3GPP Release 18 Description and Summary of Work Items

The first official release of 3GPP TR 21.918: "Release 18 Description; Summary of Rel-18 Work Items" has been published. It's the first official version of 5G-Advanced. Quoting from the report: 

Release 18 specifies further improvements of the 5G-Avanced system. 

These improvements consist both in enhancements of concepts/Features introduced in the previous Releases and in the introduction of new topics.

Some of the key improvements are:

• a further integration of the Satellite (NTN) access (introduced in Rel-17) in the 5G System (5GS), 
• a more efficient support of Internet of Things (IoT), Machine-Type Communication (MTC), including by satellite coverage
• and also several aspects of proximity communication and location (Sidelink, Proximity, Location and Positioning, better support of the industrial needs (Verticals, Industries, Factories, Northbound API), Multicast and Broadcast Services (MBS), Network Slicing or Uncrewed Aerial Vehicles (UAV).

As for the new topics, some of the key aspects are:

• Energy Efficiency (EE)
• Artificial Intelligence (AI)/Machine Learning (ML)
• eXtended, Augmented and Virtual Reality (XR, AR, VR), immersive communications

The following list is from the v1.0.0 table of contents to make it easier to find the list of topics. If it interests you, download the latest version technical report from the directory here.

5 Satellite / Non-Terrestrial Network (NTN)

5.1 General aspects

5.1.1 User plane: “5G system with satellite backhaul”

5.1.2 Discontinuous coverage: “Satellite access Phase 2”

5.1.3 Radio: "NR NTN enhancements"

5.1.4 Charging and Management aspects of Satelite

5.2 Specific aspects

5.2.1 IoT (Internet of Things) NTN enhancements

5.2.2 Guidelines for Extra-territorial 5G Systems

5.2.3 5G system with satellite access to Support Control and/or Video Surveillance

