Nokia veterans Harri Holma and Antti Toskala explain 5G Basics

An online conference on 5G is currently going on. 'Backed by 5G: Technology for Impact', is hosted by Start North as a part of the Aalto University Summer Course 5G Hack the Mall.

It is a two-week online conference which gathers the industry experts, entrepreneurs and policymakers together to discuss, present and question how 5G will affect our society, economy and everyday life. We want you to join the change by offering a chance to learn from the best, to start or strengthen your journey to expertise in 5G. With the support of our partners, you have the possibility to listen and get your questions answered by the global 5G leaders from the leading companies, academia, NGOs and public institutions, which all are daily involved with changing the world and enabling change with the latest technology.

Dr. Harri Holma from @nokia held a lecture yesterday on "What is Good to Know about 5G Technology Components". Thank you! If you're also interested, the lecture is to be revisited on our parallel event Backed by 5G's website, https://t.co/UfLsRcfgXy#5G #5GHacktheMall https://t.co/ClYy9gCl88

— Start North (@startnorth) June 9, 2021

The current conference features couple of Nokia experts who are well known in the industry for their books on the mobile technologies. Dr. Harri Holma, Fellow, Nokia Bell Labs, spoke on "What is Good to Know About 5G Technology Components". His talk is embedded below:

The second talk is by Dr. Antti Toskala, Fellow, Nokia Bell Labs, on Radio Access (5G Physical Layer). His talk is embedded below

Slides are shared to the 5G Summer School participants. If you are keen to get your hands on the slides, please email: hello@startnorth.com. You can watch all the videos from the event on the Start North YouTube channel here.

Related Posts: 

• The 3G4G Blog: Nokia Lectures in Collaboration with Bangalore University
• The 3G4G Blog: 5G Evolution with Matthew Baker, Nokia
• The 3G4G Blog: 5G Dynamic Spectrum Sharing (DSS)
• The 3G4G Blog: 5G Private and Non-Public Network (NPN) 

TSDSI's Low Mobility Large Cell (LMLC) Requirements in 5G

Back in November 2020, ITU completed the evaluation for global affirmation of IMT-2020 technologies. Three new technologies were successfully evaluated by ITU and were found to conform with the International Mobile Telecommunications 2020 (IMT-2020) vision and stringent performance requirements. The technologies are: 3GPP 5G-SRIT and 3GPP 5G-RIT submitted by the Third Generation Partnership Project (3GPP), and 5Gi submitted by Telecommunications Standards Development Society India (TSDSI). 

I have explained in earlier videos that 5G-SRIT  and 5G-RIT corresponds to Non-Standalone and Standalone respectively. 5Gi on the other hand is an updated version of 5G-RIT designed mainly to improve rural coverage. 

ITU completes evaluation for global affirmation of IMT-2020 technologies - https://t.co/dmALByqXh1 - So the 2 3GPP (@3GPPLive) 5G technologies 5G-SRIT and 3GPP 5G-RIT, and 5Gi submitted by TSDSI (@TSDSI_India) conform with IMT-2020 vision and stringent performance requirement. https://t.co/lFhfugcLux

— Zahid Ghadialy (@zahidtg) November 27, 2020

TSDSI announced this as follows:

TSDSI’s 5G Radio Interface Technology named as “5Gi” has cleared the rigorous processes of  International Telecommunication Union (ITU) and has been approved by the SG5 of ITU as a part of Draft Recommendation M.[IMT-2020.SPECS] in its meeting held on 23rd November 2020.

5Gi, the first  ever Mobile Radio Interface Technology contribution from India to become part of ITU-R’s  IMT recommendation, went through a rigorous evaluation process of the ITU-R working groups over the past 3 years before getting the approval.

This standard is a major breakthrough for bridging the rural-urban digital divide in 5G deployment due to enhanced coverage. It enables connecting majority of India’s villages through towers located at gram panchayats in a cost effective manner. It has found support from several countries as it addresses their regional needs from a 5G standpoint.

The standard will now be circulated by ITU to member states for adoption and approval. Specifications are expected to be published by ITU in early February 2021.

TSDSI thanks its members, the Department of Telecommunications, Govt. of India and its partners for their support over the last four years in helping get this standard reach the final stage in ITU.

In a keynote address presented to the 2020 IEEE 5G World Forum plenary session, Radha Krishna Ganti from TSDSI discusses rural connectivity challenges in India, Low Mobility Large Cell requirements, benefits of implementing LMLC for rural coverage, and internet ecosystem updates. His talk is embedded as follows:

TSDSI explains their 5Gi technology as follows:

TSDSI standard fulfils the requirements of affordable connectivity in rural, remote and sparsely populated areas. Enhanced cell coverage enabled by this standard, will be of great value in countries and regions that rely heavily on mobile technologies for connectivity but cannot afford dense deployment of base stations due to lack of deep fibre penetration,  poor economics and challenges of geographical terrain. The International Telecommunication Union (ITU), a UN body that is setting requirements for IMT 2020 (aka 5G), had earlier adopted the Low-Mobility-Large-Cell (LMLC) use case proposed by TSDSI as a mandatory 5G requirement in 2017. This test case addresses the problem of rural coverage by mandating large cell sizes in a rural terrain and scattered areas in developing as well as developed countries. Several countries supported this as they saw a similar need in their jurisdictions as well. TSDSI successfully introduced an indigenously developed 5G candidate Radio Interface Technology, compatible with 3GPP Technology, at the International Telecommunications Union (ITU) in 2019 for IMT 2020 ratification. The RIT incorporates India-specific technology enhancements that can enable larger coverage for meeting the LMLC requirements. It exploits a new transmit waveform that increases cell range developed by research institutions in India (IIT Hyderabad, CEWiT and IIT Madras) and supported by several Indian companies. It enables low-cost rural coverage and has additional features which enable higher spectrum efficiency and improved latency.

