APT 600 MHz Band Gets Approval from 3GPP

The current 600 MHz 5G band (n71) is getting an extension as 3GPP approves plan for APT 600 MHz band. Back in April, the 29th meeting of the APT Wireless Group (AWG-29) organized by the Asia Pacific Telecommunity (APT) concluded with the final approval of the new APT 600 MHz band plan that hoped to open an additional 40+40 MHz prime UHF spectrum. A similar approach back in 2013 resulted in the 45+45 MHz in the 700 MHz band, known in 3GPP as n28.

3GPP TSG RAN 96 (all docs here) approved a new work item to standardize the APT 600 MHz band plan which was initially proposed by the ITU-APT Foundation of India (IAFI).

RP-221778 (revision of RP-221062), provides a detailed justification for this new band. Quoting from the document:

The 470-694 MHz frequency range is allocated to the broadcasting service and mobile service on a co-primary basis in ITU Region 3. The frequency band 470-698 MHz, or parts thereof, was identified by WRC-15 in 7 countries in Region 3 through new footnote No. 5.296A for use by those administrations as listed wishing to implement terrestrial IMT systems. In addition, there is interest from other significant markets to do the same. Elsewhere, USA, Mexico and several other countries in ITU Region 2 also identified this band for IMT through footnotes 5.295 and 5.308A. It is noted that resolves 2 of revised Resolution 224 (Rev.WRC-19) to encourage administrations to take into account results of the existing relevant ITU Radio communication Sector studies, when implementing IMT applications/systems in the frequency bands 694-862 MHz in Region 1, in the frequency band 470-806 MHz in Region 2, in the frequency band 790-862 MHz in Region 3, in the frequency band 470-698 MHz, or portions thereof, for those administrations mentioned in No. 5.296A, and in the frequency band 698 790 MHz, or portions thereof, for those administrations mentioned in No. 5.313A.

Spectrum below 1 GHz is expectedly well suited for mobile broadband applications.  In particular, the unique propagation characteristics of the bands below 1 GHz allow for wider area coverage, which in turn requires fewer infrastructures and facilitates service delivery to rural or sparsely populated areas. In this regard, the 700MHz ecosystem is growing swiftly: there are over 34 commercial networks deployments.  The APT700 band plan coming out from Region 3 played a huge role in its success globally. Outside of APAC, countries in Region 2 have adopted or plan to adopt the APT700 band plan (3GPP band 28) for LTE system deployments. The lower duplexer of APT700 plan has also been adopted for Region 1 since the conclusion of WRC-15.

As the utilisation of the 700MHz spectrum increases over time, it is desirable to look at additional spectrum that could be considered as a companion besides 3GPP Band 28. Therefore, the use of parts of the 600MHz band for the mobile broadband service would provide a vital means of delivering high quality, wide area broadband services including in rural areas and deep inside buildings. The timely availability of frequency arrangements is essential for the development of IMT specifications and standards and the early consideration by Administrations in the footnotes referred to above of suitable frequency arrangements. 

The APT region is very diverse and consists of highly developed and developing countries and some with extremely large and rural population base. The sub 1 GHz bands is well suited for the later.

During the last year or so, 3GPP RAN 4 has completed a study item on the feasibility of various duplex filter options for use in this band. The results of this study are documented in TR 38.860. This study was sent to the AWG in an LS RP-212629 in Sep 2021 with a request to provide guidance on a preferred band plan and information on regulatory aspects for the normative work to begin. The AWG 28 meeting has considered the request of the 3GPP and has provided a response to this LS. In this response the LS has indicated a preference for option B1 (full band) and has also requested for the work to begin immediately with a view to completion by Dec 2022. Additionally, the answers to the regulatory questions sought by the 3GPP have now been provided via a reply LS RP 221045.

The band plan for the option B1 that has a single duplexer or full band- is shown in Table 1 below.

The Tx-Rx is "reverse-duplex"; in other words, the downlink frequency band is below the duplex gap while the uplink frequency band is above the duplex gap. This arrangement is opposite to conventional notation; however, for this band, it provides the benefit of aligning the uplink band adjacent to 3GPP band 28 thereby minimizing interference conditions at the 703 MHz boundary.

Accordingly, the companies listed here request 3GPP to start normative work on the following option. 

• Option B1 with a single duplexer 

For anyone interested in studying this further might want to refer to 3GPP TR 38.860: Study on Extended 600 MHz NR band.

Related Posts: 

• The 3G4G Blog: LTE Band 13 mystery
• The 3G4G Blog - Radio Design Webinar: Optimising Your 700 MHz Deployments
• The 3G4G Blog: Minimum Bandwidth Requirement for 5G Non-Standalone (NSA) Deployment
• Operator Watch Blog: USA has an interesting mix of different types of 5G
• 3G4G: 50 Questions on Spectrum 

3GPP Explains TSG CT Work on UAS Connectivity, Identification and Tracking

Drones, technically Unmanned Aerial Vehicles/Systems or UAVs/UASs, have been a subject of interest for a very long time due to the wide variety of use cases they can offer. In the recent issue of 3GPP Highlights newsletter, Lena Chaponniere, 3GPP Working Group CT1 Vice-Chair has written an article about TSG CT work on UAS Connectivity, Identification and Tracking. Interestingly, the 3GPP abbreviation for UAS is slightly different, Uncrewed Aerial Systems.

Quoting from the newsletter: 

One of the defining drivers of 5G is the expansion beyond traditional mobile broadband to provide solutions meeting the needs of vertical industries.

A very good example of 3GPP rising up to this challenge is the work done in Release 17 to use cellular connectivity to support Uncrewed Aerial Systems (UAS), thereby enabling this vertical to benefit from the ubiquitous coverage, high reliability, QoS, robust security, and seamless mobility provided by the 3GPP system.

A key component of this work took place in CT Working Groups, which under the leadership of Sunghoon Kim (CT Work Item rapporteur) and Waqar Zia (rapporteur of new specifications TS 29.255 and TS 29.256) developed the necessary protocols and APIs to meet the service requirements specified in 3GPP SA1 and the architectural enhancements specified in 3GPP SA2, as part of the Release 17 Work Item on ‘ID_UAS’.

