Complete 5G NR Overview with EN-DC Connectivity

1. 5G-NR (New
Radio)Overview

2. Introduction about 5G- NR
• 5G stands for Fifth Generation Wireless technology used for voice and data calls.
• It is cellular wireless technology like GSM (2G), CDMA (3G) and LTE/LTE-advanced (4G).
• It is defined in 3GPP NR specifications under various sections like 4G (LTE).
• It operates in various licensed and unlicensed bands e.g., below 1 GHz, below 6 GHz and above 6 GHz.
• The initial 5G NR specifications are published in dec. 2017.
• There are two modes supported by 5G NR (New Radio) viz. Non-standalone and standalone. Non-standalone
deployment relies on existing 4G LTE network whereas standalone works independent gNB.
• 5G should support 20 Gbps in the downlink and 10 Gbps in the uplink as claimed by 5G network operators.
• eMBB, mMTC and URLLC are different use cases supported in 5G NR technology.

3. 5G-NR-Use Cases (eMBB, mMTC and
URLLC

4. 5G-eMBB
Following features are supported by 5G eMBB use case.
• eMBB stands for Enhanced Mobile Broadband.
• Peak data rate : 10 to 20 Gbps.
• 100Mbps whenever needed.
• 10000 times more traffic
• Supports macro and small cells.
• Supports high mobility of about 500 Kmph.
• It helps in network energy savings by 100 times.

5. 5G mMTC
Following features are supported by 5G mMTC use case.
• mMTC stands for massive Machine Type Communications.
• It supports high density of devices (about 2 x 105 in 106/Km2).
• It supports long range.
• It supports low data rate ( about 1 to 100 Kbps).
• It leverages benefits of ultra low cost of M2M.
• It offers 10 years battery life.
• It provides asynchronous access.

6. 5G URLLC
Following features are supported by 5G URLLC use case.
• URLLC stands for Ultra Reliability and Low Latency Communications.
• It provides ultra responsive connections.
• It offers less than 1 ms air interface latency.
• It offers 5 ms end to end latency between UE (i.e., mobile) and 5G eNB (i.e., base station).
• It is ultra-reliable and available 99.9999% of the time.
• It provides low to medium data rates (about 50 kbps to 10 Mbps).
• It offers high speed mobility.

7. 5G NR and 4G LTE Comparison
A Short comparison of 5G and 4G technologies is given is table below.
Technology Data Rates Latency Mobility
Support
Spectrum
Efficiency
Users Density Energy
Efficiency
5G (NR) Avg 100 Mb/s
Peak 20 Gb/s
~ 1 ms > 500 Km/h x3 Better
DL- 30 bits/Hz
UL- 15bits/Hz
1000K/square
Km
x100 Better
4G (LTE) Avg 25 Mb/s
Peak 300 Mb/s
~10- 50 ms Upto 350
Km/h
DL – 6 bits/Hz
UL- 4 Bits/Hz
~ 2K / square
Km
Moderate

8. 5G New Radio and 4G LTE Parameter Level Comparison
Parameter 4G Long Term Evolution 5G New Radio
Full Name Long Term Evolution New Radio
3GPP Release Release 8 – Release 14 (LTE, LTE-A,
LTE-Pro)
Release 15 onward
Frequency Range < 6GHz Upto 52.6 GHz
Services Voice, MBB, IoT Voice, eMBB, Low Latency
Application, Massive IoT
Waveform •DL: CP -OFDM
•UL: DFT -S-OFDM
•DL: CP-OFDM;
•UL: CP-OFDM, DFT-S-OFDM
Max Carrier Bandwidth 20 MHz •Below >6 GHz: 100 MHz;
•Above6 GHz: 400 MHz
Subcarrier Spacing (SCS) 15 KHz 15 KHz, 30 KHz, 60 KHz, 120 KHz,
240KHz
Cylic Prefix (CP) Normal CP; Extended CP •Normal CP for all SCSs;
•Extended CP for 60KHzs SCS only
Max Number of Subcarriers
Per Carrier
1200 3300
Radio Frame Length 10 ms 10 ms
Slot Size 2/7/14 OFDM symbols 1-14 OFDM symbols (including both
slot & mini-slot)

