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5G-NR

5G NR-(MIB/SIB)

5G NR-(MIB/SIB)System informationSystem 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 LTEOther one is transmitted on demand, whenever UE requested.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 BlockThe 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.MIB (Master Information Block)  ContentSystem 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-Subcanier 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. CellBarred : 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 cellbarred 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.Overall MIB / SIB transmissionMIB and SIB1 are called as ‘minimum SI’.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.SIB1 ContentscellSelectionInfo :–It includes the q-RxLevMin , q-RxLevMinOffset , q-RxLevMinSUL , q-QualMin , q-QualMinOffset. CellAccessRelatedInfo :- It includes cell access information for the serving cell .plmn-IdentityListandcellReservedForOtherUseIn 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.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 statesuac-BarringInfo : cell barring based upon Unified Access Barring (UAC).SIB2 ContentsCell re-selection information common for intra-frequency, inter-frequency and/ or inter-RATSIB3 ContentsIntra frequency cell re-selection information e.g. PCI, q-Offset, q-RxLev, q-Qual, Black cell list.SIB4 ContentsInter frequency cell re-selection information e.g. NR-ARFCN.SIB5 ContentsInter system cell re-selection toward LTE e.g. EARFCNSIB6 ContentsEarthquake and Tsunami Warning System primary notificationsSIB7 ContentsEarthquake and Tsunami Warning System secondary notificationsSIB8 ContentsCommercial Mobile Alert services (CMAS) notificationSIB9 ContentsTiming information for UTC, GPS and local timeReferences:3GPP TS 38.331 5G; NR; Radio Resource Control (RRC)

Admin

August 08, 2021

20 Min Read

5G-NR

5G-NR Radio Network Temporary Identifier (RNTI)

UE and Network IdentifiersNR 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 :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.This TPC-RNTI is assigned to a group of UEs.TPC-RNTI is divided into 3 types :TPC-PUCCH-RNTI :Transmit Power Control-PUCCH – RNTITPC-PUSCH-RNTI :Transmit Power Control-PUSCH – RNTITPC-SRS-RNTI : Transmit Power Control-Sounding Reference Symbols – RNTIMCS-C-RNTI : This MCS-C-RNTI is knows as Modulation and Coding Scheme Cell RNTI.CS-RNTI: This RNTI is know as Configured Scheduling RNTI.INT-RNTI: This RNTI is know as Interruption RNTI. This is an identification of preemption in downlink.SFI-RNTI: This RNTI is know as Slot Format Indication RNTI.SP-CSI- -RNTI: This RNTI is know as Semi-Persistent CSI RNTI reporting on PUSCH.Radio network temporary identifiers (RNTIs) in NR and their usage

Admin

August 08, 2021

20 Min Read

5G-NR

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.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.NAS and RRC Message Mapping with SRB

Admin

August 08, 2021

20 Min Read

5G-NR

5G-NR RRC STATES

Radio Resource Control (RRC) states for NRThere are Three RRC states in NRRRC IDLERRC CONNECTEDRRC INACTIVENote :UE in RRC IDLE cannot move to RRC INACTIVERRC IDLETo 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.RRC CONNECTEDTransfer 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).RRC INACTIVERRC 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.

Admin

August 08, 2021

20 Min Read

5G-NR

5G-NR Frame Structure

Numerology – Subcarrier SpacingAs we know in LTE we have only one type of subcarrier spacing i.e. 15Khz.NR support multiple type of subcarrier spacing.NR supports a flexible OFDM numerology with subcarrier spacings ranges from 15 kHz to 240 kHz with a proportional change in cyclic prefix duration.Supported Channel mapping with numerologyIt’s Not like that every numerology can be used for every physical channel.Numerologies has been specified as per certain type of physical channel.Numerology, Radio Frame Structure and Slot LengthSlot Length changes depending on numerology.Increase in subcarrier spacing will decrease slot length.Radio Frame Structuresubcarrier 15KHzsubcarrier 30KHzsubcarrier 60KHzsubcarrier 120KHzsubcarrier 240KHz

Admin

August 08, 2021

20 Min Read

5G-NR

5G Architecture

Non-standaloneE-UTRA-NR Dual Connectivity (EN-DC).UE is connected to NR and LTE simultaneously.One eNB can be connected to many gNB and vice versaNon-Standalone Base Station Architectures using the 4G Core Network (Options 3,3a and 3X)In both cases, the 4G Node B provides control plane connectivity towards the Core Networkand 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.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 is 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 BStandaloneStandalone the core is 5G.Master node will be of gNB5G CORE NETWORK Architecture5G 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 FunctionS-GW and P-GW have been divided into session management function (SMF) and user plane function (UPF)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.