The key functions of the 3GPP architecture for ID_UAS are depicted in the following figure:

The work in CT Working Groups focused on specifying support for the following features:

UAV remote identification: The CAA (Civil Aviation Administration)-Level UAV ID was introduced in the 3GPP system. It is a globally unique, electronically and physically readable, and tamper resistant identification which allows the receiving entity to address the correct USS for retrieval of UAV information and can be assigned solely by the USS, via means outside the scope of 3GPP, or assigned by the USS with assistance from 3GPP system, whereby the USS delegates the role of “resolver” of the CAA-Level UAV ID to the UAS NF.

AV USS authentication and authorization (UUAA): The first step for the owner of the UAV is to register the UAV with the USS, via a procedure outside the scope of 3GPP, which can take place offline or using internet connectivity. During this procedure, the CAA-level UAV ID is configured in the UAV and the aviationlevel information (e.g. UAV serial number, pilot information, UAS operator, etc.) is provided to the USS.

The UE at the UAV then registers with the 3GPP system by using existing procedures for 3GPP primary authentication, with the MNO credentials stored in the USIM.

After successful authentication of the UE, the UUAA procedure is performed, to enable the 3GPP Core Network to verify that the UAV has successfully registered with the USS. In 5GS, this procedure can take place during the 3GPP registration, or during the establishment of a PDU session for UAS services.

For the former, CT1 extended the registration procedure in TS 24.501 to enable the UE to indicate its CAA-Level UAV ID into a new container (Service-level-AA container) included in the Registration Request message, which triggers the AMF to initiate UUAA with the USS by invoking the Nnef_Authentication service toward the UAS NF, as specified by CT4 in new specification TS 29.256, and the UAS NF to invoke the Naf_Authentication service toward the USS, as specified by CT3 in new specification TS 29.255.

For the latter, CT1 extended the PDU session establishment procedure in TS 24.501 to enable the UE to indicate its CAA-Level UAV ID via the Service-level-AA container included in the PDU Session Establishment Request message, which triggers the SMF to initiate UUAA with the USS via the UAS NF by invoking the services mentioned above. In order to enable exchanging the authentication messages between the UE and the USS, CT1 specified a new Session Management procedure in TS 24.501, in which the SMF sends a Service-level Authentication Command to the UE in a Downlink NAS Transport message. The UE replies to this command with a Service-level Authentication Complete carried in an Uplink NAS Transport message. In EPS, the UUAA procedure takes place during PDN connection establishment, and the information exchanged to that end between the UAV and the PGW is carried in the Service-level-AA container included in the ePCO

C2 communication over cellular connectivity: C2 communication over cellular connectivity consists of the UAV establishing a user plane connection to receive C2 messages from a UAVC, or to report telemetry data to a UAVC. Authorization for C2 communication by the USS is required and includes authorization for pairing of the UAV with a UAVC, as well as flight authorization for the UAV.

C2 communication authorization may be performed:

• during the UUAA procedure (if UUAA is carried out at PDU session/PDN connection establishment) when the UAV requests establishment of a PDU Session/PDN connection for both UAS services and C2 communication
• during PDU session modification/UE requested bearer resource modification when the UAV requests to use an existing PDU session/PDN connection for C2 communication
• during a new PDU session/PDN connection establishment, if the UAV requests to use a separate PDU Session/PDN connection for C2 communication

To support this, CT1 extended the PDU session establishment and modification procedures in TS 24.501 to enable inclusion of the CAA-level UAV ID and an application layer payload containing information for UAVC pairing and for UAV flight authorization in the Service-level-AA container carried in the PDU Session Establishment Request and PDU Session Modification Request messages. The ePCO Information Element in TS 24.008 was also extended to enable it to include the above-mentioned information.

UAV location reporting and tracking: UAV location reporting and tracking was specified by CT3 and CT4 by re-using the existing Nnef_EventExposure service specified in TS 29.522 with the UAS NF acting as NEF/SCEF and interacting with other network functions (e.g. GMLC and AMF/MME) to support UAV tracking. The following tracking modes were specified:

• UAV location reporting mode: the USS subscribes to the UAS NF UAV to be notified of the location of the UAV, and can indicate the required location accuracy and whether the request is for immediate reporting or deferred reporting (e.g. periodic reporting)
• UAV presence monitoring mode: the USS subscribes for the event report of UAV moving in or out of a given geographic area
• List of Aerial UEs in a geographic area: the USS requests the UAS NF for reporting a list of the UAVs in given geographic area and served by the PLMN.

The PDF of newsletter is available here.

Related Posts: 

• Connectivity Technology Blog: Ericsson Explains Internet of Drones and 3GPP UAV Roadmap
• The 3G4G Blog: ATIS Webinar on '5G Standards Development Update in 3GPP Release 17 and 18'
• The 3G4G Blog: 3GPP Release-17 5G NR Reaches Completion
• Connectivity Technology Blog: GSMA's DIG discusses how 5G Networks will handle UAV Layer
• Connectivity Technology Blog: Vodafone and Deutsche Telekom Briefly Starts Drone War
• The 3G4G Blog: 3GPP's 5G-Advanced Workshop Summary
• Connectivity Technology Blog: 5G Drone Cell Towers
• Connectivity Technology Blog: GSMA IoT WebTalk 'Clear Skies Ahead for Mobile-Enabled Drones'
• Connectivity Technology Blog: Cellular-connected Drones to Form Part of Vodafone’s ‘Telco as a Service’ (‘TaaS’) Model
• Telecoms Infrastructure Blog: Drones, More Drones & Droneway
• Telecoms Infrastructure Blog: Flying Small Cells are here... 

2G/3G Shutdown may Cost Lives as 4G/5G Voice Roaming is a Mess

You have probably heard me a complaining about the pace of VoLTE rollout, 2G/3G shutdowns, 4G Voice roaming, etc. This post highlights all these issues coming together in a dangerous way. People often ask me why is it that it's always just me highlighting the issues. The answer is that there are other people but their voice may not reach you. In this post, I am highlighting presentations by Rudolf van der Berg, Project and programme manager at Stratix Consulting.

No more voice roaming in USA! French operator Free warns customers that telephony in USA doesn't work. 2G/#3G shutdown and lack of #VoLTE standardisation and roaming are the cause. Its customers can only use Internet and SMS, but not E.164 number based voice telephony and 911! https://t.co/cbBrNZTskq

— Rudolf van der Berg (@internetthought) April 6, 2022

Let's start with Rudolf's post from LinkedIn:

Stop the shutdown of 2G and 3G networks to save lives. This is the urgent call I make today and I hope you can help me spread it! Please call on people you know in politics, regulators and emergency services to demand a stop! Call on anyone you know in the GSMA, 3GPP, handset makers (Apple, Samsung, Qualcomm, MediaTek), network builders (Ericsson, Nokia, Huawei) to re-engineer VoLTE to an interoperable standard.

Emergency calls (112, 911) should work anywhere in the world on any phone. For GSM and 3G voice calling it did. You could fly anywhere and call emergency services and in the EU we have the roaming regulation that demands calling like at home. Voice over 4G and 5G hasn't been properly standardized and isn't interoperable between networks, devices, chipsets and firmware. People need to be able to make and receive telephone calls around the world, to each other and to emergency services. Unfortunately even according to sector itself emergency services are at risk from VoLTE. A consumer today can't know whether a phone they bought will make VoLTE calls at home or abroad, nor whether it can reach emergency services. That can't be right!

So please help EENA 112 and me share this message! Thank you #eena2022 (Slide 4 contains a mistake, T-Mo USA hasn't decided on 2G shutdown yet. that is good for availability of 911, though fundamental point remains. Apologies.)

Dear foreigner, AT&T regrets you die because you can't dial 911. Try whatsapp and ask a friend in the US to call 911 for you. https://t.co/KqliBXv4ik

— Rudolf van der Berg (@internetthought) April 15, 2022

The video and slides are embedded below:

The slides contain many useful references and links, you can download directly from here.

Back in April, iBASIS hosted a VoLTE and 5G Roaming Roundtable. You can watch the video here and download the presentation and whitepaper as well. It contains talks from Kaleido Intelligence, iBASIS, KPN, Bouygues Telecom and Telus. 

The slide from Dutch MNO KPN above highlights the VoLTE Roaming issues they are observing. Other operators will face this issue sooner or later as well. 

So they are the ones who should be asked to make sure that VoLTE and VoNR is interoperable between vendors and MNOs? Because people will die if we don't fix this. See my presentation from last week https://t.co/Ju3GadO9ie

— Rudolf van der Berg (@internetthought) May 5, 2022

The Regulators, GSMA and 3GPP have to come together to fix this important issue for once and all so no lives are lost because of this. Hopefully someone is listening!

Related Posts: 

• The 3G4G Blog: Transitioning from eCall to NG-eCall and the Legacy Problem
• The 3G4G Blog: GSMA Releases Mobile Economy Report 2022
• The 3G4G Blog: When will 2G & 3G be switched off now that 5G is here?
• The 3G4G Blog: VoLTE Hacking
• The 3G4G Blog: A quick starter on 4G voice (for beginners) 

5G Reality Check - Data Rates

One of the common questions that we encounter is why are 5G speeds so low as we were promised 5G downlink speeds of 20 Gbps. Most people do not understand how the 5G speeds are calculated and what do they depend on. In many cases, the network won’t be capable of delivering higher speeds due to some or the other limitation. 

In a new presentation, I try to explain the theoretical speeds and compare them with real world 5G data rates and even try to map it to why these speeds are what they are. Hopefully people won't mind me adding some humour as I go along.

Video and Slides embedded below

Opinion – 5G Reality Check: Speeds from 3G4G

Embedded below is the Twitter thread on Speedtests 😂

Speed Tests are 5G killer app 😉, @HarriHolma provides details in replies: Elisa 100 MHz 5G (8T8R radio) on 3.5 GHz with LTE dual connectivity (EN-DC). LTE phone gives 200-250 Mbps in the same spot. The configuration uses L800+L1800+L2100 #5GKillerApp https://t.co/5ZnS2UeFkL

— 3G4G (@3g4gUK) November 18, 2019

Related Posts: 

• The 3G4G Blog: IMT-2020 (5G) Requirements
• The 3G4G Blog: Would 5G NSA undergo Sunset? When?
• The 3G4G Blog: The Politics of Standalone vs Non-Standalone 5G & 4G Speeds
• The 3G4G Blog: 5G SpeedTests and Theoretical Max Speeds Calculations
• The 3G4G Blog: Theoretical Throughput Calculation of FDD 5G New Radio (NR)
• The 3G4G Blog: The path from 4.5G to 5G
• The 3G4G Blog: Throughput Comparison for different wireless technologies
• Operator Watch Blog: EE Combines More 4G and 5G Spectrum for Even Higher Data Rates
• Operator Watch Blog: USA has an interesting mix of different types of 5G
• Operator Watch Blog: Is Saudi Arabia Winning the 5G Race?
• Operator Watch Blog: LG Uplus Tests 5G in 28GHz band using 800MHz Bandwidth. Sees AR as 5G Killer App 

ATIS Webinar on '5G Standards Development Update in 3GPP Release 17 and 18'

Our blog post on ATIS Release-16 webinar has been one of the popular posts so it's no brainer that people will surely find this Release 17/18 update useful as well. 

The moderator for this webinar was Iain Sharp, Principal Technologist at ATIS. The following were the speakers and the topics they spoke on:

• Services: Greg Schumacher, Global Standards, T-Mobile USA
• Systems Architecture and Core Networks: Puneet Jain, Principal Engineer and Director of Technical Standards at Intel Corporation, and 3GPP SA2 Chairman
• Radio Access Network: Wanshi Chen, Senior Director,Technology at Qualcomm, and 3GPP RAN Chairman

Here is a summary of the webinar:

In Release 17, 3GPP delivered important updates to 5G specifications to broaden their range of commercial applications and improve the efficiency of networks. 3GPP is now starting standardization of Release 18. This webinar provides an up-to-date view of the completed 3GPP Release 17 work with a particular focus on how the work is expanding capabilities of 5G and enhancing the technical performance of the mobile system.

The webinar will cover:

• The status of 3GPP's work and the organization's roadmap for the future
• The main themes the delivered Release 17 features in 3GPP specifications
• How enhancements to 5G are helping the 5G market proposition (e.g., through new service opportunities, or enhanced efficiency of 5G networks)

The webinar will give a technical overview of 3GPP's Release 17 content and its benefits to 5G networks. It is suitable for people in technical roles and technical executives who want to understand the current state of 5G standardization.