While technically this sounds interesting and as discussed in the talk, would make sense due to a large market like India, there are other solutions that are already possible that probably may make this redundant.

As someone who worked with the rural communities to bring coverage in hard to reach areas, small cells and In-band backhaul was one such solution to improve coverage in not-spot areas. Examples of that here and here. Relays are other option that don't cost much but can bring coverage quickly, at a much lower price.

Typically, in practice, the cells easily reach 10km radius. In theory this distance can be as much as 100km. Last year, Australian operator Telstra and vendor Ericsson announced that they have successfully managed to increase the range of an LTE cell from 100 km to 200 km. So, we can already have large cells with existing 4G/5G cells. 

Facebook connectivity is working on SuperCell concept, a Wide-Area Coverage Solution for Increasing Mobile Connectivity in Rural Communities. Details here. NGMN published a paper on Extreme Long Range Communications for Deep Rural Coverage. Details here.

Finally, we also have 5G Integrated Access and Backhaul (IAB) that can be used for backhauling and solving backhaul issues. They will end up playing a role in rural areas as well as dense urban areas eventually.

Let me know what you think.

Related Posts:

• The 3G4G Blog: IMT-2020 (5G) Requirements
• 3G4G: 5G Terminology
• Free 6G Training: TSDSI's Vision for India to Leapfrog to 5.5G / 6G
• The 3G4G Blog: Reliance Jio and 5G Network Architecture Option 6
• The 3G4G Blog - Opinion: What is "Real 5G" or "True 5G" 

5G User Plane Redundancy

We looked at the 5G Enhanced URLLC (eURLLC) earlier. One of the ways to improve reliability is to have redundancy in the user plane. This can use different approaches like: 

• Duplicating N3
• Adding a secondary gNB using Dual connectivity
• Introducing another UPF
• Two anchor UPFs

In fact they are all built on top of each other so you can decide how critical are your user plane redundancy needs. 

I came across this short video from Mpirical embedded below that covers this topic nicely. In case you want to refresh your 5G Core Network architecture, jump to our old tutorial here.

Related Posts:

• The 3G4G Blog: 5G Enhanced URLLC (eURLLC)
• The 3G4G Blog - Ultra Reliability: 5x9s (99.999%) in 3GPP Release-15 vs 6x9s (99.9999%) in 3GPP Release-16 
• The 3G4G Blog - Tutorial: Service Based Architecture (SBA) for 5G Core (5GC)
• 3G4G: 3GPP 5G Specifications
• 3G4G: 5G (IMT-2020) Wireless 

ITU Standardization Bureau on Machine Learning for 5G

Last year I blogged about Global ITU AI/ML 5G Challenge on the theme “How to apply ITU's ML architecture in 5G networks".  The grand challenge finale happened in December. All the recording and presentations are available here.

Back in October, Bilel Jamoussi from ITU presented a keynote to the 2020 IEEE 5G World Forum plenary session where he addressed the challenges of applying machine learning in networks, ITU’s ML toolkit, and ITU’s AI/ML in 5G Competition. IEEE Tv shared the presentation only in April so the competition part is a bit outdated. It does nevertheless an interesting 20 minute talk.

ITU Recommendation Y.3174, Framework for data handling to enable machine learning in future networks including IMT-2020 is available here.

Related Posts: 

• The 3G4G Blog: Artificial Intelligence (AI) / Machine Learning (ML) in 5G Challenge by ITU
• The 3G4G Blog: IMT-2020 (5G) Requirements 

3GPP RAN Plenary Update and Evolution towards 5G-Advanced

(click on image to enlarge)

ETSI recently held a webinar to provide a 3GPP RAN Plenary update by Wanshi Chen, Senior director of technology at Qualcomm Technologies, who was appointed as the RAN Chair not too long back. The webinar video is embedded below. The following is from the 3GPP summary of the webinar:

Wanshi Chen acknowledged that Release 17 - the third release of 5G specifications - has been under pressure due to COVID-19 restrictions, but despite making the move to e-meetings, he reported that the group’s experts have managed to ensure positive progress towards the freeze of the RAN1 physical layer specifications on schedule, by December 2021.

This is to be followed by the Stage 3 freeze (RAN2, RAN3 and RAN4) by March 2022 and the ASN.1 freeze and the performance specifications completion by September 2022 – On the timeline agreed back in December 2019.

This staggered timeline has been made achievable with careful planning and management, demonstrated to the webinar viewers via a complex planning schedule, with a slide showing the array of Plenary & WG meetings and Release landmarks - Interspersed with a series of planned periods of inactivity, to allow delegates some relief from 3GPP discussions.

