Network Slicing Tutorials and Other Resources

I have received quite a few requests to do a 5G Network Slicing tutorial but have still not got around to doing it. Luckily there are so many public resources available that I can get away with not doing one on this topic. 

This Award Solutions webinar by Paul Shepherd (embedded below) provides good insights into network slicing, what it is, how it efficiently enables different services in 5G networks, and the architectural changes in 5G required to support it.

Then there is also this myth about 3 slices in the network. The GSMA slice template is a good starting point for an operator looking to do network slicing in their 5G networks. The latest version is 3.0, available here.

As this picture (courtesy of Phil Kendall) shows, it's not a straightforward task.  

That is 37 attributes each of which can take multiple values. The permutations are massive.

— Dr. Dan Warren (@TMGB) October 18, 2019

Alistair URIE from Nokia Bell Labs points out some common misconceptions people have with Network Slicing:

1. Multiple slices may share the same cell and the same RU in each slice
2. Single UE may have up to 8 active slices but must have a single CU-CP instance to terminate the common RRC 
3. Slicing supports more than 3 slices 

Back in March, China Mobile, Huawei, Tencent, China Electric Power Research Institute, and Digital Domain have jointly released the Categories and Service Levels of Network Slice White Paper to introduce the industry’s first classification of network slice levels. The new white paper dives into the definitions, solutions, typical scenarios, and evolution that make up the five levels of network slices. It serves as an excellent reference to provide guidance in promoting and commercializing network slicing, and lays a theoretical foundation for the industry-wide application of network slicing.

The whitepaper describes the different phases as:

Phase 1 (ready): As mentioned above, the 5G transport network and 5G core network support different software-based and hardware-based isolation solutions. On the 5G NR side, 5QIs (QoS scheduling mechanism) are mainly used to achieve software-based isolation in WAN scenarios. Alternatively, campus-specific 5G NR (including micro base stations and indoor distributed base stations) is used to implement hardware-based isolation in LAN scenarios. In terms of service experience assurance, 5QIs are used to implement differentiated SLA assurance between slices. In terms of slice OAM capabilities, E2E KPIs can be managed in a visualized manner. This means that from 2020 on, Huawei is ready to deliver commercial use of E2E slicing for common customers and VIP customers of the public network and common customer of general industries (such as UHD live broadcast and AR advertisement).

Phase 2 (to be ready in 2021): In terms of isolation, the 5G NR side supports the wireless RB resource reservation technology (including the static reservation and dynamic reservation modes) to implement E2E network resource isolation and slicing in WAN scenarios. In terms of service experience assurance, features such as 5G LAN and 5G TSN are enhanced to implement differentiated and deterministic SLA assurance between different slices. In terms of slice OAM, on the basis of tenant-level KPI visualization, the limited self-service of the industry for rented slices can be further supported. In this phase, operators can serve VIP customers in common industries (such as AR/VR cloud games and drone inspection), dedicated industry customers (such as electric power management information region, medical hospital campus, and industrial campus), and dedicated industry customers (such as electric power production control region and public security).

Phase 3 (to be ready after 2022): In this phase, 5G network slicing supports real dynamic closed-loop SLAs based on AI and negative feedback mechanism, implementing network self-optimization and better serving industries (such as 5G V2X) with high requirements on mobility, roaming, and service continuity. In addition, industry-oriented comprehensive service capabilities will be further enhanced and evolved.

A more technical presentation from Nokia is available here. The video below shows how innovations in IP routing and SDN work together to implement network slicing in the transport domain.

If you know some other good resources and tutorials worth sharing, add them in the comments below.

Related Posts:

• The 3G4G Blog: 5G Slicing Templates
• The 3G4G Blog: End-to-end Network Slicing in 5G
• The 3G4G Blog: AI your Slice to 5G Perfection 

Lawful Intercept in 5G Networks

Mats Näslund is a cryptologist at the National Defence Radio Establishment outside Stockholm, an agency under the Swedish dept. of defence. As part of his work, he represents Sweden in technical LI standardization in 3GPP. Mats also has a part time appointment as adjunct professor at KTH. Her recently delivered a HAIC Talk on Lawful Intercept in 5G Networks. HAIC Talks is a series of public outreach events on contemporary topics in information security, organized by the Helsinki-Aalto Institute for Cybersecurity (HAIC).