The video is embedded below and the slides are available here:

Glad to see that 3GPP Rel-19 work has already started as can be seen in the roadmap below.

(click to enlarge)

Related Posts: 

• The 3G4G Blog: 3GPP Release-17 5G NR Reaches Completion
• The 3G4G Blog: 3GPP Release-18 Work Moves Into Focus as Release-17 Reaches Maturity
• The 3G4G Blog: ATIS Webinar on '5G Standards Developments in 3GPP Release 16 and Beyond'
• Free 6G Training: Transatlantic perspectives on 6G Vision, Roadmap and Development Model 

3GPP Release-17 5G NR Reaches Completion

In the last week of March 2022, 3GPP Release 17 reached stage 3 functional freeze. Now the ASN work is ongoing and it will be frozen in June 2022. After that point, any changes will need to be submitted to 3GPP as CR (change request) and would have to be agreed by everyone (or unopposed).

Juan Montojo, Vice President, Technical Standards, Qualcomm Technoloigies, in his blog post reminds us:

Release 17 has been completed with its scope largely intact, despite the fact that the entire release was developed in the midst of a pandemic that hit the world, including 3GPP, right after the scope of the Release was approved in December 2019. 3GPP has been operating through electronic means from the latter part of January 2020 and has yet to get back to face-to-face meetings and interactions. The return to face-to-face meetings is not expected before June 2022. Release 17 completion not only marks the conclusion of the first phase of the 5G technology evolution, but it is a testament to the mobile ecosystem’s resiliency and commitment to drive 5G forward. I couldn’t be more proud of 3GPP, and our team, in particular, as Qualcomm Technologies led the efforts across a wide range of projects. Release 17 delivers another performance boost to the 5G system and continues expanding 5G into new devices, applications, and deployments.

The blog post briefly explains the 'New and enhanced 5G system capabilities' as well as features related to 'Expansion to new 5G devices and applications' as shown in the image on the top.

In addition, 3GPP Rel-17 has many other projects as can be seen in the image above. 3GPP TR 21.917: Release 17 Description; Summary of Rel-17 Work Items has a summary of all the items above but it is still undergoing revision.

Juan also did a webinar on this topic with Fierce Wireless, the video is embedded below:

The slides could be obtained from here.

Related Posts: 

• 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
• The 3G4G Blog: 5G-Advanced Flagship Features
• The 3G4G Blog: What Is the Role of AI and ML in the Open RAN and 5G Future?
• The 3G4G Blog: 5G-Advanced Flagship Features
• The 3G4G Blog: Extending 5G TDD Coverage With XDD (Cross Division Duplex)
• The 3G4G Blog: 3GPP 5G Non Terrestrial Networks (NTN) Standardization Update
• The 3G4G Blog: Introduction to 5G Reduced Capability (RedCap) Devices
• Free 6G Training: Qualcomm Pushing the boundaries of AI research
• Connectivity Technology Blog: 5G Indoor Precise Positioning 

What Is the Role of AI and ML in the Open RAN and 5G Future?

Artificial Intelligence and Machine Learning have moved on from just being buzzwords to bringing much needed optimization and intelligence in devices, networks and infrastructure; whether on site, on the edge or in the cloud.

New Study in 3GPP RAN3 on Artificial Intelligence and Machine Learning in NG-RAN - https://t.co/o4o4kq6Wpp via @3GPPLive #Free5Gtraining #3GPP #5G #ArtificialIntelligence #MachineLearning #AIML #RAN #Algorithms #SON #5GC #5GS pic.twitter.com/pvPlG9HpPC

— Free 5G Training (@5Gtraining) October 15, 2021

Qualcomm has been very active in talking about AI/ML in webinars and on their site. A detailed blog post looking at 'What’s the role of artificial intelligence in the future of 5G and beyond?' is available here. It was posted in time for a Light Reading webinar where Gabriel Brown, Principal Analyst – Mobile Networks and 5G, Heavy Reading and Tingfang Ji, Senior Director, Engineering - Wireless R&D, Qualcomm discuss the topic. The video is embedded below and slide deck is available here.

Standardizing AI/ML in cellular communication systems. From #Qualcomm presentation, The essential role of AI in the 5G future - How machine learning is accelerating wireless innovations in the new decade and beyond - https://t.co/fwxtoKIZKR#Free5Gtraining #3G4G5G #5G #AI #ML pic.twitter.com/YS5w8KXQuw

— Free 5G Training (@5Gtraining) September 27, 2021

Louis Scialabba, Senior Director of Marketing at Mavenir, looking at AI and Analytics spoke at Layer 123 conference on the topic, 'AI/ML for Next Gen 5G Mobile Networks'. His talk is embedded below and a blog post by him on the topic, 'The RIC Opens a New World of Opportunities for CSPs' is available here.

Related Posts: 

• Free 6G Training: Qualcomm Pushing the boundaries of AI research
• The 3G4G Blog: 3GPP Release-18 Work Moves Into Focus as Release-17 Reaches Maturity
• The 3G4G Blog: 5G-Advanced Flagship Features
• Connectivity Technology Blog: 5G Indoor Precise Positioning
• The 3G4G Blog: ITU Standardization Bureau on Machine Learning for 5G
• The 3G4G Blog: AI your Slice to 5G Perfection
• The 3G4G Blog: Qualcomm Explains 5G Millimeter Wave (mmWave) Future & Integrated Access and Backhaul (IAB)
• The 3G4G Blog: Qualcomm Demoes Sub-band Half Duplex (SBHD)
• Connectivity Technology Blog: Super Uplink to improve 5G Coverage and Speeds
• Free 6G Training: One XR Device to Rule Them All! 

Extending 5G TDD Coverage With XDD (Cross Division Duplex)

A new 3GPP Technical report, TR 38.858 (draft not available yet) will look at Study on evolution of NR duplex operation (FS_NR_duplex_evo) in Rel-18. RP-213591 provides a justification on why this new duplex evolution needs to be studied:

TDD is widely used in commercial NR deployments. In TDD, the time domain resource is split between downlink and uplink. Allocation of a limited time duration for the uplink in TDD would result in reduced coverage, increased latency and reduced capacity. As a possible enhancement on this limitation of the conventional TDD operation, it would be worth studying the feasibility of allowing the simultaneous existence of downlink and uplink, a.k.a. full duplex, or more specifically, subband non-overlapping full duplex at the gNB side within a conventional TDD band.

