5G RAN2.1 NSA/SA Architecture Introduction
HUAWEI TECHNOLOGIES CO., LTD.
5G Networking Options
SA/NSA Definition (38.801)
Non-standalone NR: A deployment configuration where the gNB requires an LTE eNB as anchor for control plane connectivity to EPC, or an eLTE
eNB as anchor for control plane connectivity to NGC.
Non-standalone E-UTRA: A deployment configuration where the eLTE eNB requires a gNB as anchor for control plane connectivity to NGC.
Non-standalone NR: LTE/eLTE as control plane anchor
S1-C
Option 3
Option 3a
Option 3x
Option 4
Option 4a
EPC
EPC
EPC
NGC
NGC
S1-U
LTE
NG-C
Standalone NR: NR as control plane anchor
S1-C
S1-U
LTE
NR
S1-U
NR
S1-U
S1-C
LTE
NG-C
S1-U
eLTE
NR
NG-U
NG-U
eLTE
NR
Option 7
Option 7a
Option 7x
Option 2
NGC
NGC
NGC
NGC
NG-U
eLTE
NG-C
NR
NG-U
eLTE
NG-U
NR
NG-C
NG-U
eLTE
Signaling anchor
HISILICON SEMICONDUCTOR
NG-U
NR
NG-C
NG-C
NG-U
NR
NG-U
NR
Data split point
2
5G Networking Options
SA/NSA Definition (38.801)
EN-DC Model EUTRA-NEW RADIO Dual Connectivity Model: NSA sees the existing LTE architecture augmented with the addition of a 5G radio
carrier. gNB is working as Secondary node in EN-DC model. Based on the dual connectivity.
EN-DC utilized the End to End LTE system with the addition of gNB.
EN-DC USER PLANE CONNECTIVTY: There are 4 different E-RAB configuration that we can potentially have with EN-DC.
HISILICON SEMICONDUCTOR
3
5G Networking Options
SA/NSA Definition
Protocol Stack of EN-DC as per Network Perspective & UE perspective.
HISILICON SEMICONDUCTOR
4
SA (Standalone)

Generation Core (NGC) to provide all 5G services such as eMBB,
NGC
AMF/UPF
5G SA networking will use the standard 5G RAN and Next
URLLC, mMTC, and eV2X.
AMF/UPF

Based on the 3GPP Release 15 protocols, the SA architecture is
supported by the service-oriented core (SOC).
NG-RAN

New interfaces: Uu/NG/Xn

New QoS architecture: QoS-flow-based QoS architecture (SDAP layer and
gNB
gNB
gNB
(From 38.300)
Reflective QoS)