9. 5G NR band Description
NR Bands Classification
Apart from FR (frequency range) NR bands can be classified into three into categories.
•Frequency Division Duplex Bands (FDD)
•Time Division Duplex Bands (TDD)
•Supplementary Bands (SUL) : Downlink Supplement Bands & Uplink Supplement Bands
NR has introduced a new notation for band which starts with “n” e.g. Band 20 is noted as n20
where in LTE it was termed as B20.
Supplementary Downlink ( SDL ) and Supplementary Uplink ( SUL ) are modes that
allow only downlink or uplink in those bands. SDL and SUL are meant to provide additional
capacity to the Existing bands.
Frequency Range Designation Corresponding Frequency Range
FR1 410 MHz – 7125 MHz
FR2 24250 MHz – 52600 MHz

10. 5G NR Frequency Bands
NR FR1 Band Band Alias Bandwidth Duplex Mode
n1 2100 60 MHz FDD
n2 1900 PCS 60 MHz FDD
n3 1800 75 MHz FDD
n5 850 25 MHz FDD
n7 2600 70 MHz FDD
n8 900 35 MHz FDD
n20 800 30 MHz FDD
n28 700 APT 45 MHz FDD
n66 AWS-3 70/90 MHz FDD
n70 AWS-4 15/25 MHz FDD
n71 600 35 MHz FDD
n74 L-Band 43 MHz FDD
n77 TD 3700 900 MHz TDD
n78 TD 3500 500 MHz TDD
n79 TD 4500 600 MHz TDD
n38 TD 2600 50 MHz TDD
n41 TD 2500 194 MHz TDD
n50 TD 1500+ 85 MHz TDD
n51 TD 1500- 5 MHz TDD
NR
FR2 Band
Band
Alias
Bandwidt
h
Duplex
Mode
n257 28 GHz
3000
MHz
TDD
n258 26 GHz
3250
MHz
TDD
n260 39 GHz
3000
MHz
TDD
Supplementary bands in 5G NR
FR1
Band
Band Alias
Bandwid
th
Duplex
Mode
n75 DL 1500+ 85 MHz SDL
n76 DL 1500- 5 MHz SDL
n81 UL 900 35 MHz SUL
n82 UL 800 30 MHz SUL
n83 UL 700 45 MHz SUL
n84 UL 2100 60 MHz SUL

11. 5G-NR Architecture

12. 5G Architecture (Non-Standalone)
Non-standalone
E-UTRA-NR Dual Connectivity
(EN-DC).
UE is connected to NR and LTE
simultaneously.
One eNB can be connected to
many gNB and vice versa


13. Non-Standalone Base Station Architectures using the 4G
Core Network (Options 3,3a and 3X)
Non-Standalone option-3a

14. Non-Standalone Option-3

15. •In both cases, the 4G Node B provides control plane connectivity towards the Core
Network and acts as the Master Node (MN).
• The 5G gNodeB has control plane connectivity across the X2 interface and acts as
the Secondary Node (SN).
•Option 3 -All user plane data tunnel through eNodeB . PDCP in eNodeB dynamically
splits the downlink data between the eNode B and gNodeB.
•In Option 3a- user plane connectivity between the S-GW and gNode B is provided
.Here also eNodeB will remain the master node depending upon EPS type eNodeB
may divide the work like Speech type data may be directed towards eNodeB and EPS
transferring data may be directed towards gNodeB.

