Mobile Network Architecture: How did we get here & where should we go?

Lorenzo Casaccia, Vice President of Technical Standards, IP Qualcomm Europe, Inc. has been with Qualcomm since 2000. During that time he's had a variety of roles related to wireless communication, including research and system design, regulatory aspects, product management, and technical standardization. He currently leads a team of engineers across three continents driving Qualcomm’s activities in 3GPP, the standards body designing technologies for 4G and 5G.

Couple of his well known articles on Qualcomm OnQ Blog on 'Counting 3GPP contributions' and 'ETSI SEP database manipulations' are available here and here respectively.

Fascinating & rather heretical presentation by @Qualcomm on the 6G Core workshop - suggesting that maybe a new architecture is needed that massively reduces role/complexity of the core

Is most slicing-skeptic I’ve seen from a big vendor

(Sorry don’t have screenshots)

— Dean Bubley (@disruptivedean) September 12, 2023

At the recent NIST/IEEE Future Networks 6G Core Networks Workshop he was able to bring in his experience to deliver a fantastic talk looking at how the mobile network architecture has diverged from the Data Networks (Internet) architecture and how this has limited innovation in the mobile networks.

He concludes by providing a solution on how to fix this network architecture in 6G by limiting any new services going in the control plane as well as ensuring over the time all services move to the user plane. The control plane will then stop being 'G' specific which will benefit the network innovation in the long term. 

There is no provision to embed the video so please look at the top of the page here. Lorenzo's talk starts at 03:03:50. The Q&A session for the panel starts at 03:53:20 for anyone interested.

Related Posts: 

• Free 6G Training: Nokia's Presentation from NIST/IEEE Future Networks 6G Core Networks Workshop
• The 3G4G Blog: Preparing for Metaverse-Ready Networks
• Free 6G Training: SK Telecom Claims ‘Bare Metal-Based Cloud-Native 5G Core’ as Foundation for 6G Evolution
• The 3G4G Blog: CUPS for Flexible U-Plane Processing Based on Traffic Characteristics
• Free 6G Training: Design aspects for emerging 6G Organic Core Networks
• The 3G4G Blog: IP Multimedia Subsystem (IMS) Support for Service Based Architecture (SBA)
• Free 6G Training: China Mobile's view of how to define a 6G Network
• The 3G4G Blog: Three New Standards to Accelerate 5G Wireless Wireline Convergence (WWC) 

Preparing for Metaverse-Ready Networks

Metaverse means different things for different people. If you explain Metaverse with an example, many people understand but they are generally looking at things from a different point of view. A bit like blind men and an elephant. Similarly when we talk about Metaverse-ready networks, it can mean different things to different people, depending on their background.

Back in Oct 2021, Facebook changed its name to Meta with a vision to bring the metaverse to life and help people connect, find communities and grow businesses. This was followed by a blog post by Dan Rabinovitsj, Vice President, Meta Connectivity, highlighting the high-level requirements for these metaverse-ready networks. 

At Fyuz 2022, the Telecom Infra Project (TIP) announced the launch of Metaverse-Ready Networks Project Group primary whose objective is to accelerate the development of solutions and architectures that enhance network readiness to support metaverse experiences. Meta Platforms, Microsoft, Sparkle, T-Mobile and Telefónica are the initial co-chairs of this Project Group.

A blast from the past - I'm listening to a Nokia CTO, Alessandro Bovone, setting out Nokia's view of the future #CWIC2022 pic.twitter.com/DSN96eK2qh

— David Wood (@dw2) November 2, 2022

Cambridge Wireless' CWIC 2022 discussed 'The Hyperconnected Human'. One of the sessions focussed on 'Living in the Metaverse' which I think was just brilliant. The slides are available from the event page and the video is embedded below:

Coming back to metaverse-ready networks, the final day of Fyuz 2022 conference featured 'The Meta Connectivity Summit' produced by Meta. 

8.3 milliseconds is the magic number to have a seamless experience in the Metaverse#Metaverse #MetaverseConnectivity #Fyuz22 https://t.co/UsqDEgvBEU

— Zahid Ghadialy (@zahidtg) October 27, 2022

The main stage featured a lot of interesting panel sessions looking at metaverse use cases and applications, technology ecosystem, operator perspectives as well as a talk by CIO of Softbank. The sessions are embedded below. The breakout sessions were not shared. 

Metaverse is also being used as a catch-all for use cases and applications in 6G. While many of the requirements of Metaverse will be met by 5G and beyond applications, 6G will bring in even more extreme requirements which would justify the investments in the Metaverse-Ready Networks.