New RRC state management: RRC_INACTIVE

Mobility, VoIP, and CA/DC mechanisms for SA only

gNodeB relationships in NSA architecture and SA architecture

E2E slice architecture
A new coverage network (new RAN and new core network) supports differentiated services of 5G.
HISILICON SEMICONDUCTOR
New Interfaces (Uu Interface Channel Model)
Downlink Physical Channel and
Signal
SS
RRCRecfg/
RRCResume
RRCSetupReq/
RRCResumeReq
MIB
RRCSetup/
RRCReject
SIB1/SI
Paging
Logical
Channels
PCCH
BCCH
CCCH
DCCH
DTCH
Transport
Channels
PCH
BCH
DMRS
Physical
Channels
PSS
SSS CSI-RS
PBCH
SRS
PDCCH
DL-SCH
UL-SCH
DMRS
DMRS
PT-RS
PT-RS
PDSCH
PUSCH
Msg1
HISILICON SEMICONDUCTOR
RACH
DMRS
PUCCH
Msg2
Synchronization signal
Time-frequency synchronization, and cell search
Physical broadcast
channel
Carries system broadcast messages.
PDCCH
Physical downlink control
channel
Transmits control signaling such as uplink and
downlink scheduling and power control.
PDSCH
Physical downlink shared
channel
Carries downlink user data.
DMRS
Demodulation reference
signal
Downlink data demodulation, and time-frequency
synchronization
PT-RS
Phase tracking reference
signal
Downlink phase noise tracking and compensation
CSI-RS
Channel state
information-reference
signal
Downlink channel measurement, beam
management, RRM/RLM measurement, and
refined time-frequency tracing等
PBCH
RRCRecfgCmp/
MeasReport
PRACH
Function
Uplink Physical Channel and Signal
Function
PRACH
Physical random access
channel
User random access request information
PUCCH
Physical uplink control
channel
L1/L2 control signaling, such as HARQ
feedback, CQI feedback, and scheduling
request indication
PUSCH
Physical uplink shared
channel
Carries uplink user data.
DMRS
Demodulation reference
signal
Uplink data demodulation, and time-frequency
synchronization
PT-RS
Phase tracking reference
signal
Uplink phase noise tracking and compensation
SRS
Sounding reference signal
Uplink channel measurement, time-frequency
synchronization, and beam management
Physical Channel
Downlink
Physical
Channel
PBCH
PDCCH
PDSCH
Uplink
Physical
Signal
PSS/SSS
DMRS
PT-RS
CSI-RS
Physical
Channel
PRACH
PUCCH
PUSCH
Physical
Signal
Downlink Physical Channel/Signal
Function
SS
Synchronization Signal
Used for time-frequency synchronization and cell
search.
PBCH
Physical Broadcast Channel
Carries system information to be broadcast.
PDCCH
Physical Downlink Control Channel
Transmits control signaling, such as signaling for
uplink and downlink scheduling and power control.
PDSCH
Physical Downlink Shared Channel
Carries downlink user data.
DMRS
Demodulation Reference Signal
Used for downlink data demodulation and timefrequency synchronization.
PT-RS
Phase Tracking Reference Signal
Tracks and compensates downlink phase noise.
CSI-RS
Channel State Information
Reference Signal
Used for downlink channel measurement, beam
management, RRM/RLM measurement, and refined
time-frequency tracking.
DMRS
PT-RS
SRS
Uplink Physical Channel/Signal
Function
PRACH
Physical Random Access Channel
Carries random access request information.
PUCCH
Physical Uplink Control Channel
Transmits L1/L2 control signaling, such as signaling
for HARQ feedback, CQI feedback, and scheduling
request indicator.
PUSCH
Physical Uplink Shared Channel
Carries uplink user data.
DMRS
Demodulation Reference Signal
Used for uplink data demodulation and time-frequency
synchronization.
PT-RS
Phase Tracking Reference Signal
Tracks and compensates uplink phase noise.
SRS
Sounding Reference Signal
Used for uplink channel measurement, time-frequency
synchronization, and beam management.
Compared with LTE, NR removes the PHICH, PCFICH, and CRS, adds the PT-RS, and enhances the DMRS and CSI-RS.
HISILICON SEMICONDUCTOR
NR Physical Channels: Application Scenarios & Processes

Physical channels involved in cell search
–
gNodeB
PSS/SSS -> PBCH -> PDCCH -> PDSCH
PSS/SSS

Physical channels involved in random access
–
RMSI
MIB
(PDCCH,
(PBCH) PDSCH)
UE
Preamble
(PRACH)
...
HARQ excluded
from RAR
PRACH -> PDCCH -> PDSCH -> PUSCH
Cell search

Physical channels involved in downlink data transmission gNodeB
–
PDCCH -> PDSCH -> PUCCH/PUSCH
CSI
(PUCCH/
PUSCH)
...
CSI-RS

