Applications & requirements Concepts Architecture …...SDN and NFV provide means to fulfill future...
Transcript of Applications & requirements Concepts Architecture …...SDN and NFV provide means to fulfill future...
5G
Applications & requirements
Concepts
Architecture and protocols
Cellular Communication Systems 2Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Applications and Requirements
Limits of 4G New Applications 5G Requirements
Cellular Communication Systems 3Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
5G – Extension of Current Limits
Dramatic change of mobile communication landscape Data-hungry applications requiring further increase of network capacity Internet of Things (IoT) results in a huge number of connected
devices New applications with extreme low latency and high reliability
requirements (M2M, V2X)
Limits of 4G to fulfill these requirements due to applied methods and system structure
Limits in network capacity due to access scheme and resource management
Latency limit > 20ms due to frame structure and network topology
Transmission techniques are further advancing Increased signal processing capabilities allow new approaches Modern components (amplifier, mixers, etc.) allow cost-efficient use also
on higher frequency bands, esp. > 10 GHz
Target: 5G mobile communication systems for 2020
Cellular Communication Systems 4Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
5G – Applications
Source: “NGNM 5G White paper,” NGNM Alliance, Feb. 2015
Cellular Communication Systems 5Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Key Capabilities
Key capabilities for different usage scenarios
Enhancement of key capabilities from IMT-Advanced to IMT-2020
Source: “IMT Vision – Framework and overall objectivesof the future development of IMT for 2020 and beyond,“ Recommendation ITU-R M.2083-0, Sep. 2015
Cellular Communication Systems 6Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
5G Requirements and Performance Targets
High Data Rates
10 – 100 x increaseeven for high mobility
High System Capacity
1000 x improvementin capacity per area
Massive DeviceConnectivity
100 x improvementeven in crowded areas
Reduced Latency
Latency < 1msend-to-end
Energy Saving &Cost Reduction
Network & terminalsincl. backhaul
Cellular Communication Systems 7Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Concepts
New Spectrum Duplex Scheme Physical Layer Flexibility Beam Forming Device-to-Device Communication Ultra-Lean Design Decoupling of User Data and System Control Information Integration and Internetworking with 4G Software-Defined Networking Network Virtualization Network Slicing
Cellular Communication Systems 8Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
New Spectrum
From sub-GHz to mm-Wave
Lower frequencies for full-area coverage
Complementary use of higher frequencies
⇒ Achieve extreme traffic capacity and data rates in dense scenarios
Cellular Communication Systems 9Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
OFDM as a Base for Physical Layer Flexibility
Modifying characteristicsby digital signal processing
Cellular Communication Systems 10Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Enhanced Multiple-Access Schemes
Application of non-orthogonal access schemes (NOMA) or sparce code multiple access (SCMA)
Usage of advanced interference cancellation techniques Exploitation of pathloss differences between the users Random access based data transmission
Source: Saito et al: Non-Orthogonal Multiple Access (NOMA) for Future Radio Access, VTC, 2013
5G
Cellular Communication Systems 11Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Duplex Arrangement
FDD dominating in lower (licensed) bands Coverage benefits Avoids some nasty interference
situations (BS ↔ BS, device ↔ device)
TDD more relevant for higher bands targeting very wide bandwidths in dense deployments Easier to find unpaired spectrum More dynamic traffic variations Access nodes and devices
becoming more similar
Cellular Communication Systems 12Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Beam-Forming
5G air-interface optimized for beam-formed operation Beam-centric design considerations:
Self-contained transmissions allowing for rapid beam re-direction “Beam mobility” – Mobility between beams rather than nodes System plane matched to beam-formed user plane
Cellular Communication Systems 13Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Device-to-Device Communication