Related Posts: 

• The 3G4G Blog: Demystifying and Defining the Metaverse
• Free 6G Training: What is Metaverse and will it play a big part in 6G?
• The 3G4G Blog: 5G eXtended Reality (5G-XR) in 5G System (5GS)
• The 3G4G Blog: A look at 5G Applications, Application Functions & Application Servers
• Free 6G Training: What is Extended Reality (XR)?
• Free 6G Training: Three Degrees of Freedom (3DoF) vs Six (6DoF) in Extended Reality
• Free 6G Training: One XR Device to Rule Them All!
• Free 6G Training: Nokia Bell Labs eBook and Talks on 6G
• Free 6G Training: Presentations from The 2022 Brooklyn 6G Summit (B6GS) 

EPS Fallback Mechanism in 5G Standalone Networks

Ralf Kreher explained EPS Fallback mechanism in his post earlier, which is still quite popular. This post contains couple of videos that also explain this procedure. 

The first is a very short and simple tutorial from Mpirical, embedded below:

The second is a slightly technical presentation explaining how 5G system can redirect the 5G VoNR capable device to the 4G system to continue for IMS based VoLTE voice call.

Related Posts:

• The 3G4G Blog: EPS Fallback in 5G Standalone Deployments
• The 3G4G Blog: IP Multimedia Subsystem (IMS) Support for Service Based Architecture (SBA)
• The 3G4G Blog: Two Types of SMS in 5G
• The 3G4G Blog: 5G User Plane Redundancy
• The 3G4G Blog: Network Slicing using User Equipment Route Selection Policy (URSP)
• The 3G4G Blog: Voice over New Radio (VoNR) Establishment and Release between NG RAN and 5G Core
• The 3G4G Blog: A quick starter on 4G voice (for beginners) 

CUPS for Flexible U-Plane Processing Based on Traffic Characteristics

I looked at Control and User Plane Separation (CUPS) in a tutorial, nearly five years back here. Since then most focus has been on 5G, not just on my blogs but also from the industry. 

Earlier this year, NTT Docomo's Technical Journal looked at CUPS for Flexible U-Plane Processing Based on Traffic Characteristics. The following is an extract from the article:

At the initial deployment phase of 5th Generation mobile communication systems (5G), the 5G Non-Stand-Alone (NSA) architecture was widely adopted to realize 5G services by connecting 5G base stations to the existing Evolved Packet Core (EPC). As applications based on 5G become more widespread, the need for EPC to achieve higher speed and capacity communications, lower latency communications and simultaneous connection of many terminals than ever has become urgent. Specifically, it is necessary to increase the number of high-capacity gateway devices capable of processing hundreds of Gbps to several Tbps to achieve high-speed, high-capacity communications, to distribute gateway devices near base station facilities to achieve even lower latency communications, and to improve session processing performance for connecting massive numbers of terminals simultaneously.

Conventional single gateway devices have both Control Plane (C-Plane) functions to manage communication sessions and control communications, and User Plane (U-Plane) functions to handle communications traffic. Therefore, if the previously assumed balance between the number of sessions and communications capacity is disrupted, either the C-Plane or the U-Plane will have excess processing capacity. In high-speed, high-capacity communications, the C-Plane has excess processing power, and in multiple terminal simultaneous connections, the U-Plane has excess processing power because the volume of communications is small compared to the number of sessions. If the C-Plane and U-Plane can be scaled independently, these issues can be resolved, and efficient facility design can be expected. In addition, low-latency communications require distributed deployment of the U-Plane function near the base station facilities to reduce propagation delay. However, in the distributed deployment of conventional devices with integrated C-Plane and U-Plane functions, the number of sessions and communication volume are unevenly distributed among the gateway devices, resulting in a decrease in the efficiency of facility utilization. Since there is no need for distributed deployment of C-Plane functions, if the C-Plane and U-Plane functions can be separated and the way they are deployed changed according to their characteristics, the loss of facility utilization efficiency related to C-Plane processing capacity could be greatly reduced.