Wanshi Chen noted that the efficiency of e-meetings has not been comparable with physical meetings, in terms of getting everything done. To compensate for that, the companies involved have planned two RAN1 meetings in 4Q21 and two meetings for each of the RAN working groups in the 1Q22. He observed: “We will monitor Release 17 RAN progress closely and take the necessary actions to make sure we can get the release completed on time.”

Release 18 Planning

Looking forward to Release 18 and the start of work on 5G-Advanced, Chen outlined the schedule for an online RAN workshop from June 28 – July 2, to define what will be in the release. The workshop will set the scene for email discussions about the endorsed topics for consideration. The work will culminate with Release 18 Package Approval, at the December 2021 Plenary (RAN#94).

The high-level objective of the workshop will be to gather company proposals in three areas:

• eMBB driven work;
• Non-eMBB driven functionality;
• Cross-functionality for both.

Wanshi Chen concluded that during the Release 18 planning process, some capacity must be kept in hand; keeping around 10% of WG effort in reserve, for workload management and to meet late, emerging critical needs from commercial deployments.

The following Q&A topics were covered, along with the time stamps:

• The effect of the pandemic and eMeeting management schedules and tools (19.25).
• Balance between commercial needs and societal needs, emergency services, energy efficiency, sustainability (21.20).
• The importance of the verticals in the second phase of 5G – With 5G-Advanced. How will this Rel-18 workshop compare in scale with the 5G Phoenix workshop in 2015? (23.00)
• The job of the Chair is to be impartial…but Wanshi guesses that Antennas, MiMo enh., Sidelink, Positioning, xR, AI machine learning…. could come up in Rel-18! (26.15)
• Will 5G-Advanced have a strong identity & support? (30.05)
• The potential for hybrid meetings – No clear answers yet, but we have learnt a lot in the past year.(34.35)
• The link between gathering new requirements and use cases in SA1 and RAN work and RAN1’s role in focusing these needs for radio work. (40.10)
• Software-ization of the RAN. Do you see more open RAN work coming to 3GPP? (44.18)
• Machine type communications and IoT – Where is IoT going in 3GPP RAN? (47.01)
• Some thoughts on Spectrum usage from a 3GPP point of view, is that difficult to fathom for non-experts? (52.00)
• Can Standards writing become more agile, less linear? (54.00)

If you want to get hold of the slides, you will have to register on BrightTALK here and then download from attachments.

Signals Research Group has a short summary of 3GPP RAN #91 electronic plenary held in late March. It is available to download after registration from here.

xoxoxoxoxoxo Updated later, 07 June 2021 oxoxoxoxoxoxox 

5G-Advanced logo is now available as shown above. Guidelines on how to use the logo is available on 3GPP here.

Related Posts:

• The 3G4G Blog: Initiative to Remove Non-inclusive terms from 3GPP Specifications
• The 3G4G Blog: ATIS Webinar on '5G Standards Developments in 3GPP Release 16 and Beyond'
• The 3G4G Blog: Anritsu Webinar on 'Evolution of 5G from 3GPP Rel-15 to Rel-17 and Testing Challenges'
• The 3G4G Blog: Spectrum for 5G NR beyond 52.6 GHz 

Positioning in 5G networks

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

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

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

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

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

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

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

Definitely worth a read if you like hardcore technical papers.

Related Posts:

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

A look at 5G Applications, Application Functions & Application Servers

We often get questions about 5G Service Based Architecture. Luckily, we have a tutorial that we can redirect people to. It's available here and the video just crossed 50K views. One of the questions that people often want to understand, is about the Application Function (AF) and how does it fit in the Applications Architecture.

To explain this, we made a tutorial. The slides and videos are embedded below. In that we have used the examples from our XR, V2X and Private Networks tutorials. All links are available at the bottom of this post.

Video:

Slides:

Intermediate: 5G Applications Architecture - A look at Application Functions & Application Servers from 3G4G

Related Posts:

• 3G4G: 5G Service Based Architecture (SBA)
• The 3G4G Blog: 5G eXtended Reality (5G-XR) in 5G System (5GS)
• The 3G4G Blog: An Introduction to Vehicle to Everything (V2X) and Cellular V2X (C-V2X)
• The 3G4G Blog: 5G Private and Non-Public Network (NPN)
• 3G4G: 3GPP 5G Specifications 

5G RAN Functional Splits

I have been meaning to write a post on RAN functional splits and even make a video. Recently I came across multiple of these things so I am taking a shortcut by posting them here. 

The first is this basic introductory video from Parallel Wireless where they explain why you need RAN splits providing examples of various functional splits for 4G and 5G mobile networks. It is embedded below:

The next one is slightly detailed video from the book "5G Radio Access Network Architecture: The Dark Side of 5G" by Sasha Sirotkin (Editor). I wrote a review of the book here and Sasha kindly made a video for our channel which is embedded below:

Finally, RCR Wireless published an article looking at the 5G functional splits in detail, by Ankur Sharma, Associate Vice President, Product Management and Strategy, Radisys. The article 'Exploring functional splits in 5G RAN: Tradeoffs and use cases' is available here.

