Showing posts with label 5G Stand-Alone. Show all posts
Showing posts with label 5G Stand-Alone. Show all posts

Thursday 20 October 2022

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:

Tuesday 2 August 2022

GSMAi Webinar: Is the Industry Moving Fast Enough on Standalone 5G?

I recently participated in a webinar, discussing one of my favourite topics, 5G Standalone (5G SA). If you do not know about 5G SA, you may want to quickly watch my short and simple video on the topic here.

Last year I blogged about GSA's 5G Standalone webinar here. That time we were discussing why 5G SA is taking time to deliver, it was sort of a similar story this time. Things are changing though and you will see a lot more of these standalone networks later this year and even early next year. 

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

Here are some of my thoughts on why 5G SA is taking much longer than most people anticipated:

  • 5G SA will force operators to move to 5G core which is a completely new architecture. The transition to this is taking much longer than expected, especially if there are a lot of legacy services that needs to be supported.
  • Many operators are moving towards converged core with 4G & 5G support to simply the core. This transition is taking long.
  • For taking complete advantage of 5G architecture, cloud native implementation is required. Some operators have already started the transition to cloud native but others are lagging.
  • 5G SA speeds will be lower than NSA speeds hence some operators who don't have a lot of mid-band spectrum are delaying their 5G SA rollouts.
  • Many operators have managed to reduce their latency as they start to move to edge datacentres, hence the urgency for 5G standalone has reduced.
  • Most operators do not see any new revenue opportunities because of 5G SA, hence they want to be completely ready before rolling out 5G SA
  • Finally, you may hear a lot about not enough devices supporting 5G SA but that's not the device manufacturers views.  See this tweet from GSA ðŸ‘‡

Do you agree with my reasoning? If not, please let me know in the comments.

Related Posts

Monday 23 May 2022

5G Reality Check - Data Rates

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

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

Video and Slides embedded below

Embedded below is the Twitter thread on Speedtests ðŸ˜‚

Related Posts

Thursday 24 February 2022

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:

Tuesday 1 February 2022

Bug hunting in 5G Networks and Devices

Pentests or Penetration testing is ethical hacking that is an authorized simulated cyberattack on a computer system, performed to evaluate the security of the system. They are performed to identify weaknesses or vulnerabilities, including the potential for unauthorized parties to gain access to the system's features and data, as well as strengths, enabling a full risk assessment to be completed.

Sébastien Dudek, Founder and Security Engineer at PentHertz did a presentation at No Hat conference 2021. The outline of his talk says:

Expected to be released in 2021, we only see the early stage of 5G-NR connectivity in rare places around the world and we cannot talk yet about "real 5G" as current installations are put on the Non-Standalone mode (NSA) using 4G infrastructures. But in the meantime, it is important to get prepared for this upcoming technology and ways we can practically simulate real-world attacks in the future, with Standalone (SA) mode-capable devices and networks. In this presentation, we will see how to conduct practical security assignments on future 5G SA devices and networks, and how to investigate the protocol stack. To begin the presentation, we briefly present the differences with 2G-5G in terms of security applied to security assessment contexts, i.e. the limit we are left with, and how to circumvent them. Then we see how a 5G-NR security testbed looks like, and discuss what type of bugs are interesting to spot. Third, we make more sense about some attacks on devices by showing attacks that could be performed on the core side from the outside. Finally, we briefly introduce how we could move forward by looking at the 5G protocol stack and the state of the current mean.

Slides are available here and the video is embedded below:

A post on their website also looks at penetration of standalone 5G core. The post contains a video as well which can also be directly accessed here.

A new white paper from 5G Americas provides nearly annual updates around the topic of security in wireless cellular networks. The current edition addresses emerging challenges and opportunities, making recommendations for securing 5G networks in the context of the evolution to cloud-based and distributed networks. 

Additionally, the white paper provides insight into securing 5G in private, public, and hybrid cloud deployment models. Topics such as orchestration, automation, cloud-native security, and application programming interface (API) security are addressed. The transition from perimeter-based security to a zero-trust architecture to protect assets and data from external and internal threats is also discussed.

Related Posts

Tuesday 7 December 2021

What will 5G Standalone deliver?