D2D communication as well-integrated part of the overall wireless access solution Direct peer-to-peer D2D communication as an overall more efficient mode Direct D2D communication as a means to extend coverage (device-based
relaying) High-speed inter-device communication provides “joint” transmission
and/or reception between multiple devices (cooperative devices)
Cellular Communication Systems 14Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Ultra-Lean Design
Minimization of network transmissions not directly related to user-data delivery Resources are treated as
undefined unless explicitly indicated otherwise
Advantages Reduced interference Higher achievable data rates Enhanced network energy
performance Future-proof design
Cellular Communication Systems 15Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Decoupling of User Data and System Control Information
Scaling of user-plane capacity independently of system control resources Well-matched to beam-formed radio-interface design Well-aligned with ultra-lean design
Cellular Communication Systems 16Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Integration with 4G/LTE-A-Pro
Evolution of existing technology + New radio-access technology LTE will be integral part of the overall 5G radio solution Application of selected 5G technologies also to LTE-Advanced
Cellular Communication Systems 17Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Interworking of Technologies
5G shall tightly interwork with existing 4G networks Offers a smooth way for migration to 5G
Dual connectivity Initial deployment on higher
bands for extreme traffic capacity and data rates
LTE on lower bands for full coverage and robust mobility
Smooth introduction of 5Gin new spectrum
User plane aggregation Migration into legacy bands
while retaining full bandwidthavailability for new devices
Smooth migration of new RAT into legacy bands
Cellular Communication Systems 18Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
SDN & NFV as Enablers for 5G
Network Function Virtualization (NFV) is complementary to Software Defined Networking (SDN) SDN: Abstraction and programmability of virtualized transport NFV: Realization of network functions on commodity IT servers by means
of virtualization and cloud technologies
SDN and NFV provide means to fulfill future requirements of 5G architecture Open interfaces To help
integrate different componentsholistically
HW independency Possibledue to decoupling of SW and HW
Pre-standardization by ETSI NFV-ISG Source: “Network Functions Virtualisation –Introductory White Paper,” ETSI, 2012
Cellular Communication Systems 19Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Software Defined Networking (SDN)
Cellular Communication Systems 20Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Network Function Virtualisation (NFV)
Source: “Network Functions Virtualisation – Introductory White Paper,” ETSI, 2012
Cellular Communication Systems 21Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
SDN & NFV Properties
Benefits CAPEX reduction
Use of high volume industry standard hardware Open interface for holistic integration of components & applications Multi-vendor ecosystem for HW, platform and telco applications (avoiding vendor
lock-in) Multiplexing gain: Optimization of resource sharing between different services
OPEX reduction Quick & easy deployment of new services Dynamic and flexible resource allocation (scale-in/ scale-out) Energy-efficient operation (shut-down of unused resources)
Resiliency Fault tolerance - resource usage by different geographical areas Auto-healing
Challenges Significant overhead: processing power, signaling, etc. Increased complexity of operation Handling of latency for delay-critical items
Cellular Communication Systems 22Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Network Slicing
Slicing of a single physical network into multiple, virtual, end-to-end networks Logical isolation of devices, access, transport and core network for different
types of services with different characteristics and requirements Dedicated (virtual) resources for each slice isolated from other slices Single physical network to support a variety of devices
with different characteristics and needs, e.g. mobile broadband, massive IoT, mission-critical IoT, etc.
with different features wrt mobility, charging, security, policy control, latency, reliability, etc.
5G Use Case Example RequirementsMobile Broadband 4K/8K UHD, hologram,
AR/VRHigh capacity, video cache
Massive IoT Sensor network (metering, agriculture, building, logistics, city, home, etc.)
Massive connection (200,000/km2)mostly inmobile devices
Mission-critical IoT Motion control, autonomous driving, automated factory, smart-grid
Low latency (ITS 5ms, motion control 1 ms)high reliability
Cellular Communication Systems 23Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Network Slicing
Cellular Communication Systems 24Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Network Slicing, SDN and NFV
Cellular Communication Systems 25Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Mobile Network Architecture – Evolution Path
Cellular Communication Systems 26Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
5G Architecture and Protocols (Rel. 15)
Network Architecture Service Based Architecture Protocol Architecture and Protocols Mobility Management Quality of Service Ultra-Reliable Low Latency Communication (URLLC)
Cellular Communication Systems 27Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
5G Architecture: Next Generation-RAN and 5G Core
UPF User Plane FunctionAMF Access and Mobility Management FunctiongNB Node providing NR user plane and control plane protocol terminations towards the UE, and
connected via the NG interface to the 5GCng-eNB Node providing E-UTRA user plane and control plane protocol terminations towards the UE,
and connected via the NG interface to the 5GC
gNB
ng-eNB
NG
NG NG
Xn
NG-RAN
5GC
AMF/UPF
gNB
ng-eNB
NG
NG NG
Xn
AMF/UPF
Xn
Xn
NG NG
Source: TS 38.300: NR; NR and NR-RAN Overall description (Stage 2)
Cellular Communication Systems 28Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Functional Split between NG-RAN and 5GC
internet
gNB or ng-eNB
RB Control
Connection Mobility Cont.
MeasurementConfiguration & Provision
Dynamic Resource Allocation (Scheduler)
AMF
UPF
Inter Cell RRM
Radio Admission Control
NG-RAN 5GC
Mobility Anchoring
Idle State Mobility Handling
NAS Security
SMF
UE IP address allocation
PDU Session Control
PDU Handling
internet
eNB
RB Control
Connection Mobility Cont.
eNB MeasurementConfiguration & Provision
Dynamic Resource Allocation (Scheduler)
PDCP
PHY
MME
S-GW
S1MAC
Inter Cell RRM
Radio Admission Control
RLC
E-UTRAN EPC
RRC
Mobility Anchoring
EPS Bearer Control
Idle State Mobility Handling
NAS Security
P-GW
UE IP address allocation
Packet Filtering
LTE
5G
Source: TS 38.300: NR; NR and NR-RAN Overall description (Stage 2)
Cellular Communication Systems 29Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Functional Split between NG-RAN and 5GC
internet
gNB or ng-eNB
RB Control
Connection Mobility Cont.
MeasurementConfiguration & Provision
Dynamic Resource Allocation (Scheduler)
AMF
UPF
Inter Cell RRM
Radio Admission Control
NG-RAN 5GC
Mobility Anchoring
Idle State Mobility Handling
NAS Security
SMF
UE IP address allocation
PDU Session Control
PDU Handling
internet
eNB
RB Control
Connection Mobility Cont.
eNB MeasurementConfiguration & Provision
Dynamic Resource Allocation (Scheduler)
PDCP
PHY
MME
S-GW
S1MAC
Inter Cell RRM
Radio Admission Control
RLC
E-UTRAN EPC
RRC
Mobility Anchoring
EPS Bearer Control
Idle State Mobility Handling
NAS Security
P-GW
UE IP address allocation
Packet Filtering
LTE
5G
Source: TS 38.300: NR; NR and NR-RAN Overall description (Stage 2)
Cellular Communication Systems 30Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Control Plane: 3GPP services (AAA, Mobility, Call control, QoS, etc.)User Plane: data and additional (application-specific, network agnostic) service signaling
Source: E. Guttman: System and Core Network Aspects. Workshop on 3GPP Submission towards IMT-2020, Oct. 2018
Service Based Architecture – User Plane5G Architecture – Control-User Plane Split
Cellular Communication Systems 31Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Technologies: Orchestration and Virtualization: Decouple logical function from HW Slicing: Logical end-2-end networks tailored to customer needs Mobile Edge Computing (MEC): Resources where they are needed (URLLC) Service Based Architecture: stateless, open, flexible Access agnostic solutions
Service Based Architecture – User Plane5G Service Based Architecture
Control plane
User plane
Cellular Communication Systems 32Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
UPF (User Plane Function): packet routing & forwarding, packet inspection, QoS handling external PDU session point of interconnect to Data Network (DN) anchor point for intra- & inter-RAT mobility
Source: TS25.301: System Architecture for the 5G System (Stage 2)
Service Based Architecture – User PlaneService Based Architecture – User Plane
User plane
Cellular Communication Systems 33Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Protocol Architecture – User Plane
Source: TS 23.501: Systems Architecture for the 5G System (Stage 2)
5G-AN Protocol
Layers
L1
5G-ANProtocolLayers
L2
UDP/IP
GTP-U
PDU Layer
Application
Relay
L1
L2
UDP/IP
GTP-U
L1
L2
UDP/IP
GTP-U
PDU Layer
L1
L2
UDP/IP
GTP-U
Relay
UE 5G-AN UPF UPF(PDU Session Anchor)
N3 N9 N6
gNB
PHY
UE
PHY
MAC
RLC
MAC
PDCPPDCP
RLC
SDAPSDAP
Cellular Communication Systems 34Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Control Plane provides a set of Network Functions (NFs) with service-based interfaces which can be accessed by any other authorized NF
Service Based Architecture – Control Plane
Control plane
Cellular Communication Systems 35Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
AMF (Access and Mobility Management function ≈ MME): termination of NAS signaling (N1) NAS ciphering & integrity protection registration management connection management mobility management access authentication and authorization security context management
SMF (Session Management function): session management UE IP address allocation, DHCP
functions termination of NAS signaling
related to session management DL data notification traffic steering configuration for
UPF (N4)
AUSF (Authentication Server Function ≈ HSS/AuC)
Service Based Architecture – Control Plane
Cellular Communication Systems 36Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
[7]
PCF (Policy Control Function ≈ PCRF): policy framework, providing policy rules to C plane functions access subscription information for policy decisions in UDR (Unified Data
Repository)AF (Application Function ≈ AF in EPC): application influence on traffic routing accessing NEF (Network Exposure Function, i.e. signaling GW) interaction with policy framework for policy controlUDM (Unified Data Management ≈ HSS): generation of Authentication and Key Agreement (AKA) credentials user identification handling, access authorization & subscription management
Service Based Architecture – Control Plane
Cellular Communication Systems 37Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
[7]
New Functions:NSSF (Network Slice Selection Function): selecting of the Network Slice instances to serve the UE determining the allowed NSSAI (Network Slice Selection Assistance Information)
slice/service type (SST) slice differentiator (SD) to differentiate among slides of the same type
determining the AMF set to be used to serve the UENEF (Network Exposure Function): exposure of capabilities and events, secure provision of information from external
application to 3GPP network, translation of internal/external informationNRF (NF Repository Function): service discovery function, maintains NF profile and available NF instances
Service Based Architecture – Control Plane
Cellular Communication Systems 38Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Mobility Management, Connection Management and RRC States
MM states: deregistered registered
CN (Core Network) states: idle connected
RRC states: Idle: no context in gNB, cell reselection and TAI updates, TA paging Inactive (new): context in gNB, cell reselection and RAN updates, RAN paging Connected: context in gNB, handovers