Physical channels involved in uplink data transmission
–
RAR
(PDCCH,
PDSCH)
Msg3
(PUSCH)
HARQ included
in Msg4
Random access
Data
(PDCCH,
PDSCH)
ACK/NACK
(PUCCH/
PUSCH)
Data
(PDCCH,
PDSCH)
UE
...
Paging
(PDCCH,
PDSCH)
Downlink data transmission
PUCCH -> PDCCH -> PUSCH
gNodeB
SRS
...
SR
(PUCCH)
BSR/Data
(PUSCH)
UL Grant
(PDCCH)
BSR/Data
(PUSCH)
ACK/NACK
(PDCCH)
UE
Uplink data transmission
Physical channels in NR and LTE are used almost in the same way.
HISILICON SEMICONDUCTOR
Msg4
(PDCCH,
PDSCH)
RS Design
SS
LTE RS
Function
NR RS
SS (PSS/SSS)
Coarse Timing/Frequency
Tracking
SS (PSS/SSS)
DMRS
CSI-RS
CSI-RS (TRS)
Demodulation for PBCH
DMRS for PBCH
Demodulation for PDCCH
DMRS for PDCCH
CRS, DMRS
Demodulation for PDSCH
DMRS for PDSCH
DMRS for
PUCCH/PUSCH
Demodulation for
PUCCH/PUSCH
DMRS for
PUCCH/PUSCH
CRS
RRM
CSI-RS, SSB
–

–
DMRS
–
–
–
–
CSI-RS, SRS
\
Beam Management (NR new
function)
\
Phase Noise Tracking (NR new
PT-RS
function)
SRS
–
PT-RS
All RSs are bound to the cell IDs.
CSI-RS was introduced in 3GPP Release 10 but few UEs
support the CSI-RS.
NR RS design: CRS free, RS function reassembly
CSI-RS
CRS, CSI-RS, SRS Channel State Information
SRS
SS
LTE RS design: Focus on the CRS
–
Fine Timing/Frequency
Tracking
CRS
CRS

All RSs except for the PSS/SSS/PBCH are decoupled from
the cell ID.
Beamformed PSSs/SSSs are transmitted in a narrow
beam.
DMRS demodulation applies to both PDCCH and PDSCH.
Enhancements are made to the DMRS type, port quantity,
and configuration.
CSI-RS pattern and configurations are enhanced for RRM,
CSI acquisition, beam management, and refined timefrequency tracking.
PT-RS is added for phase noise tracking on high frequency
bands.
Compared with LTE, NR removes the CRS and reassembles and enhances RS functions.
HISILICON SEMICONDUCTOR
New Interfaces (Uu Interface Protocol Stack and Function Description)
Uu-C
Interface
TS 38.300/38.331
UE
gNB
AMF
NAS
NAS
RRC
RRC
PDCP
PDCP
RLC
RLC
MAC
MAC
PHY
PHY
Scenario
Network search &
camping
System information broadcast: AS and NAS information
UE calling
Paging initiated by the core network or gNodeB
Signaling plane
setup
RRC connection setup, management, and release
Authentication and
interaction
NAS transparent transmission: identity authentication between
UEs and the CN, security, and others
User plane setup
SRB and DRB setup, configuration, and release
Uu-C
Mobility management
Anytime and
anywhere (wireless)
Uu-U
TS 38.323/38.322/38.321, 37.324
UE
UE measurement control and report
Radio link detection and recovery
gNB
Air interface security
Security mechanism
SDAP
SDAP
PDCP
PDCP
RLC
RLC
MAC
MAC
Segmentation and retransmission (RLC layer)
PHY
PHY
Scheduling, multiplexing, and HARQ retransmission (MAC layer)
QoS flow control (SDAP layer)
HISILICON SEMICONDUCTOR
Uu-U
Data transmission
Header compression, sorting, integrity protection, and encryption
protection (PDCP layer)
New RRC State Management

RRC_CONNECTED
NR
RRC CONNECTED
FFS/Connection
inactivation
If a UE in RRC_CONNECTED mode does not
transmit data for a period of time, the UE enters
•
UE context management
•
Data transmission
•
Measurement control and
initiate data transmission, the UE transits to
mobility management
RRC_CONNECTED mode through the RRC
the RRC_INACTIVE mode.

RRCResume
RRCRelease
If the UE in RRC_INACTIVE mode needs to
connection resume procedure.