The following is the description from HAIC website:

Our societies have been prospering, much due to huge technological advances over the last 100 years. Unfortunately, criminal activity has in many cases also been able to draw benefits from these advances. Communication technology, such as the Internet and mobile phones, are today “tools-of-the-trade” that are used to plan, execute, and even hide crimes such as fraud, espionage, terrorism, child abuse, to mention just a few. Almost all countries have regulated how law enforcement, in order to prevent or investigate serious crime, can sometimes get access to meta data and communication content of service providers, data which normally is protected as personal/private information. The commonly used term for this is Lawful Interception (LI). For mobile networks LI is, from a technical standpoint, carried out according to ETSI and 3GPP standards. In this talk, the focus will lie on the technical LI architecture for 5G networks. We will also give some background, describing the general, high-level legal aspects of LI, as well as some current and future technical challenges.

The slides are available here.

Related Posts:

• The 3G4G Blog: Everything you need to know about 5G Security
• The 3G4G Blog: Key Technology Aspects of 5G Security by Rohde & Schwarz
• The 3G4G Blog: 5G Roaming with SEPP (Security Edge Protection Proxy)
• The 3G4G Blog: Exploiting Possible 5G Vulnerabilities
• The 3G4G Blog: Presentations from ETSI Security Week 2019 (#ETSISecurityWeek)
• The 3G4G Blog: VoLTE Hacking
• The 3G4G Blog: Evolution of Security from 4G to 5G 

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

Understanding the Dual Active Protocol Stack (DAPS) Handover in 5G

In this video I explain the principles and signaling procedures related to the DAPS handover.

The DAPS handover is a new feature for URLLC services defined by 3GPP in Rel. 16.

Related Article:

• Techplayon: 5G NR Dual Active Protocol Stack (DAPS) Handover – 3GPP Release 16

5G Enhanced URLLC (eURLLC)

One of the interesting features of 5G is Ultra-Reliability and Low-Latency Communication or URLLC. It has been enhanced as part of 3GPP Release-16. A summary of the changes in eURLLC can be seen in the picture above. 

This ATIS webinar that I blogged about last week covered this topic as well. For example L1/L2 changes have been summarised nicely in this Qualcomm slide above while the slide from Intel speaker below looks at redundant transmission and session continuity.

Redundant transmission in the user plane is an extremely useful feature, especially if the packets are mission critical and have to reach from the source to their destination in a guaranteed time / reliability.

Dual connectivity will enable this redundant path when required to meet a guaranteed reliability. 

Here is a short video from the training company Mpirical, explaining the the 5G eURLLC feature: 

Related Posts:

• The 3G4G Blog: ATIS Webinar on '5G Standards Developments in 3GPP Release 16 and Beyond'
• The 3G4G Blog: Carrier Aggregation (CA) and Dual Connectivity (DC)
• The 3G4G Blog - Ultra Reliability: 5x9s (99.999%) in 3GPP Release-15 vs 6x9s (99.9999%) in 3GPP Release-16
• The 3G4G Blog: Anritsu Webinar on 'Evolution of 5G from 3GPP Rel-15 to Rel-17 and Testing Challenges'
• The 3G4G Blog: 2-step RACH Enhancement for 5G New Radio (NR) 

ATIS Webinar on '5G Standards Developments in 3GPP Release 16 and Beyond'

3GPP Organizational Partner, ATIS (Alliance for Telecommunications Industry Solutions), recently delivered a webinar (video & slides below) titled "5G Standards Developments in 3GPP Release 16 and Beyond". 

3GPP News details:

An expert panel brings you up-to-speed on the current state of 5G standardization. The webinar delivers a broad overview of 3GPP's work and introduces some of the key technology elements. It is suitable for people in technical roles and technical executives who want to understand the current state of 5G standardization.

In Release 16, 3GPP delivered important updates to 5G specifications to broaden their range of commercial applications and improve the efficiency of networks. 3GPP is now further enhancing 5G in Release 17 and starting to plan Release 18. This webinar provides an up-to-date view of the completed 3GPP Release 16 work with a particular focus on how the work is expanding capabilities of 5G and enhancing the technical performance of the mobile system. It also looks ahead to future 3GPP deliverables and their use cases.

The webinar features, Iain Sharp, Principal Technologist at ATIS (Moderator), Greg Schumacher, Global Standards at T-Mobile USA and 3GPP SA and SA1 Vice Chairman, Puneet Jain, Director of Technical Standards at Intel and 3GPP SA2 Chairman and Wanshi Chen, Senior Director, Technology at Qualcomm and 3GPP RAN1 Chairman

Many interesting topics have been covered including the updates on mMTC and URLLC. 

There is also details about new features coming in 3GPP Release-17 and an early look at what 3GPP Release-18 might include, as can be seen in the picture above.