For details on RRC Protocol, RRC states and transitions see TS 38.331 For comparison with LTE see Junseo Kim, Dongmyoung Kim, Sunghyun Choi: 3GPP SA2 architecture and
functions for 5G mobile communication system, ICT Express, Volume 3, Issue 1, March 2017, Pages 1-8
MM-DEREGISTERED CN-IDLE
RRC-IDLE
MM-REGISTERED CN-IDLE
RRC-IDLE
MM-REGISTERED CN-CONNECTED
RRC-CONNECTED
RRC-INACTIVE
CONNECTED
Cellular Communication Systems 39Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Mobility Management – Inter-gNB Handover Procedure
Source: TS 38.300, V 15.2.0: NR; NR and NR-RAN Overall description (Stage 2)
Target gNB
4. Handover Complete
Source gNB
AdmissionControl
2. Handover Acknowledgement3. Handover Command
UE
Switch to New Cell
1. Handover Request
1. Source gNB initiates handover and issues a Handover Request over the Xn interface2. Target gNB performs admission control and provides the RRC configuration as part of the Handover
Acknowledgement3. Source gNB provides the RRC configuration to the UE in the Handover Command (cell ID, information
required to access the target cell so that the UE can access the target cell without reading system information
4. UE moves the RRC connection to the target gNB and replies the Handover CompleteHandover mechanism triggered by RRC requires UE to reset the MAC entity and re-establish RLC and PDCP
Cellular Communication Systems 40Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Mobility Management in RRC Inactive State
RRC Inactive State: UE context stays in last serving gNB Transferred towards current gNB in case of transition to RRC connected state
Network-triggered Transition from RRC-Inactive to RRC-Connected
Last serving gNB gNB AMF
2. RAN Paging
UE
UE in RRC_INACTIVE / CM-CONNECTED
1. RAN Paging trigger
4. Resuming from RRC_INACTIVE
3. Paging the UE (Editor’s Note: details FFS)
Source: TS 38.300, V 15.2.0: NR; NR and NR-RAN Overall description (Stage 2)
Cellular Communication Systems 41Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Radio Access Protocols – User Plane
Segm.ARQ
Multiplexing UE1
Segm.ARQ...
HARQ
Multiplexing UEn
HARQ
Scheduling / Priority Handling
Logical Channels
Transport Channels
MAC
RLC Segm.ARQ
Segm.ARQ
PDCPROHC ROHC ROHC ROHC
Radio Bearers
Security Security Security Security
...
RLC Channels
SDAP QoS flowhandling
QoS Flows
QoS flowhandling
Multiplexing
...
HARQ
Scheduling
Transport Channels
MAC
RLC
PDCP
Segm.ARQ
Segm.ARQ
Logical Channels
RLC Channels
ROHC ROHC
Radio Bearers
Security Security
SDAP
QoS Flows
QoS flowhandling
Downlink Uplink
Source: TS 38.300: NR; NR and NR-RAN Overall description (Stage 2)
Cellular Communication Systems 42Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
PDCP, RLC, MAC (compared to LTE)
PDCP:• Simplified, streamlined• Always reordering, or out of
sequence delivery (if configured)• Packet duplication
MAC:• Optimized PDU structure• Flexible HARQ support• Logical channel prioritization rules
for numerology, cell, etc.• SR, BSR specific rules for URLLC• 2x semi-persistent scheduling• On-demand system information
RLC:• No concatenation• Pre-processing of PDUs before
grant is available• Always out of sequence delivery• Simplified segmentation
gNB
PHY
UE
PHY
MAC
RLC
MAC
PDCPPDCP
RLC
SDAPSDAP
Simplified protocols for faster processing and higher flexibility
SDAP:• Flexible mapping of QoS flows
to data radio bearers (DRBs) according to QoS requirements
Cellular Communication Systems 43Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Added SDAP sublayer to offers QoS flows to 5G Core Network
Service Data Adaptation Protocol (SDAP)
Sources: • TS 38.300: NR; NR and NR-RAN Overall description (Stage 2)• TS 37.324: E-UTRA and NR; Service Data Adaptation Protocol (SDAP) specification
PDU Session
SDAP sublayer
PDCP sublayer
SDAP - PDU
PDCP - SDU
SDAP-SAP SDAP-SAP
...
SDAP entity SDAP entity
Radio Bearers
PDCP entity
PDCP entity
PDCP entity
PDCP entity
...
PDCP-SAP PDCP-SAP
...
QoS Flows
PDU Session
...
QoS Flows
• Marking of QoS flow ID in both DL and UL• QoS Flow Index (QFI) for both UL and DL packets
• explicit configuration• reflective mapping
Flexible mapping of QoS flows to data radio bearers (DRBs)
⇒ Highly specific handling of packets in PDCP, RLC, MAC and PHY layers to adapt to specific service demands
Cellular Communication Systems 44Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Quality of Service
P-GWS-GW PeerEntity
UE eNB
EPS Bearer
Radio Bearer S1 Bearer
End-to-end Service
External Bearer
Radio S5/S8
Internet
S1
E-UTRAN EPC
Gi
E-RAB S5/S8 Bearer
LTE
NR UPFNBUE
PDU Session
Radio NG-U
NG-RAN 5GC
Radio Bearer NG-U TunnelQoS Flow
QoS Flow
Radio BearerQoS Flow
Source: http://std-share.itri.org.tw/Content/Files/Event/Files/4.%20From%20LTE%20to%205G%20NR_ASUSTeK_v4.2.ppt
EPS Bearer turns into QoS Flow flexible mapping of QoS flows
on underlying bearers by SDAP, e.g. radio bearers suited to specific service (low frequency band to URLLC, mmWave freq. to eMMB)
Cellular Communication Systems 45Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
URLLC: Higher Reliability requirements (1-10-6 to 1-10-9) Low latency (< 0.5ms in RRC connected state)
Control Plane implemented by Master Node (MgNB) User Plane: leveraging radio resources across MgNB and Secondary Node (SgNB)
PDCP
RLC
MAC
PHY
PDCP
MgNB SgNB
RLC
MAC
PHY
Packet Duplication
Single/Multi-shot transmission –repetition, Fast HARQ, Flexible
BLER, Different CQI to MCS table, LCP Restriction of numerology,
UL/DL Preemption
Larger SCS, low code rate, mini-slot, larger bandwidth, front
loaded DMRS
5G Solutions for URLLC
Ultra Reliable Low Latency Communications (URLLC)
Cellular Communication Systems 46Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Packet Duplication in PDCP to increase reliability of Signaling Radio Bearer (SRB) and Data Radio Bearer (DRB) for URLLC
Note that buffering and reordering in RLC does not make sense for duplicated packets!
Carrier Aggregation (same cell)
Dual Connectivity(different cells and possibly carriers)
URLLC – Packet Duplication
Source: http://std-share.itri.org.tw/Content/Files/Event/Files/4.%20From%20LTE%20to%205G%20NR_ASUSTeK_v4.2.ppt
Cell1 Cell1
PDCPData
Data Data
RLC RLC
MAC
Data Data
PDCPData
Data
RLC RLC
MAC
PDCPData
Data Data
RLC RLC
MAC
Data Data
PDCPData
Data
RLC RLC
MAC MAC MAC
Cell2
Cellular Communication Systems 47Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Logical channel prioritization: map logical channels to MAC PDUs for transmission
Logical channel 1:- Priority 1 (high)
Logical channel 2:- Priority 2 (low)
LC1 LC2
Grant
LC1 LC2
MAC PDU
LCP
URLLC – Logical Channel Prioritization (LCP) in LTE
Source: http://std-share.itri.org.tw/Content/Files/Event/Files/4.%20From%20LTE%20to%205G%20NR_ASUSTeK_v4.2.ppt
Cellular Communication Systems 48Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
For achieving URLLC service requirements with latency ≦ 0.5ms Multiple numerologies/TTI (Transmission Time Interval) durations used
Logical channel scheduling limitations Sub-Carrier Spacing (SCS) Time information
Logical channel 1:- Priority 1 (high)- SCS index 1 (time)
Logical channel 2:- Priority 2 (low)- SCS index 2 (bandwidth)
LC1 LC2
Grant on SCS 2
LC1 LC2
MAC PDU
LCP
URLLC – LCP Enhancement in NR
Source: http://std-share.itri.org.tw/Content/Files/Event/Files/4.%20From%20LTE%20to%205G%20NR_ASUSTeK_v4.2.ppt
Cellular Communication Systems 49Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