Feel free to suggest other videos, articles, etc. in comments.

Related Posts:

• 3G4G: Book review - 5G Radio Access Network Architecture: The Dark Side of 5G by Sasha Sirotkin (Editor)
• The 3G4G Blog: The Status of 5G Standalone (5G SA) Networks - March 2021
• The 3G4G Blog: Initiative to Remove Non-inclusive terms from 3GPP Specifications
• The 3G4G Blog: Everything you need to know about 5G Security
• The 3G4G Blog: Open RAN Explanation, Videos, White papers and Other Resources
• The 3G4G Blog: Free 6G Training 

The Status of 5G Standalone (5G SA) Networks - March 2021

I wonder if you have seen as many adverts talking about the 5G revolution as I have. In fact I have collected many of them here. The problem is that most of these promised 5G awesomeness can only be delivered when 5G Standalone networks are launched. 

Before going further, if you don't know what 5G standalone (SA) and non-standalone (NSA) networks are, then you may want to check one of my tutorials/video. For beginners here and slightly advanced version here. If you just want to learn about the 5G core, tutorial here.

I believe that the 5G Non-standalone networks are a hack that were designed mainly to show just the 5G icon and in some cases it also provided enhanced speeds. Some operators have realised this and are thinking about the 5G NSA sunset. There are some potential issues with 5G SA speeds that need sorting out though.

The transition from NSA to SA 5G may happen sooner than most people expect. This keynote from ZTE at Layer123 World Congress provides insights from China - https://t.co/Q0Sm7AkS3r via @layer123live#Free5Gtraining #5G #5GNetworks #5GC #5GCore #5GTechnology #5GSA #5GNSA #ZTE pic.twitter.com/R0jeixFKCf

— 5G Training (@5Gtraining) November 2, 2020

GSA recently held a webinar looking at the status of 5G Standalone networks. The video of the webinar is embedded at the end of the post. The webinar summarised the stats as following:

• By mid-March 2021, 428 operators in 132 countries/territories were investing in 5G
• 176 operators in 76 countries/territories had announced they had deployed 3GPP compliant 5G technology in their live networks
• Of those, a total of 153 operators in 64 countries/territories had launched one or more 3GPP-compliant 5G services
• 145 operators in 60 countries/territories had launched 3GPP-compliant 5G mobile services
• 51 operators in 29 countries/territories had launched 3GPP-compliant 5G FWA or home broadband services
• For comparison, there are 807 public LTE networks worldwide
• GSA has identified 68 operators in 38 countries/territories that are investing in 5G standalone for public mobile networks
• Of those, a total of 7 operators in 5 countries/territories had launched 5G SA networks
• Operators in China have deployed/upgraded hundreds of thousands of base stations 
• T-Mobile has a nationwide network
• Plus China Mobile HK, Rain (South Africa) and DirecTV (Colombia)
• Also ITC KSA (soft launch), STC KSA deployed, Telstra 5G core deployed, plus various contracts for 5G core systems

Private Networks, Non-public networks (NPN) and Industrial 5G Networks are also expected to make use of standalone 5G networks. As 5G networks get virtualized and open, we will see a lot more of these.

The webinar also highlighted the progress of 5G devices:

• There has been rapid growth in the numbers and types of 5G devices being announced and launched
• As of end February:
• 628 5G devices announced
• 404 commercially available (up from 303 at the end of November)
• 104 vendors
• 21 announced form factors
• Majority are phones (306 announced, 274 commercial)
• 5G SA devices are also appearing
• 298 devices announced with 5G SA support
• 204 commercial devices state support for 5G SA
• Software upgrades likely to be required
• Steadily climbing up as % of all 5G devices
• Now >47% of announced
• >50% of commercial

Here is the webinar:

Related Posts: 

• Free 5G Training: 5G Adverts
• 3G4G: 5G for Absolute Beginners
• The 3G4G Blog: 5G Network Architecture Options 
• The 3G4G Blog: The Politics of Standalone vs Non-Standalone 5G & 4G Speeds
• The 3G4G Blog - Tutorial: Service Based Architecture (SBA) for 5G Core (5GC)
• The 3G4G Blog: When does your 5G NSA Device Show 5G Icon?
• The 3G4G Blog: Would 5G NSA undergo Sunset? When?
• Operator Watch Blog: The Many Firsts of STC Kuwait
• The 3G4G Blog: 5G Private and Non-Public Network (NPN)
• The 3G4G Blog: Challenges and Future Perspectives of Industrial 5G
• The 3G4G Blog: Open RAN Explanation, Videos, White papers and Other Resources
• The 3G4G Blog: 5G Remote Surgery and Telehealth Solutions 

Everything you need to know about 5G Security

5G & Security are both big topics on this blog as well as on 3G4G website. We reached out to 3GPP 5G security by experts from wenovator, Dr. Anand R. Prasad & Hans Christian Rudolph to help out audience understand the mysteries of 5G security. Embedded below is video and slides from a webinar they recorded for us.

You can ask any security questions you may have on the video on YouTube

5G Security Briefing from 3G4G

The slides could be downloaded from SlideShare.