CUPS is an architecture defined in 3GPP TS 23.214 that separates the Serving GateWay (SGW)/Packet data network GateWay (PGW) configuration of the EPC into the C-Plane and U-Plane. The CUPS architecture is designed so that there is no difference in the interface between the existing architecture and the CUPS architecture - even with CUPS architecture deployed in SGW/PGW, opposing devices such as a Mobility Management Entity (MME), Policy and Charging Rules Function (PCRF), evolved NodeB (eNB)/ next generation NodeB (gNB), and SGWs/PGWs of other networks such as Mobile Virtual Network Operator (MVNO) and roaming are not affected. For C-Plane, SGW Control plane function (SGW-C)/PGW Control plane function (PGW-C), and for U-Plane, SGW User plane function (SGW- U)/PGW User plane function (PGW-U) are equipped with call processing functions. By introducing CUPS, C-Plane/U-Plane capacities can be expanded individually as needed. Combined SGW-C/PGW-C and Combined SGW-U/PGW-U can handle the functions of SGW and PGW in common devices. In the standard specification, in addition to SGW/PGW, the Traffic Detection Function (TDF) can also be separated into TDF-C and TDF-U, but the details are omitted in this article.

From above background, NTT DOCOMO has been planning to deploy Control and User Plane Separation (CUPS) architecture to realize the separation of C-Plane and U-Plane functions as specified in 3rd Generation Partnership Project Technical Specification (3GPP TS) 23.214. Separating the C-Plane and U-Plane functions of gateway devices with CUPS architecture makes it possible to scale the C-Plane and U-Plane independently and balance the centralized deployment of C-Plane functions with the distributed deployment of U- Plane functions, thereby enabling the deployment and development of a flexible and efficient core network. In addition to solving the aforementioned issues, CUPS will also enable independent equipment upgrades for C-Plane and U-Plane functions, and the adoption of U-Plane devices specialized for specific traffic characteristics.

In the user perspective, the introduction of CUPS can be expected to dramatically improve the user experience through the operation of facilities specializing in various requirements, and enable further increases in facilities and lower charges to pursue user benefits by improving the efficiency of core network facilities.

Regarding the CUPS architecture, a source of value for both operators and users, this article includes an overview of the architecture, additional control protocols, U-Plane control schemes based on traffic characteristics, and future developments toward a 5G Stand-Alone (5G SA) architecture.

The article is available here.

Related Posts: 

• The 3G4G Blog: Control and User Plane Separation of EPC nodes (CUPS) in 3GPP Release-14
• The 3G4G Blog: IP Multimedia Subsystem (IMS) Support for Service Based Architecture (SBA)
• The 3G4G Blog: Different Types of RAN Architectures - Distributed, Centralized & Cloud
• The 3G4G Blog: 5G RAN Functional Splits
• Telecoms Infrastructure Blog: NTT Docomo's 5G Network is based on 'Open RAN' Principles
• Telecoms Infrastructure Blog: NTT Docomo's 5G RAN Infrastructure
• The 3G4G Blog: A look at 5G Applications, Application Functions & Application Servers
• The 3G4G Blog: Three New Standards to Accelerate 5G Wireless Wireline Convergence (WWC)
• Free 6G Training: NTT Docomo is Hoping to Repeat 5G Experimental Trials Success with 6G
• Free 6G Training: NTT Docomo's revised '5G Evolution and 6G' White Paper 

Realizing Zero Trust Architecture for 5G Networks

Over the last couple of years, I keep on coming across Zero-Trust Architecture (ZTA). A simple way to explain is that the standard model of security is known as perimeter security model, where everything within the perimeter can be trusted. In zero-trust (ZT) model, no assumptions is made about trustworthiness and hence it is also sometimes known as perimeterless security model.

This short video from IBM clearly explains what ZT means:

This blog post from Palo Alto Networks also clearly explains ZT:

By definition, Zero Trust is a strategic approach to cybersecurity that secures an organization by eliminating implicit trust and continuously validating every stage of a digital interaction. Zero Trust for 5G removes implicit trust regardless of what the situation is, who the user is, where the user is or what application they are trying to access.

The impact of Zero Trust on network security specifically protects the security of sensitive data and critical applications by leveraging network segmentation, preventing lateral movement, providing Layer 7 threat prevention and simplifying granular user-access controls. Where traditional security models operate under the assumption that everything inside an organization’s perimeter can be trusted, the Zero Trust model recognizes that trust is a vulnerability.

In short, Zero Trust for 5G presents an opportunity for service providers, enterprises and organizations to re-think how users, applications and infrastructure are secured in a way that is scalable and sustainable for modern cloud, SDN-based environments and open-sourced 5G networks. Delivering the Zero Trust Enterprise means taking Zero Trust principles, making them actionable and effectively rebuilding security to keep pace with digital transformation. 

