any QR code
scanner app from Google play store or Apple Store and then scan the code from the app.
—Follow the steps on your screen to login, details below will be asked:
—Login using your Ericsson email id & password
—Provide passcode, generate it from VIP Access app on your mobile
—The survey will appear and will have 8 questions.
—Submission of evaluation will also be a feed for your attendance in ITM. Hence, it is important that you
provide feedback.
Note to Instructor: Right click on the box and click on copy link to share with
participants if needed.
Link
Training Evaluation_Slot1_SOID 502226
—Kindly have your mobile connected to internet.
—Scan the QR Code shown on screen from your mobile camera and slightly tilt the phone to read the code,
if QR code is not being read.
—In case your mobile camera is not able to access the QR code at all, advise is to download any QR code
scanner app from Google play store or Apple Store and then scan the code from the app.
—Follow the steps on your screen to login, details below will be asked:
—Login using your Ericsson email id & password
—Provide passcode, generate it from VIP Access app on your mobile
—The survey will appear and will have 8 questions.
—Submission of evaluation will also be a feed for your attendance in ITM. Hence, it is important that you
provide feedback.
Note to Instructor: Right click on the box and click on copy link to share with
participants if needed.
Link