What is a Multi-Band Cell?

Multi-band cells became very popular in modern RAN environment and beside many benefits they also come with some challenges for performance measurement and radio network optimization.

A multi-band cell consists of a default band that shall be used by UEs for initial cell selection and a set of additional frequency band carriers that typically become involved as soon as a dedicated radio bearer (DRB) for payload transmission is established in the radio connection.

The exact configuration of a multi-band cell including all available frequency bands is broadcasted in SIB 1 as shown in the example below.

Different from legacy RAN deployments where – to take the example of a LTE cell – a pair of PCI/eARFCN (Physical Cell Identity/eUTRAN Absolute Radio Frequency Number) always matches a particular ECGI (eUTRAN Cell Global Identity) the multi-band cell has many different PCI/eARFCN combinations belonging to a single ECGI as you can see in the next figure.

Now performance measurement (PM) counters for e.g. call drops are typically counted on the cell ID (ECGI) and thus, in case of mulit-band cells do not reveal on which frequency a radio link failure occurred.

However, knowing the frequency is essential to optimize the radio network and minimize connectivity problems. More detailed information must be collected to find out which of the different frequency bands performs well and which need improvement.

This becomes even more interesting if multi-band cells are used in MORAN RAN sharing scenarios.

In my next blog post I will have a closer look at this special deployment.

Related Posts:

• The 3G4G Blog: How Multiband-Cells are used for MORAN RAN Sharing 

Tutorial on 4G/5G Mobile Network Uplink Working and Challenges

People involved with mobile technology know the challenges with uplink for any generation of mobile network. With increasing data rates in 4G and 5G, the issue has become important as most of the speeds are focused on download but upload speeds are quite poor.

Speedtests are still the 5G killer app (#5GKillerApp) right now. Fantastic speeds from Verizon 5G Ultra Wideband (UWB) #5GBuiltRight. Upload speeds 250+ Mbps but notice how to hold the phone right to get these speeds 🤫https://t.co/DS18IOw8AW

— 3G4G (@3g4gUK) February 12, 2021

Even without massive MIMO mobile networks are uplink limited. We've always engineered networks accordingly.

— Andy Sutton (@960sutton) June 5, 2019

People who follow us across our channels know of many of the presentations we share across them from various sources, not just ours. One such presentation by Peter Schmidt looked at the uplink in details. In fact we recommend following him on Twitter if you are interested in technical details and infrastructure.

The details of his talk as follows:

The lecture highlights the influences on the mysterious part of mobile communications - sources of interference in the uplink and their impact on mobile communication as well as practices for detecting sources of RF interference.

The field strength bar graph of a smartphone (the downlink reception field strength) is only half of the truth when assessing a mobile network coverage. The other half is the uplink, which is largely invisible but highly sensitive to interference, the direction from the end device to the base stations. In this lecture, sources of uplink interference, their effects and measurement and analysis options will be explained.

Cellular network uplink is essential for mobile communication, but nobody can really see it. The uplink can be disrupted by jammers, repeaters, and many other RF sources. When it is jammed, mobile communication is limited. I will show what types of interference sources can disrupt the uplink and what impact this has on cellular usage and how interference hunting can be done.

First I explain the necessary level symmetry of the downlink (from the mobile radio base station - eNodeB to the end device) and the uplink (from the end device back to the eNodeB). Since the transmission power of the end device and eNodeB are very different, I explain the technical background to achieving symmetry. In the following I will explain the problems and possibilities when measuring uplink signals on the eNodeB, it is difficult to look inside the receiver. In comparison, the downlink is very easy to measure, you can see the bars on your smartphone or you can use apps that provide detailed field strength information etc. However, the uplink remains largely invisible. However, if this is disturbed on the eNodeB, the field strength bars on the end device say nothing. I will present a way of observing which some end devices bring on board or can be read out of the chipset with APPs. The form in which the uplink can be disrupted, the effects on communication and the search for uplink sources of disruption will complete the presentation. I will also address the problem of 'passive intermodulation' (PIM), a (not) new source of interference in base station antenna systems, its assessment, measurement and avoidance.

The slides are available here. The original lecture was in German, a dubbed video is embedded below:

If you know of some other fantastic resources that we can share with our audience, please feel free to add them in the comments.

Related Posts: 

• The 3G4G Blog - Radio Design Webinar: Optimising Your 700 MHz Deployments
• The 3G4G Blog: 2G/3G Shutdown may Cost Lives as 4G/5G Voice Roaming is a Mess
• The 3G4G Blog: Lawful Intelligence and Interception in 5G World with Data and OTT Apps
• The 3G4G Blog: Transitioning from eCall to NG-eCall and the Legacy Problem
• The 3G4G Blog: ATIS Webinar on '5G Standards Development Update in 3GPP Release 17 and 18'
• The 3G4G Blog: 3GPP Release-17 5G NR Reaches Completion
• The 3G4G Blog: 5G Network Slicing for Beginners
• The 3G4G Blog: Everything you need to know about 5G Security 

2G/3G Shutdown may Cost Lives as 4G/5G Voice Roaming is a Mess

You have probably heard me a complaining about the pace of VoLTE rollout, 2G/3G shutdowns, 4G Voice roaming, etc. This post highlights all these issues coming together in a dangerous way. People often ask me why is it that it's always just me highlighting the issues. The answer is that there are other people but their voice may not reach you. In this post, I am highlighting presentations by Rudolf van der Berg, Project and programme manager at Stratix Consulting.

No more voice roaming in USA! French operator Free warns customers that telephony in USA doesn't work. 2G/#3G shutdown and lack of #VoLTE standardisation and roaming are the cause. Its customers can only use Internet and SMS, but not E.164 number based voice telephony and 911! https://t.co/cbBrNZTskq

— Rudolf van der Berg (@internetthought) April 6, 2022

Let's start with Rudolf's post from LinkedIn:

Stop the shutdown of 2G and 3G networks to save lives. This is the urgent call I make today and I hope you can help me spread it! Please call on people you know in politics, regulators and emergency services to demand a stop! Call on anyone you know in the GSMA, 3GPP, handset makers (Apple, Samsung, Qualcomm, MediaTek), network builders (Ericsson, Nokia, Huawei) to re-engineer VoLTE to an interoperable standard.

Emergency calls (112, 911) should work anywhere in the world on any phone. For GSM and 3G voice calling it did. You could fly anywhere and call emergency services and in the EU we have the roaming regulation that demands calling like at home. Voice over 4G and 5G hasn't been properly standardized and isn't interoperable between networks, devices, chipsets and firmware. People need to be able to make and receive telephone calls around the world, to each other and to emergency services. Unfortunately even according to sector itself emergency services are at risk from VoLTE. A consumer today can't know whether a phone they bought will make VoLTE calls at home or abroad, nor whether it can reach emergency services. That can't be right!

So please help EENA 112 and me share this message! Thank you #eena2022 (Slide 4 contains a mistake, T-Mo USA hasn't decided on 2G shutdown yet. that is good for availability of 911, though fundamental point remains. Apologies.)

Dear foreigner, AT&T regrets you die because you can't dial 911. Try whatsapp and ask a friend in the US to call 911 for you. https://t.co/KqliBXv4ik

— Rudolf van der Berg (@internetthought) April 15, 2022

The video and slides are embedded below:

The slides contain many useful references and links, you can download directly from here.

Back in April, iBASIS hosted a VoLTE and 5G Roaming Roundtable. You can watch the video here and download the presentation and whitepaper as well. It contains talks from Kaleido Intelligence, iBASIS, KPN, Bouygues Telecom and Telus. 

The slide from Dutch MNO KPN above highlights the VoLTE Roaming issues they are observing. Other operators will face this issue sooner or later as well. 

So they are the ones who should be asked to make sure that VoLTE and VoNR is interoperable between vendors and MNOs? Because people will die if we don't fix this. See my presentation from last week https://t.co/Ju3GadO9ie

— Rudolf van der Berg (@internetthought) May 5, 2022

The Regulators, GSMA and 3GPP have to come together to fix this important issue for once and all so no lives are lost because of this. Hopefully someone is listening!

Related Posts: 

• The 3G4G Blog: Transitioning from eCall to NG-eCall and the Legacy Problem
• The 3G4G Blog: GSMA Releases Mobile Economy Report 2022
• The 3G4G Blog: When will 2G & 3G be switched off now that 5G is here?
• The 3G4G Blog: VoLTE Hacking
• The 3G4G Blog: A quick starter on 4G voice (for beginners) 

Transitioning from Cloud-native to Edge-Native Infrastructure

We have looked at what we mean by cloud-native in an earlier post here. Recently we also looked at edge-native infrastructure here. While we have been debating between cloud and edge for a while, in a new presentation (embedded below), Gorkem Yigit, Principal Analyst, Analysys Mason argues that the new, distributed IT/OT applications will drive the shift from cloud-native to edge-native infrastrcuture.

The talk by Gorkem on '5G and edge network clouds: industry progress and the shape of the new market' from Layer123 World Congress 2021 is as follows:

A blog post by ADVA has a nice short summary of the image on the top that was also presented at a webinar earlier. The following is an extract from that blog post: 

The diagram compares hyperscale (“cloud-native infrastructure”) on the left with hyper-localized (“edge-native infrastructure”) on the right.

• Computing: The traditional hyperscale cloud is built on centralized and pooled resources. This approach enables unlimited scalability. In contrast, compute at the edge has limited scalability, and may require additional equipment to grow applications. But the initial cost at the edge is correspondingly low, and grows linearly with demand. That compares favorably to the initial cost for a hyperscale data center, which may be tens of millions of dollars.
• Location sensitivity and latency: Users of the hyperscale data center assume their workloads can run anywhere, and latency is not a major consideration. In contrast, hyper-localized applications are tied to a particular location. This might be due to new laws and regulations on data sovereignty that require that information doesn’t leave the premises or country. Or it could be due to latency restrictions as with 5G infrastructure. In either case, shipping data to a remote hyperscale data center is not acceptable.
• Hardware: Modern hyperscale data centers are filled with row after row of server racks – all identical. That ensures good prices from bulk purchases, as well as minimal inventory requirements for replacements. The hyper-localized model is more complicated. Each location must be right-sized, and supply-chain considerations come into play for international deployments. There also may be a menagerie of devices to manage.
• Connectivity: Efficient use of hyperscale data centers depends on reliable and high-bandwidth connectivity. That is not available for some applications. Or they may be required to operate when connectivity is lost. An interesting example of this case is data processing in space, where connectivity is slow and intermittent.
• Cloud stack: Hyperscale and hyper-localized deployments can host VMs and containers. In addition, hyper-localized edge clouds can host serverless applications, which are ideal for small workloads.
• Security: Hyperscale data centers use a traditional perimeter-based security model. Once you are in, you are in. Hyper-localized deployments can provide a zero-trust model. Each site is secured as with a hyperscale model, but each application can also be secured based on specific users and credentials.

You don’t have to choose upfront

So, which do you pick? Hyperscale or hyper-localized?

The good news is that you can use both as needed, if you make some good design choices.

• Cloud-native: You should design for cloud-native portability. That means using technologies such as containers and a micro-services architecture.
• Cloud provider supported edge clouds: Hyperscale cloud providers are now supporting local deployments. These tools enable users to move workloads to different sites based on the criteria discussed above. Examples include IBM Cloud Satellite, Amazon Outposts, Google Anthos, Azure Stack and Azure Arc.

You can also learn more about this topic in the Analysys Mason webinar, “From cloud-native to edge-native computing: defining the cloud platform for new use cases.”. You can also download the slides from there after registration.

Related Posts: 

• The 3G4G Blog: What is Cloud Native and How is it Transforming the Networks?
• The 3G4G Blog: Realizing Zero Trust Architecture for 5G Networks
• The 3G4G Blog: Edge Computing Tutorial from Transforma Insights
• The 3G4G Blog: 3GPP Standards on Edge Computing
• The 3G4G Blog: Edge Computing - Industry Vertical Viewpoints
• The 3G4G Blog: Webinar: Where Edge Meets Cloud by Dean Bubley
• Telecoms Infrastructure Blog: AWS for Public and Private 5G Networks
• Telecoms Infrastructure Blog: SK Telecom’s 5G MEC Status and Plan
• Telecoms Infrastructure Blog: Operator Cloud Infrastructure and Innovation Strategy
• Operator Watch Blog: How is KT Reducing the Latency of their 5G Network 

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

Opinion – 5G Reality Check: Speeds from 3G4G

Embedded below is the Twitter thread on Speedtests 😂

Speed Tests are 5G killer app 😉, @HarriHolma provides details in replies: Elisa 100 MHz 5G (8T8R radio) on 3.5 GHz with LTE dual connectivity (EN-DC). LTE phone gives 200-250 Mbps in the same spot. The configuration uses L800+L1800+L2100 #5GKillerApp https://t.co/5ZnS2UeFkL

— 3G4G (@3g4gUK) November 18, 2019

Related Posts: 

• The 3G4G Blog: IMT-2020 (5G) Requirements
• The 3G4G Blog: Would 5G NSA undergo Sunset? When?
• The 3G4G Blog: The Politics of Standalone vs Non-Standalone 5G & 4G Speeds
• The 3G4G Blog: 5G SpeedTests and Theoretical Max Speeds Calculations
• The 3G4G Blog: Theoretical Throughput Calculation of FDD 5G New Radio (NR)
• The 3G4G Blog: The path from 4.5G to 5G
• The 3G4G Blog: Throughput Comparison for different wireless technologies
• Operator Watch Blog: EE Combines More 4G and 5G Spectrum for Even Higher Data Rates
• Operator Watch Blog: USA has an interesting mix of different types of 5G
• Operator Watch Blog: Is Saudi Arabia Winning the 5G Race?
• Operator Watch Blog: LG Uplus Tests 5G in 28GHz band using 800MHz Bandwidth. Sees AR as 5G Killer App 

Lawful Intelligence and Interception in 5G World with Data and OTT Apps

Not long ago we looked at the 'Impact of 5G on Lawful Interception and Law Enforcement' by SS8. David Anstiss, Senior Solutions Architect at SS8 Networks gave another interesting talk on Evolving Location and Encryption Needs of LEAs in a 5G world at Telecoms Europe Telco to Techco virtual event in March.

In this talk, David provided an insight in​to how 5G is impacting lawful interception and the challenges Law Enforcement Agencies face as they work with Communication Service Providers to gather intelligence and safeguard society. While there is an overlap with the previous talk, in this video David looked at a real world example with WhatsApp. The talk also covered:

• Real-world problems with 5GC encryption
• 5G location capabilities and the impact on law enforcement investigations
• Optimal solutions for both CSPs and LEAs

The video of the talk is embedded below:

Related Posts:

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

Transitioning from eCall to NG-eCall and the Legacy Problem

eCall (an abbreviation of "emergency call") is an initiative by the European Union, intended to bring rapid assistance to motorists involved in a collision anywhere within the European Union. The aim is for all new cars to incorporate a system that automatically contacts the emergency services in the event of a serious accident, sending location and sensor information. eCall was made mandatory in all new cars sold within the European Union as of April 2018.

In UK, the National Highways have a fantastic summary of the eCall feature here. The following video explains how this feature works:

Last year, ETSI hosted the Next Generation (NG) eCall webinar and Plugtests. The presentations from the event are available here. The presentations from GSMA, Qualcomm and Iskratel have a fantastic summary of many of the issues and challenges  with eCall and transitioning to NG eCall.

From the Qualcomm presentation:

The eCall standardisation began in 2004 when 2G networks were prevalent and 3G was being deployed. The chosen solution was in-band modem and Circuit Switched (CS) 112 call. The in-band modem was optimised for GSM (2G) and UMTS (3G) as the standard completed in 2008.

eCall for 4G (NG eCall) standardisation was started in 2013 and completed in 2017. As there is no CS domain in 4G/5G, IMS emergency calling will replace circuit switched emergency call. Next generation (NG) eCall provides an extension to IMS emergency calls and support for 5G (NR) has since been added.

The picture above from GSMA presentation highlights the magnitude of the problem if NG eCall deployment is delayed. GSMA is keen for the mobile operators to switch off their 2G/3G networks and only keep 4G/5G. There are problems with this approach as many users and services may be left without connectivity. Fortunately the European operators and countries are leaving at least one previous generation of technology operational for the foreseeable future.

GSMA's presentation recommends the following:

• New technology neutral eCall Regulation (type approval and related acts) to be amended, adopted by European Commission and enter into force by end 2022 the latest.
• OEMs to start installing NG eCall /remotely programable/exchangeable modules by end 2022; by end 2024 all new vehicles sold in the market should be NG eCall only
• New vehicle categories to start with NG eCall only by 2024
• MNOs have initiated to phase out 2G/3G between 2020 and 2025 , whereas the optimal transition path of their choice beyond this date will depend on market and technology specifics, and may require alignment with NRAs.
• By 2022 , the industry will develop solutions for the transition period that need to be implemented country by country, which will also assess the amount of needed public funding to be economically feasible.
• Retrofitting to be acknowledged, completed and formalised as a process by end 2024; standards should already be available in 2022.
• Aftermarket eCall solution to be completed (including testing) and formalised by end 2024; standards should already be available in 2022.
• The European Commission to make available public funding to support OEMs and alternative solutions to legacy networks starting from 2022 , under the RRF/ recovery package (or other relevant instruments)
• Legacy networks availability until 2030 at the latest. By then deployment of all alternative solutions simultaneously would have ensured that the remaining legacy fleet will continue to have access to emergency services through NG eCall.

EENA, the European Emergency Number Association, is a non-governmental organisation whose mission is to contribute to improving people’s safety & security. One of the sessions at the EENA 2021 Conference was on eCall. The video from that is embedded below and all information including agenda and presentations are available here.

Related Posts:

• The 3G4G Blog: When will 2G & 3G be switched off now that 5G is here?
• The 3G4G Blog: GSMA Releases Mobile Economy Report 2022
• The 3G4G Blog: Are there 50 Billion IoT Devices yet?
• The 3G4G Blog: Study of Use cases and Communications Involving IoT devices in Emergency Solutions 

ATIS Webinar on '5G Standards Development Update in 3GPP Release 17 and 18'

Our blog post on ATIS Release-16 webinar has been one of the popular posts so it's no brainer that people will surely find this Release 17/18 update useful as well. 

The moderator for this webinar was Iain Sharp, Principal Technologist at ATIS. The following were the speakers and the topics they spoke on:

• Services: Greg Schumacher, Global Standards, T-Mobile USA
• Systems Architecture and Core Networks: Puneet Jain, Principal Engineer and Director of Technical Standards at Intel Corporation, and 3GPP SA2 Chairman
• Radio Access Network: Wanshi Chen, Senior Director,Technology at Qualcomm, and 3GPP RAN Chairman

Here is a summary of the webinar:

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

The webinar will cover:

• The status of 3GPP's work and the organization's roadmap for the future
• The main themes the delivered Release 17 features in 3GPP specifications
• How enhancements to 5G are helping the 5G market proposition (e.g., through new service opportunities, or enhanced efficiency of 5G networks)

The webinar will give a technical overview of 3GPP's Release 17 content and its benefits to 5G networks. It is suitable for people in technical roles and technical executives who want to understand the current state of 5G standardization.

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

Glad to see that 3GPP Rel-19 work has already started as can be seen in the roadmap below.

(click to enlarge)

Related Posts: 

• The 3G4G Blog: 3GPP Release-17 5G NR Reaches Completion
• The 3G4G Blog: 3GPP Release-18 Work Moves Into Focus as Release-17 Reaches Maturity
• The 3G4G Blog: ATIS Webinar on '5G Standards Developments in 3GPP Release 16 and Beyond'
• Free 6G Training: Transatlantic perspectives on 6G Vision, Roadmap and Development Model 

Edge Computing Tutorial from Transforma Insights

Jim Morrish, Founding Partner of Transforma Insights has kindly made an in-depth Edge Computing Tutorial for our channel. Slides and video is embedded below.

In this tutorial Jim covers the following topics:

• Definitions of Edge Computing.
• How and why Edge Computing is used.
• Planning for deployment of Edge Computing.
• Forecasts for Edge Computing.

Technology Introduction Series: Edge Computing tutorial.pdf from 3G4G

We would love to know if this answers your questions on this topic. If not, please feel free to post your questions below.  

Related Posts: 

• The 3G4G Blog: 3GPP Standards on Edge Computing
• The 3G4G Blog: Edge Computing - Industry Vertical Viewpoints
• The 3G4G Blog: 3GPP Presentations from CEATEC Japan 2021
• The 3G4G Blog: What is Cloud Native and How is it Transforming the Networks?
• The 3G4G Blog - Webinar: Where Edge Meets Cloud by Dean Bubley
• The 3G4G Blog: Can Augmented & Mixed Reality be the Killer App 5G needs?
• Telecoms Infrastructure Blog: AWS for Public and Private 5G Networks
• Telecoms Infrastructure Blog: Edge Computing and the Future of Small Cell Networks
• Telecoms Infrastructure Blog: SK Telecom’s 5G MEC Status and Plan
• Telecoms Infrastructure Blog: Operator Cloud Infrastructure and Innovation Strategy
• Free 6G Training - 6G in the sky: On-demand intelligence at the edge of 3D networks
• Operator Watch Blog: How is KT Reducing the Latency of their 5G Network
• Connectivity Technology Blog: C-V2X and 5G for Vehicular Connectivity
• The 3G4G Blog: Are there 50 Billion IoT Devices yet? 

Holographic Display - The *Wow* Demo from MWC 2022

(click image to see larger picture)

We often associate holograms with futuristic technology and even 6G nowadays but what if holograms could be done in a very simple way just by playing with light? 

This is a *wow* demo from Japan Pavilion in Hall 4 at #MWC22 pic.twitter.com/0SYPBPCB8E

— Zahid Ghadialy (@zahidtg) March 2, 2022

At Mobile World Congress 2022, the demo that impressed me most was by a Japanese company called Asukanet. Their ASKA 3D Plate projects images in mid air. This in combination with a 3D sensor allows to manipulate the display without touching. It may be easier to understand this by looking at how this works in the largest convenience store in Japan as shown in the video below:

This is the demo video that I got at MWC

This is us playing with the hologram

While it may not be straightforward, it would complement our smartphones or tablets display nicely. 

You can watch some of the use cases on their page here.

Let me know what you think?

Related Posts:

• Free 6G Training: Fujitsu’s Vision of B5G and 6G
• Free 6G Training: 6G may just make Teleportation a Reality
• Free 6G Training: Transmission of Taste gets a Step Closer to Reality
• The 3G4G Blog: A quick case study on Smartwatches
• The 3G4G Blog: The Futuristic Concept of 'Smart & Intelligent' Batteries