Related Posts:

• The 3G4G Blog: Lawful Intercept in 5G Networks
• 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: Evolution of Security from 4G to 5G
• The 3G4G Blog - Tutorial: Service Based Architecture (SBA) for 5G Core (5GC)
• 3G4G: Security in 2G, 3G, 4G & 5G Mobile Networks
• 3G4G: 5G (IMT-2020) Wireless 

How to Identify Network Slices in NG RAN

In my last post I described how NG RAN resources can be divided into network slices. 

Now I would like to show how these network slices and the traffic they carry can be identified. 

The key to this is a parameter from the NG Application Protocol (NGAP) called the Single Network Slice Selection Assistance Information (S-NSSAI). When configuring virtual network functions in NG RAN there are lists of S-NSSAI exchanged, e.g. between gNB-CU CP and AMF during NGAP Setup procedure, to negotiate which network slices have to be supported in general. 

When it comes to connection establishment starting with NGAP Initial Context Setup for each PDU session that is established its individual S-NSSAI is signaled. 

The S-NSSAI - as show in the figure below - consists of two parameters, the Slice/Service Type (SST - 8 bit) and the optional Slice Differentiator (SD - 24 bit). The exact format and numbering ranges are defined in 3GPP 23.003.

3GPP 23.501 defines a set of default values for SST as listed in the following table:

Slice/Service type	SST value	Characteristics
eMBB	1	Slice suitable for the handling of 5G enhanced Mobile Broadband.
URLLC	2	Slice suitable for the handling of ultra- reliable low latency communications.
MIoT	3	Slice suitable for the handling of massive IoT.
V2X	4	Slice suitable for the handling of V2X services.

So when looking back at the figure it emerges that for each subscriber represented by an IMSI the SST allows to identify which services are running. 

On the other hand allows to see if in which virtual network the subscriber is active. In my example I have defined that the resources are shared among a Public MNO that I consider the owner of the network hardware and two different private (campus) networks. While IMSI 1 and IMSI 2 are not allowed to use any other network slice the IMSI 3 is allowed to "roam" betweent the public slice and the two private network slices. This explains why a slice-specific authentication functionality as defined in Rel. 16 is necessary. 

Related Posts:

• The 3G4G Blog: Network Slicing in NG RAN 

Network Slicing in NG RAN

I have been asked to explain in a nutshell how network slicing works in NG RAN. The most important facts you will find in the infographic below.

A network slice is virtual part of a network that offers full end-to-end connectivity for particular services and - optionally - for tenants. A tenant is a 3rd-party company that rents a virtual part of a public mobile operator's network. This allows the tenant to run its own private nation-wide mobile network without owning any hardware.

The network slicing is enabled by virtualization and all network functions can be divided into different slices as well. Thus, you can find in the figure the User Plane Function (UPF), gNB Central Unit for User Plane (gNB-CU UP) and gNB Distributed Unit (gNB-DU) all sliced.

It is also possible that a network function is dedicated for a particular network slice as in case of (gNB-) CU UP 2. 

In general - and this is the benefit of the cloudification - the NG RAN is a highly dynamic environment in which additional NW functions can be added (and later released) whenever this is necessary. Mostly this will be triggered by the load on CPU and memory resources. Here comes the automation into the games that deals in large parts with load balancing. Ideally automation enables a zero-touch network management. 

(click to enlarge)

However, the most precious of all RAN resources, the radio resources, cannot be administrated so flexibly and easily. Indeed, there are several automation instances that deal with radio resource management. Open RAN Alliance has defined the RAN Intelligent Controller (RIC) that is split into the Near-Realtime-RIC (RT RIC) that shall operate with a latency between 10 and 500 ms while the Non-Realtime RIC (NRT RIC) deals with non-time critical task, e.g. typical SON functions like Automatic Neighbor Reporting (ANR).

While the RIC can deal with a lot of problems there is one thing it cannot do: adding physical layer radio resources on demand. The physical resources are limited by the number of remote radio heads/antennas and as long as we have only static beamforming the physical resources covering a geographical sector are also limited by hardware and their distribution must be carefully planned. Thus, I think it is fair to say that the RIC (or a similar proprietary automation function) has to deal with the most complex situations in the RAN.

Radio resources can also be sliced in different ways. My figure illustrates a kind of slicing on the physical layer where different physical resource blocks (PRB) are allocated to different network slices. 

However, this is not the only way how the resources of a cell or a beam can be sliced. Beside a split of PRBs it is also possible to slice on the MAC layer where logical channels (slice-specific radio bearers) are mapped onto transport channels or on PDPC layer as it was described and demonstrated by the 5G NORMA project (Chapter 2.1, page 17 ff.).

What in the end will be implemented by the RAN equipment manufacturers is a question I that cannot answer today. 

Reducing 5G Device Power Consumption Using Connected-mode Discontinuous Reception (C-DRX)

Back in 2019, when we were still participating in physical event, I heard Sang-Hoon Park, ESVP, Head of Regional Network O&M Headquarter, KT talk about 'KT’s journey to large-scale 5G rollout' at Total Telecom Congress.

Interesting nugget from KT about battery life. 63% of users care about battery life but only 19% about design. Also the battery capacity has evolved significantly over generations. Finally C-DRX will play a big role in 5G battery saving @totaltelecom #TTCongress pic.twitter.com/665sokRH0T

— 3G4G (@3g4gUK) October 30, 2019

South Korea is blessed with three highly competitive MNOs and due to this, the government asked them to launch their 5G networks at the same time in 2018. I have also blogged about how KT is working on reducing the latency of their network here.

Anyway, as you can see in the picture above, using Connected-mode Discontinuous Reception (C-DRX), KT was able to show huge power saving in the 5G Samsung smartphone. They also made a video embedded below:

KT has some more details from their blog post back in 2019 here. Also some more details on RayCat here. Both the sites are in Korean but you can use Google translate to get more details.

What is KT battery saving technology (C-DRX)?

KT's'battery saving technology' is shortened to'Connected Mode Discontinuous Reception' and is called C-DRX. In simple terms, it is one of the technologies that reduces battery usage by periodically switching the communication function of a smartphone to a low power mode while data is connected.

In CDRX technology, the base station and the terminal share CDRX information through RRC setting and reconfiguration, so when there is no packet transmission/reception by the terminal, the terminal transmission/reception terminal can be turned off to reduce battery consumption, and the CDRX setting is optimized to reduce the user's battery consumption. It is possible to increase the available time for related applications.

In order to reduce the battery consumption of the terminal, it is a technology that controls the PDCCH monitoring activity, which is a downlink control channel related to the terminal identifier, through RRC. The base station controls the CDRX through RRC, and how the communication company optimizes and applies this was a big task. Is the first in Korea to optimize this technology and apply it to the national network.

In simple terms, the smartphone is not using communication, but it turns off the power completely and enters the standby state to reduce power consumption. When not in use, it completely turns off the power wasted in transmitting and receiving even during the standby time, thus extending the user's smartphone usage time.

As can be seen from the picture above, battery saving technology saves battery by completely turning off the communication function when there is no data or voice call. If the network does not have the battery saving technology applied, it is always connected to the communication network and waits even when not in use. Then, the battery is always connected to the communication function and the battery saving technology overcomes this part.

When Qualcomm announced their Industry’s First Mobile Platform with Integrated 5G back in 2019, the press release said:

The new integrated Snapdragon 5G mobile platform features Qualcomm® 5G PowerSave technology to enable smartphones with the battery life users expect today. Qualcomm 5G PowerSave builds on connected-mode discontinuous reception (C-DRX, a feature in 3GPP specifications) along with additional techniques from Qualcomm Technologies to enhance battery life in 5G mobile devices – making it comparable to that of Gigabit LTE devices today. Qualcomm 5G PowerSave is also supported in the Snapdragon X50 and X55 5G modems, which are expected to power the first waves of 5G mobile devices introduced this year.

The picture is from the slide deck here. See links in further reading below to learn more about this feature.

Further Reading:

• All about Wired and Wireless Technology: LTE Connected Mode DRX (link)
• Netmanias: Future LTE Designed by SK Telecom: ​(2) Application of C-DRX, July 2017 (link)
• Ericsson: A technical look at 5G mobile device energy efficiency, Feb 2020 (link)
• ZTE via IEEE Access: Power Saving Techniques for 5G and Beyond, July 2020 (link)

Related Posts:

• Operator Watch Blog: All three mobile network operators in South Korea launched 5G on Dec 1, 2018
• Operator Watch Blog: How is KT Reducing the Latency of their 5G Network 

Open RAN Explanation, Videos, White papers and Other Resources

Couple of years back, just before MWC 2019, we made what I would like to think of as the first proper explanation of Open RAN. I posted it on this blog here and the video has been viewed nearly 45,000 times. At that time, the concept of Open RAN was still quite new and in my day job with Parallel Wireless*, I was spending quite some time explaining what it really means.

Anyway, I think it made the concept of Open RAN so easy to understand that I have seen tens, if not hundreds, of people copy it, but only a few kind people give credit. 

With the Telecom Infra Project (TIP) and O-RAN driving the ecosystem further, I along with my Parallel Wireless colleagues, created a series of videos to explain the concept a bit more in detail. As expected, the introductory videos have been extremely popular while the others have been reasonably popular as well. The concept from these videos have been copied even far and wider than the original one. 

Embedded below is the playlist of all the videos (6 currently but 1 more in works):

In addition to these, I maintain a list of Open RAN whitepapers (publicly available without registration), some good articles, etc. on the 3G4G website here. I try and update the site on a regular basis so feel free to put any resources in the comments of this post and I will add them on the site during the next update.

Related Posts:

• The 3G4G Blog: O-RAN Introduction for Beginners
• The 3G4G Blog: A quick tutorial on Open RAN, vRAN & White Box RAN
• 3G4G: Open RAN, OpenRAN and O-RAN
• Telecoms Infrastructure Blog: Small Cells World Summit Open RAN Webinar
• The 3G4G Blog: From traditional RAN to Open RAN - O-RAN: Goals and Challenges
• Telecoms Infrastructure Blog: NTT Docomo's 5G Network is based on 'Open RAN' Principles 

*Full Disclosure: I work for Parallel Wireless as a Senior Director, Technology & Innovation Strategy. This blog is maintained in my personal capacity and expresses my own views, not the views of my employer or anyone else. Anyone who knows me well would know this. 