16. Non-Standalone option-3X

17. •3x has developed to overcome the issues of with Options 3 and 3a.
•In this case, the user plane paths are between the eNode B, gNode B
and S-GW.
•The eNode B remains the Master Node and able to control the selection
of the downlink data path from the S-GW, i.e., the eNode B can provide
the MME with the IP address of the gNode B for some EPS Bearers,
while it can provide the MME with its own IP address for other EPS
Bearers.
•If coverage from the gNode becomes weak then the gNode B can
dynamically forward data across the X2 interface towards the eNode B

18. Standalone
•Standalone the core is
5G.
•Master node will be of
gNB

19. 5G CORE NETWORK Architecture

20. 5G Network Functions
User Equipment (UE)Radio Access Network
 (UPF) User plane Function
 (DN) Data network
 (AUSF) Authentication Server Function
(AMF) Core Access and Mobility Management Function
(SMF) Session Management Function
(NSSF) Network Slice Selection Function
(NEF) Network Exposure Function
(NRF) NF Repository Function
(PCF) Policy Control function
(UDM) Unified Data Management
(AF) Application Function
S-GW and P-GW have been divided into session management function (SMF) and user plane
function (UPF)

21. Functions :
(AUSF) :Subscriber authentication, during registration or re-registration with 5G, is managed by
the Authentication Server Function.
(AMF) :NAS signaling termination and security, Access Authentication, Support of Network
Slicing. Support of intra-system and inter-system mobility, Mobility management control
(subscription and policies).
 (SMF) : UE IP address allocation and management; Session Management, Selection and control
of UP function, Control part of policy enforcement and QoS.
(UPF) :Anchor point for Intra-/Inter-RAT mobility, Packet routing & forwarding, External PDU
session point of interconnect to Data Network, DL packet buffering and DL data notification
triggering.

22. 5G-NR-RRC STATES
Radio Resource Control (RRC) states for NR
There are Three RRC states in NR
RRC IDLE
RRC CONNECTED
RRC INACTIVE
Note :UE in RRC IDLE cannot move to RRC INACTIVE

23. 5G-NR RRC
STATES

24. RRC IDLE
To complete cell selection and cell reselection ,the SI is necessary.
UE read SI from BCCH.
SI also provides the information related to complete the Random Access and RRC Connection Setup procedures.
The UE performing mobility triggered Registration Area updates to ensure that the UE is always reachable by the
AMF(knows where to forward the paging message).
UE monitors the PDCCH (DCI) Format 1 0 using the P-RNTI defined by the Discontinuous Reception (DRX) pattern.
5G-S-TMSI is used to address UE within Paging message.
5G-S-TMSI is allocated by AMF.
To improve security 5G doesn’t support IMSI based paging.
UE is unable to transfer application data while in RRC Idle.

25. RRC Connected
Transfer of both application data and signaling between the UE and network is done in connected
mode.
Application data transferred by using DRB and signaling can be transferred using SRB.
CRNTI is provided by Base station to address UE during RACH.
AMF maintains NG signaling connection with Base Station.
UPF maintains GTP-U tunnels with Base Station.
UE monitors Control Channels for Resource Allocations.
The UE reports Channel State information (CSI).It includes CQI,RI,PMI,LI,CRI (CSI-RS Resource Indicator)
and SSBRI (SS/PBCH Block Resource Indicator).

26. RRC INACTIVE
RRC context and CORE network connection is kept in both the UE and the gNB.
Transition to connected state for data transfer is fast.
RRC inactive make the device in sleep like an idle state, but the mobility is handled through cell
reselection without involvement of network.
Its acts like mix combo of IDLE and Connected state.

27. 5G-NR SRB (Signaling
Radio Bearers)
5G-NR SRB (Signaling Radio Bearers)
SRB (Signaling Radio Bearer)
For carrying signaling message the type of bearer that
required is known as SRB (Signaling Radio Bearer).
The SRBs are radio bearers that are used for the
transmission of RRC and NAS messages.
There are four different type of SRB in NR as
per TS38.331.