Slides are available here and video is embedded below.

Related Posts:

• The 3G4G Blog: Anritsu Webinar on 'Evolution of 5G from 3GPP Rel-15 to Rel-17 and Testing Challenges'
• The 3G4G Blog: 2-step RACH Enhancement for 5G New Radio (NR)
• The 3G4G Blog: Mobile Initiated Connection Only (MICO) mode in 5G System
• The 3G4G Blog: 3GPP MDT - How it works and what is new in Rel. 16
• The 3G4G Blog: Interfacing HSS and UDM in 5GS with UDICOM (a.k.a NU1 / Nhss)
• The 3G4G Blog: Would 5G NSA undergo Sunset? When?
• The 3G4G Blog - Tutorial: Service Based Architecture (SBA) for 5G Core (5GC)
• The 3G4G Blog: 5G and Fixed-Mobile Convergence (FMC) 

Reliance Jio and 5G Network Architecture Option 6

Last week I read about Jio looking at 5G Network Architecture Option 6. There were also a few discussions on Twitter with users sounding a bit confused. So here is my attempt to explain what is Option 6. Video and slides embedded below. 

Why does Jio want 5G Network Architecture Option 6? from 3G4G

You can also see this original video where Satish Jamadagni, Vice President - Network Planning Engineering, Head of Standards at Reliance Jio talks about the need for Option 6. 

Feel free to leave your thoughts in the comments below.

Related Posts:

• Operator Watch Blog: Jio going it alone for 5G Development
• Operator Watch Blog: Jio is the Largest Mobile Network in India by Subscriber Numbers
• Operator Watch Blog: Jio Makes Another Set of Extremely Bold Announcements
• The 3G4G Blog: 5G Network Architecture Options (Updated)
• The 3G4G Blog: The Politics of Standalone vs Non-Standalone 5G & 4G Speeds
• The 3G4G Blog: What about 5G Network Architecture Option 4 (a.k.a. NE-DC) ?
• The 3G4G Blog: Would 5G NSA undergo Sunset? When?
• The 3G4G Blog - Tutorial: Service Based Architecture (SBA) for 5G Core (5GC)
• 3G4G: Free 2G, 3G, 4G & 5G Training Videos
• 3G4G: 5G (IMT-2020) Wireless
• 3G4G: 3GPP 5G Standards and Specifications
• Free 5G Training

Interfacing HSS and UDM in 5GS with UDICOM (a.k.a NU1 / Nhss)

Back in 2012, we were talking about migration from HLR to HSS. Now we are discussing how to interface HSS to the UDM (Unified Data Management in 5G Core).

In the recent 5G World event, Richard Band, Head of 5G Core, HPE talked about 4G to 5G transition planning. During the talk he mentioned about UDICOM, which is the Standardised new interface between HSS and UDM as defined in 3GPP TS 23.632.

5G Security, Openness, and Trust Considerations: How an open and transparent 5G core design can bolster confidence - A joint paper written by @mobileworldlive and @HPE - https://t.co/XkJHUaaGTM#Free5Gtraining #5G #5GNetwork #5GC #5GCore #HPE #MWL #Security #5GSecurity pic.twitter.com/NWVgnl9INQ

— 5G Training (@5Gtraining) September 6, 2020

UDICOM allows operators to deploy separate HSS and UDM, even from different vendors. Supported features include:

• Authentication
• Single Registration Handover
• IMS
• SMS over NAS

3GPP TS 23.632 (Technical Specification Group Core Network and Terminals; User data interworking, coexistence and migration; Stage 2; Release 16) does not use the term UDICOM. It does however describe the interface details, system architecture, system procedures and network function service procedures of UDM-HSS interface.

As can be seen in the picture above, the following reference points are realized by service-based interfaces:
NU1: Reference point between the HSS and the UDM.
NU2: Reference point between the HSS and the 5GS-UDR.

The following Service based interfaces are defined for direct UDM-HSS interworking:
Nudm: Service-based interface exhibited by UDM.
Nhss: Service-based interface exhibited by HSS.

I am not going in more details here but anyone wanting to learn more about the interface should start with 3GPP TS 23.632.

Finally, this talk from HP Enterprise below provides more details of UDICOM.