If the UE in RRC_INACTIVE mode does not
transmit data for a period of time, the UE enters
NR
RRC INACTIVE
Connection
establishment/release
FFS
NR
RRC_IDLE
(From 38.804)
RRCRelease
(suspend)
RRCSetup
RRC_INACTIVE
RRC_IDLE
•
PLMN selection
•
System information broadcast
•
Cell-reselection-based mobility
•
5GC paging
RRC_IDLE mode.
RRCRelease
•
PLMN selection
•
System information broadcast
•
Cell-reselection-based mobility
•
RAN paging
•
UE context management
(From 38.300)
NR vs. LTE: The introduced RRC_INACTIVE mode features shorter access delay (compared with RRC_IDLE mode) and more power-efficient (compared with RRC_CONNECTED mode).
HISILICON SEMICONDUCTOR
SA Architecture
HISILICON SEMICONDUCTOR
RAN Functions
User Plane Processing
gNB or ng-eNB
AMF
Inter Cell RRM
SMF
UE IP address
allocation
NAS Security
PDU
SDAP
PDCP
RLC
MAC
PHY
SDAP
PDCP
RLC
MAC
PHY
PDU
GTP-U
UDP
IP
L2
L1
GTP-U
UDP
IP
L2
L1
Transfer of User Data
Ciphering & deciphering
Integrity protection
Header compression
…
RB Control
Connection Mobility Cont.
Idle State Mobility
Handling
PDU Session
Control
gNB(CU/DU)
Radio Admission Control
Measurement
Configuration & Provision
NG-U
UU
UPF
NGC(AMF/SMF/UPF)
NG-C
Control Plane Processing
Mobility Anchoring
System Information
Dynamic Resource
Allocation (Scheduler)
Paging
PDU Handling
internet
NG-RAN
5GC
(From 38.300)
HISILICON SEMICONDUCTOR
NAS
RRC
PDCP
RLC
MAC
PHY
RRC
PDCP
RLC
MAC
PHY
NGAP
SCTP
IP
L2
L1
NAS
NGAP
SCTP
IP
L2
L1
Conn Setup & Release
Distribution of NAS message
Session Management
Contacting UE in Inactive Mode
Handover
…
Signaling Process Overview
UE
DN
AMF
System Information
Initial
Access
EPC
NGC
gNB
Paging
Random access
N26
RRC
NG
NG
NG
Connection
Management
Xn
gNB
gNB
gNB
eNB
NG-C signaling connection &
Initial UE context establishment
Radio bearer management
Session
Management
Initial
Access
RRC connection
establishment
PDU session setup
PDU Session & UE context release
UU
IntraRAT HO based Xn
IntraRAT HO
based Xn
UE
IntraRAT HO
based NG
InterRAT HO
Mobility
Management
IntraRAT HO based NG
InterRAT HO
HISILICON SEMICONDUCTOR
eNB
MME
Signaling Process: System Information Broadcast (Introduction)
System Information Introduction
System Information Classes
Class Subclass
Content
Sending Mode
Huawei
Planning
Periodic broadcast
18B
Periodic broadcast
19B
WHY
MIB
The UE obtains the basic network information through
and SSB offset) and RMSI capturing method information.
the system information broadcast process, and
Also called SIB1. It provides mandatory information for UEs to access the network,
therefore camps on the network and initiates a call.

including:
AS information: includes common channel
MSI
information, timers required by some UEs, cell

Initial access information (including the system frame number, subcarrier spacing,
 Cell selection information
RMSI
 Cell access information (PLMN, TAC, and Cell ID)
selection/reselection information, and neighboring
 SI scheduling information (SI period, window size, and SIB mapping)
cell information.
 Cell configuration information (band, frequency, bandwidth, and initial BWP channel
NAS information: includes operator information.
configuration)
Cell reselection parameters, including intra-frequency, inter-frequency, and inter-RAT
reselection parameters
SIB2
WHEN

Cell selection (for example, power-on)

Cell reselection

Incoming handover

Incoming inter-RAT handover

Return to the coverage area after disconnection

System information update

System information beyond the validity period
(three hours)
HISILICON SEMICONDUCTOR
SIB3
Intra-frequency neighboring cell information
SIB4
Inter-frequency neighboring cell information
SIB5
Inter-RAT (E-UTRAN) neighboring cell information
SIB6
ETWS notification
SIB7
ETWS supplementary notification
SIB8
Commercial mobile alert system (CMAS)
SIB9
GPS timing
OSI
Periodic or on-demand
19B
broadcast
Periodic or on-demand
19B
broadcast
Periodic or on-demand
20A
broadcast
Periodic or on-demand
19B
broadcast
Periodic or on-demand
To be planned
broadcast
Periodic or on-demand
To be planned
broadcast
Periodic or on-demand
To be planned
broadcast
Periodic or on-demand
20A
broadcast
Signaling Process: System Information Broadcast (Signaling)
Message Routing (Channel Mapping)
Signaling Process
Send sync signal
Power on and search for cells
Obtain DL clock sync and cell IDs
MasterInformationBlock
SystemInformationBlock1
SystemInformation messages
(Periodic)
MIB carries a
parameter
instructing the UE
to capture SIB1.
SIB1 carries a
parameter indicating
periodic or ondemand broadcast
for other SI.
SystemInformation Request
Broadcast MIB
@gNB
@gNB
BCH
DL-SCH
RACH
Transport
Channels
Receive and parse PBCH
Obtain timing info and SS/PBCH block index
@UE
Obtain time-frequency info for broadcasting SIB1
DMRS
Broadcast SIB1
Receive SIB1
Obtain basic access info
Obtain OSI sending method info
Broadcast OSI
Receive OSI
Obtain mobility info
HISILICON SEMICONDUCTOR
Logical
Channels
BCCH
@UE
@gNB
@UE
SystemInformation messages
(On Request)
SIB1/
SI
MIB
@gNB
@UE
PSS
SSS
PBCH
PDCCH
DMRS
PT-RS
PDSCH
Physical
PRACHChannels
PSS/SSS:
 Performs downlink synchronization, including clock synchronization, frame
synchronization, and symbol synchronization.
 Obtains the cell ID.
PBCH:
 Broadcasts the system frame number (SFN), SSB Index, and RMSI time-frequency
domain information.
 The combination of the PBCH, PSS, and SSS is called SSB block. The PSS occupies
four consecutive symbols in the time domain and 20 RBs in the frequency domain. The
modulation mode is QPSK.
 The period is 80 ms.
Signaling Process: Random Access
CBRA
CFRA
1. SIB1
PDCCH Order or RRCRecfg
(Assign Dedicated Preamble)
RA preamble resource
2
3 ..
1
2. Acquire PRACH
resource configuration
UE
#1
MSG1(Preamble)
PRACH
UE
#2
3. Transmit PRACH
Preamble with RA-RNTI
MSG2(RAR)
PDCCH&PDSCH
4. MSG1(Preamble,RA-RNTI)
PRACH
RAR
Window
5. Send DCI format 1_0
with RA-RNTI, allocation
resource for RAR
6. MSG2(TC-RNTI,TA,UL-Grant)
PDCCH&PDSCH
7. MSG3(UEID)
PUSCH
CR
Timer
8. Send DCI format 1_0
with TC-RNTI, allocation
resource for CR
9. MSG4(UEID, …)
PDCCH&PDSCH
10. MSG5
PDCCH&PDSCH
HISILICON
SEMICONDUCTOR
T1
T2
T3
MSG4
(ueid=1)
RA
Sponsor
1
RRC Setup
CBRA
UE
2
RRC Reestablish
CBRA
UE
3
RRC Resume
CBRA
UE
4
HO
(SA and EN-DC)
CFRA or CBRA
gNB RRC
signaling
5
DL Data arrival when
“non-synchronized”
6
time
UE
#1
MSG3
(ueid=2)
UE
#2
Triggered Event
T4
time
MSG1
MSG2
MSG3
(RAPID=2)
(ueid=1)
No.
CR Timer
time
CFRA or CBRA
gNB PDCCH
order
UL Data arrival when
“non-synchronized”
CBRA
UE
7
ODOSI
MSG1:CFRA
MSG3:CBRA
UE
8
Beam recovery
CBRA or CFRA
UE
Signaling Process: RRC Connection Management
4
SRB0
SDAP
SDAP
RRC
SRB1
SRB2
PDCP
PDCP
PDCP
PDCP
PDCP
RLC
RLC
RLC
RLC
RLC
DCCH
DCCH
DTCH
DTCH
DTCH
DRB1
DRB2
DRB3
1. MSG1
RA
RRC:-----------------------------------ue-Identity
establishmentCause
2. MSG2
3. RRCSetupRequest
(on SRB0)
RRC
Setup
3.1. UE context
setup
3.2. Admission and
SRB1 resource
allocation
4. RRCSetup
(on SRB0)
5. RRCSetupComplete
(on SRB1)
HISILICON SEMICONDUCTOR
RRC:-----------------------------------RadioBearerConfig
srb-ToAddModList
srb-Identity
pdcp-Config
masterCellGroup
rlc-BearerToAddModList
logicalChannelIdentity
srb-Identity
rlc-Config
mac-LogicalChannelConfig
mac-CellGroupConfig
drx-Config
schedulingRequestConfig
bsr-Config
physicalCellGroupConfig
…
CCCH
MAC
RACH
PRACH
DL-SCH
UL-SCH
PDCCH/PDSCH
PUCCH/PUSCH
2
3
1
5
SA and NSA Co-existence: Data Flows
SA/NSA dual-mode UE
MME
AMF
S-GW
Which cell is selected for UE access when the NR SA cell and EN-DC cell are in the same coverage
UPF
area? Depends on the implementation of the UE.