μ No. of slots per subframe
015 KhHz
1(1 slot x 1ms = 1ms)
130 KhHz
2(2 slots x 500 μs = 1ms)
260 KhHz
4(4 slots x 250 μs = 1ms)
3120 KhHz
8(8 slots x 125 μs = 1ms)
4240 KhHz
16(16 slots x 62.5 μs = 1ms)
5480 KhHz
32(32 slots x 31.25 μs = 1ms)
URLLC – NR Sub-Carrier Spacing (SCS) and Slot length
Source: http://www.sharetechnote.com/html/5G/5G_FrameStructure.html
Time vs. bandwidth
Cellular Communication Systems 50Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
5G radio frame: 10ms 1 Subframe: 1ms
NR provides slot based scheduling, each slot has 14 OFDM symbols Mini-slot scheduling with 2, 4 or 7 OFDM symbols (Shortening-TTI)
1ms Subframe
0.250ms Subframe (14 OS)
0.50ms Subframe (14 OS)
0.125ms Subframe (14 OS)
Mini-slot scheduling (2, 4 or 7 OFDM symbols)
URLLC – NR Frame Structure for Low Latency
Cellular Communication Systems 51Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Scheduling Request (SR) is for UE to autonomously request resources on data channel
Multiple SR configurations associated with different resource demands to achieve lower latency
SR configuration 1 SR1 SR1 SR1
SR configuration 2 SR2 SR2 SR2 SR2 SR2
UE BSSR
Uplink grant
BSR+data
UE BSSR1 / SR2
Uplink grant1/grant2
BSR+data1/data2
URLLC – Scheduling Request Enhancement
BSR: Buffer Status ReportSource: http://std-share.itri.org.tw/Content/Files/Event/Files/4.%20From%20LTE%20to%205G%20NR_ASUSTeK_v4.2.ppt
Cellular Communication Systems 52Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
Scheduling of Resources (MAC Layer)
Source: FANTASTIC-5G: Final results for the flexible 5G air interface multi-node/multi-antenna solution, Public Deliverable D4.2, April 2017
Factors influencing packet scheduling:- UE: QoS requirements, buffer states, HARQ mode, link state, UE capabilities- Cell configuration: carrier config., ICIC config., reserved channels capacity
Cellular Communication Systems 53Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
MR-DC is a generalization of the Intra-E-UTRA Dual Connectivity where a multiple Rx/Tx UE may be configured to utilize resources provided by two different nodes, one providing E-UTRA access and the other one providing NR access
One is Master Node and other is the Secondary Node MR-DC with the EPC MR-DC with the 5GC (not shown)
E-UTRA-NR Dual Connectivity NR-E-UTRA Dual Connectivity
en-gNB
eNB
S1-U
S1 S1
X2
E-UTRAN
EPC
MME/S-GW
en-gNB
eNB
S1-U
S1 S1X2
MME/S-GW
X2
X2-U
S1-U S1-U
Multi-RAT Dual Connectivity (MR-DC)
Source: 3GPP TS 38.300 V 15.2.0
Cellular Communication Systems 54Andreas Mitschele-Thiel, Jens Mueckenheim Nov. 2018
5G Literature
Books on 5G P. Marsch, Ö. Bulakci, O. Queseth, M. Boldi: “5G System Design – Architectural
and Functional Considerations and Long Term Research,”, Wiley, June 2018 E. Dahlman, S Parkvall, J. Skold: “5G NR: The Next Generation Wireless Access
Technology,“ Academic Press, August 2018 Afif Osseiran, Jose F. Monserrat, Patrick Marsch: “5G Mobile and Wireless
Communications Technology,” Cambridge University Press, June 2016
More information on 5G 3GPP 5G – Briefing for Evaluation Groups, Oct. 2018: http://www.3gpp.org/news-
events/3gpp-news/1987-imt2020_workshop RWS-180006: mIoT, URLLC RWS-180007: NR Phy, channels, etc RWS-180009: NR architecture, SA/NSA, CP-UP split, gNB vs. ng-eNB, deployment
options RWS-180010: Air IF protocol architecture, protocols, RRC states, procedures