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!

3GPP MDT - How it works and what is new in Rel. 16

Today I launched my first video. It is about the 3GPP Minimization of Drive Test (MDT) and what is new for this feature in Rel. 16 / 5G networks.

This video explains the overall concept of the MDT feature defined by 3GPP. Individual signaling procedures for immediate and logged mode MDT reporting are presented as well as the latest enhancements for 5G networks defined in 3GPP Release 16.

Enjoy watching

Multi-SIM Terminology

This new video and presentation looks at the operation and terminology associated with multiple SIMs in mobile cellular devices.

Slides and video embedded below introduces the concept of transceivers, active and standby states and then look at Dual Sim Single & Dual Standby (DSSS / DSDS), Dual SIM Dual Active (DSDA), Triple SIM Triple Standby (TSTS) and finally, Quad SIM Quad Standby (QSQS) in case of four SIM cards.

Beginners: Multi-SIM Operation from 3G4G

Related Posts:

• The 3G4G Blog: Embedded SIM (eSIM) and Integrated SIM (iSIM)
• 3G4G: MNO, MVNO, MVNA, MVNE: Different types of mobile operators
• The 3G4G Blog: The Journey from Communications Service Provider (CSP) to Digital Service Provider (DSP)
• The 3G4G Blog: M2M embedded UICC (eSIM) Architecture and Use Cases

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

Telecom Services and Data Pricing

With the mobile technology gaining even more subscribers and smartphones becoming common, the telecom services pricing that includes voice, SMS and data is falling. Many operators are now including bundles with generous amounts to satisfy everyone. In many European countries, it is very common to have plans with unlimited everything. 

One of the reports that ITU releases is called "Measuring Digital Development: ICT Price Trends". The latest report for 2019 was released in May this year. The press release says:

On average, prices for mobile-voice, mobile-data and fixed-broadband services are decreasing steadily around the world, and in some countries even dramatically. The reduction in price relative to income is even more dramatic, suggesting that, globally, telecommunication and information and communication technology services are becoming more affordable. However, both trends do not translate into rapidly increasing Internet penetration rates which suggests that there are other barriers to Internet use, concludes ITU in its new statistical report, Measuring Digital Development: ICT Price Trends 2019.

The latest statistics from ITU confirm that affordability may not be the only barrier to Internet uptake, and that other factors such as: 

• low level of education, 
• lack of relevant content, 
• lack of content in local languages, 
• lack of digital skills, and a 
• low-quality Internet connection may also prevent effective use. 

Key results​:

• An entry-level mobile-voice basket remains broadly affordable in most countries. In 70 countries, a low-usage mobile-voice plan was available for less than 1 per cent of gross national income (GNI) per capita, and in a further 37 countries it stood below 2 per cent. Although causality is difficult to prove, price reductions have undoubtedly helped contribute to the rapid rise in the mobile-voice penetration rate, alongside growing competition and better price monitoring and evaluation by regulators.
• The expansion of bundled services has further reduced prices, as combined data-and-voice baskets are generally less expensive than the sum of the two separate baskets in most markets.
• Prices have decreased from 2013 to 2019 relative to GNI per capita The global average price of a mobile-data basket of 1.5 GB shrank from 8.4 per cent of GNI per capita in 2013 to 3.2 per cent in 2019, at a compound annual growth rate of almost -15 per cent. When expressed in USD, the global average price of a mobile-data basket of at least 1.5 GB dropped by 7 per cent on average annually between 2013 and 2019.
• Good progress has been made towards the Broadband Commission for Sustainable Development's target of achieving affordable broadband costing 2-5 per cent of GNI per capita by 2025, but still more remains to be done. There are still nine developing countries and 31 LDCs that have yet to reach the 2 per cent target by 2025.
• Fixed-broadband packages remain generally more expensive than mobile-data packages (although data allowances are not always directly comparable). Over the past four years, the affordability of fixed broadband has not changed substantially, but advertised download speeds continue to increase.

(click on the image to enlarge)

Some of the results are quite interesting as shown in the image above. The picture on top left shows the different types of packages. The report analyses price data for five key services based on the following five baskets:

1. mobile-data-and-voice basket (i.e. voice, SMS and mobile data combined) – low consumption (70 minutes, 20 SMSs and 500 MB);
2. mobile-data-and-voice basket – high consumption (140 minutes, 70 SMSs and 1.5 GB);
3. mobile-voice (including voice and SMS);
4. mobile-data;
5. fixed-broadband.

Chart 1 shows Mobile data and voice baskets in USD for 2019. LDCs stands for Least Developed Countries

Chart 2 shows Mobile data and voice baskets in PPP$, where PPP stands for purchasing power parity. This is defined as basket of goods based comparison approach (see here)

Finally, chart 3 shows Mobile data and voice basket as a % of GNI p.c. GNI stands for gross national income. Expressing prices relative to GNI per capita (GNI p.c.), as a measure of affordability, reveals huge gaps between prices for different levels of development. In developed countries, the price of a low-consumption mobile-data-and-voice basket was equivalent to 1 per cent of GNI p.c. in 2019. In developing countries, this basket cost 7.5 per cent of GNI p.c., while in the LDCs this rose sharply to 17 per cent. For high-consumption mobile-data-and-voice baskets, the differences were even larger.

Source - Visual capitalist. Click link to see complete picture

Visual Capitalist has a nice summary of data prices for 1GB of Mobile data in different parts of the world. A striking trend worth noting is that four out of five of the most expensive countries (Malawi, Benin, Chad, Yemen & Botswana) for mobile data are in Sub-Saharan Africa (SSA).

Cable.co.uk have an interactive map here, that allows you to see prices in different parts of the world. As you would guess, the cheapest data prices in the world is in India.

Finally, eXtensia has a list of data costs in African countries from 2019 here, a lot has changed in the last year so you may have to check if the information you need is correct as of today.

Related Posts:

• The 3G4G Blog: Changes in LTE pricing strategies
• The 3G4G Blog: Mobile can help with United Nations SDGs, only if prices go down
• The 3G4G Blog - Finland: A country with only Unlimited Data Plans
• The 3G4G Blog: Mobile Voice Communications is neither Dying, nor Dead!
• Operator Watch Blog: Vodafone UK Launches 5G, Plans Disruption With Unlimited Data Plans

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
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• 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