The NR TDD specifications allow the dynamic/flexible allocation of downlink and uplink in time and CLI handling and RIM for NR were introduced in Rel-16. Nevertheless, further study may be required for CLI handling between the gNBs of the same or different operators to enable the dynamic/flexible TDD in commercial networks. The inter-gNB CLI may be due to either adjacent-channel CLI or co-channel-CLI, or both, depending on the deployment scenario. One of the problems not addressed in the previous releases is gNB-to-gNB CLI.

This study aims to identify the feasibility and solutions of duplex evolution in the areas outlined above to provide enhanced UL coverage, reduced latency, improved system capacity, and improved configuration flexibility for NR TDD operations in unpaired spectrum. In addition, the regulatory aspects need to be examined for deploying identified duplex enhancements in TDD unpaired spectrum considering potential constraints.

Samsung has a technical white paper on this topic which they refer to as XDD (Cross Division Duplex), available here. The abstract says:

XDD (Cross Division Duplex) is one of the key technologies that Samsung is proposing as part of Rel-18 NR (5G-Advanced) to address the coverage issue observed during the initial phase of 5G deployment. XDD provides improved coverage, capacity, and latency compared to conventional TDD. Instead of relying solely on orthogonal time resources for DL-UL separation as in TDD, XDD allows simultaneous DL-UL operation by using non-overlapping frequency resources within a carrier bandwidth.

This white paper provides a high level description of XDD concept, benefits, and implementation challenges. First, an overview of XDD including a comparison with conventional TDD and FDD is provided. Next, the implementation challenges of XDD especially at the base station to handle self-interference mitigation is provided. Furthermore, several features that we consider critical in realizing XDD in actual deployment scenarios are provided along with some performance results. Finally, Samsung’s view on XDD for the next phase of 5G (5G-Advanced) is provided.

An open access IEEE Access paper, 'Extending 5G TDD Coverage With XDD', written by Samsung researchers provides a much more detailed insight into this topic. The abstract says:

In this paper, an advanced duplex scheme called cross-division duplex (XDD) is proposed to enhance uplink (UL) coverage in time division duplex (TDD) carriers by utilizing self-interference cancellation (SIC) capability at a base station. With XDD, it is possible to combine TDD’s ability to efficiently handle asymmetric UL and downlink (DL) traffic with frequency division duplex’s coverage advantage. To do so, XDD simultaneously operates UL and DL on the same TDD carrier but on different frequency resources. Such operation leads to severe interference on the received UL signal at the base station which requires two levels of SIC implementation; antenna and digital SIC. More than 50 dB of interference is removed through the antenna SIC using electromagnetic barriers between the transmitting and receiving antennas. The remaining interference is removed by the digital SIC based on estimating the non-linear channel of the circuit at the receiver baseband. It is verified by simulation and analysis that with the proposed XDD, the UL coverage can be improved by up to 2.37 times that of TDD. To check the feasibility of XDD, a Proof-of-Concept was developed where it was observed that the benefits of XDD can indeed be realized using the proposed SIC techniques

In the segment of the video embedded below, Dr. Hyoung Ju Ji, Principal Engineer, Samsung Electronics, Korea explains how XDD is a Realistic Option for Full Duplex Realization.

Related Posts:

• 3G4G - 5G Technology: Full Duplex Explained
• The 3G4G Blog: Qualcomm Demoes Sub-band Half Duplex (SBHD)
• Telecoms Infrastructure Blog: Will Distributed FD-MIMO be next big MIMO Enhancement?
• Free 6G Training: The Potential of Full Duplex in Beyond 5G and 6G
• Free 6G Training: Samsung talks about 6G Progress and Demos 

3GPP Release-18 Work Moves Into Focus as Release-17 Reaches Maturity

In early December 2021, 3GPP reached a consensus on the scope of 5G NR Release-18. With the 3GPP Rel-17 functional freeze set for March 2022, Release-18 work is moving into focus. This is being billed as a significant milestone marking the beginning of 5G Advanced — the second wave of wireless innovations that will fulfil the 5G vision. Release 18 is expected to build on the solid foundation set by 3GPP Releases 15, 16, and 17, and it sets the longer-term evolution direction of 5G and beyond.

(click on the image to enlarge - PDF here)

The 3GPP Release-18 page has a concise summary of all that you need to know, including the timeline. For anyone interested in going through features one-by-one, start navigating from here, select Rel-18 from the top.

New white paper from Nokia, "5G-Advanced: Expanding 5G for the connected world" - https://t.co/7HADpzHhAS #Free5Gtraining #3G4G5G #3GPP #Release18 #5G #5GAdvanced #5GTechnology #5GNetworks #5Gexperience #5Gextension #5Gexpansion #OperationalExcellence #XR #WWC #NetworkSlicing pic.twitter.com/6CYyKPp1Ff

— Free 5G Training (@5Gtraining) January 21, 2022

For others who may be more interested in summary rather than a lot of details, here are some good links to navigate:

• Nokia whitepaper - 5G-Advanced: Expanding 5G for the connected world (link)
• Paper by Ericsson researcher, Xingqin Lin, 'An Overview of 5G Advanced Evolution in 3GPP Release 18' (link)
• Marcin Dryjański, Rimedo Labs - 3GPP Rel-18: 5G-Advanced RAN Features (link)
• Bevin Fletcher, FierceWireless: Next 3GPP standard tees up 5G Advanced (link)

As always, Qualcomm has a fantastic summary of 5G evolution and features in 3GPP Release-18 on their page here. The image above nicely shows the evolution of 5G from Release-15 all the way to Release-18. The image below shows a summary of 3GPP Release-18, 5G-Advanced features.

They also hosted a webinar with RCR wireless. The webinar is embedded below.

The slides can be downloaded from GSA website (account required, free to register) here.