A research paper looking at Intelligent ZTA (i-ZTA) provides an interesting approach to security in 5G and beyond. The paper can be downloaded from here. The abstract states:

While network virtualization, software-defined networking (SDN), and service-based architectures (SBA) are key enablers of 5G networks, operating in an untrusted environment has also become a key feature of the networks. Further, seamless connectivity to a high volume of devices in multi-radio access technology (RAT) has broadened the attack surface on information infrastructure. Network assurance in a dynamic untrusted environment calls for revolutionary architectures beyond existing static security frameworks. This paper presents the architectural design of an i-ZTA upon which modern artificial intelligence (AI) algorithms can be developed to provide information security in untrusted networks. We introduce key ZT principles as real-time Monitoring of the security state of network assets, Evaluating the risk of individual access requests, and Deciding on access authorization using a dynamic trust algorithm, called MED components. The envisioned architecture adopts an SBA-based design, similar to the 3GPP specification of 5G networks, by leveraging the open radio access network (O-RAN) architecture with appropriate real-time engines and network interfaces for collecting necessary machine learning data. The i-ZTA is also expected to exploit the multi-access edge computing (MEC) technology of 5G as a key enabler of intelligent MED components for resource-constraint devices.

Ericsson Technology Review covered Zero Trust in 5G Networks in one of their issues. Quoting from the article:

The 3GPP 5G standards define relevant network security features supporting a zero trust approach in the three domains: network access security, network domain security and service-based architecture (SBA) domain security. 

The network access security features provide users with secure access to services through the device (mobile phone or connected IoT device) and protect against attacks on the air interface between the device and the radio node. Network domain security includes features that enable nodes to securely exchange signaling data and user data, for example, between radio and core network functions (NFs).

The 5G SBA is built on web technology and web protocols to enable flexible and scalable deployments using virtualization and container technologies and cloud-based processing platforms. SBA domain security specifies the mechanism for secure communication between NFs within the serving network domain and with other network domains. 

While the new requirements and functionality introduced in the 5G specifications are already aligned with many of the zero trust tenets. It is already evident, however, that further technology development, standardization and implementation are needed in areas such as policy frameworks, security monitoring and trust evaluation to support the adoption of zero trust architecture in new telecom environments that are distributed, open, multi-vendor and/or virtualized.

While various technologies can support organizations in adhering to the guiding principles of zero trust as part of their total active defense strategy, it is important to remember that technology alone will never be sufficient to realize the full potential of zero trust. Successful implementation of a network based on zero trust principles requires the concurrent implementation of information security processes, policies and best practices, as well as the presence of knowledgeable security staff. Regardless of where a CSP is in its transition toward a zero trust architecture, the three pillars of people, processes and technology will continue to be the foundation of a robust security architecture.

Related Posts:

• 3G4G: 5G Security Overview by Mpirical
• The 3G4G Blog: Key Technology Aspects of 5G Security by Rohde & Schwarz
• The 3G4G Blog: Bug hunting in 5G Networks and Devices
• The 3G4G Blog: Impact of 5G on Lawful Interception and Law Enforcement.
• The 3G4G Blog: AT&T Cybersecurity Experts Provide 5G Security Overview
• The 3G4G Blog: Everything you need to know about 5G Security
• The 3G4G Blog: Nokia Lectures in Collaboration with Bangalore University
• The 3G4G Blog: Lawful Intercept in 5G Networks
• The 3G4G Blog: 5G Roaming with SEPP (Security Edge Protection Proxy) 

IP Multimedia Subsystem (IMS) Support for Service Based Architecture (SBA)

I looked at IMS briefly in my LTE voice tutorial here. The Nokia Lectures covered IMS in-depth in part 5 of the video. I recently came across a short overview of IMS for SBA. You can see our old tutorial on Service Based Architecture (SBA) for 5G Core (5GC) here.

I came across this short video from Mpirical that nicely explains the IMS support for SBA. It's embedded below. The related posts at the bottom may also be worth checking out.

Related Posts:

• The 3G4G Blog: A quick starter on 4G voice (for beginners)
• The 3G4G Blog: Nokia Lectures in Collaboration with Bangalore University
• The 3G4G Blog - Tutorial: Service Based Architecture (SBA) for 5G Core (5GC)
• The 3G4G Blog: A look at 5G Applications, Application Functions & Application Servers
• The 3G4G Blog: EPS Fallback in 5G Standalone Deployments
• The 3G4G Blog: Voice over New Radio (VoNR) Establishment and Release between NG RAN and 5G Core
• The 3G4G Blog: Two Types of SMS in 5G
• The 3G4G Blog: 5G User Plane Redundancy
• The 3G4G Blog: Network Slicing using User Equipment Route Selection Policy (URSP) 

When can we Stop the 5G NSA Experiment?

Cross posting from LinkedIn, please post any comments there!

One of the advantages of having been in the industry for a very long time is one knows (and in my case, remembers) the hacks of each generation of mobile technology.

In case of UMTS (3G), the initial version had very poor data rates. Even though 3G was designed to bring data to the masses, there were hardly any applications that could take advantage of the mobile data connectivity. In addition, you could hardly get over 128 kbps (yes, kilo bits per second, not mega bits).

Most people think that the data part was added later on, as HSDPA, HSUPA (collectively HSPA) and HSPA+ from 3GPP Release-5 onwards. This is just one side of the story. The initial version of 3G had Downlink Shared Channel (DSCH) and Uplink Common Packet Channel (CPCH). As nearly all the patents were held by one very small company, none of the big vendors (both in network side as well and device side) implemented it (cartel?) and those channels eventually got removed from the standards.

Politics aside, until the arrival of HSPA, people couldn’t take advantage of mobile broadband.

LTE had already started being standardised while HSPA was being rolled out. LTE promised much higher data rates and reduction in the device power consumption, and it delivered! But… 

Have you heard this industry joke? When the standards engineers were designing 3G, 2G voice and SMS was generating most of income for the operators. Naturally they focussed on Voice and SMS and forgot to design data properly. When it came to design LTE, they focussed so much on data, they forgot to design the voice part.

Not My Job

Well, to be honest, 4G was always planned to be a packet switched (PS) only network, with a flatter and simplified architecture and protocols. With CS domain gone, the RRC and NAS protocols could be simplified. From a RAN engineer point of view, the voice calls would be voice over IP (VoIP) but the people who design the network telephony part didn’t get the memo.

The first set of LTE standards in Release-8 had to rely on this hack called CS Fallback. When nobody was taking ownership of the issue on hand, GSMA stepped in and created Voice over LTE (VoLTE) standards. It was based on the IMS standards that were bandied about for a long time but never got deployed fully. The standards was also complex and even after 8 years of it being standardised, it has still not been deployed everywhere.

5G for Everyone

I have been closely following the developments in 5G for over 6 years now. If you saw and heard the things I did, you would have believed that 5G is a panacea for all the world’s ills. In fact, in reality, it is just another generation of mobile network standards, astutely referred to as 5G JAG (Just Another Generation) by the outspoken industry analyst, Dean Bubley.

In the race to launch 5G by hook or by crook, the Non-Standalone (NSA) version of 5G, option 3 (technical name EN-DC) was launched. It gives the operators the ability to show 5G icon on you smartphones easily while not having to worry too much about delivering all the promises. If an operator has spare or a lot of spectrum, they can then use (some of) it to start transmitting on 5G New Radio (NR). If they don’t have much spectrum then they will have to do some kind of Dynamic Spectrum Sharing (DSS) to show the 5G icon. The problem with DSS is that while it would provide some kind of 5G to everyone capable of receiving it, it spoils the experience of the 4G users who are satisfied or happy with their LTE network.

5G Stands Alone

While all this had been going on, the operators have started buying new 5G spectrum, and started preparing and in many cases rolling out the Real Standalone 5G Network. If an operator has sufficient spectrum and the right kind of spectrum, they can now start to deliver on some of the actual 5G promises. 

I am aware of some of the operators who are already thinking about switching off their Non-Standalone EN-DC networks within the next couple of years. The initial 5G smartphones did not support the Standalone version of 5G networks so the operators will give them enough time to switch over to a newer device capable of standalone network.

So what would happen to a 5G device only supporting NSA 5G, after the NSA network is switched off?

Nothing really. It would still be able to do 4G (and 2G, 3G) which is generally good enough. They would stop seeing the 5G icon and in some cases, won’t benefit with the extra speeds boost.

Switching off 5G NSA will benefit the operator with the simplification of the network, not just from deployment point of view but also from optimization as there is no need for 4G-5G dual connectivity and for the 5G cell to be planned based on the 4G cell.

Industry’s View

5G Training ran a poll on LinkedIn to ask people involved in the 5G industry if they were happy with 5G NSA or would rather go with Standalone 5G, 6G or just satisfied with 4G. Surprisingly most people in the 5G industry said they were waiting for Standalone 5G. This was followed by “Looking forward to 6G!”. “Happy with existing 5G” got the least number of votes. 

This poll is by no measure reliable but it should force the operators, vendors and everyone else to ponder if it makes sense to move to SA sooner rather than later and to switch off NSA as soon as possible.