NWDAF in 3GPP Release-16 and Release-17

We looked at Network Data Analytics Function, NWDAF, in detail here. While the 3GPP Release-16 work just starting back then, we have now completed Rel-16 and looking at Release 17. 

The 5G Core (5GC) supports the application of analytics to provide Intelligent Automation of the network, In Rel-16 the set of use cases that are proposed for the NWDAF has been widely expanded. 

In an earlier post, we looked at the ATIS webinar discussing Release-16 & forthcoming features in Rel-17. Puneet Jain, Director of Technical Standards at Intel and 3GPP SA2 Chairman talked briefly about NWDAF. The following is from his talk:

Release-16 provides support for Network Automation and Data Analytics.  Network Data Analytics Function (NWDAF) was defined to provide analytics to 5G Core Network Functions (NFs) and to O&M. It consists of several services that were defined in 3GPP Rel-16 and work is now going in Release 17 to further extend them. 

In release 16 Slice load level related network data analytics and observed service experience related network data analytics were defined. NF load analytics as well Network Performance analytics was also specified. NWDAF provides either statistics or prediction on the load communication and mobility performance in the area of interest. 

Other thing was about the UE related analytics which includes UE mobility analytics, UE communication analytics, Expected UE behavior parameter, Related network data analytics and abnormal behavior related network data analytics.

The NWDAF can also provide user data congestion related analytics. This can be done by one time reporting or continuous reporting in the form of statistics or prediction or both to any other network function. 

QoS sustainability analytics, this is where the consumer of QoS sustainability analytics may request NWDAF analytics information regarding the QoS change statistic for a specific period in the past in a certain area or the likelihood of QoS change for a specific period in future, in certain areas. 

In Release 17, studies are ongoing for network automation phase 2. This includes some leftover from Release 16 such as UE driven analytics, how to ensure that slice SLA is guaranteed and then also new functionality is being discussed that includes things like support for multiple NWDAF instance in one PLMN including hierarchies, how to enable real-time or near-real-time NWDAF communications, how to enable NWDAF assisted user pane optimization and last which is very interesting is about interaction between NWDAF and AI model and training service owned by the operator.

This article on TM Forum talks about NWDAF deployment challenges and recommendations:

To deploy NWDAF, CSPs may encounter these challenges:

• Some network function vendors may not be standards compliant or have interfaces to provide data or receive analytics services.
• Integrating NWDAF with existing analytics applications until a 4G network is deployed is crucial as aggregated network data is needed to make decisions for centralized analytics use cases.
• Many CSPs have different analytics nodes deployed for various use cases like revenue assurance, subscriber/marketing analytics and subscriber experience/network management. Making these all integrated into one analytics node also serving NWDAF use cases is key to deriving better insights and value out of network data.
• Ensuring the analytics function deployed is integrated to derive value (e.g., with orchestrator for network automation, BI tools/any UI/email/notification apps for reporting).

Here are some ways you can overcome these challenges and deploy efficient next-generation analytics with NWDAF:

• Mandate a distributed architecture for analytics too, this reduces network bandwidth overhead due to analytics and helps real-time use cases by design.
• Ensure RFPs and your chosen vendors for network functions have, or plan to have, NWDAF support for collecting and receiving analytics services.
• Look for carrier-grade analytics solutions with five nines SLAs.
• Choose modular analytics systems that can accommodate multiple use cases including NWDAF as apps and support quick development.
• Resource-efficient solutions are critical for on-premise or cloud as they can decrease expenses considerably.
• Storage comes with a cost, store more processed smart data and not more raw big data unless mandated by law.
• In designing an analytics use case, get opinions from both telco and analytics experts, or ideally an expert in both, as they are viewed from different worlds and are evolving a lot.

This is such an important topic that you will hear more about it on this blog and elsewhere.

Related Posts:

• The 3G4G Blog: ATIS Webinar on '5G Standards Developments in 3GPP Release 16 and Beyond'
• The 3G4G Blog: Automating the 5G Core using Machine Learning and Data Analytics
• The 3G4G Blog: Artificial Intelligence - Beyond SON for Autonomous Networks
• 3G4G: 5G Service Based Architecture (SBA) 

Banana and Egg gets 5G Telesurgery

Last year I wrote a detailed post on '5G Remote Surgery and Telehealth Solutions' here. Since then many people with little or no understanding of how the technology works have got in touch with me to educate me about all the 5G remote surgeries taking place. 

I am always prepared to learn new things and looked at both of these surgeries (detailed below) with open mind. I was still unable to see the 5G angle here. In fact in the case of banana, I don't even know if 5G was used.

Back in 2014, a BBC article detailed how a surgeon in Canada has performed over 20 remote surgeries with the help of a robot including colon operations and hernia repairs. The article goes on to ask, "The technology behind long-distance surgery is now mature enough to be used more widely, allowing people to access world-leading expertise and better healthcare without having to travel. Could it become the norm in hospitals?"

The first case is from Aug 2020 as shown in the video above where Doctor Liu Rong from a hospital in Beijing takes on the challenge of remotely controlling a medical robot in distant Qingdao City via the 5G network to finish an egg membrane suture surgery in 90 minutes.