Admin

August 08, 2021

20 Min Read

5G-NR

LTE Q & A (13/11/2020)

Until the UE is paged and bearers are setup which node is responsible to buffer the packets for the mean time in LTE?A. PGWB. PCRFC. SGWD. Visited PCRFWhere is PCEF situated?OCSUDRPDN GWDRAIn LTE Authentication process, Upto Authentication response which kind of security done?IntegrityCipheringTill Authentication response no security got setupIntegrity and CipheringIn RACH T300 timer start at which msgMSG 2MSG 3MSG 4MSG 5In authentication process, the master key ‘ K ‘ is stored inMME and UEUE and SIMSIM and HSSUE and HSS

Admin

August 08, 2021

20 Min Read

5G-NR

5G-NR Q&A (20/10/2020)

1. In 5G-NR Extended Cyclic Prefix (CP) is supported in which subcarrier spacing15 kHz60 kHz120 kHz240 kHzAns. 60 kHz2. In 5G-NR when we are using numerology-2 what would be the Slot length?0.25 ms0.5 ms0.125 ms1 msAns. 0.25 ms3.Which RS in not in 5G NRDMRSSRS & CRSSRSCRSAns. CRS4.What is CUPS in 5G?Controlling user plane separationControl and user plane separationControl and user plane SegmentationControlling user plane SegmentationAns . Control and user plane separation5. In 5G-NR SRB0 uses the channel?PBCHDCCHBCCHCCCHAns. CCCH

Admin

August 07, 2021

20 Min Read

5G-NR

Function Splits In ORAN/5G-NR:

Function Splits in ORAN/5G NR:Centralized baseband processing was introduced several years ago to ease installation of base stations in large buildings. Digital radio interfaces and remote radio heads (RRHs) both was enabled by it, which allowed the connection between RRHs and digital baseband units (BBUs) to be carried over fiber.The concept introduced to span larger areas involving many radio sites while still using a central BBU. With the increase in deployment fiber and availability of required fronthauls (FHs) became a major problem. In recent years, due to new 5G requirements, 3GPP and other standards bodies started different activities to address this issue.By distributing protocol stacks between different components (different splits between CU & DU ), solution providers focus on addressing the tight requirements for a near perfect fronthauls between RRHs and BBUs. This splitting is basically known as function split in 5G NR.Below figure represents functional split in 5G NR:Functional Splits:Option 1 (RRC/PCDP 1A-like split)Option 2 (PDCP/RLC Split 3C-like split)Option 3 (High RLC/Low RLC split, Intra RLC split)Option 4 (RLC-MAC split)Option 5 (Intra MAC split)Option 6 (MAC-PHY split)Option 7 (Intra PHY split)Option 8 (PHY-RF split)Option 1 (RRC/PDCP, 1A-like split):  RRC is in the central unit while PDCP, RLC, MAC, physical layer and RF are kept in the distributed unit. Thus the entire user plane is in the distributed unit.Option 2 (PDCP/RLC split): Option 2 may be a base for an X2-like design due to similarity on U-plane, but some functionality may be different e.g. C-plane since some new procedures may be needed. There are two possible variants available in this option.Option 2-1: Split U-plane only (3C like split): In this split option, RRC, PDCP are in the central unit. RLC, MAC, physical layer and RF are in the distributed unit.Option 2-2: In this split option, RRC, PDCP are in the central unit. RLC, MAC, physical layer and RF are in the distributed unit.  In addition, this option can be achieved by separating the RRC and PDCP for the CP stack and the PDCP for the UP stack into different central entities.Option 3 (High RLC/Low RLC Split): In this option, two approaches are taken based on Real time/Non-Real time functions split which are as follows:Option 3-1 Split based on ARQOption 3-2 Split based on TX RLC and RX RLCOption 3-1 Split based on ARQLow RLC may be composed of segmentation functions;High RLC may be composed of ARQ and other RLC functions;This option splits the RLC sublayer into High RLC and Low RLC sublayers such that for RLC Acknowledge Mode operation, all RLC functions may be performed at the High RLC sublayer residing in the central unit, while the segmentation may be performed at the Low RLC sublayer residing in the distributed unit. Option 3-2 Split based on TX RLC and RX RLCLow RLC may be composed of transmitting TM RLC entity, transmitting UM RLC entity, a transmitting side of AM and the routing function of a receiving side of AM, which are related to downlink transmission.High RLC may be composed of receiving TM RLC entity, receiving UM RLC entity and a receiving side of AM except for the routing function and reception of RLC status reports, which are related to uplink transmission.Option 4 (RLC-MAC split): In this split option, RRC, PDCP, and RLC are in the central unit. MAC, physical layer, and RF are in the distributed unit.Option 5 (Intra MAC split):Central Unit- Higher part of the MAC layer (High-MAC), RLC and PDCP.Distributed Unit – RF, physical layer and lower part of the MAC layer (Low-MAC).High-MAC sub layer : the centralized scheduling in the High-MAC sub layer will be in charge of the control of multiple Low-MAC sub layers. It takes high-level centralized scheduling decision. Low-MAC Sublayer the time-critical functions with stringent delay requirements (e.g. HARQ) or the functions where performance is proportional to latency (e.g. radio channel and signal measurements from PHY, random access control). It reduces the delay requirements on the fronthaul interface.Option 6 (MAC-PHY split): The MAC,RLC, PDCP & RRC are in the central unit (CU). PHY layer and RF are in the DU.Option 7 (Intra PHY split): We have 3 types of Sub splits in option 7 as given below:Option 7-1 UL: FFT, CP removal and possibly PRACH filtering functions reside in the DU, the rest of PHY functions reside in the CU.Option 7-1 DL : iFFT and CP addition functions reside in the DU, the rest of PHY functions reside in the CU.Option 7-2 UL: FFT, CP removal, resource de-mapping and possibly pre-filtering functions reside in the DU and rest of PHY functions reside in the CU.Option 7-2 DL:  iFFT, CP addition, resource mapping and precoding functions reside in the DU, the rest of PHY functions reside in the CU.Option 8 (PHY-RF split): This option allows to separate the RF and the PHY layer. Legacy C-RAN. Option 7.2 is called as ORAN split option. For more updates on types of splits and advantages stay tuned on ORAN page of site.

Admin

August 07, 2021

20 Min Read

5G-NR

5G-NR RACH (Random Access Procedure)