Huawei UE: searches for 5G signals first. If SA service attempts fail, it searches for 4G signals and
tries NSA services.

Huawei CPE: searches for 4G signals first. If NSA service attempts fail, it searches for 5G signals
and tries SA services.
SA/NSA dual-mode cell (base station)
Set the SA/NSA networking mode based on the PLMN granularity within the base station. One cell
allows access of both SA and NSA UEs.

The operator networking mode is set to NSA+SA. UEs in different modes in the same PLMN are
allowed to perform different services after network access.
eNB
gNB#2
gNB#1

In MOCN scenarios, two operators share a network, and the networking mode is set to NSA and SA,
respectively. UEs of different operators are allowed to perform different services after network
access (temporarily not supported in 19B).
5G
Signaling plane #0
User plane (NSA UE)
HISILICON SEMICONDUCTOR
5G
5G
Service switch between SA and NSA
#1
(SA UE)
#2
(SA UE)
Implemented through inter-RAT handover or redirection

SA > NSA: through N2L inter-RAT handover or redirection

NSA > SA: through L2N redirection (L2N inter-RAT handover temporarily not supported in 19B)
Technical Comparison
HISILICON SEMICONDUCTOR
Current Project Summary
HISILICON SEMICONDUCTOR
Project Summary:
 654 sites antenna swap ongoing for refarming
 About 250 sites antenna swap completed
Responsibility









Responsible for KPIs for 2G, 3G and LTE after antenna Swap
Meet the KPIs targets (Same as before antenna Swap or better)
GSM: New Antenna Swap sites KPIs analysis and action plan for any dip
UMTS: New Antenna Swap sites KPIs analysis and action plan for any dip
LTE: New Antenna Swap sites KPIs analysis and action plan for any dip
Traffic Analysis for 2G, 3G and LTE after antenna Swap
Site Audit report check if required
Supporting for 2G, 3G and LTE KPIs and Traffic for old cases analysis & solution
VIP Customer Complain Handling
HISILICON SEMICONDUCTOR
Thank you
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HISILICON SEMICONDUCTOR