Related Posts:

• The 3G4G Blog - Tutorial: Service Based Architecture (SBA) for 5G Core (5GC)
• The 3G4G Blog: Two Types of SMS in 5G
• The 3G4G Blog: 5G Roaming with SEPP (Security Edge Protection Proxy)
• The 3G4G Blog: 5G eXtended Reality (5G-XR) in 5G System (5GS)
• The 3G4G Blog: 5G and Fixed-Mobile Convergence (FMC)
• Connectivity Technology Blog: Fixed Wireless Access (FWA) and the Path to 5G Wireless Wireline Convergence (WWC)
• The 3G4G Blog: 5G Network Architecture Options (Updated)
• The 3G4G Blog: What about 5G Network Architecture Option 4 (a.k.a. NE-DC) ?
• The 3G4G Blog: Would 5G NSA undergo Sunset? When?

Two Types of SMS in 5G

GSMA recently published updated "5G Implementation Guidelines: SA Option 2". It explains the two types of SMS in 5G, the same way there were 2 types of SMS in LTE.

Within 5GC, SMS Function (SMSF) supports SMS over NAS (SMSoNAS) defined in 3GPP TS 23.501. Besides, SMSoIP can also be considered as IMS based SMS solution under 5G network. SMSoIP can be deployed simultaneously with voice service over IMS to provide both voice and short message service. It is recommended to use SMSoNAS solution if voice services over IMS is not supported or for a 5G data card/Machine Type Communications (MTC)/Non-IMS device without voice service. The network architecture of SMSoIP and SMSoNAS is shown in Figure.

Two Types of SMS in 5G: SMS over NAS (SMSoNAS) & SMS over IP/IMS (SMSoIP / SMSoIMS) - https://t.co/A88ayY8F1x via @3g4gUK #Free5Gtraining #3G4G5G #GSMA #Mpirical #4G #5G #5GNetworks #5Gtechnology #SMS #5GSMS #Messaging #5GMessaging #SMSoNAS #SMSF #SMSoIP #IMS #SMSoIMS pic.twitter.com/ceI7wGEWBt

— Free 5G Training (@5Gtraining) May 31, 2021

Mpirical explains it in the video as embedded below:

You may also find "5G SMS is Very Real and Here to Stay" by William Dudley useful. It covers a lot of technical details and signalling. It's available here.

Related  posts:

• The 3G4G Blog: Mobile Voice Communications is neither Dying, nor Dead!

Would 5G NSA undergo Sunset? When?

I have been thinking about the long term evolution of 5G and have now reached the conclusion that it would make sense in the long run to switch off non-standalone 5G. This would of course be only after 5G core has been tested and used extensively. Instead of writing my reasoning, here is a 10 minute video and the corresponding slides.

Opinion: Would 5G NSA undergo Sunset? from 3G4G

Let me know what you think in the comments below. If you agree, when do you think is the best time for 5G NSA Sunset?


Related Posts:

• The 3G4G Blog: 5G Network Architecture Options (Updated)
• The 3G4G Blog: The Politics of Standalone vs Non-Standalone 5G & 4G Speeds
• The 3G4G Blog: What about 5G Network Architecture Option 4 (a.k.a. NE-DC) ?
• Operator Watch Blog: The Many Firsts of STC Kuwait 
• The 3G4G Blog: Service Based Architecture (SBA) for 5G Core (5GC)
• The 3G4G Blog: 5G Dynamic Spectrum Sharing (DSS)
• 3G4G: Free 2G, 3G, 4G & 5G Training Videos
• 3G4G: 5G (IMT-2020) Wireless
• 3G4G: 3GPP 5G Standards and Specifications
• Free 5G Training

What about 5G Network Architecture Option 4 (a.k.a. NE-DC) ?

You heard the news about Standalone (SA) 5G network(s)? T-Mobile USA announced this week that "T-Mobile is the first operator in the world to launch a commercial nationwide standalone 5G network". Nationwide is the key word here. Back in February, the Saudi operator STC announced that "stc - Kuwait first to launch 5G E2E SA network in MENA". We will see a lot more announcements about SA 5G this year.

Our blog post on 5G Network Architecture Options has crossed 10K+ views - https://t.co/7aValtx2Ej - Its not that complicated, just remember Standalone (SA) & Non-Standalone (NSA). In NSA you then have EN-DC, NE-DC & NGEN-DC #5GS #5GC pic.twitter.com/qOPoXIReLF

— 3G4G (@3g4gUK) February 1, 2019

I blogged in detail about the 5G Network Architecture options in this post earlier here. There we looked at the different options in details and typical migration path between the options. Whenever any operator / vendor talks about SA 5G today, they are talking about Option 2. That was back in 2018. Since then, many of the options have lost momentum.

As we all know, the current 5G networks are Non-Standalone or NSA. They are also known as Option 3 or EN-DC. The next evolution is Standalone of SA deployment. It is also known as Option 2. Right now, not many operators or vendors are talking about other options.