5.2.4 Introduction of the satellite L-/S-band for NR

5.2.5 Other band-related aspects of satellite

6 Internet of Things (IoT), Machine-Type Communication (MTC)

6.1 Personal IoT and Residential networks

6.2 Enhanced support of Reduced Capability (RedCap) NR devices

6.3 NR RedCap UE with long eDRX for RRC_INACTIVE State

6.4 Application layer support for Personal IoT Network

6.5 5G Timing Resiliency System

6.6 Mobile Terminated-Small Data Transmission (MT-SDT) for NR

6.7 Adding new NR FDD bands for RedCap in Rel-18

6.8 Signal level Enhanced Network Selection

6.9 IoT NTN enhancements

7 Energy Efficiency (EE)

7.1 Enhancements of EE for 5G Phase 2

7.2 Network energy savings for NR

7.3 Smart Energy and Infrastructure

8 Uncrewed Aerial Vehicles (UAV), UAS, UAM

8.1 Architecture for UAV and UAM Phase 2

8.2 Architecture for UAS Applications, Phase 2

8.3 NR support for UAV

8.4 Enhanced LTE Support for UAV

9 Sidelink, Proximity, Location and Positioning

9.1 5GC LoCation Services - Phase 3

9.2 Expanded and improved NR positioning

9.3 NR sidelink evolution

9.4 NR sidelink relay enhancements

9.5 Proximity-based Services in 5GS Phase 2

9.6 Ranging-based Service and sidelink positioning

9.7 Mobile Terminated-Small Data Transmission (MT-SDT) for NR

9.8 5G-enabled fused location service capability exposure

10 Verticals, Industries, Factories, Northbound API

10.1 Low Power High Accuracy Positioning for industrial IoT scenarios

10.2 Application enablement aspects for subscriber-aware northbound API access

10.3 Smart Energy and Infrastructure

10.4 Generic group management, exposure and communication enhancements

10.5 Service Enabler Architecture Layer for Verticals Phase 3

10.6 SEAL data delivery enabler for vertical applications

10.7 Rel-18 Enhancements of 3GPP Northbound and Application Layer interfaces and APIs

10.8 Charging Aspects of B2B

10.9 NRF API enhancements to avoid signalling and storing of redundant data

10.10 GBA_U Based APIs

10.11 Other aspects

11 Artificial Intelligence (AI)/Machine Learning (ML)

11.1 AI/ML model transfer in 5GS

11.2 AI/ML for NG-RAN

11.3 AI/ML management & charging

11.4 NEF Charging enhancement to support AI/ML in 5GS

12 Multicast and Broadcast Services (MBS)

12.1 5G MBS Phase 2

12.2 Enhancements of NR MBS

12.3 UE pre-configuration for 5MBS

12.4 Other MBS aspects

13 Network Slicing

13.1 Network Slicing Phase 3

13.2 Enhancement of NSAC for maximum number of UEs with at least one PDU session/PDN connection

13.3 Enhancement of Network Slicing UICC application for network slice-specific authentication and authorization

13.4 Charging Aspects of Network Slicing Phase 2

13.5 Charging Aspects for NSSAA

13.6 Charging enhancement for Network Slice based wholesale in roaming

13.7 Network Slice Capability Exposure for Application Layer Enablement

13.8 Other slice aspects

14 eXtended, Augmented and Virtual Reality (XR, AR, VR), immersive

14.1 XR (eXtended Reality) enhancements for NR

14.2 Media Capabilities for Augmented Reality

14.3 Real-time Transport Protocol Configurations

14.4 Immersive Audio for Split Rendering Scenarios  (ISAR)

14.5 Immersive Real-time Communication for WebRTC

14.6 IMS-based AR Conversational Services

14.7 Split Rendering Media Service Enabler

14.8 Extended Reality and Media service (XRM)

14.9 Other XR/AR/VR items

15 Mission Critical and emergencies

15.1 Enhanced Mission Critical Push-to-talk architecture phase 4

15.2 Gateway UE function for Mission Critical Communication

15.3 Mission Critical Services over 5MBS

15.4 Mission Critical Services over 5GProSe

15.5 Mission Critical ad hoc group Communications

15.6 Other Mission Critical aspects

16 Transportations (Railways, V2X, aerial)

16.1 MBS support for V2X services

16.2 Air-to-ground network for NR

16.4 Interconnection and Migration Aspects for Railways

16.5 Application layer support for V2X services; Phase 3

16.6 Enhanced NR support for high speed train scenario in frequency range 2 (FR2)

17 User Plane traffic and services

17.1 Enhanced Multiparty RTT

17.2 5G-Advanced media profiles for messaging services

17.3 Charging Aspects of IMS Data Channel

17.4 Evolution of IMS Multimedia Telephony Service

17.5 Access Traffic Steering, Switch and Splitting support in the 5G system architecture; Phase 3

17.6 UPF enhancement for Exposure and SBA

17.7 Tactile and multi-modality communication services

17.8 UE Testing Phase 2

17.9 5G Media Streaming Protocols Phase 2

17.10 EVS Codec Extension for Immersive Voice and Audio Services

17.11 Other User Plane traffic and services items

18 Edge computing

18.1 Edge Computing Phase 2

18.2 Architecture for enabling Edge Applications Phase 2

18.3 Edge Application Standards in 3GPP and alignment with External Organizations

19 Non-Public Networks

19.1 Non-Public Networks Phase 2

19.2 5G Networks Providing Access to Localized Services

19.3 Non-Public Networks Phase 2

20 AM and UE Policy

20.1 5G AM Policy

20.2 Enhancement of 5G UE Policy

20.3 Dynamically Changing AM Policies in the 5GC Phase 2

20.4 Spending Limits for AM and UE Policies in the 5GC

20.5 Rel-18 Enhancements of UE Policy

21 Service-based items

21.1 Enhancements on Service-based support for SMS in 5GC

21.2 Service based management architecture

21.3 Automated certificate management in SBA

21.4 Security Aspects of the 5G Service Based Architecture Phase 2

21.5 Service Based Interface Protocol Improvements Release 18

22 Security-centric aspects

22.1 IETF DTLS protocol profile for AKMA and GBA

22.2 IETF OSCORE protocol profiles for GBA and AKMA

22.3 Home network triggered primary authentication

22.4 AKMA phase 2

22.5 5G Security Assurance Specification (SCAS) for the Policy Control Function (PCF)

22.6 Security aspects on User Consent for 3GPP services Phase 2

22.7 SCAS for split-gNB product classes

22.8 Security Assurance Specification for AKMA Anchor Function Function (AAnF)

22.9 Other security-centric items

23 NR-only items

23.1 Not band-centric

23.1.1 NR network-controlled repeaters

23.1.2 Enhancement of MIMO OTA requirement for NR UEs

23.1.3 NR MIMO evolution for downlink and uplink

23.1.4 Further NR mobility enhancements

23.1.5 In-Device Co-existence (IDC) enhancements for NR and MR-DC

23.1.6 Even Further RRM enhancement for NR and MR-DC

23.1.7 Dual Transmission Reception (TxRx) Multi-SIM for NR

23.1.8 NR support for dedicated spectrum less than 5MHz for FR1

23.1.9 Enhancement of NR Dynamic Spectrum Sharing (DSS)

23.1.10 Multi-carrier enhancements for NR

23.1.11 NR RF requirements enhancement for frequency range 2 (FR2), Phase 3

23.1.12 Requirement for NR frequency range 2 (FR2) multi-Rx chain DL reception

23.1.13 Support of intra-band non-collocated EN-DC/NR-CA deployment

23.1.14 Further enhancements on NR and MR-DC measurement gaps and measurements without gaps

23.1.15 Further RF requirements enhancement for NR and EN-DC in frequency range 1 (FR1)

23.1.16 Other non-band related items

23.2 Band-centric

23.2.1 Enhancements of NR shared spectrum bands

23.2.2 Addition of FDD NR bands using the uplink from n28 and the downlink of n75 and n76

23.2.3 Complete the specification support for BandWidth Part operation without restriction in NR

23.2.4 Other NR band related topics

24 LTE-only items

24.1 High Power UE (Power Class 2) for LTE FDD Band 14

24.2 Other LTE-only items

25 NR and LTE items

25.1 4Rx handheld UE for low NR bands (<1GHz) and/or 3Tx for NR inter-band UL Carrier Aggregation (CA) and EN-DC

25.2 Enhancement of UE TRP and TRS requirements and test methodologies for FR1 (NR SA and EN-DC)

25.3 Other items

26 Network automation

26.1 Enablers for Network Automation for 5G phase 3

26.2 Enhancement of Network Automation Enablers

27 Other aspects

27.1 Support for Wireless and Wireline Convergence Phase 2

27.2 Secondary DN Authentication and authorization in EPC IWK cases

27.3 Mobile IAB (Integrated Access and Backhaul) for NR

27.4 Further NR coverage enhancements

27.5 NR demodulation performance evolution

27.6 NR channel raster enhancement

27.7 BS/UE EMC enhancements for NR and LTE

27.8 Enhancement on NR QoE management and optimizations for diverse services

27.9 Additional NRM features phase 2

27.10 Further enhancement of data collection for SON (Self-Organising Networks)/MDT (Minimization of Drive Tests) in NR and EN-DC

27.11 Self-Configuration of RAN Network Entities

27.12 Enhancement of Shared Data ID and Handling

27.13 Message Service within the 5G system Phase 2

27.14 Security Assurance Specification (SCAS) Phase 2

27.15 Vehicle-Mounted Relays

27.16 SECAM and SCAS for 3GPP virtualized network products

27.17 SECAM and SCAS for 3GPP virtualized network products

27.18 MPS for Supplementary Services

27.19 Rel-18 enhancements of session management policy control

27.20 Seamless UE context recovery

27.21 Extensions to the TSC Framework to support DetNet

27.22 Multiple location report for MT-LR Immediate Location Request for regulatory services

27.23 Enhancement of Application Detection Event Exposure

27.24 General Support of IPv6 Prefix Delegation in 5GS

27.25 5G Timing Resiliency System

27.26 MPS when access to EPC/5GC is WLAN

27.27 Data Integrity in 5GS

27.28 Security Enhancement on RRCResumeRequest Message Protection

28 Administration, Operation, Maintenance and Charging-centric Features

28.1 Introduction

28.2 Intent driven Management Service for Mobile Network phase 2

28.3 Management of cloud-native Virtualized Network Functions

28.4 Management of Trace/MDT phase 2

28.5 Security Assurance Specification for Management Function (MnF)

28.6 5G performance measurements and KPIs phase 3

28.7 Access control for management service

28.8 Management Aspects related to NWDAF

28.9 Management Aspect of 5GLAN

28.10 Charging Aspects of TSN

28.11 CHF Distributed Availability

28.12 Management Data Analytics phase 2

28.12 5G System Enabler for Service Function Chaining

28.13 Other Management-centric items

29 Other Rel-18 Topics

If you find them useful then please get the latest document from here.

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• Free 6G Training: ATIS Webinar on 'Introduction to 3GPP Release 19 and 6G Planning'
• The 3G4G Blog: 3GPP TSG RAN and TSG SA Release-19 Workshop Summary
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• The 3G4G Blog: 3GPP Release 16 Description and Summary of Work Items
• The 3G4G Blog: ATIS Webinar on "3GPP Release 18 Overview: A World of 5G-Advanced"
• The 3G4G Blog: ATIS Webinar on '5G Standards Development Update in 3GPP Release 17 and 18'
• The 3G4G Blog: 3GPP Release-18 Work Moves Into Focus as Release-17 Reaches Maturity
• The 3G4G Blog: An Early View of 3GPP Release-18 5G-Advanced Topics 

Positioning in 5G networks

I have written about the 5G positioning techniques not that long back on this blog here and on connectivity technology blog here. With Release-16 now ready for deployment, Huawei has already announced world's first in 5G Indoor Positioning. Their announcement said:

China Mobile Suzhou and Huawei reached a new milestone with the verification of the 5G indoor positioning capability in metro transport scenarios in Suzhou — a major city located along the southeastern edge of Jiangsu Province in eastern China. The verification showed that, even with pRRUs being hidden, a positioning precision of 3 to 5 m can be achieved in 90% of the platform and hall areas. This is the first time that 5G indoor positioning has been verified on live networks in the world, providing valuable experience for the commercial growth of 5G positioning in vertical industries.

Indoor location-based services are in high demand of vertical applications, such as indoor navigation, asset tracking, geofencing, logistics management, and personnel management, which reflects the huge market space of indoor positioning. Currently, indoor positioning technologies are of great variety and most of them need to be deployed and maintained individually, resulting in high end-to-end costs. As a part of the continuous evolution of 5G, positioning has been added to 3GPP Release 16 finalized in mid 2020 to realize indoor positioning by leveraging the ultra-high signal resolution empowered by 5G's high bandwidth, multi-point measurements, and multi-access edge computing (MEC) deployment.

The verification was based on Huawei's 5G digital indoor solution LampSite and leading MEC solution. The LampSite units measure the radio signals of 5G devices and work with MEC to analyze the signal characteristics. Based on the results of the analysis, leading algorithms are used to precisely locate 5G devices.

We wrote about Huawei's Lampsite on Telecoms Infrastructure blog last year here.

A group of Ericsson engineers have written a research paper on 5G positioning recently. It's available on arXiv here. Here is the abstract:

In this paper we describe the recent 3GPP Release 16 specification for positioning in 5G networks. It specifies positioning signals, measurements, procedures, and architecture to meet requirements from a plethora of regulatory, commercial and industrial use cases. 5G thereby significantly extends positioning capabilities compared to what was possible with LTE. The indicative positioning performance is evaluated in agreed representative 3GPP simulation scenarios, showing a 90 percentile accuracy of a few meters down to a few decimeters depending on scenarios and assumptions.

Definitely worth a read if you like hardcore technical papers.

Related Posts:

• The 3G4G Blog: Positioning Techniques for 5G NR in 3GPP Release-16
• Connectivity Technology Blog: 5G Indoor Precise Positioning
• Telecoms Infrastructure Blog: Huawei 5G Lampsite wins awards and speed tests 

Positioning Techniques for 5G NR in 3GPP Release-16

I realised that I have not looked at Positioning techniques a lot in our blogs so this one should be a good summary of the latest positioning techniques in 5G.

Qualcomm has a nice short summary here: Release 16 supports multi-/single-cell and device-based positioning, defining a new positioning reference signal (PRS) used by various 5G positioning techniques such as roundtrip time (RTT), angle of arrival/departure (AoA/AoD), and time difference of arrival (TDOA). Roundtrip time (RTT) based positioning removes the requirement of tight network timing synchronization across nodes (as needed in legacy techniques such as TDOA) and offers additional flexibility in network deployment and maintenance. These techniques are designed to meet initial 5G requirements of 3 and 10 meters for indoor and outdoor use cases, respectively. In Release 17, precise indoor positioning functionality will bring sub-meter accuracy for industrial IoT use cases.

I wrote about the 5G Americas white paper titled, "The 5G Evolution: 3GPP Releases 16-17" highlighting new features in 5G that will define the next phase of 5G network deployments across the globe. The following is from that whitepaper:

Release-15 NR provides support for RAT-independent positioning techniques and Observed Time Difference Of Arrival (OTDOA) on LTE carriers. Release 16 extends NR to provide native positioning support by introducing RAT-dependent positioning schemes. These support regulatory and commercial use cases with more stringent requirements on latency and accuracy of positioning.25 NR enhanced capabilities provide valuable, enhanced location capabilities. Location accuracy and latency of positioning schemes improve by using wide signal bandwidth in FR1 and FR2. Furthermore, new schemes based on angular/spatial domain are developed to mitigate synchronization errors by exploiting massive antenna systems.