Non-Standalone Part 2

When the first set of 5G standards were being defined, it was felt that there should be a path to transition from 4G to 5G in the future. While the initial Option 3 (EN-DC) relied on 4G Core or EPC, these future NSA options can rely on 5G core.

Sometimes, in their zeal and enthusiasm, engineers define things that would make everyone’s lives difficult. These options are very much like that. While some operators have asked for Option 4, most people realise that it doesn’t make sense, at least right now to be creating more fragmentation in 5G deployment.

Hopefully rationality will prevail and any major architecture changes we do with 5G going forward will only be done after lots of analysing and thinking about the long term consequences. 

Please post any comments on LinkedIn as comments have been disabled on this post.

Different Types of RAN Architectures - Distributed, Centralized & Cloud

I come across a question relating to the different type of RAN architectures once per month on an average. Even though we have covered the topic as part of some or the other tutorial, we decided to do a dedicated tutorial on this.

The video and slides are embedded below

Beginners: Different Types of RAN Architectures - Distributed, Centralized & Cloud from 3G4G

As always, feedback and comments welcome.

Related Posts:

• The 3G4G Blog: Open RAN Terminology and Players
• The 3G4G Blog: A quick tutorial on Open RAN, vRAN & White Box RAN
• The 3G4G Blog: Open RAN Explanation, Videos, White papers and Other Resources
• The 3G4G Blog: O-RAN Introduction for Beginners
• Telecoms Infrastructure Blog: NTT Docomo's 5G Network is based on 'Open RAN' Principles
• Telecoms Infrastructure Blog: NTT Docomo's 5G RAN Infrastructure
• The 3G4G Blog: 5G RAN Functional Splits
• The 3G4G Blog: From traditional RAN to Open RAN - O-RAN: Goals and Challenges
• 3G4G: Open RAN, OpenRAN and O-RAN 

O-RAN Introduction for Beginners

Having been writing about Open RAN for a while, I thought it was important to make simple beginners tutorials for O-RAN. As my full time job* is with a company that is heavily involved in Open RAN and O-RAN, I had an insiders view for doing this project. 

I am making a series of videos for Parallel Wireless to help the industry become familiar with the technology and terminology. The playlist is embedded below:

Four of these are ready and more will be added as and when I get some time. Here is a summary of the videos available. Some of them also have a corresponding blog that I am linking below.

1. Introduction to O-RAN Philosophy: This explains the basics of O-RAN and how O-RAN is transforming the mobile networks industry towards open, intelligent, virtualized and fully interoperable RAN.
2. Introduction to O-RAN Timeline and Releases: This part looks at important timelines from the O-RAN Alliance, understand the O-RAN Software Community (OSC) and the role it plays in O-RAN, and finally, looks at the O-RAN Open-Source Software releases.
3. Introduction to O-RAN Architecture: This part looks at how the basic OpenRAN architecture is evolving into the O-RAN Alliance based Intelligent, Virtualized and Fully Interoperable RAN. It starts with a high-level ORAN architecture and then delves into details of Service Management and Orchestration (SMO), Non-Real-Time (Non-RT) RAN Intelligent Controller (RIC), Near-RT RIC and O-Cloud.
4. O-RAN Technical Steering Committee (TSC) & Workgroups: This part looks at O-RAN Technical Steering Committee (TSC) & Workgroups (WGs). The O-RAN TSC decides or gives guidance on O-RAN technical topics and approves O-RAN specifications prior to the Board approval and publication. The TSC consists of Member representatives and the technical workgroup co-chairs, representing both Members and Contributors. Within the TSC, there are 10 work groups, 4 focus groups, Open-Source Community and Minimum Viable Plan Committee. These have all been discussed within the video.
5. O-RAN Workgroup1: Task Groups and Deliverables: This part looks at O-RAN Workgroup#1 (WG1), its task groups and sub-task groups and finally the deliverables produced by WG1.
6. O-RAN Alliance Workgroup 2 and Workgroup 3: Specifications and Other Deliverables: This part looks at O-RAN Workgroup#2 (WG2) and Workgroup#3 (WG3) deliverables.

I am hoping that I will be able to do a few more parts and add a lot more information to the basics so a handy resource is available for anyone interested. Feel free to add links, suggestions, etc. in the comments below. 

Finally, The O-RAN ALLIANCE Story, June 2021 via @TelecomTV - https://t.co/tbU2fsabHi#Free5Gtraining #3G4G5G #4G #5G #OpenRAN #ORAN #ORANalliance #MWC21

— Free 5G Training (@5Gtraining) June 28, 2021

Related Posts:

• The 3G4G Blog: Open RAN Explanation, Videos, White papers and Other Resources
• 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.

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 

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 

Three New Standards to Accelerate 5G Wireless Wireline Convergence (WWC)

It's been just over a year since I wrote a detailed post on what I called '5G and Fixed-Mobile Convergence (FMC)'. The technical term being used in the industry for this feature is Wireless Wireline Convergence (WWC). 

BBF (@Broadband_Forum) has published 3 new standards to accelerate global 5G adoption - https://t.co/ufoHRfK3BE - Wireless Wireline Convergence (#WWC) allows Wi-Fi and other wireline technologies to be part of 5G#Free5Gtraining #5G #5GNetworks #5GTechnology #FMC #5GConvergence pic.twitter.com/OcCyLYix2b

— 5G Training (@5Gtraining) November 26, 2020

Broadband Forum, the communications industry’s leading open standards development organization focused on accelerating broadband innovation, standards, and ecosystem development has just announced the publication of three new standards to accelerate global 5G adoption. The press release said:

Building on the Forum’s mission to drive a future consolidated approach to 5G, the standards will reduce development time, as well as capex and opex, from the traditional disparate fixed broadband and 5G networks. Ultimately, they will deliver a common and managed broadband experience to the end-user whatever the final connectivity technology.

There are three major sets of technical specifications that have been finalized, including 5G Wireless Wireline Convergence Architecture (TR-470), Access Gateway Function (AGF) Functional Requirements (TR-456) and Device Data Model (TR-181). Together, these documents provide functions and interfaces for Fixed Mobile Convergence (FMC), the AGF, and customer premises equipment (CPE) such as 5G-enabled routers.

TR-470 – produced in conjunction with 3GPP – describes the 5G FMC architecture, providing a high-level guide for network architects and planners and enabling fixed and mobile functions to coexist over a shared infrastructure. This will facilitate multi-access connectivity and give consumers a seamless, access-independent service experience.

For operators, the network functions required to operate their infrastructure will be streamlined and common technology, on-boarding, training, services and subscriber management between fixed and mobile divisions can be achieved. Furthermore, additional revenue streams will be created, with FMC extending the geographical reach of 5G core networks and the service offering of fixed networks.

TR-456 describes the functional requirements of the AGF. The AGF resides between fixed access networks and the 5G core network to support 5G and wireline Residential Gateways, creating a truly converged deployment. Alongside this, Broadband Forum’s Device: 2 data model (TR-181 Issue 2 Amendment 14), which is used by User Services Platform (USP), has been extended to address 5G Residential Gateways. The Device: 2 data model applies to all types of TR-069 or USP-enabled devices, including end devices, Residential Gateways, and other network infrastructure devices

In addition, the Functional Requirements for Broadband Residential Gateway Devices (TR-124) specification is expected to be finalized in Q4 2020. Moving from the network into the home, TR-124 has been extended to add requirements related to the 5G Residential Gateway extending the 5G control plane to the premises to open up new service opportunities with real time fulfillment.

In the video below, David Allan, Work Area Director for Wireless-Wireline Convergence at Broadband Forum and Christele Bouchat, Innovation Group Director at Broadband Forum discuss what is coming up in the next phase of 5G work and what opportunities this has opened up for the industry

WWC has a great potential to allow wireline and trusted/untrusted Wi-Fi to work with 5G so I am hopeful that operators will adopt this sooner, rather than later.

Follow the links below to learn more about this feature.

Related Posts:

• Connectivity Technology Blog: 5G Wireline Access Architecture
• The 3G4G Blog: 5G and Fixed-Mobile Convergence (FMC)
• The 3G4G Blog: Introduction to 5G ATSSS - Access Traffic Steering, Switching and Splitting
• The 3G4G Blog: Exploring Network Convergence of Mobile, Broadband and Wi-Fi
• Operator Watch Blog: BT's Converged Core to Launch in 2023
• Operator Watch Blog: Jio Makes Another Set of Extremely Bold Announcements 

5G Non IP Data Delivery and Lightweight M2M (LwM2M) over NIDD

Earlier this year, MediaTek had announced that its MT2625 NB-IoT chip has been validated for LwM2M over NIDD on SoftBank Corp.’s cellular network across Japan. This achievement marks the first global commercial readiness of LwM2M over NIDD; a secure, ultra-efficient IoT communications technique that is being adopted by operators worldwide. The benefits of LwM2M over NIDD include security improvements, cost-efficient scalability and reduced power consumption.

LwM2M over NIDD is a combination of the communication technology "NIDD (Non-IP Data Delivery)" that does not use an IP address in LTE communication NB-IoT for IoT and the device management protocol "LwM2M (Lightweight M2M)" advocated by the Open Mobile Alliance. It's been a while since I wrote about Open Mobile Alliance on this blog. OMA SpecWorks is the successor brand to the Open Mobile Alliance. You can read all about it here.

OMA SpecWorks’ LightweightM2M is a device management protocol designed for sensor networks and the demands of a machine-to-machine (M2M) environment. With LwM2M, OMA  SpecWorks has responded to demand in the market for a common standard for managing lightweight and low power devices on a variety of networks necessary to realize the potential of IoT. The LwM2M protocol, designed for remote management of M2M devices and related service enablement, features a modern architectural design based on REST, defines an extensible resource and data model and builds on an efficient secure data transfer standard called the Constrained Application Protocol (CoAP). LwM2M has been specified by a group of industry experts at the OMA SpecWorks Device Management Working Group and is based on protocol and security standards from the IETF.

You can get all the LwM2M resources here and the basic specs of 'Lightweight M2M 1.1: Managing Non-IP Devices in Cellular IoT Networks' here.

The 5G Americas whitepaper 'Wireless Technology Evolution Towards 5G: 3GPP Release 13 to Release 15 and Beyond' details how Current Architecture for 3GPP Systems for IOT Service Provision and Connectivity to External Application Servers. It also talks about Rel-13 Cellular IoT EPS Optimizations which provide improved support of small data transfer over control plane and user plane. Control Plane CIoT EPS Optimization transports user data (measurements, ID, status, etc.) via MME by encapsulating user data in NAS PDUs and reduces the total number of control plane messages when handling a short data transaction. Control Plane CIoT EPS optimization, designed for small infrequent data packets, can also be used for larger data bursts depending in UE Radio capability.

User data transported using the Control Plane CIoT EPS Optimization, has special characteristics, as different mobility anchor and termination nodes.

Therefore, the Preferred Network Behavior signaling must include information on:

• Whether Control Plane CIoT EPS optimization is supported
• Whether User Plane CIoT EPS optimization is supported
• Whether Control Plane CIoT EPS optimization is preferred or whether User Plane CIoT EPS optimization is preferred

These optimizations have enabled:

• Non-IP Data Delivery (NIDD) for both: mobile originated and mobile terminated communications, by using SCEF (Service Capability Exposure Function) or SGi tunneling. However, it has to be taken into account that Non-IP PDUs may be lost and its sequence is not guaranteed
• For IP data, the UE and MME may perform header compression based on Robust Header Compression (ROHC) framework
• NB-IoT UE can attach but not activate any PDN connection
• High latency communication handled by the buffering of downlink data (in the Serving GW or the MME)
• SMS transfer
• EPS Attach, TA Update and EPS Detach procedures for NB-IoT only UEs, with SMS service request
• Procedures for connection suspend and resume are added
• Support for transfer of user plane data without the need for using the Service Request procedure to establish Access Stratum context in the serving eNodeB and UE

When selecting an MME for a UE that is using the NB-IoT RAT, and/or for a UE that signals support for CIoT EPS Optimizations in RRC signaling, the eNodeB’s MME selection algorithm shall select an MME taking into account its Release 13 NAS signaling protocol.

Mpirical has a nice short video explaining 5G Non IP Data Delivery. It is embedded below.

IoT has not taken off as expected and prophesised for years. While the OMASpecWorks is doing some fantastic work by defining simplified approach for IoT deployment, its current member list doesn't have enough operators to drive the uptake required for its spec adoption. They would argue that it doesn't matter how many members there are as the NIDD approach is completely optional and over-the-top. Let's wait and see how it progresses.

Related Posts:

• 3G4G: 5G Service Based Architecture (SBA)
• The 3G4G Blog: Mobile Initiated Connection Only (MICO) mode in 5G System
• The 3G4G Blog: Embedded SIM (eSIM) and Integrated SIM (iSIM)
• The 3G4G Blog: 5G and Industry 4.0
• 3G4G: Internet of Things (IoT) and Machine-2-Machine (M2M)
• The 3G4G Blog: M2M vs IoT
• The 3G4G Blog: What is Industrial IoT (IIoT) and how is it different from IoT?
• The 3G4G Blog: New 3GPP Release-17 Study Item on NR-Lite (a.k.a. NR-Light) 

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) 

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?