This is the model I see as having most traction right now in 5G Core: NSA (using EN-DC) and SA in parallel in the same network. Question is when are options 4/7/5 needed? https://t.co/ZVa0c1pT2x

— Gabriel Brown (@Gabeuk) April 27, 2019

NGMN recently did a press release to say that NGMN operators also require support of options 4, 5 and 7 as they look to introduce 5G services across their networks." https://t.co/LSrp2apksY - Check out our video on these options and when they will arrivehttps://t.co/r8MZ8zebZ4

— 3G4G (@3g4gUK) May 15, 2019

While some of the operators have toned down asking for Option 7 (NGEN-DC) & 4 (NE-DC) support, others haven't. Deutsche Telekom is one such operator.

In a webinar on the topic 'The Journey to Standalone 5G' back in March (available on demand here - for DT part, jump to 39 minutes point), Peter Stevens, Principal Engineer, Mobile Access, Deutsche Telekom UK discussed why DT views Option 4 as important for them. In fact if you look at the picture above, you see that they even refer to Option 4 as SA.

One of the motivations from RAN point of view is that because many UEs are not accepting low-low LTE-NR band combinations. So if an operator decided to go with nationwide SA, they have to make the cell sizes smaller than they have to be. This can create coverage gaps with 5G SA. Of course many of the newer features work far better with 5G core (5GC) so option 4 will provide speed benefits of Option 3 NSA without the limitations of 4G EPC.

Standalone without Option 4 can reduce data rates as you can see in the picture above and explained in another of our posts here.

Finally, this last picture summaries the alternatives to Option 4, Dynamic Spectrum Sharing (DSS) or fallback to NSA when 5GC services are not needed. As the slide says, neither of these options is considered a good mainstream alternative to Option 4.

Let me know your thoughts about this in the comments below.

Related Posts:

• The 3G4G Blog: 5G Network Architecture Options (Updated)
• The 3G4G Blog: The Politics of Standalone vs Non-Standalone 5G & 4G Speeds
• The 3G4G Blog: 5G Dynamic Spectrum Sharing (DSS)
• 3G4G: Free 2G, 3G, 4G & 5G Training Videos
• 3G4G: 5G (IMT-2020) Wireless
• 3G4G: 3GPP 5G Standards and Specifications
• Free 5G Training

Artificial Intelligence (AI) / Machine Learning (ML) in 5G Challenge by ITU

ITU is conducting a global ITU AI/ML 5G Challenge on the theme “How to apply ITU's ML architecture in 5G networks". If you don't know the difference between AI & ML, this picture from the old blog post may help.

The ITU website says:

Artificial Intelligence (AI) will be the dominant technology of the future and will impact every corner of society. In particular, AI / ML (machine learning) will shape how communication networks, a lifeline of our society, will be run. Many companies in the ICT sector are exploring how to make best use of AI/ML. ITU has been at the forefront of this endeavour exploring how to best apply AI/ML in future networks including 5G networks. The time is therefore right to bring together the technical community and stakeholders to brainstorm, innovate and solve relevant problems in 5G using AI/ML. Building on its standards work, ITU is conducting a global ITU AI/ML 5G Challenge on the theme “How to apply ITU's ML architecture in 5G networks". 

Participants will be able to solve real world problems, based on standardized technologies developed for ML in 5G networks. Teams will be required to enable, create, train and deploy ML models (such that participants will acquire hands-on experience in AI/ML in areas relevant to 5G). Participation is open to ITU Member States, Sector Members, Associates and Aca​demic Institutions and to any individual from a country that is a member of ITU. ​ ​

There are also some cash prizes, etc. There are various topics with presentation slides & recordings freely available. 

I found the slides from ITU AI/ML in 5G Challenge —”Machine Learning for Wireless LANs + Japan Challenge Introduction” (link) very interesting. There are many other topics including AR / VR / XR, etc, as well.

Have a look at the ITU website here.


Related Posts:

• The 3G4G Blog: An Introduction to Vehicle to Everything (V2X) and Cellular V2X (C-V2X)
• The 3G4G Blog: 5G Remote Surgery and Telehealth Solutions
• The 3G4G Blog: 5G eXtended Reality (5G-XR) in 5G System (5GS)
• The 3G4G Blog: Real-life 5G Use Cases for Verticals from China

Key Technology Aspects of 5G Security by Rohde & Schwarz

The 3G4G page contains a lot of useful papers and links to security here but we have also looked at evolution of security from 4G to 5G here. Rohde & Schwarz has a short 8-minute video in which wireless technology manager, Reiner Stuhlfauth, explains the key technology aspects ensuring 5G security. The video is embedded below.