5G-NR RACH (Random Access Procedure)Random Access ProcedureRA Procedure is of two different types.Contention based RA ProcedureContention Free RA ProcedureContention based RA ProcedureIn 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.Contention based RA ProcedureContention Free RA ProcedureIn 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.RRCContention Free RA ProcedureEvent which trigger 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).Random Access Resource SelectionRandom Access Resource Selection is almost similar to LTE.Except below:beam failure recoveryOn-demand System Information (SI reiquets)other CFRA cases that we will discuss.RA resource selection for CBRA:The UE first needs to select an SSB before selecting RA preamble. The UE then selects an RA Preamble randomly with equal probability from the RA Preambles associated with the selected SSB and the selected RA Preambles group.RA resource selection for BFR:For BFR, CFRA is used if RRC provides BeamFailureRecoveryConfig , otherwise, CBRA is used.The IEofBeamFailureRecoveryConfig:candidateBeamRSList rsrp-ThresholdSSBRA resource selection for SI request (On-Demand SI)For UEs in RRC_IDLE and RRC_INACTIVE,Other SI  request is triggered for RA procedure. If UE is configured by network  with PRACH resources for SI request, CFRA is used, otherwise CBRA is used . The network may configure the UE with dedicated RACH resources for SI request purpose within SI-RequestConfig which is transmitted in SI-SchedulingInfo IE (in SIB1). In this case Msg1 is used to indicate the requested Other SI.When CBRA is used for SI request via Msg3, the gNB acknowledges the request in Msg4For reconfiguration with sync like Handover the RA configuration to be used is provided by the gNB within RACH-ConfigDedicated.        Random Access Preamble Transmission:This is almost same as LTE.RA_RNTI is used to address the UE on PDCCH which in turn used for decoding of PDSCH for Random Access Response (RAR).Random Access Response ReceptionOnce the RA preamble is transmitted, the UE waits for the acknowledgement from the gNB in the form of Random-Access Response (RAR).The UE monitors for RAR by attempting to detect a DCI format 1_0 with CRC scrambled by RA-RNTI/C-RNTI within a window configured by ra-ResponseWindow.For CFRA procedure, the UE after receiving RA response, considers the RA procedure as successfully completed.For CBRA procedure, the UE transmits Msg3 over PUSCH using UL grant received in MAC RAR and proceeds to the next step (Contention Resolution)Msg3 TransmissionFor CBRA procedure, the UE transmits Msg3 over PUSCH using UL grant received in the MAC RAR. The UE includes an identity in the Msg3 which is used later in the process of contention resolution.Contention ResolutionOnce Msg3 is transmitted, the UE starts or restarts (applicable for Msg3 retransmission) the timer ra-ContentionResolutionTimer and monitor for PDCCHCase1: UE already had a C-RNTICase2: UE didn’t have a C-RNTIn both Case1 and Case2 above, if the contention resolution is not successful, the UE discards Temporary-RNTI and goes back to “Random Access Resource selection procedure” and retry RA procedure.

Admin

August 07, 2021

20 Min Read

5G-NR

5G NR-(MIB/SIB)

5G NR-(MIB/SIB)System informationSystem 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 LTEOther one is transmitted on demand, whenever UE requested.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 BlockThe 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.MIB (Master Information Block)  ContentSystem 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-Subcanier 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. CellBarred : 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 cellbarred 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.Overall MIB / SIB transmissionMIB and SIB1 are called as ‘minimum SI’.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.SIB1 ContentscellSelectionInfo :–It includes the q-RxLevMin , q-RxLevMinOffset , q-RxLevMinSUL , q-QualMin , q-QualMinOffset. CellAccessRelatedInfo :- It includes cell access information for the serving cell .plmn-IdentityListandcellReservedForOtherUseIn 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.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 statesuac-BarringInfo : cell barring based upon Unified Access Barring (UAC).SIB2 ContentsCell re-selection information common for intra-frequency, inter-frequency and/ or inter-RATSIB3 ContentsIntra frequency cell re-selection information e.g. PCI, q-Offset, q-RxLev, q-Qual, Black cell list.SIB4 ContentsInter frequency cell re-selection information e.g. NR-ARFCN.SIB5 ContentsInter system cell re-selection toward LTE e.g. EARFCNSIB6 ContentsEarthquake and Tsunami Warning System primary notificationsSIB7 ContentsEarthquake and Tsunami Warning System secondary notificationsSIB8 ContentsCommercial Mobile Alert services (CMAS) notificationSIB9 ContentsTiming information for UTC, GPS and local timeReferences:3GPP TS 38.331 5G; NR; Radio Resource Control (RRC)

Admin

August 07, 2021

20 Min Read

5G-NR

RU/DU/CU Architecture

Radio Unit Interface & Architecture :5G NR radio unit shall be connected to DU through fronthaul RAN low layer split. The DU shall be connected to the CU which connects to the 5G enabled EPC to work along with LTE eNB in Non StandAlone (NSA) mode. At a later time, when the 5G core is ready, the CU will connect to the 5G core as well to support StandAlone (SA) mode Option 2.For the local display Status Indicator LED in the radio unit, it shall have at least the following status indicators:• One for fronthaul transport interface (optical fiber or wireless) indicating on/off status• One for power supply to show on/off status• One for radio transmission link on/off statusFigure below shows RU Interface & Architecture RequirementsRadio Unit HardwareThe radio unit shall be designed in a modular format that each module is connected through a standard interface such as PCIe. The RU is composed of RF front end, digital front end, Ethernet fronthaul transport, synchronization and lower PHY layer baseband processing. The RU functional module diagram is shown in Figure belowThe lower PHY layer processing shall be done by using FPGAs or ASICs. It includes functions of FFT/iFFT, CP addition, PRACH and digital beamforming.The RF front end is composed of antenna element arrays, bandpass filters, power amplifiers, low noise amplifiers, digital analog converters, and analog digital converters.The digital front end consists of digital up converter, digital down converter, digital pre-distortion and crest factor reduction.Distributed Unit:The Distributed Unit (DU) connects to multiple radio units in the southbound interface, and to the Centralized Unit (CU) in the northbound interface. The DU has a centralized, virtualized baseband pool that performs the functions of high PHY layer, MAC and RLC, synchronization, OAM, Ethernet, as well as F1 interface function. The DU function module diagram is shown in Figure below:Distributed Unit Capacity and Software Support:The distributed unit is the baseband processing unit that handles high physical layer, MAC and RLC layer with network function virtualization. The operating system for DU shall support RHEL CentOS 7.x, Ubuntu 16.xx or later release versions. RAN performance KPIs shall be guaranteed under the virtualization implementation. Features such as DPDK, SRIOV are required to enhance the performance. Given the maturity and security, virtualization shall be implemented in VM. Implementation in container will be considered in the future when it becomes mature.Centralized UnitThe Centralized Unit (CU) shall perform the layer three functions such as the functions of RRC, PDCP, SDAP, X2-U, F1-U, NG-U, S1-U, X2AP (X2-C), F1AP (F1-C), NGAP (NG-C), S1AP (S1-C) and OAM . Figure below is the diagram that shows the functions that the CU will perform:NG-U/C interface is used to connect with the 5G core network while the S1-U/C interface is used to connect to the 5G enabled EPC. The simultaneous connection with both core networks is required in order to support different UE capabilities. The initial implementation with connecting to EPC only for NSA architecture is accepted.Ref: Control, User and Synchronization Plane Specifiction, ORAN-WG4.CUS.0-v02.00, Management Plane Specification, ORAN-WG4.MP.0-v02.00.00

Admin

August 07, 2021

20 Min Read

5G-NR

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.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.NAS and RRC Message Mapping with SRB

Admin

August 07, 2021

20 Min Read

5G-NR

5G-NR Radio Network Temporary Identifier (RNTI)

UE and Network IdentifiersNR 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 :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.This TPC-RNTI is assigned to a group of UEs.TPC-RNTI is divided into 3 types :TPC-PUCCH-RNTI :Transmit Power Control-PUCCH – RNTITPC-PUSCH-RNTI :Transmit Power Control-PUSCH – RNTITPC-SRS-RNTI : Transmit Power Control-Sounding Reference Symbols – RNTIMCS-C-RNTI : This MCS-C-RNTI is knows as Modulation and Coding Scheme Cell RNTI.CS-RNTI: This RNTI is know as Configured Scheduling RNTI.INT-RNTI: This RNTI is know as Interruption RNTI. This is an identification of preemption in downlink.SFI-RNTI: This RNTI is know as Slot Format Indication RNTI.SP-CSI- -RNTI: This RNTI is know as Semi-Persistent CSI RNTI reporting on PUSCH.Radio network temporary identifiers (RNTIs) in NR and their usage

Admin

August 07, 2021

20 Min Read

5G-NR

Objective Of Virtualization In Telco Cloud

What is virtualization:Virtualization 1st apply to the given server, traditionally each server is loaded with single O.S & it host of given 1 set of Application presented below like Application & Operating system.Virtualization introduces as a abstraction layer between Operating system  & Hardware resources such as processor, storage and N/W. Separating the O/S from the server H/W means the multiple type of  an instances of the O.S  with associated diff Application many reside on a single server H/W Platform.The Virtualization is based on new Software Component called Hypervisor. The most common type of hypervisor used now a days is EXSI Vmware, KVM, hyperv by Microsoft & Zen by Citrix.Each Operating system with its set of application is seems as a single VM, The O.S within VM is named Guest O.S.Virtualization allows Multiple 0/S & App to share common resources (Storage, processor, N/W).Advantage: H/W Resources of the server are used more efficient when shared by multiple O/S, App & UsersWhy Virtualization?Before the use of virtualization in Telco for integrating each nodes, it takes much time.Now virtualization made it more efficient and seamless integration of services for faster deployment.Below figure shows approximate time taken for Integrating the nodes before and after Virtualization.Benefits of VirtualizationFast SW and RAN feature upgrade/deploymentSeamless integration of services and RAN for revenue opportunities and faster service deploymentAdapt to unexpected – elasticityMore efficient testing : Sharing a large pool of resources by multiple Application allows more capacity to play more optimal uses of hardware and to sharing workload provide ability to relocate the hardware.E2E Service management – orchestrationVirtualization enable this benefit, in practice they are fully achieved with cloud managementIndustrial Benefit

Admin

August 07, 2021

20 Min Read

5G-NR

Rakuten Mobile Launches 5G Service

Source : https://global.rakuten.com/corp/news/press/2020/0930_02.html?year=2020&month=9&category=mobile5G service launches today in a number of regionTokyo, September 30, 2020 – Rakuten Mobile, Inc. today announced the launch of its 5th generation mobile communications system (5G) service and a new and enhanced “Rakuten UN-LIMIT V*1” service plan which offers customers access to 5G services .From today, existing subscribers of the Rakuten UN-LIMIT 2.0 service plan will be able to use 5G services for no additional cost, in 5G service areas*2 with a 5G-compatible device.Mickey Mikitani, Chairman and CEO of Rakuten, Inc., and Representative Director, Chairman and CEO of Rakuten Mobile, Inc. commented, “Less than six months since full-scale commercial launch of the world’s first fully virtualized mobile network, today Rakuten Mobile takes another step forward to transform the mobile industry: We’re offering customers 4G and 5G combined in one simple plan – Rakuten UN-LIMIT V – at the same low price as 4G.Rakuten Mobile built the world’s first*3 end-to-end fully virtualized cloud-native mobile network and launched full-scale commercial carrier services on the network in April 2020. The network architecture allows for substantial reductions in capital investment and operating costs, enabling the operator to offer the Rakuten UN-LIMIT V service plan, which includes both 4th generation mobile communications system (4G) and 5G services, for the same monthly fee of 2,980 yen. By leveraging the synergies between 5G and various offerings from the broad portfolio of Rakuten Group businesses to develop engaging new content and services, Rakuten Mobile aims to provide customers with a next-generation mobile experience.Rakuten Mobile’s Fully Virtualized 5G Mobile NetworkRakuten Mobile’s 4G network is the world’s first fully virtualized cloud native mobile network*3. In its 5G network, excluding the core network, all 5G network functions, such as the virtualized OpenRAN, cloud and OSS, are run on the Rakuten Communications Platform (RCP), a telco platform that is based on containers for more flexible and stable development. Rakuten Mobile’s telecommunications platform utilizes equipment and software from trusted partners.Rakuten Mobile’s network offers Non-Stand Alone (NSA) 5G service from September 30, 2020. Stand Alone (SA)*9 5G service is planned for launch in the second quarter of 2021. 

Admin

August 07, 2021

20 Min Read

5G-NR

5G-NR RRC STATES

Radio Resource Control (RRC) states for NRThere are Three RRC states in NRRRC IDLERRC CONNECTEDRRC INACTIVENote :UE in RRC IDLE cannot move to RRC INACTIVERRC IDLETo 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.RRC CONNECTEDTransfer 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).RRC INACTIVERRC 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.

Admin

August 07, 2021

20 Min Read

5G-NR

5G-NR Frame Structure

Numerology – Subcarrier SpacingAs we know in LTE we have only one type of subcarrier spacing i.e. 15Khz.NR support multiple type of subcarrier spacing.NR supports a flexible OFDM numerology with subcarrier spacings ranges from 15 kHz to 240 kHz with a proportional change in cyclic prefix duration.Supported Channel mapping with numerologyIt’s Not like that every numerology can be used for every physical channel.Numerologies has been specified as per certain type of physical channel.Numerology, Radio Frame Structure and Slot LengthSlot Length changes depending on numerology.Increase in subcarrier spacing will decrease slot length.Radio Frame Structuresubcarrier 15KHzsubcarrier 30KHzsubcarrier 60KHzsubcarrier 120KHzsubcarrier 240KHz

Admin

August 07, 2021

20 Min Read

5G-NR

5G Architecture

Non-standaloneE-UTRA-NR Dual Connectivity (EN-DC).UE is connected to NR and LTE simultaneously.One eNB can be connected to many gNB and vice versaNon-Standalone Base Station Architectures using the 4G Core Network (Options 3,3a and 3X)In both cases, the 4G Node B provides control plane connectivity towards the Core Networkand 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.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 is 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 BStandaloneStandalone the core is 5G.Master node will be of gNB5G CORE NETWORK Architecture5G 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 FunctionS-GW and P-GW have been divided into session management function (SMF) and user plane function (UPF)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.

Admin

August 07, 2021

20 Min Read

5G-NR

5G Call Flow (ENB – GNB Dual Connectivity)

ENDC -Dual Connectivity (EN-DC) which enables 5G services and 4G network.UEs supporting EN-DC can connect simultaneously to LTE Master Node eNB and 5G-NR Secondary Node gNB.UE first register with 4G EPC through ENDC.Based on UE supportability it starts reporting measurement on 5G Frequencies and LTE nodeB communicate with g-NB For 5G resource assignment.The 5G-NR resource assignment is then signaled to the UE via an LTE RRC Connection Reconfiguration message.After RRC Connection Reconfiguration procedure completion, the UE simultaneously connects to the 4G and 5G networks.RRC Connection setup complete carries the NAS Attach Request.The DCNR bit in the “UE Network Capability” IE is set.This signals is confirmation to the 4G Core Network that the UE supports dual connectivity with LTE and 5G-NR.The NAS messages from the UE are signaled to the Core Network via the Initial UE message.MME initiates the authentication procedure.     Authentication is successfully completed.MME initiates NAS level security procedure.NAS level security procedure is completed.MME responds eNB withS1AP Initial Context Setup Request.NAS Attach Accept.Activate Default Bearer Request.UE capabilities are requested for 4G-LTE (utra), EN-DC (eutra-nr) and 5G (nr).EUTRA-NR specific capabilities are specified in the UE-MRDC-Capability container. The message also contains information about the supported 5G frequency bands.UE capabilities are transferred to the MME.security set between the eNB and the UE.Ciphering is enabled in both directions.RRC Connection reconfiguration is sent for activation of default radio bearer.It also contains attach accept message.It contains measurement objects for 5G-NR frequency.Initial Context Setup message contains the GTP TEID that used for sending downlink data to the eNBAttach Complete is sent by UE to MMEMME modifies the bearer and sends the TEID to use for downlink data.Respond back to MME.UE acquires the 5G-NR PSS and SSS.5G signal is then reported to LTE.The LTE eNB decides to add the 5G-NR as a secondary node.The gNB provide with information about the radio resources and bearers admitted with the 5G network.The NR RRC configuration message is included in the message.UE acquires the 5G-NR PSS & SSS.UE acquires the 5G-NR Broadcast Channel.The UE initiates the RACH procedure with the 5G gNB.NR PDCCH signals downlink resource allocation for the RA Response.The 5G secondary node gNB responds with an RAR.UE reports the Power Headroom (PHR) to eNB periodically.The PHR MAC CE contains the power headroom for the cells on the eNB and gNB cells.UE reports measurements  to e-NB include results from 5G NR cells.gNB reports the usage data for 5G NR bearers to the eNB.gNB also reports any overload information to the eNB.