Surely you have heard me talk about the benefits of 5G Standalone and why is it needed. At Telecoms Europe 5G 2021, Dr. Kim K Larsen, CTIO, T-Mobile Netherlands, presented a talk on what exactly will 5G Standalone deliver. The video of his talk and slides are embedded below.

If mobile economics is an area of interest, you may want to check out his old blog posts which are quite detailed. Here.

Related Posts:

Tuesday 30 November 2021

Will Wi-Fi Help 3GPP Bring Reliable Connectivity Indoors?

I have argued a few times now that it would make much more sense to be able to make access and core independent of each other. 3GPP 5G Standards already have a feature available from Release-16 onwards that enables this with 5G Core, Standalone networks.

We use our smart devices currently for voice and data communications. When we are indoor, many times the data goes over Wi-Fi. This is what tempted operators to move to WiFi for voice solution as well. Many operators are now enabling Voice of WiFi in their network to provide reliable voice coverage indoors.

While this works currently without any issues, when operators start offering new native services and applications, like XR over 5G, the current approach won't help. When our devices are connected over Wi-Fi at present, they are unable to take advantage of operator core or services. With access and core independence, this will no longer be an issue.

I gave a short (15 mins) virtual presentation at 5G Techritory this year. I argued not just for WWC but also looked at what 5G features have a potential for revolution. It's embedded below.

Related Posts:

Thursday 11 November 2021

Network Slicing using User Equipment Route Selection Policy (URSP)

Google announced that its latest smartphone OS will include support for 5G network slicing. Last week Telecom TV brought this news to my attention. The article explains:

It's a move designed to leverage its expertise in devices in order to give it the edge over its rival hyperscalers.

It comes in two flavours. The first is for enterprise-owned handsets, and routes all data sent and received by a device over the network slices provided by that company's mobile operator. Android 12 gives operators the ability to manage slices using a new dynamic policy control mechanism called User Equipment Route Selection Policy (URSP). URSP enables devices to automatically switch between different network slices according to which application they are using. For example, someone working for a financial institution might require a highly-secure network slice for sending and receiving sensitive corporate data, but will then require a reliable, high-throughput, low-latency slice so they can participate in a video meeting.

The second flavour is implemented in the work profile. For years, enterprises have had the option of creating work profiles on Android devices – irrespective of whether they are owned by the organisation or the individual – to use as a separate repository for enterprise apps and data. When Android 12 comes out next year, enterprises will be able to route data to and from that repository over a network slice.

Google said it has already carried out network slicing tests with both Ericsson and Nokia using test versions of its recently released Pixel 6 smartphone running on the as-yet-unreleased Android 12 OS.

Last week Taiwanese operator Far EasTone (FET) and Ericsson announced they have completed the world’s first proof of concept (PoC) for simultaneously connecting multiple network slices per device running on Android 12 commercial release. The press release said:

The trial, carried out on FET’s 5G standalone (SA) infrastructure built on Ericsson’s radio access network and cloud-native Core network, successfully demonstrated the 5G user equipment slicing policy feature (User Equipment Route Selection Policy, or URSP) on multiple Android devices. This marks a breakthrough in network slicing capabilities on a 5G standalone network and paves the way for further ecosystem development in this important area.

With more 5G networks evolving to standalone architecture around the globe, end-to-end network slicing, which includes Ericsson RAN Slicing to secure Quality of Service (QoS) differentiation, plays a key role in enabling new services for end users, with which multiple virtual 5G networks are created on top of one physical network. The 5G trial, in collaboration with FET, Ericsson and Android, went even further in network slicing capabilities by introducing and demonstrating 5G user equipment (UE) slicing policy (URSP) features that allow devices to simultaneously operate on dynamic policy control and selection between multiple 5G network slices. This enables the steering of applications and services with specific requirements to defined slices without switching devices.

Multiple slices allow devices to have multiple profiles to secure different levels of experience, security, and privacy requirements, based on the needs of the different applications and in correspondence with the user profile.  For instance, a device can have a personal profile with private data from apps or off-work entertainment, and a work profile with enterprises productivity apps. With URSP features, employers can customize the work profile with increased security and enable better use of RAN Slicing with QoS so that enterprise-related apps can work even during network congestion.