Related Links:

• The 3G4G Blog: Everything you need to know about 5G Security
• 3G4G: Security in 2G, 3G, 4G & 5G Mobile Networks
• The 3G4G Blog: 5G Roaming with SEPP (Security Edge Protection Proxy)
• The 3G4G Blog: Evolution of Security from 4G to 5G

Mobile Initiated Connection Only (MICO) mode in 5G System

Mobile Initiated Connection Only (MICO) mode is designed for IoT devices that send small amounts of data and do not need to be paged. An example of this could be a smart bin that sends a message to the waste collection company saying it is 50% full, etc. This way the bin emptying lorry can plan to empty it in the next collection round. Here there is no reason to page the bin as there is no mobile terminated data that would be required.

MICO mode has to be negotiated between the device and AMF in 5GC. A device in MICO mode cannot be paged as it would not listen to paging to conserve battery power. This extreme power saving mode can ensure that the battery can last for very long time, ideally years thereby making this vision of billions of connected IoT devices a reality.

In an earlier post on RRC Inactive state, we looked at NAS states, along with RRC states. When the UE is in MICO mode, the AMF in 5GC will consider the UE to be unreachable when it is in CM-IDLE state. In addition, a periodic registration timer is also allocated to the MICO mode UEs. The UE has to confirm the MICO mode again during registration update.

The video and presentation are embedded below:

Intermediate: Mobile Initiated Connection Only (MICO) from 3G4G

Related Posts:

• The 3G4G Blog: A Technical Introduction to 5G NR RRC Inactive State
• The 3G4G Blog: Anritsu Webinar on 'Evolution of 5G from 3GPP Rel-15 to Rel-17 and Testing Challenges'
• 3G4G: 3GPP 5G Specifications
• 3G4G: 5G (IMT-2020) Wireless

Anritsu Webinar on 'Evolution of 5G from 3GPP Rel-15 to Rel-17 and Testing Challenges'

At the TSG#88e Plenary meetings that ended on 03 July 2020, Release 16 was completed with both the Stage 3 freeze and the ASN.1 and OpenAPI specification freeze being approved. The 3GPP Release-16 page has more details on timelines but they may shift. See at the bottom of this post.

Anritsu have uploaded a short presentation on their channel that I am embedding below. I have skipped the beginning part but of you feel like you want to listen, jump to the beginning.




Meanwhile in the recently concluded TSG#88e Plenary meetings, there is a discussion on some of the timelines for Release-17 and Rel-18 moving. This graph below is from SP-200606.

In another piece of 3GPP news, RAN Working Group 6 (WG6 or RAN6) – responsible for the GERAN and UTRAN radio and protocol work - was formally closed.  No new features but specs will be maintained as necessary, of course.

Finally, here is a short video interview by 3GPP in which Balazs Bertenyi looks back at the recent TSG RAN Plenary e-meeting. He talks about the challenges, about IMT-2020, Rel-16 being just on time & the prospects for Rel-17.

Release 16 - RAN progress from 3GPPlive on Vimeo.


Related Posts:

• 3G4G: 3GPP 5G Specifications
• 3G4G: 5G Health & Safety
• 3G4G: 5G (IMT-2020) Wireless
• The 3G4G Blog: A Technical Introduction to 5G NR RRC Inactive State
• The 3G4G Blog: An Introduction to Vehicle to Everything (V2X) and Cellular V2X (C-V2X)
• The 3G4G Blog: A Look into 5G Virtual/Open RAN - Part 6: Inter-gNB CU Handover involving Xn
• The 3G4G Blog: Carrier Aggregation (CA) and Dual Connectivity (DC)
• The 3G4G Blog: 5G Roaming with SEPP (Security Edge Protection Proxy)
• The 3G4G Blog: Embedded SIM (eSIM) and Integrated SIM (iSIM)

A Technical Introduction to 5G NR RRC Inactive State

I looked at the RRC Inactive state back in 2017, but the standards were not completely defined. In the meantime standards have evolved and commercial 5G networks are rolling out left, right and centre. I made a short technical introduction to the RRC_INACTIVE state, comparing it with the 4G states in RRC and NAS. I also looked at some basic signalling examples and there are lots of relevant references at the end. Video and slides embedded below.

Advanced: 5G NR RRC Inactive State from 3G4G

Related Posts:

• The 3G4G Blog: Comparison Layer 2 Measurements LTE vs. 5G NR
• The 3G4G Blog: A Look into 5G Virtual/Open RAN - Part 3: Connection Release and Suspend
• The 3G4G Blog: How LTE RRC (4G) and NR RRC (5G) Protocols are used in Parallel in EN-DC (5G NSA)
• The 3G4G Blog: EPS Fallback in 5G Standalone Deployments
• The 3G4G Blog: RRC states in 5G

An Introduction to Vehicle to Everything (V2X) and Cellular V2X (C-V2X)

We made an introductory tutorial explaining vehicle to everything. There are 2 different favours of V2X as shown in this tweet below

We have a new section on 3G4G homepage - Vehicle to Everything (V2X) - https://t.co/enOdeIcLE5#3G4G5G #V2V #V2X #V2I #V2P #V2N #CAVs #ConnectedCars #AutonomousCars #3GPP #Specifications #Standards #Whitepapers #Webinars

— 3G4G (@3g4gUK) June 28, 2020

One is based on IEEE 802.11p (802.11bd in future). It is known by different names, DSRC, ITS-G5, etc. The other is the cellular V2X or C-V2X. It started as basic D2D but has evolved over the time. The slides and video are embedded below but this topic will need revisiting with more details.

Intermediate: Vehicle to Everything (V2X) Introduction from 3G4G

Related Posts:

• Connectivity Technology Blog: Introduction to Connected and Autonomous Vehicles (CAVs)
• 3G4G: Vehicle to Everything (V2X)
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• The 3G4G Blog: 5G New Radio Standards and other Presentations

Comparison Layer 2 Measurements LTE vs. 5G NR

Yesterday (2020-06-22) 3GPP uploaded the version 1.0 of TS 38.314 "Layer 2 Measurements" for 5G New Radio Rel. 16.

I was wondering about the difference compared to the same LTE standard defined in 3GPP TS 36.314.

The initial look at the table of contents shows significantly less measurements in the NR spec, but a new counter for the number of stored inactive UE contexts. This is due to the introduction of RRC Inactive state in NR RRC specified in 3GPP TS 38.331)

All other differences in the NR standard are related to chapter number 4.2.1.6 "Other measurements defined in TS 28.552".

Here one finds the references to Data Volume, Average Throughput Measurement per UE and DRB as well as PRB usage measurements.

Adding these additional measurements to the list we see in the table of contents it emerges that indeed the number of stored inactive UE contexts is the only major difference in comparison with the LTE standard. 

Carrier Aggregation (CA) and Dual Connectivity (DC)

This topic keeps coming up every few months with either someone asking me for clarifications or someone asking us to make a video. While I don't think I will mange to get round to making a video sometime soon, there are some excellent resources available that should help a new starter. Here they are in an order I think works best



The first resource that I think also works best is this webinar / training from Award Solutions. It covers this topic well and the image at the top of the post is a god summary for someone who already understands the technology.

It may also help to understand that in the 5G NSA can have 4G carrier aggregation as well as 5G carrier aggregation in addition to dual connectivity.

If you saw the video earlier, you noticed that DC actually came as part of LTE in Release-12. We covered it in our Telecom Infrastructure blog here. NTT Docomo Technical journal had a detailed article on 'Carrier Aggregation Enhancement and Dual Connectivity Promising Higher Throughput and Capacity' that covered DC in a lot more technical detail, albeit from LTE point of view only. The article is available here. A WWRF whitepaper from the same era can also provide more details on LTE Small Cell Enhancement by Dual Connectivity. An archived copy of the paper is available here.

Another fantastic resource is this presentation by Rapeepat Ratasuk and Amitava Ghosh from Mobile Radio Research Lab, Nokia Bell Labs. The presentation is available here and details the MCG (Master Cell Group) Split Bearer and SCG (Secondary Cell Group) Split Bearer, etc. This article from Ericsson also provides more detail on this topic while ShareTechNote takes it one level even deeper with technical details and signalling here and here.

So hopefully this is a good detailed starting point on this topic, until we manage to make a simple video someday.

5G Roaming with SEPP (Security Edge Protection Proxy)

SEPP (Security Edge Protection Proxy) is part of the roaming security architecture as shown in the figure above. Ericsson's article, "An overview of the 3GPP 5G security standard" describes the use of SEPP as follows:

The use of SBA has also pushed for protection at higher protocol layers (i.e. transport and application), in addition to protection of the communication between core network entities at the internet protocol (IP) layer (typically by IPsec). Therefore, the 5G core network functions support state-of-the-art security protocols like TLS 1.2 and 1.3 to protect the communication at the transport layer and the OAuth 2.0 framework at the application layer to ensure that only authorized network functions are granted access to a service offered by another function.

The improvement provided by 3GPP SA3 to the interconnect security (i.e. security between different operator networks) consists of three building blocks:

• Firstly, a new network function called security edge protection proxy (SEPP) was introduced in the 5G architecture (as shown in figure 2). All signaling traffic across operator networks is expected to transit through these security proxies
• Secondly, authentication between SEPPs is required. This enables effective filtering of traffic coming from the interconnect
• Thirdly, a new application layer security solution on the N32 interface between the SEPPs was designed to provide protection of sensitive data attributes while still allowing mediation services throughout the interconnect

The main components of SBA security are authentication and transport protection between network functions using TLS, authorization framework using OAuth2, and improved interconnect security using a new security protocol designed by 3GPP.

NG.113 5G Roaming Guidelines v2.0 clarifies:

4.2 Inter PLMN (N32) Interface

The Inter-PLMN specification 3GPP TS 29.573 has been produced by 3GPP to specify the protocol definitions and message flows, and also the APIs for the procedures on the PLMN (Public Land Mobile Network) interconnection interface (i.e. N32)

As stated in 3GPP TS 29.573 the N32 interface is used between the SEPPs of a VPLMN and a HPLMN in roaming scenarios. Furthermore, 3GPP has specified N32 to be considered as two separate interfaces: N32-c and N32-f.

N32-c is the Control Plane interface between the SEPPs for performing the initial handshake and negotiating the parameters to be applied for the actual N32 message forwarding. See section 4.2.2 of 3GPP TS 29.573.

Once the initial HTTP/2 handshake is completed the N32-c connection is torn down. This connection is End-to-End between SEPPs and does not involve IPX to intercept the HTTP/2 connection; although the IPX may be involved for IP level routing.

N32-f is the Forwarding interface between the SEPPs, that is used for forwarding the communication between the Network Function (NF) service consumer and the NF service producer after applying the application level security protection. See section 4.2.3 of 3GPP TS 29.573.

N32-f can provide Application Level Security (ALS) as specified in 3GPP TS 33.501 between SEPPs, if negotiated using N32-c. ALS provides the following protection functionalities: -

• Message protection of the information exchanged between NF service consumer and producer
• Forwarding of the application layer protected message from a SEPP in one PLMN to another PLMN by way of using IPX providers on the path. The IPX providers on the path may involve the insertion of content modification instructions which the receiving SEPP applies after verifying the integrity of such modification instructions.

The HTTP/2 connection used on N32-f is long lived; and when a SEPP establishes a connection towards another PLMN via IPX, the HTTP/2 connection from a SEPP terminates at the next hop IPX.

N32-f makes use of the HTTP/2 connection management requirements specified in 3GPP TS 29.500. Confidentiality protection shall apply to all IE’s for the JOSE protected message forwarding procedure, such that hop-by-hop security between SEPP and the IPXs should be established using an IPSec or TLS VPN.

If an IPX is not in the path between SEPPs, then an IPSec of Transport Layer Security, TLS VPN will be established directly.

Note: N32-f shall use “http” connections generated by a SEPP, and not “https”

The SEPP will act as a non-transparent Proxy for the NF’s when service based interfaces are used across PLMNs, however inside IPX service providers, an HTTP proxy may also be used to modify information elements (IE’s) inside the HTTP/2 request and response messages.

Acting in a similar manner to the IPX Diameter Proxy used in EPC roaming, the HTTP/2 Proxy can be used for inspection of messages, and modification of parameters. 

A new version of @GSMA 5G Roaming Guidelines was released in May 2020 - https://t.co/GCcDG68wnK#Free5Gtraining #5G #5GNetworks #5GS #5GC #5GRoaming #VPLMN #HPLMN #SEPP #LBO #HR #EPC pic.twitter.com/ZzL1io0QF5

— 5G Training (@5Gtraining) June 8, 2020

The picture in the tweet above shows how SEPP will play a role in Local Break Out (LBO) roaming as well as Home Routed (HR) roaming.

Related Posts:

• The 3G4G Blog: Everything you need to know about 5G Security
• 3G4G: Security in Mobile Cellular Systems
• The 3G4G Blog: Service Based Architecture (SBA) for 5G Core (5GC) Tutorial
• The 3G4G Blog: 5G eXtended Reality (5G-XR) in 5G System (5GS)
• The 3G4G Blog: Guest Post - Exploring Network Convergence of Mobile, Broadband and Wi-Fi