The positioning requirements for regulatory (e.g. E911) and commercial applications are described in 3GPP TR 38.855. For regulatory use cases, the following are the minimum performance requirements:

• Horizontal positioning accuracy better than 50 meters for 80% of the UEs.
• Vertical positioning accuracy better than 5 meters for 80% of the UEs.
• End-to-end latency less than 30 seconds.

For commercial use cases, for which the positioning requirements are more stringent, the following are the starting-point performance targets

• Horizontal positioning accuracy better than 3 meters (indoors) and 10 meters (outdoors) for 80% of the UEs.
• Vertical positioning accuracy better than 3 meters (indoors and outdoors) for 80% of the UEs.
• End-to-end latency less than 1 second.

Figure 3.11 above shows the RAT-dependent NR positioning schemes being considered for standardization in Release 16:

• Downlink time difference of arrival (DL-TDOA): A new reference signal known as the positioning reference signal (PRS) is introduced in Release 16 for the UE to perform downlink reference signal time difference (DL RSTD) measurements for each base station’s PRSs. These measurements are reported to the location server.
• Uplink time difference of arrival (UL-TDOA): The Release-16 sounding reference signal (SRS) is enhanced to allow each base station to measure the uplink relative time of arrival (UL-RTOA) and report the measurements to the location server.
• Downlink angle-of-departure (DL-AoD): The UE measures the downlink reference signal receive power (DL RSRP) per beam/gNB. Measurement reports are used to determine the AoD based on UE beam location for each gNB. The location server then uses the AoDs to estimate the UE position.
• Uplink angle-of-arrival (UL-AOA): The gNB measures the angle-of-arrival based on the beam the UE is located in. Measurement reports are sent to the location server.
• Multi-cell round trip time (RTT): The gNB and UE perform Rx-Tx time difference measurement for the signal of each cell. The measurement reports from the UE and gNBs are sent to the location server to determine the round trip time of each cell and derive the UE position.
• Enhanced cell ID (E-CID). This is based on RRM measurements (e.g. DL RSRP) of each gNB at the UE. The measurement reports are sent to the location server.

UE-based measurement reports for positioning:

• Downlink reference signal reference power (DL RSRP) per beam/gNB
• Downlink reference signal time difference (DL RSTD)
• UE RX-TX time difference

gNB-based measurement reports for positioning:

• Uplink angle-of-arrival (UL-AoA)
• Uplink reference-signal receive power (UL-RSRP)
• UL relative time of arrival (UL-RTOA)
• gNB RX-TX time difference

NR adopts a solution similar to that of LTE LPPa for Broadcast Assistance Data Delivery, which provides support for A-GNSS, RTK and OTDOA positioning methods. PPP-PTK positioning will extend LPP A-GNSS assistance data message based on compact “SSR messages” from QZSS interface specifications. UE-based RAT-dependent DL-only positioning techniques are supported, where the positioning estimation will be done at the UE-based on assistance data provided by the location server.

Rohde&Schwarz have a 5G overview presentation here. This picture from that presentation is a good summary of the 3GPP Release-16 5G NR positioning techniques. This nice short video on "Release 16 Location Based Services Requirements" complements it very well. 

Related Posts:

• Connectivity Technology Blog: 5G Indoor Precise Positioning
• The 3G4G Blog: R&S Webinar on LTE-A Pro and evolution to 5G

R&S Webinar on LTE-A Pro and evolution to 5G

Rohde & Schwarz recently uploaded a webinar video on their YouTube channel. I found it really useful. It's embedded below.

Topics covered:

• LTE-M / NB-IoT
• feMTC
• UE Category M2
• OTDOA based positioning
• UE Categories
• Unlicensed Spectrum Overview
• LTE in Unlicensed Spectrum
• LWA, LWIP
• LAA, eLAA
• Wi-Fi
• LBT
• LWA mobility
• Carrier Aggregation Enhancements
• Multi-user superposition transmission (MUST)
• Single cell - point to multipoint transmission (SC-PTM)
• SC-PTM Channel Structure
• SC-PTM Channel Flow
• Massive MIMO
• V2X Overview
• eNB scheduling - transmission mode 3
• Distributed scheduling - transmission mode 4
• Direct communication
• LTE Advanced Pro (Release 15)
• Further NB-IoT Enhancements
• Even further enhanced MTC - eMTC4 (Rel-15)

Related Posts:

• LTE-Advanced Pro (a.k.a. 4.5G)
• New LTE UE Categories (Downlink & Uplink) in Release-13
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