Related Posts: 

• The 3G4G Blog: Will Wi-Fi Help 3GPP Bring Reliable Connectivity Indoors?
• The 3G4G Blog: 3GPP Presentations from CEATEC Japan 2021
• The 3G4G Blog: 5G-Advanced Flagship Features
• The 3G4G Blog: An Early View of 3GPP Release-18 5G-Advanced Topics
• The 3G4G Blog: 3GPP's 5G-Advanced Workshop Summary
• The 3G4G Blog: 3GPP's 5G-Advanced Technology Evolution from a Network Perspective Whitepaper
• The 3G4G Blog: '5G RAN Release 18 for Industry Verticals' Webinar Highlights
• The 3G4G Blog: 3GPP RAN Plenary Update and Evolution towards 5G-Advanced
• The 3G4G Blog: Initiative to Remove Non-inclusive terms from 3GPP Specifications
• The 3G4G Blog: 3GPP Release 16 Description and Summary of Work Items
• The 3G4G Blog: 3GPP Standards on Edge Computing
• The 3G4G Blog: Artificial Intelligence (AI) / Machine Learning (ML) in 5G Challenge by ITU
• The 3G4G Blog: ITU Standardization Bureau on Machine Learning for 5G
• The 3G4G Blog: Introduction to 5G Reduced Capability (RedCap) Devices
• The 3G4G Blog: 5G eXtended Reality (5G-XR) in 5G System (5GS)
• The 3G4G Blog: Energy Consumption in Mobile Networks and RAN Power Saving Schemes 

3GPP 5G Non Terrestrial Networks (NTN) Standardization Update

We have looked at 5G Non Terrestrial Networks (NTN) in many different posts in our blogs. If you are new to this topic then this tutorial with a video is a good place to start or just follow this IEEE Comsoc article or this short update from R&S here.

Nicolas Chuberre is the rapporteur of the NR_NTN_solutions work item (TSG RAN) and of the FS-5GET study item (WG SA1) from Thales Alenia Space. In the October 2021 issue of 3GPP Highlights newsletter, he along with Munira Jaffar, Lead delegate representing EchoStar and Hughes Standards in ESOA (EMEA Satellite Operators Association) Standards Working Group, wrote a summary of 'Status of NTN & Satellite in 3GPP Releases 17 & 18'.

Quoting from the article:

The approval of normative activities on Non-Terrestrial Networks (NTN) in Rel-17 has generated growing interest in the topic. The Rel-17 NTN work items are supported by a wide range of vendors (terminal, chipset, network), as well as service providers from both the mobile and space industries and vertical user groups including ESOA.

The Rel-17 NTN and satellite work items in Technical Specification Group (TSG) RAN and TSG SA have been progressing towards the goal of satellite inclusion in 3GPP technical specifications. The focus is on transparent payload architecture with FDD systems where all UEs are assumed to have GNSS capabilities. The normative phase includes adaptation to the physical & access layer aspects, radio access network and system architecture, radio resource management, and RF requirements for targeted satellite networks operating at LEO, MEO or GEO orbits.

With an expected completion date of March 2022, the 3GPP Rel-17 specifications will support New Radio (NR) based satellite access deployed in FR1 bands serving handheld devices for global service continuity. Equally exciting, the 3GPP Rel-17 specification will support NB-IoT and eMTC based satellite access to address massive Internet of Things (IoT) use cases in areas such as agriculture, transport, logistics and many more. 

This joint effort between mobile and satellite industries will enable the full integration of satellite in the 3GPP ecosystem and define a global standard for future satellite networks. This will address the challenges of reachability and service continuity in unserved/underserved areas, enhance reliability through connectivity between various access technologies, and improve network resilience and dependability in responding to natural and manmade disasters.

Upon completion of Rel-17 the long-awaited standard for satellite networks serving handheld devices should be in place by 2022, with commercial product availability expected sometime in 2024. Including satellite as part of the 3GPP specifications will support the promise of worldwide access to 5G services and drive explosive growth in the satellite industry. 

Looking ahead, ESOA members and other NTN stakeholders have started discussions during the 3GPP Rel-18 June workshop and are continuing to work on a further list of enhancements for both NR-NTN and IoT-NTN to be considered in Rel-18. Plans are also underway to further define the enablers for NR based satellite access in bands above 10 GHz to serve fixed and moving platforms (e.g., aircraft, vessels, UAVs) as well as building- mounted devices (e.g., businesses and premises). The goal of these efforts is to further optimize satellite access performance, address new bands with their specific regulatory requirements, and support new capabilities and services as the evolution of 5G continues.

At Mobile Korea 2021, Nicolas Chuberre gave a talk on '3GPP NTN standardization: past, current and future'. The talk nicely summarizes Release-17 progress and the features planned for 3GPP Release-18. His talk is embedded below:

Related Posts:

• Free 6G Training: Huawei explains Perspectives and Challenges of 6G-NTN
• Connectivity Technology Blog: OneWeb presents their Vision for LEO Satellites and 6G Connectivity
• Connectivity Technology Blog: SoftBank to Promote Non-Terrestrial Network (NTN) Solutions
• Connectivity Technology Blog: 5G Ready' OneWeb Megaconstellation is Getting Ready for Commercial Launch
• Connectivity Technology Blog: ITU Satellite Webinars 2020
• Connectivity Technology Blog: OneWeb has Global Connectivity Ambitions
• Connectivity Technology Blog: R&S Technical Explainer on 3GPP 5G Non Terrestrial Networks (NTN)
• IEEE Comsoc: Connectivity From Top to Bottom
• The 3G4G Blog: An Introduction to Non-Terrestrial Networks (NTN) 

3GPP Presentations from CEATEC Japan 2021

3GPP and its Japanese Organizational Partners TTC (Telecommunication Technology Committee) and ARIB (Association of Radio Industries and Businesses) hosted a “3GPP Summit” online workshop at CEATEC 2021, back in October. The event was co-located with the Japanese Ministry of Internal Affairs and Communications (MIC) and 5G Mobile Communications Promotion Forum (5GMF) 5G day at the event. Here is a summary of the event from 3GPP news:

The “3GPP Summit” featured all three Technical Specification Group (TSG) Chairs and one Japanese leader from each group. After the presentations, they exchanged their views and expectations for 3GPP work – as the industry starts to look at research beyond 5G. The event attracted almost 700 people, keen to understand what is going on in 3GPP.

The first session covered Release 17 and 18 evolution, with each TSG Chair and a domestic leader jointly presenting. Wanshi Chen introduced the latest schedule of each release and potential projects for Release 18 with the result of 3GPP Release 18 workshop held in June. Then, Hiroki Takeda presented some key features on Release 17 such as Redcap, RAN slicing and evolution of duplex.

TSG SA Chair, Georg Mayer introduced the group’s latest activities alongside Satoshi Nagata, covering key Release 17 features, such as enhanced support on Non-public Networks, Industrial IoT and Edge computing.

Next up was the TSG CT Chair, Lionel Morand, presenting the latest activities and roadmap for Core Network evolution from Release 15 to 17. Hiroshi Ishikawa also presented, covering 5G core protocol enhancements and some activities driven by operators.

The second part of the session focused more on activities ‘Beyond 5G’. First, Takaharu Nakamura introduced the latest activities on the topic in Japan. A panel discussion followed, with Satoshi Nagata joining the other 3GPP speakers, to give feedback on 5G developments and future use.

You can download the PPT of presentations from 3GPP site here or get the PDF from 3G4G page here.

Please feel free to add your thoughts as comments below.

Related Posts: 

• The 3G4G Blog: 5G-Advanced Flagship Features
• The 3G4G Blog: An Early View of 3GPP Release-18 5G-Advanced Topics
• The 3G4G Blog: 3GPP's 5G-Advanced Workshop Summary
• The 3G4G Blog: 3GPP's 5G-Advanced Technology Evolution from a Network Perspective Whitepaper
• The 3G4G Blog: '5G RAN Release 18 for Industry Verticals' Webinar Highlights
• The 3G4G Blog: 3GPP RAN Plenary Update and Evolution towards 5G-Advanced
• The 3G4G Blog: Initiative to Remove Non-inclusive terms from 3GPP Specifications
• The 3G4G Blog: 3GPP Release 16 Description and Summary of Work Items
• The 3G4G Blog: 3GPP Standards on Edge Computing
• The 3G4G Blog: Artificial Intelligence (AI) / Machine Learning (ML) in 5G Challenge by ITU
• The 3G4G Blog: ITU Standardization Bureau on Machine Learning for 5G
• The 3G4G Blog: Introduction to 5G Reduced Capability (RedCap) Devices
• The 3G4G Blog: 5G eXtended Reality (5G-XR) in 5G System (5GS)
• The 3G4G Blog: Energy Consumption in Mobile Networks and RAN Power Saving Schemes 

An Early View of 3GPP Release-18 5G-Advanced Topics

5G is hot at the moment. While the operators are busy rolling out the networks based on Release-15/16 features, 3GPP is working on finalising Release-17 specifications and laying the foundations for Rel-18.

The latest issue of 3GPP Highlights magazine (I prefer the PDF) contains a lot of valuable technical content, in addition to many other articles. The technical content includes:

• An early view of the RAN Topics for 5G-Advanced
• 5G Advanced in the Making – The TSG SA approach to Release 18
• Application Enablement Standards in 3GPP – Maximizing the potential of 5G!
• RAN3 flourishing in this time of change
• Enhanced support of Industrial IoT in the 5G System (Rel-17)
• Autonomous Network standardization in WG SA5
• Rel-17 Edge Computing and Network Slicing charging (WG SA 5)
• Media Production over 5G NPN

While I am not going into too much detail here, I want to highlight the 5G-Advanced topics that will be under discussion over the next couple of months. The final list will be approved by 3GPP TSGs SA, RAN and CT in December 2021.

Dr. Wanshi Chen, 3GPP TSG RAN Chair provided an early view of the RAN topics for 5G-Advanced. 

Topics Under Discussion

As well as taking a tentative decision on an 18-month duration for Release 18, the RAN workshop endorsed a list of topics for subsequent email discussions. Some of the topics in the following list also have a set of example areas, serving as a starting point for further refinement:

• Evolution for downlink MIMO, with the following example areas:
• Further enhancements for CSI (e.g., mobility, overhead, etc.)
• Evolved handling of multi-TRP (Transmission Reception Points) and multi-beam
• CPE (customer premises equipment) -specific considerations
• Uplink enhancements, with the following example areas:
• >4 Tx operation
• Enhanced multi-panel/multi-TRP uplink operation
• Frequency-selective precoding
• Further coverage enhancements
• Mobility enhancements, with the following example areas:
• Layer 1/layer 2 based inter cell mobility
• DAPS (Dual Active Protocol Stack)/CHO (Conditional HandOver) related improvements
• FR2 (frequency range 2)-specific enhancements
• Additional topological improvements (IAB and smart repeaters), with the following example areas:
• Mobile IAB (Integrated Access Backhaul)/Vehicle mounted relay (VMR)
• Smart repeater with side control information
• Enhancements for XR (eXtended Reality), with the following example areas:
• KPIs/QoS, application awareness operation, and aspects related to power consumption, coverage, capacity, and mobility
• Note: only power consumption/coverage/mobility aspects specific to XR
• Sidelink enhancements (excluding positioning), with the following example areas:
• SL enhancements (e.g., unlicensed, power saving enhancements, efficiency enhancements, etc.)
• SL relay enhancements
• Co-existence of LTE V2X & NR V2X
• RedCap evolution (excluding positioning), with the following example areas:
• New use cases and new UE bandwidths (5MHz?)
• Power saving enhancements
• NTN (Non-Terrestrial Networks) evolution
• Including both NR & IoT (Internet of Things) aspects
• Evolution for broadcast and multicast services
• Including both LTE based 5G broadcast and NR MBS (Multicast Broadcast Services)
• Expanded and improved Positioning, with the following example areas:
• Sidelink positioning/ranging
• Improved accuracy, integrity, and power efficiency
• RedCap positioning
• Evolution of duplex operation, with the following example areas:
• Deployment scenarios, including duplex mode (TDD only?)
• Interference management
• AI (Artificial Intelligence)/ML (Machine Learning), with the following example areas:
• Air interface (e.g., Use cases to focus, KPIs and Evaluation methodology, network and UE involvement, etc.)
• NG-RAN
• Network energy savings, with the following example areas:
• KPIs and evaluation methodology, focus areas and potential solutions
• Additional RAN1/2/3 candidate topics, Set 1:
• UE power savings
• Enhancing and extending the support beyond 52.6GHz
• CA (Carrier Aggregation)/DC (Dual-Connectivity) enhancements (e.g., MR-MC (Multi-Radio/Multi-Connectivity), etc.)
• Flexible spectrum integration
• RIS (Reconfigurable Intelligent Surfaces)
• Others (RAN1-led)
• Additional RAN1/2/3 candidate topics, Set 2:
• UAV (Unmanned Aerial Vehicle)
• IIoT (Industrial Internet of Things)/URLLC (Ultra-Reliable Low-Latency Communication)
• <5MHz in dedicated spectrum
• Other IoT enhancements/types
• HAPS (High Altitude Platform System)
• Network coding
• Additional RAN1/2/3 candidate topics, Set 3:
• Inter-gNB coordination, with the following example areas:
• Inter-gNB/gNB-DU multi-carrier operation
• Inter-gNB/gNB-DU multi-TRP operation
• Enhancement for resiliency of gNB-CU
• Network slicing enhancements
• MUSIM (Multiple Universal Subscriber Identity Modules)
• UE aggregation
• Security enhancements
• SON (Self-Organizing Networks)/MDT (Minimization of Drive Test)
• Others (RAN2/3-led)
• Potential RAN4 enhancements