Admin

August 07, 2021

20 Min Read

5G-NR

MIB (Master Information Block) And SIB (System Inf

MIB (Master Information Block)MIB – Master Information BlockPeriodicity – 40 ms at RRC (10 ms at Physical Layer)Location – 1st Subframe 2nd  Time Slot First 4rth  OFDM SymbolChannel – PBCHInformation Elements (I.E)- SFNNumber of Tx AntennaBandwidthPHICH infoPCID (Physical Cell ID)SIB (System Information Block)Types of SIB:SIB 1 : Cell Selection, Cell Access, SI Scheduling.SIB 2 : RACH, Access Barring, UL frequency Information, MBSFN Config.SIB 3 : Intra Frequency Cell Reselection.SIB 4 : Intra Frequency Neighbour Cell.SIB 5 : Inter Frequency Neighbour Cell.SIB 6 : UTRAN Neighbour Cell.SIB 7 : GERAN Neighbour Cell.Note : SIBs other than SIB1 are carried in SI messages and mapping of SIBs to SI is done by “schedulingInfoList” List include in SIB1.System Information Block Type1 (SIB 1)SIB1 : It contains information relevant when evaluating if a UE is allowed to access a cell and defines the scheduling of other system information.Its periodicity is of 80 ms and repetitions made within 80 ms.SIB1 related information:plmn-IdentityList : List of PLMN identities.sib-MappingInfo : List of the SIBs mapped to this SI message. There is no mapping information of SIB2, it is always present in the first SI message listed in schedulingInfoList list.si-Periodicity : Periodicity of the SI-message in radio frames.Si-WindowLength: Common SI scheduling window for all SI’s.trackingAreaCode : A trackingAreaCode that is common for all the PLMNs listedsystemInfoValueTag : indicates if a change has occurred in the SI messages.schedulingInfoList : The transmission cycles for other SIBs are determinedSystem Information Block Type2 (SIB 2)There is no mapping information of SIB2It is always present in the first System Information message listed in the schedulingInfoList list.

Admin

August 07, 2021

20 Min Read

5G-NR

5G-NR RRC STATES

Radio Resource Control (RRC) states for NRThere are Three RRC states in NRRRC IDLERRC CONNECTEDRRC INACTIVENote :UE in RRC IDLE cannot move to RRC INACTIVERRC IDLETo 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.RRC CONNECTEDTransfer 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).RRC INACTIVERRC 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.

Admin

August 07, 2021

20 Min Read

5G-NR

5G-NR Frame Structure

Numerology – Subcarrier SpacingAs we know in LTE we have only one type of subcarrier spacing i.e. 15Khz.NR support multiple type of subcarrier spacing.NR supports a flexible OFDM numerology with subcarrier spacings ranges from 15 kHz to 240 kHz with a proportional change in cyclic prefix duration.Supported Channel mapping with numerologyIt’s Not like that every numerology can be used for every physical channel.Numerologies has been specified as per certain type of physical channel.Numerology, Radio Frame Structure and Slot LengthSlot Length changes depending on numerology.Increase in subcarrier spacing will decrease slot length.Radio Frame Structuresubcarrier 15KHzsubcarrier 30KHzsubcarrier 60KHzsubcarrier 120KHzsubcarrier 240KHz

Admin

August 07, 2021

20 Min Read

5G-NR

5G Architecture

Non-standaloneE-UTRA-NR Dual Connectivity (EN-DC).UE is connected to NR and LTE simultaneously.One eNB can be connected to many gNB and vice versaNon-Standalone Base Station Architectures using the 4G Core Network (Options 3,3a and 3X)In both cases, the 4G Node B provides control plane connectivity towards the Core Networkand 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.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 is 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 BStandaloneStandalone the core is 5G.Master node will be of gNB5G CORE NETWORK Architecture5G 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 FunctionS-GW and P-GW have been divided into session management function (SMF) and user plane function (UPF)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.

Admin

August 07, 2021

20 Min Read

5G-NR

5G-NR

5G New Radio5G-NR is the Release 15/16 as per 3gpp. There are two release and Phases of 5G. Two releases are Rel 15 & 16 stated as phase 1 and phase two respectively.Topics5G Architecture5G-NR Frame structure5G-NR RRC STATES5G-NR SRB (Signaling Radio Bearers)5G-NR Radio Network Temporary Identifier (RNTI)SS Block in 5G-NR5G NR-(MIB/SIB)5G-NR RACH (Random Access Procedure)5G Call Flow (eNB – gNB dual connectivity)

Admin

August 07, 2021

20 Min Read