28. 5G-NR SRB (Signaling Radio Bearers)
SRB0: This SRB is for RRC messages using the Common Control Channel (CCCH) logical channel.
SRB1: This SRB is for RRC messages (which may include a piggybacked NAS message) as well as
for NAS messages prior to the establishment of SRB2, all using DCCH logical channel.
SRB2: This SRB is for NAS messages, all using DCCH logical channel. SRB2 has a lower priority
than SRB1 and is always configured by the network after security activation.
SRB3: This SRB is for specific RRC messages when UE is in EN-DC, all using DCCH logical channel.
SRB 3: SRB3 can be setup at the request of the SG Secondary Node.
SRB3 is used for signaling procedures which are time sensitive with respect to the gNode B,
e.g., mobility procedures.
SRB3 supports a limited number of signaling messages, i.e., RRC Reconfiguration, RRC
Reconfiguration Complete and Measurement Report messages.

29. NAS and RRC
Message
Mapping with
SRB

30. 5G-NR Radio Network Temporary Identifier (RNTI)
UE and Network Identifiers
NR UE uses temporary identifiers to communicate gNB.
RNTI is 16-bit identifier, and its value depends on type of RNTI.
Many RNTI of LTE and NR are same.
Below are the identifiers as per 38.321 for NR :

31. 5G-NR Radio Network Temporary Identifier (RNTI)
C-RNTI: Cell RNTI A unique UE identification used as an identifier of the RRC connection and for
scheduling purposes. The gNB assigns different C-RNTI values to different UEs. CRNTI is used by gNB to
differentiate uplink transmissions (e.g., PUSCH, PUCCH) of a UE from others.
SI-RNTI: System Information RNTI is used for broadcasting System information.SI-RNTI is of 16-bit
length. Broadcast of SI uses BCCH-DL-SCH-PDSCH.
P-RNTI: Paging RNTI is used by UE reception of paging. It is not allocated to any UE explicitly. It is of
16-bit in length. Paging message is carried by PCCH-PCH-PDSCH.
RA-RNTI: RA-RNTI is used for Random Access procedure .gNB’s MAC generates Random Access Response
(RAR) as a response to the Random-Access Preamble transmitted by the UE.RA-RNTI can be addressed to
multiple UEs, i.e., multiple UEs might decode PDCCH scrambled by the same.
TC-RNTI: This RNTI is also used in Random access procedure. gNB’s MAC generates Random Access
Response (RAR) as a response to the Random-Access Preamble transmitted by the UE. MAC RAR contains
Temporary C-RNTI. During contention based random access procedure, the UE stores received Temp C-
RNTI (received in RAR) and uses it during random access procedure. The UE shall discard the Temporary
C-RNTI value received in RAR during non-contention based random access procedure. The UE shall use
Temp C-RNTI for scrambling of msg3.
TPC RNTI : This TPC RNTI is knows as Transmit Power Control RNTI. This RNTI is basically used for
uplink power control purpose.

32. Radio network temporary identifiers (RNTIs) in NR and
their usage

33. 5G NR-(MIB/SIB)
System information
System Information (SI) is consisting of 2 parts-
MIB (Master Information Block)
SIBs (System Information Block)
In NR there are two version of SIBs .
One being transmitted periodically same as LTE
Other one is transmitted on demand, whenever UE requested.

34. 5G NR-(MIB/SIB)
MIB (Master Information Block)
MIB transmission will always be on BCH transport channel and PBCH physical channel.
Periodicity of MIB will be 80 ms.
MIB includes the parameters which are required to acquire SIB1 from cell.
The PBCH is transmitted as part of SS/PBCH Block.
The actual payload of the MIB occupies 23 bits but an additional 1 bit is required to indicate the
BCCH message type. Thus, the MIB requires a total of 24 bits.

35. MIB (Master Information Block) Content
System Frame Number: It provides the 6 Most Significant Bits (MSB) of the current System Frame
Number (SFN).
 Sub Carrier Spacing Common: defines the subcarrier spacing to be used for the reception of SIB I,
other broadcast System Information, paging messages and the MSG2 /MSG4 transmitted during initial
access.
ssb-Subcarrier Offset: defines the 4 Least Significant Bits of the subcarrier offset.
 DMRS-TypeA-Position: It specifies the first symbol used by the Demodulation Reference Signal (DMRS)
when using ‘Mapping Type A’. This information element is applicable to the DMRS for both the PDSCH and
PUSCH.
 Cell-Barred : A UE is not permitted to complete cell selection nor cell reselection onto a cell which is
barred so this column is to indicate about cell barred or not.
IntraFreqReselection : This is applicable when the current cell is lo be treated as barred. a value of
‘allowed’ indicates that the UE is permitted to reselect another cell on the same frequency.

36. Overall MIB / SIB transmission

37. System Information Block Type 1 (SIB1)
SIB1is transmitted on
the DL-SCH.
Periodicity of SIB1is 160
ms and
repetitive transmission
done during 160 ms.
Periodic broadcast basis
or only on-demand
basis of other SIBs is
indicated by SIB1.

38. SIB1 Contents
cellSelectionInfo :–It includes the q-RxLevMin, q-RxLevMinOffset, q-RxLevMinSUL, q-QualMin,
q-QualMinOffset.
 CellAccessRelatedInfo :- It includes cell access information for the serving cell .
plmn-IdentityListandcellReservedForOtherUse
In PLMN-IdentityInfo it will be having plmn-IdentityList,TAC,RAN-AreaCode(ranac), cellIdentity.
 ConnEstFailureControl :It is used to configure parameters for connection establishment failure control.
 SI-SchedulingInfo : Its is needed for acquisition of SI messages. It contains schedulingInfoList((maximum 32) , si-
WindowLength, si-RequestConfig, si-RequestConfigSUL, systemIn.formationAreaID.
 servingCellConfigCommon : ServingCellConfigCommon is used to configure cell specific parameters of a UE’s
serving cell in SIB1.

39. •ims-EmergencySupport:It indicates about the supportability of IMS
emergency bearer services.
• eCallOverIMS-Support : Indicates whether the cell supports
emergency call over IMS services.
•UE-TimersAndConstants: This contains timers' info in all UE states.
•uac-BarringInfo : cell barring based upon Unified Access Barring
(UAC).

40. SIB2 Contents
Cell re-selection information common for intra-frequency, inter-frequency and/ or
inter-RAT
SIB3 Contents
Intra frequency cell re-selection information e.g. PCI, q-Offset, q-RxLev, q-Qual,
Black cell list.
SIB4 Contents
Inter frequency cell re-selection information e.g. NR-ARFCN.
SIB5 Contents
Inter system cell re-selection toward LTE e.g. EARFCN.
SIB6 Contents
Earthquake and Tsunami Warning System primary notifications.
SIB7 Contents
Earthquake and Tsunami Warning System secondary notifications.
SIB8 Contents
Commercial Mobile Alert services (CMAS) notification.
SIB9 Contents
Timing information for UTC, GPS and local time.

41. 5G-NR RACH
(Random Access
Procedure)
RA Procedure is of two different types.
Contention based RA Procedure
Contention Free RA Procedure
Contention based RA Procedure
In CBRA, the UE randomly selects an RA preamble from a pool of
preambles shared with other UEs in the cell. If multiple UEs
select/transmit same preamble (Msg1), all those UEs decode same Msg2
content and transmit Msg3 on the same UL time/frequency resources. In
the next step (Msg4), the network resolves the contention.

42. Contention Free RA
Procedure
In CFRA, the UE uses a dedicated
preamble provided by the network
specifically to this UE via RRC signaling or
PDCCH order.
The RA procedure is initiated by:
 A PDCCH order from the gNB.
The UE’s MAC entity itself.
RRC

43. Event which
trigger in
Random
Access (RA)
procedure:
Initial access (CBRA).
RRC Connection Re-establishment procedure (CBRA).
SR failure (CBRA).
DL and UL data arrival during RRC_CONNECTED when UL
synchronization status is Out-of-Sync (CBRA or CFRA).
During Handover (CBRA or CFRA).
Transition from RRC_INACTIVE (CBRA)
Request for On-demand System Information (CBRA or
CFRA).
Beam failure recovery (CBRA or CFRA).