Dr. Georg Mayer, 3GPP TSG SA Chair provides the TSG SA approach to 3GPP Release-18

The candidate items for Rel-18 include:

• Immersive Media and Virtual/Artificial/Extended Reality (XR) Media support in Working Group (WG) SA4 and WG SA2.
• New work areas for Internet of Things (e.g. passive IoT (WG SA2) and application capability exposure for IoT platforms (WG SA6)).
• Proposals to for Artificial Intelligence and Machine Learning Services Transport and Management (WGs SA2, SA5).
• Concepts for integration and migration of existing vertical infrastructure, e.g. for railway networks (WG SA6).
• Examples for proposed enhancements to existing 3GPP services and functionalities include:
• Network Slicing (WGs SA2, SA5)
• Edge Computing (WGs SA2, SA5, SA6)
• Autonomous Networks (WG SA5)
• Service Based Architecture (WGs SA2, SA5)
• Northbound APIs (WG SA6)
• Non-Public Networks (WG SA2)
• Satellite 5G Networks (WG SA2)
• Drone support (WG SA2)
• 5G Multicast and Broadcast (WG SA2)
• Location Services (WG SA2, SA6)
• Management Data Analytics (WG SA5)
• Mission Critical Services (WG SA6)

None of these features are final but we will know in the next few months what will be included as part of Rel-18 and what won't. In the meantime, do check out the latest issue of 3GPP Highlights here.

Related Posts: 

• The 3G4G Blog: 3GPP's 5G-Advanced Workshop Summary
• The 3G4G Blog: 3GPP's 5G-Advanced Technology Evolution from a Network Perspective Whitepaper
• The 3G4G Blog: '5G RAN Release 18 for Industry Verticals' Webinar Highlights
• The 3G4G Blog: 3GPP RAN Plenary Update and Evolution towards 5G-Advanced
• The 3G4G Blog: Initiative to Remove Non-inclusive terms from 3GPP Specifications
• The 3G4G Blog: 3GPP Release 16 Description and Summary of Work Items
• The 3G4G Blog: 3GPP Standards on Edge Computing 

5G NR-Unlicensed (NR-U)

I have been talking about unlicensed LTE since 2013. With all the debate around LTE-U and LAA now non-existent, the technology has evolved with every new release. As can be seen from this picture by Ericsson above, 5G NR-U in Release-16 supports:

• License-exempt Downlink (DL)
• License-exempt scheduled Uplink (UL)
• License-exempt autonomous UK
• Standalone license-exempt operation

5G New Radio Unlicensed (NR-U): Challenges and Evaluation - https://t.co/RFyhHHddzh #Free5Gtraining #3G4G5G #5G #5GNR #NRU #NRunlicensed #UnlicensedSpectrum #5GNetworks #5GTechnology #Release16 pic.twitter.com/aiTg2RCECR

— Free 5G Training (@5Gtraining) October 17, 2021

The Release-16 work item summary details the following deployment scenarios for NR-based access to unlicensed spectrum:

• Scenario A: Carrier aggregation between NR in licensed spectrum (PCell) and NR in shared spectrum (SCell);
• A.1: SCell is not configured with UL (DL only); 
• A.2: SCell is configured with UL (DL+UL). 
• Scenario B: Dual connectivity between LTE in licensed spectrum and NR in shared spectrum (PSCell);
• Scenario C: NR in shared spectrum (PCell);
• Scenario D: NR cell in shared spectrum and uplink in licensed spectrum;
• Scenario E: Dual connectivity between NR in licensed spectrum (PCell) and NR in shared spectrum (PSCell)

5G New Radio Unlicensed: Challenges and Evaluation, available on arXiv here provides a lot of useful information on different kind of operations within the unlicensed band and the challenges of co-existence with Wi-Fi

Finally, Qualcomm has quite a few resources on this topic. Last year, they hosted a webinar on the topic, "How does unlicensed spectrum with NR-U transform what 5G can do for you?". The slides from that are available here and a video of that is available here. RCR Wireless also has this short article from one of the webinar presenters here.

Related Posts: 

• The 3G4G Blog: 3GPP Release 16 Description and Summary of Work Items
• The 3G4G Blog: Introduction to 5G Reduced Capability (RedCap) Devices
• The 3G4G Blog: Positioning in 5G networks
• The 3G4G Blog: Qualcomm Explains 5G Millimeter Wave (mmWave) Future & Integrated Access and Backhaul (IAB)
• The 3G4G Blog: '5G RAN Release 18 for Industry Verticals' Webinar Highlights
• The 3G4G Blog: Qualcomm Demoes Sub-band Half Duplex (SBHD)
• The 3G4G Blog: Reducing 5G Device Power Consumption Using Connected-mode Discontinuous Reception (C-DRX)
• The 3G4G Blog: Positioning Techniques for 5G NR in 3GPP Release-16
• The 3G4G Blog: 5G Enhanced URLLC (eURLLC)