The question here is that where exactly was 5G used and why? Did both the ends have 5G or just one end? Etc. I was unable to find a schematic to show the end-to-end details that would provide credibility to such a scenario.

To explain what I mean, when Vodafone UK launched 5G, they demonstrated low latency by giving an example of Haptic tackle using TeslaSuit. You can read the details and watch the video here. 

As you can see, the end-to-end solution architecture is nicely explained as shown in this picture. I would expect a similar kind of schematic for the surgery scenario. While I can clearly understand the use case for sports outdoor, I am not able to understand the use case for the surgery indoors. Where was the access point? What frequency was used? Was this Standalone or Non-Standalone network? And many other questions like these. 

The second case was a more recent one. The video is embedded below.

Even though the video mentions 5G and many other sites (see this LinkedIn post with nearly 2.5 million views) that have picked this up mention 5G, the original Instagram video does not mention 5G. In all likelihood there is no 5G connection with this one.

Surely there will be a real life 5G remote surgery use case someday that will capture our imagination but not today.

Related Posts:

• The 3G4G Blog: 5G Remote Surgery and Telehealth Solutions 
• The 3G4G Blog: Real-life 5G Use Cases for Verticals from China 

UE Radio Capability Signaling Optimization (RACS) in Rel. 16

The data volume of UE Radio Capability Information defined in 3GPP 38.306 is already high and will further increase starting with Rel. 16 due to additional supported bands and other features.

Due to this 3GPP has standardized in Release 16 what is called UE Radio Capability Signaling Optimization (RACS) for both, E-UTRAN/EPS and NG RAN/NGC networks. 

Release 16 RACS does not apply to NB-IoT.

The first key element of this feature set is the introduction of a new UE Radio Capability ID that is structured as defined in 3GPP 23.003 and shown in figure 1 below:

Figure 1: UE Radio Capability ID according to 3GPP 23.003

The components of this new ID are:

•    TF - Type Field (TF): identifies the type of UE radio capability ID.

            Type = 0 -> manufacturer-assigned UE radio capability ID
            Type = 1 -> network-assigned UE radio capability ID

•  The Vendor ID is an identifier of UE manufacturer and only present if TF = 0. The vendor IDs are provided by Internet Assigned Numbers Authority (IANA). The complete list of assigned numbers is publicly available here: https://www.iana.org/assignments/enterprise-numbers/enterprise-numbers

•  The Version ID configured by the UE Capability Management Function (UCMF) that is part of the EPS/5GC. The Version ID value makes it possible to detect whether a UE Radio Capability ID is current or outdated.

·      The Radio Configuration Identifier (RCI) identifies the UE radio configuration.

The PLMN-assigned UE Radio Capability ID is assigned to the UE using the Non-Access Stratum UE Configuration Update Command or Registration Accept message (figure 2).

Figure 2: PLMN-assigned UE Radio Capability Update according to 3GPP 23.743

The new UCMF (UE radio Capability Management Function) stores All UE Radio Capability ID mappings in a PLMN and is responsible for assigning every PLMN-assigned UE Radio Capability ID.

Due to introduction of the UMCM in the core networks the new Nucmf service-based interface is defined for the 5GC and new S17 reference point is defined for the EPS as shown in figure 3.

Figure 3: Network Architecture with UCMF according to 3GPP 21.916

Each UE Radio Capability ID stored in the UCMF can be associated to one or both UE radio capabilities formats specified in 3GPP TS 36.331 [LTE RRC] and 3GPP TS 38.331 [NR RRC]. The AMF must only be able ot handle the NR RRC format while the MME uses the LTE RRC format. Which format is required by the UCMF is configurable.

If at any time the AMF/MME has neither a valid UE Radio Capability ID nor any stored UE radio capabilities for the UE, the AMF/MME may trigger the RAN to provide the UE Radio Capability information and subsequently request the UCMF to allocate a UE Radio Capability ID.

In NG RAN the UE Capability Request can be requested by the AMF as a flag in any NGAP Downlink NAS Transport message or by sending a NGAP UE Radio Capability Check Request (for checking compatibility of IMS voice capabilities). This triggers a NR RRC UE Capability Transfer procedure and subsequently NGAP UE Radio Capability Info Indication or NGAP UE Radio Capability Check Response (for IMS voice support parameters).

Using the NGAP UE Capability ID Mapping procedure the NG RAN node is able to request the most recent UE Capability ID mapping information from the core network functions AMF/UCMF. The same functionality is implemented in S1AP for signaling between eNB and MME/UCMF.

If the volume of the LTE/NR RRC UE Capability to be sent by the UE is larger than the maximum supported size of a PDCP SDU (specified in 3GPP 38.323) then the UE Capability Info can be transported in LTE/NR RRC using a chain of UL Dedicated Message Segment messages.

Figure 4: RRC UL Dedicated Segment Message transporting UE Radio Capability Information according to 3GPP 36.331 and 38.331

Each of these message will have a dedicated segment number and the last one has the rrc-MessageSegmentType =  “lastSegment”, which triggers reassembly of the orignal UE Capabability information in the receiving entity.