Some security-sensitive apps, such as mobile banking, can also benefit from different routing mechanisms of the traffic enabled by URSP. For instance, the banking app would not need to send its traffic to the internet and then to the app server as it does today. Instead, it could go straight to the app server and avoid the routing through internet. With the shortest route by connecting to a defined slice, users could reduce the risk of being attacked by hackers.

In their technical whitepaper on Network Slicing, Samsung explains: 

Along with the concept of network slicing and features in the RAN and Core network, UE Route Selection Policy (URSP) is introduced as a way to manage network slice information for the UE. URSP is a network slice feature enabled by the PCF which informs the network slice status to the UE via the AMF. In 4G network systems, it was near impossible to install new services in the network for a UE. But through the URSP feature, 5G network operators can easily configure new service for a UE. Figure 12 (top of this blog post) shows the difference in network slice selection in 4G and 5G Network. In 5G network, slice selection policy can be configured dynamically through URSP, while slice selection policy is pre-defined and cannot be changed dynamically in 4G network.

URSP contains OSId, AppId, IP descriptors to define the application and Single-Network Slice Selection Assistance Information (S-NSSAI), Data Network Name (DNN), Session and Service Continuity (SSC) mode information for the application and network slice mapping.

The S-NSSAI identifies each network slice service and provides information to properly assign network slice/functions. An S-NSSAI is comprised of:

  • A Slice/Service type (SST), which refers to the expected network slice behavior in terms of features and services;
  • A Slice Differentiator (SD), which is an optional information that complements the Slice/Service type(s) to differentiate amongst multiple network slices of the same Slice/Service type.

3GPP allows the use of the Slice Differentiator (SD) field that can build customized network slices. The SD field can be used to describe services, customer information and priority.

Here is a short video from Mpirical explaining 5G UE Route Selection.

It it worth reminding here that this feature, like many of the other 5G features, is dependent on 5G Core. We hope that the transition to 5G Standalone Networks happens as soon as possible.

Related Posts:

Thursday 4 November 2021

Voice over New Radio (VoNR) Establishment and Release between NG RAN and 5G Core

In this video I explain how QoS Flows for VoNR are established and released especially on N2 reference point between 5G Core and NG RAN.

The pervious video about generic aspects of "QoS Flow Establishments in 5G Standalone RAN and Core" you will find in the first link of the Related Posts listed below:

Monday 20 September 2021

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.

Monday 14 June 2021

A mmWave Special Cell in Open RAN Environment

NR RRC signaling messages exchanged for establishing a 5G radio connection, in particular the NR RRC Reconfiguration and NR RRC CG Config messages, contain a parameter called "SpCellID", which refers to the Special Cell ID. 

The concept of the Special Cell already exists in 3GPP LTE Advanced standards. Here a Special Cell is set of physical cells with same or different carrier frequency and physical cell ID (PCI) that overlap in a certain geographical area and thus, are combined for data transmission to/from UEs located in this area.

This concept now also gains high importance for 5G NR mmWave spectrum and here is why:

Many 5G mmWave radio transmitters can only handle a maximum bandwidth of 100 MHz, but the radio sector shall be covered with total bandwidth of e.g. 600 MHz. To achieve this six mmWave radio transmitters are installed in parallel at the same spot covering the same footprint. 

Each transmitter is identified on the radio interface by its own dedicated NR ARFCN (carrier frequency) and PCI. Thus, from UE point of view the sector is covered with 6 dedicated NR cells that all together form a Special Cell.

When a UE gets radio resources assigned in this 5G sector one of  the 6 cells is the Primary Cell, which NR CGI (Cell Global Identity) is then used as Special Cell ID in layer 3 signaling messages. All other cells act as Secondary Cells.

In an Open RAN environment the F1AP protocol allows perfect analysis of the SpCell resource allocation since it contains the SpCellID as well as all SCellIDs to be setup in the call. 

If the gNB-DU fails to allocated resources for a particular Secondary Cell this will also be signaled together with a failure cause value on F1AP as illustrated in the figure below. Also radio link failures occurring within the Special Cell will be signaled on F1AP including a cause value that provides deeper insight than  protocol causes seen on X2AP (in case of 5G NSA connections) or NGAP (in case of 5G SA connections). 

(click on image to enlarge)


Sunday 21 March 2021

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.

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

Thursday 6 August 2020

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

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


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

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



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


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


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


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


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

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

Related Posts: