QoS Flow Establishments in 5G Standalone RAN and Core

Today I launched a new video on my YouTube channel that explains how QoS Flows are established in 5G RAN and Core. It also highlights the main differences between 4G E-RAB handling and 5G QoS Flows.

Related Posts: 

• The 3G4G Blog: Anomaly Detection and other AI Algorithms in RAN Optimization
• The 3G4G Blog: How to Identify Network Slices in NG RAN
• The 3G4G Blog: Network Slicing in NG RAN
• The 3G4G Blog: Network Slicing Tutorials and Other Resources
• The 3G4G Blog: Artificial Intelligence (AI) / Machine Learning (ML) in 5G Challenge by ITU
• The 3G4G Blog: Conditional Handover (Rel. 16) Explained
• The 3G4G Blog: UE Radio Capability Signaling Optimization (RACS) in Rel. 16 

A Look at the same RRC Message in LTE and 5G Stand-alone Call Scenarios

Some weeks ago the differences in 4G LTE RRC (3GPP 36.331) and 5G NR RRC (3GPP 38.331) and how both protocols interact in EN-DC call scenarios have been discussed in another blog post.

Now I would like to share a visual comparison of the RRC (Connection) Setup Complete message as it is seen in LTE (including EN-DC) and 5G stand-alone (SA) radio connections.

From the figure below one can see that although this message fulfills the same purpose in both radio access technologies its particular contents may look quite differently.

Different variants of RRC (Connection) Setup Complete message in LTE and 5G stand-alone call scenarios

IEEE Globecom 2014 Keynote Video: 5G Wireless Goes Beyond Smartphones

Embedded below is a video from the keynote session by Dr. Wen Tong of Huawei. I do not have the latest presentation but an earlier one (6 months old) is also embedded below for reference. It will give you a good idea on the 5G research direction

5G Wireless Goes Beyond Smartphones from Zahid Ghadialy

You may also be interested in this other presentation from Huawei in IEEE Globecom 2014, 5G: From Research to Standardization (what, how, when)

Are there 50 Billion IoT Devices yet?

Detailed post below but if you are after a quick summary, it's in the picture above.

Couple of weeks back someone quoted that there were 50 billion devices last year (2020). After challenging them on the number, they came back to me to say that there were over 13 billion based on GSMA report. While the headline numbers are correct, there are some finer details we need to look at.

It all started back in 2010 when the then CEO of Ericsson announced that there will be 50 Billion IoT Devices by 2020. You could read all about it here and see the presentation here. While it doesn't explicitly say, it was expected that the majority of these will be based on cellular technologies. I also heard the number 500 Billion by 2030, back in 2013.

So the question is how many IoT devices are there today and how many of these are based on mobile cellular technologies?

The headline number provided by the GSMA Mobile Economy report, published just in time for MWC 2021, is 13.1 billion in 2020. It does not provide any further details on what kind of connectivity these devices use. I had to use my special search skills to find the details here.

As you can see, only 1.9 billion of these are based on cellular connections, of which 0.2 billion are based on licensed Low Power Wide Area (licensed LPWA, a.k.a. LTE-M and NB-IoT) connections. 

Ericsson Mobility Report, June 2021, has a much more detailed breakdown regarding the numbers as can be seen in the slide above. As of the end of 2020, there were 12.4 billion IoT devices, of which 10.7 billion were based on Short-range IoT. Short-range IoT is defined as a segment that largely consists of devices connected by unlicensed radio technologies, with a typical range of up to 100 meters, such as Wi-Fi, Bluetooth and Zigbee.

Wide-area IoT, which consists of segment made up of devices using cellular connections or unlicensed low-power technologies like Sigfox and LoRa had 1.7 billion devices. So, the 1.6 billion cellular IoT devices also includes LPWAN technologies like LTE-M and NB-IoT.

Figures are connections/SIMs sold - not all will be live yet.

— Tom Rebbeck (@tomrebbeck) September 29, 2021

I also reached out to IoT experts at analyst firm Analysys Mason. As you can see in the Tweet above, Tom Rebbeck, Partner at Analysys Mason, mentioned 1.6 billion cellular (excluding NB-IoT + LTE-M) and 220 million LPWA (which includes NB-IoT, LTE-M, as well as LoRa, Sigfox etc.) IoT connections.

If I understand this correctly, as of June 2021 there were 1.55 billion cellular IoT connections. Do these include NB-IoT as well as LTE-M?

— Zahid Ghadialy (@zahidtg) October 2, 2021

I also noticed this interesting chart in the tweet above which shows the growth of IoT from Dec 2010 until June 2021. Matt Hatton, Founding Partner of Transforma Insights, kindly clarified that the number as 1.55 billion including NB-IoT and LTE-M.

As you can see, the number of cellular IoT connections are nowhere near 50 billion. Even if we include all kinds of IoT connectivity, according to the most optimistic estimate by Ericsson, there will be just over 26 billion connections by 2026.

Just before concluding, it is worth highlighting that according to all these cellular IoT estimates, over 1 billion of these connections are in China. GSMA's 'The Mobile Economy China 2021' puts the number as 1.34 billion as of 2020, growing to 2.29 billion by 2025. Details on page 9 here.

Hopefully, when someone wants to talk about Internet of Thing numbers in the future, they will do a bit more research or just quote the numbers from this post here.

Related Posts: 

• 3G4G: Internet of Things (IoT) and Machine-2-Machine (M2M)
• Connectivity Technology Blog: The Wide Variety of Internet of Things (IoT) Technologies for Different Situations
• The 3G4G Blog: '5G RAN Release 18 for Industry Verticals' Webinar Highlights
• The 3G4G Blog: Introduction to 5G Reduced Capability (RedCap) Devices
• Connectivity Technology Blog: Cellular Connectivity Technology Landscape and Standards for Industrial IoT
• The 3G4G Blog: 5G Non IP Data Delivery and Lightweight M2M (LwM2M) over NIDD
• The 3G4G Blog: Mobile Initiated Connection Only (MICO) mode in 5G System
• The 3G4G Blog: Embedded SIM (eSIM) and Integrated SIM (iSIM)
• Connectivity Technology Blog: Operators Are Looking Up to SpaceMobile for All Gs and IoT Connectivity
• Connectivity Technology Blog: GSMA IoT WebTalk 'Clear Skies Ahead for Mobile-Enabled Drones' 

Disaster Roaming in 3GPP Release-17

One way all operators in a country/region/geographic area differentiate amongst themselves is by the reach of their network. It's not in their interest to allow national roaming. Occasionally a regulator may force them to allow this, especially in rural or remote areas. Another reason why operators may choose to allow roaming is to reduce their network deployment costs. 

In case of disasters or emergencies, if an operator's infrastructure goes down, the subscribers of that network can still access other networks for emergencies but not for normal services. This can cause issues as some people may not be able to communicate with friends/family/work. 

A recent example of this kind of outage was in Japan, when the KDDI network failed. Some 39 million users were affected and many of them couldn't even do emergency calls. If Disaster Roaming was enabled, this kind of situation wouldn't occur.

South Korea already has a proprietary disaster roaming system in operation since 2020, as can be seen in the video above. This automatic disaster roaming is only available for 4G and 5G.

I've been waiting for this for many years. https://t.co/Wcl34M1aZy Disaster roaming, now part of 3gpp rel17. https://t.co/F4LAyIp7VE

— Silke Holtmanns (@SHoltmanns) October 2, 2022

In 3GPP Release-17, Disaster Roaming has been specified for LTE and 5G NR. In case of LTE, the information is sent in SIB Type 30 while in 5G it is in SIB Type 15.

3GPP TS 23.501 section 5.40 provides summary of all the other information needed for disaster roaming. Quoting from that:

Subject to operator policy and national/regional regulations, 5GS provides Disaster Roaming service (e.g. voice call and data service) for the UEs from PLMN(s) with Disaster Condition. The UE shall attempt Disaster Roaming only if:

• there is no available PLMN which is allowable (see TS 23.122 [17]);
• the UE is not in RM-REGISTERED and CM-CONNECTED state over non-3GPP access connected to 5GCN;
• the UE cannot get service over non-3GPP access through ePDG;
• the UE supports Disaster Roaming service;
• the UE has been configured by the HPLMN with an indication of whether Disaster roaming is enabled in the UE set to "disaster roaming is enabled in the UE" as specified in clause 5.40.2; and
• a PLMN without Disaster Condition is able to accept Disaster Inbound Roamers from the PLMN with Disaster Condition.

In this Release of the specification, the Disaster Condition only applies to NG-RAN nodes, which means the rest of the network functions except one or more NG-RAN nodes of the PLMN with Disaster Condition can be assumed to be operational.

A UE supporting Disaster Roaming is configured with the following information:

• Optionally, indication of whether disaster roaming is enabled in the UE;
• Optionally, indication of 'applicability of "lists of PLMN(s) to be used in disaster condition" provided by a VPLMN';
• Optionally, list of PLMN(s) to be used in Disaster Condition.

The Activation of Disaster Roaming is performed by the HPLMN by setting the indication of whether Disaster roaming is enabled in the UE to "disaster roaming is enabled in the UE" using the UE Parameters Update Procedure as defined in TS 23.502 [3]. The UE shall only perform disaster roaming if the HPLMN has configured the UE with the indication of whether disaster roaming is enabled in the UE and set the indication to "disaster roaming is enabled in the UE". The UE, registered for Disaster Roaming service, shall deregister from the PLMN providing Disaster Roaming service if the received indication of whether disaster roaming is enabled in the UE is set to "disaster roaming is disabled in the UE".

Check the specs out for complete details. 

From my point of view, it makes complete sense to have this enabled for the case when disaster strikes. Earlier this year, local governments in Queensland, Australia were urging the Federal Government to immediately commit to a trial of domestic mobile roaming during emergencies based on the recommendation by the Regional Telecommunications Independent Review Committee. Other countries and regions would be demanding this sooner or later as well. It is in everyone's interest that the operators enable this as soon as possible.

Related Posts:

• The 3G4G Blog: 2G/3G Shutdown may Cost Lives as 4G/5G Voice Roaming is a Mess
• The 3G4G Blog: Transitioning from eCall to NG-eCall and the Legacy Problem
• The 3G4G Blog: Study of Use cases and Communications Involving IoT devices in Emergency Solutions
• The 3G4G Blog: enhanced Public Warning System (ePWS) in 3GPP Release-16
• The 3G4G Blog: ETWS detailed in LTE and UMTS 

A Different Approach for Mobile Network Densification

I am fascinated by and have previously written blog posts about transparent antennas. Back in 2019 NTT Docomo announced that they have been working with glass manufacturer AGC to create a new transparent antenna that can work with a base station to become an antenna. Then in 2021, NTT Docomo and AGC announced that they have developed a prototype technology that efficiently guides 28-GHz 5G radio signals received from outdoors to specific locations indoors using a film-like metasurface lens that attaches to window surfaces. Transparent antennas/lens are one of the pillars of Docomo’s 6G vision as can be seen here.

I succeeded in my quest to find a wow product finally at #MWC24. Wavethru by AGC is an amazing solution for densification by providing coverage inside-out. Lookout for a post on the Telecoms Infrastructure blog in a few weeks time #3G4G5G pic.twitter.com/RmuD1NQ7nS

— Zahid Ghadialy (@zahidtg) February 29, 2024

Every year at Mobile World Congress I look for a wow product/demo. While there were some that impressed me, the suite of products from Wave by AGC (WAVEANTENNA, WAVETHRU and WAVETRAP) blew me away. Let’s look at each of them briefly:

WAVEANTENNA is the transparent glass antenna which is generally installed indoors, on a window or a glass pane. It can be used to receive signals from outdoors (as in case of FWA) or can be used to broadcast signal outdoors (for densification based on inside-out coverage). In the newer buildings that has thermal insulation films on the glass, the radio signals are highly attenuated in either direction, so this solution could work well in that scenario in conjunction with WAVETHRU.

The WAVETHRU process applies a unique laser pattern to the glazing with 30 µm laser engraved lines that are nearly invisible to the naked eye. Treatment is so gentle, it does not affect the physical properties of the glazing, which remain the same. This radio-friendly laser treatment improves the indoor radio signal by around 25 dB, to achieve almost the same level of performance as the street signal. Just 20% to 30% of the window and floors 0 to 4 need to be treated to improve the indoor signal on all frequency ranges under 6GHz.

In case of coverage densification by providing inside-out radio signals, WAVETRAP can be used for EM wave shielding by stopping back-lobes within the building. 

This video from WAVE by AGC explains the whole densification solution:

 

Now the question is, why was I impressed with this solution? Regular readers of this and the Telecoms Infrastructure Blog will have noticed the various solutions I have been writing about for mobile network densification in downtown areas and historic cities with listed buildings where limited space for infrastructure deployment presents several challenges. 

In brief, we can categorise these challenges as follows:

• Physical Space Constraints like lack of space or strict regulations as in case of listed buildings and heritage sites. 
• Aesthetics and Visual Impact could be an important consideration in certain historic city centres. Deploying large antennae or towers can clash with the architectural character and heritage of the area and may require concealing antennae within existing structures like chimneys, bus shelters, phone boxes & lampposts, or using disguised designs like fake trees to minimize visual impact.
• Technical Challenges can arise in dense urban environments due to interference from neighbouring cells, unreliable backhaul connectivity, interruptions in the power supply due to siphoning, etc.
• Community Engagement and Perception is another important area to consider. There is no shortage of NIMBY (Not in my back yard) activists that may oppose new infrastructure due to health concerns, aesthetics, or fear of property devaluation. Engaging with the community, providing accurate information about EMF exposure, and addressing misconceptions are crucial.
• Regulatory and Permitting Hurdles that may arise due to many cities and councils imposing zoning and permits requirements. Obtaining permits for infrastructure deployment involves navigating local regulations, zoning laws, and historic preservation boards. There may also be height restrictions that may hinder optimal antenna placement.
• Finally, Cost and ROI are important consideration factors as all of the above increases the costs as well as the time required. Customized designs, site acquisition, and compliance with regulations are one of the major factors that not only increase costs but also delays infrastructure rollouts. Operators often weigh the benefits of improved coverage and capacity against all the expenses and headaches of infrastructure deployment and then decide on what to deploy and where.

A solution like WAVEANTENNA in conjunction with WAVETHRU and WAVETRAP can significantly reduce the hurdles and improve coverage significantly. 

While I have talked about the solution in general, it can also be applied indoors to Wi-Fi, in addition to 4G/5G. This may be useful in case of Enterprise Networks where appearance is of importance and probably not of much use in case of warehouses or Industrial/Factory Networks. 

Do let me know what you think.

Related Posts: 

• Connectivity Technology Blog: Futuristic Glass Antenna by NTT Docomo and AGC
• Connectivity Technology Blog: Docomo and AGC use Metasurface Lens to Guide Millimeter Waves (mmWaves) Indoors
• Free 6G Training: Special Articles on 5G Evolution & 6G in NTT Docomo Technical Journal
• Telecoms Infrastructure Blog: UK will make Street Furniture accessible for Telecoms Infrastructure
• Telecoms Infrastructure Blog: Deutsche Telekom 5G Small Cells in Phone Boxes
• Telecoms Infrastructure Blog: Vodafone UK improving coverage with Phone Boxes, Mini-masts & Manhole Covers
• Telecoms Infrastructure Blog: Disguising Small Cells in Rural areas
• Telecoms Infrastructure Blog: Small Cells in BT Phone Boxes
• Telecoms Infrastructure Blog: Small Cells in the Bus Stop
• The 3G4G Blog - AT&T Blog: "Providing Connectivity from Inside a Cactus"
• The 3G4G Blog: The Art of Disguising Cellular Antennas 

Wi-Fi 6 (a.k.a. 802.11ax) and other Wi-Fi enhancements

Last year I wrote about how Wi-Fi is getting new names. 802.11ax for example, the latest and greatest of the Wi-Fi standards is known as Wi-Fi 6. There were many announcements at MWC 2019 about WiFi 6, some of which I have captured here.

I came across a nice simple explanatory video explaining Wi-Fi 6 for non-technical people. Its embedded below.


The video is actually sponsored by Cisco and you can read more about Wi-Fi 6 and comparison of Wi-Fi 6 and 5G on their pages.

At MWC19, Cisco was showing Passpoint autoconnectivity on Samsung Galaxy S9, S9+ or Note 9 device. According to their blog:

Together, we’re working to provide a better bridge between mobile and Wi-Fi networks. At Mobile World Congress in Barcelona we’ll show the first step in that journey. Anyone using a Samsung Galaxy S9, S9+ or Note 9 device (and those lucky enough to have an early Galaxy S10) over the Cisco-powered guest wireless network will be able to seamlessly and securely connect – without any manual authentication. No portal, no typing in passwords, no picking SSIDs, no credit cards — just secure automatic connectivity.  How?  By using credentials already on your phone, like your operator SIM card.  Even if your operator doesn’t currently support Passpoint autoconnectivity, your Samsung smartphone will!  As a Samsung user, you already have an account for backups and device specific applications. This credential can also be used for a secure and seamless onboarding experience, supporting connectivity to enterprise, public and SP access networks.

It's worth mentioning here that the WPA2 authentication algorithm is being upgraded to WPA3 and we will see broad adoption this year, in conjunction with 802.11ax. See the tweet for details

WPA2 is being upgraded to WPA3 and we will see broad adoption this year, in conjunction with 802.11ax #Privacy #Security - slides from @RSAConference #RSCA2019 - https://t.co/gXYu9rlomX - via @avrilsalterUSA pic.twitter.com/BnpwAD4Fkb

— 3G4G (@3g4gUK) March 31, 2019

Broadcom announced their new BCM43752, Dual-Band 802.11ax Wi-Fi/Bluetooth 5 Combo Chip. Motley Fool explains why this is interesting news:

The chip specialist is rounding out its Wi-Fi 6 portfolio to address lower price points.

When Samsung announced its Galaxy S10-series of premium smartphones, wireless chipmaker Broadcom announced, in tandem, that its latest BCM4375 Wi-Fi/Bluetooth connectivity combination chip is powering those new flagship smartphones. That chip was the company's first to support the latest Wi-Fi 6 standard, which promises significant performance improvements over previous-generation Wi-Fi technology.

The BCM4375 is a high-end part aimed at premium smartphones, meaning that it's designed for maximum performance, but its cost structure (as well as final selling price) is designed for pricier devices that can handle relatively pricey chips.

Broadcom explains that the BCM43752 "significantly reduces smartphone bill of materials by integrating [radio frequency] components such as power amplifiers (PAs) and low-noise amplifiers (LNAs) into the device."

The idea here is simple: Since these components are integrated in the chip that smartphone makers are buying from Broadcom, those smartphone makers won't need to buy those components separately.

In the press release, Broadcom quoted Phil Solis, research director at the market research company IDC, as saying that this chip "reduced costs by going down to single core, 2X2 MIMO for Wi-Fi, integrating the PAs and LNAs, and offering flexible packaging options while keeping the same functionality as their flagship combo chip." 

Broadcom explains that this chip is targeted at "the broader smartphone market where high performance and total solution cost are equally important design decisions."

In addition to these, Intel showed a demo of Wi-Fi 6 at 6GHz. Most people are aware that Wi-Fi uses 2.4 GHz, 5 GHz & 60 GHz band. According to Wi-Fi Now:

So why is that important? Simply because 6 GHz Wi-Fi is likely the biggest opportunity in Wi-Fi in a generation – and because Intel’s demo shows that Wi-Fi chipset vendors are ready to pounce on it. The demonstration was a part of Intel’s elaborate Wi-Fi 6 (802.11ax) demonstration set at MWC.

“When this enhancement [meaning 6 GHz spectrum] to Wi-Fi 6 rolls out in the next couple of years, it has the potential to more than double the Wi-Fi spectrum with up to 4x more 160 MHz channel deployment options,” said Doron Tal, Intel’s General Manager Wireless Infrastructure Group, in his blog here. Doron Tal emphasises that the prospect of including 6 GHz bands in Wi-Fi for the time being realistically only applies to the US market.

Intel also says that a growing number of currently available PCs already support 160 MHz channels, making them capable of operating at gigabit Wi-Fi speeds. This means that consumers will get ‘a pleasant surprise’ in terms of speed if they invest in a Wi-Fi 6 home router already now, Intel says.

It may however take a while before US regulator FCC finally rules on allowing Wi-Fi to operate in the 6 GHz bands. Right now the FCC is reviewing dozens of response submissions following the issuing of the NPRM for unlicensed 6 GHz operation – and they will likely have their hands full for months while answering a litany of questions as to prospective new 6 GHz spectrum rules.

Also an important part of the 6 GHz story is the fact that the IEEE only weeks ago decided that – as far as the 802.11 standards are concerned – only Wi-Fi 6 (802.11ax) will be specified to operate in the 6 GHz band. That means 6 GHz will be pristine legacy-free territory for Wi-Fi 6 devices.

That brings us to the Wi-Fi evolution that will be coming after 802.11ax. IEEE 802.11 Extremely High Throughput (EHT) Study Group was formed late last year that will be working on defining the new 802.11be (Wi-Fi 7?) standards. See tweet below:

IEEE 802.11be Extremely High Throughput (EHT) is the next generation of Wi-Fi Technology, beyond 802.11ax. One of the interesting enhancements will be that new tech will be able to work from 1GHz to 7.125 GHz. More in this paper: https://t.co/ESs95805d4 pic.twitter.com/QtTMJRHTZG

— 3G4G (@3g4gUK) April 20, 2019

The interesting thing to note here is that the Wi-Fi spectrum will become flexible to operate from 1 GHz to 7.125 GHz. Of course the rules will be different in different parts of the world. It will also have to avoid interference with other existing technologies like cellular, etc.

According to Fierce Wireless, Huawei has completed a global deployment of its enterprise-class Wi-Fi 6 products under the new AirEngine brand. Speaking at the company’s Global Analyst Summit, Huawei said its Wi-Fi 6 products have been deployed on a large scale in five major regions worldwide.

Back at MWC, Huawei was showing off their Wi-Fi 6 enabled CPEs. See tweet below:

@Huawei touting it's broad portfolio of connected devices.

Meet the Huawei's 5G CPE router for Smart Home which drives Wi-Fi 6 with 5G backhaul.
Also include Huawei's HiLink smart home platform for controlling third party smart home devices#MWC19 #ConnectingTheFuture pic.twitter.com/lO7DcVHYbO

— Neil Shah (@neiltwitz) February 24, 2019

Huawei has many different enterprise networking products that are already supporting Wi-Fi 6 today. You can see the details along with whitepapers and application notes here. In addition, the Top 10 Wi-Fi 6 misconceptions are worth a read, available here.

Related Posts: 

• Operator Watch Blog: South Korea's Ministry promotes Wi-Fi 6, says WiFi is like 5G
• Connectivity Technology Blog: IEEE 802.11be Extremely High Throughput (EHT), a.k.a. Wi-Fi 7 

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) 

Slides from IEEE 5G Webinar: 5G mmWave Revolution & New Radio

Some of you may find this useful.

5G Study Item (SI) for RAN Working Groups Approved

This is from a Linkedin post by Eiko Seidel.

Earlier this month (7-10 March 2016), 3GPP TSG RAN Plenary RAN Meeting #71 took place in Göteborg, Sweden. The first 5G study item for the working groups is was approved. It involves RAN1, RAN2, RAN3 and RAN4. For details please have a look at RP-160671. 

The study aims to develop an next generation radio access technology to meet a broad range of use cases including enhanced mobile broadband, massive MTC, critical MTC, and additional requirements defined during the RAN requirements study. 

The new RAT will consider frequency ranges up to 100 GHz. 

Detailed objectives of the study item is a single technical framework addressing all usage scenarios, requirements and deployment scenarios including Enhanced mobile broadband, Massive machine-type-communications and Ultra reliable and low latency communications. 

The new RAT shall be inherently forward compatible. It is assumed that the normative specification would occur in two phases: Phase I (to be completed in June 2018) and Phase II (to be completed in December 2019). 

The fundamental physical layer signal waveform will be based on OFDM, with potential support of non-orthogonal waveform and multiple access. Basic frame structure(s) and Channel coding scheme(s) will be developed. 

Architecture work is going to be interesting, with a study of different options of splitting the architecture into a “central unit” and a “distributed unit”, with potential interface in between, including transport, configuration and other required functional interactions between these nodes. Furthermore RAN-CN interface and functional split needs to be studied, the realization of Network Slicing, QoS support etc.


The proposed timeline for 5G was also presented in a presentation as follows:

Explaining Telecoms

Over the years we have made a lot of tutorials explaining mobile wireless technology (list here). Here is another one that came up as part of a discussion where many experienced telecom engineers seemed to be struggling explaining what telecoms mean. Slides and video embedded below:

Slides:

Beginners: What Does ‘Telecommunications’ or ‘Telecoms’ Mean? from 3G4G

Video:

You can download the pdf from here.

Related Posts: 

• 3G4G: Free 2G, 3G, 4G & 5G Training Videos
• The 3G4G Blog: Short Tutorial on Mission Critical Services in LTE and 5G
• The 3G4G Blog: Private Networks Introductory Series
• The 3G4G Blog: A Quick Introduction to 3GPP
• The 3G4G Blog: 5G and Cyber Security 

Self-backhauling: Integrated access and backhaul links for 5G

One of the items that was proposed during the 3GPP RAN Plenary #75 held in Dubrovnik, Croatia, was Study on Integrated Access and Backhaul for NR (NR = New Radio). RP-17148 provides more details as follows:

One of the potential technologies targeted to enable future cellular network deployment scenarios and applications is the support for wireless backhaul and relay links enabling flexible and very dense deployment of NR cells without the need for densifying the transport network proportionately. 

Due to the expected larger bandwidth available for NR compared to LTE (e.g. mmWave spectrum) along with the native deployment of massive MIMO or multi-beam systems in NR creates an opportunity to develop and deploy integrated access and backhaul links. This may allow easier deployment of a dense network of self-backhauled NR cells in a more integrated manner by building upon many of the control and data channels/procedures defined for providing access to UEs. An example illustration of a network with such integrated access and backhaul links is shown in Figure 1, where relay nodes (rTRPs) can multiplex access and backhaul links in time, frequency, or space (e.g. beam-based operation).

The operation of the different links may be on the same or different frequencies (also termed ‘in-band’ and ‘out-band’ relays). While efficient support of out-band relays is important for some NR deployment scenarios, it is critically important to understand the requirements of in-band operation which imply tighter interworking with the access links operating on the same frequency to accommodate duplex constraints and avoid/mitigate interference. 

In addition, operating NR systems in mmWave spectrum presents some unique challenges including experiencing severe short-term blocking that cannot be readily mitigated by present RRC-based handover mechanisms due to the larger time-scales required for completion of the procedures compared to short-term blocking. Overcoming short-term blocking in mmWave systems may require fast L2-based switching between rTRPs, much like dynamic point selection, or modified L3-based solutions. The above described need to mitigate short-term blocking for NR operation in mmWave spectrum along with the desire for easier deployment of self-backhauled NR cells creates a need for the development of an integrated framework that allows fast switching of access and backhaul links. Over-the-air (OTA) coordination between rTRPs can also be considered to mitigate interference and support end-to-end route selection and optimization.

The benefits of integrated access and backhaul (IAB) are crucial during network rollout and the initial network growth phase. To leverage these benefits, IAB needs to be available when NR rollout occurs. Consequently, postponing IAB-related work to a later stage may have adverse impact on the timely deployment of NR access.

There is also an interesting presentation on this topic from Interdigital on the 5G Crosshaul group here. I found the following points worth noting:

• This will create a new type of interference (access-backhaul interference) to mitigate and will require sophisticated (complex) scheduling of the channel resources (across two domains, access and backhaul).
• One of the main drivers is Small cells densification calling for cost-effective and low latency backhauling
• The goal would be to maximize efficiency through joint optimization/integration of access and backhaul resources
• The existing approach of Fronthaul using CPRI will not scale for 5G, self-backhaul may be an alternative in the shape of wireless fronthaul

Let me know what you think.

Related Links:

• Backhauling problems driving up deployment costs?

5G Synchronisation Requirements

5G will probably introduce tighter synchronization requirements than LTE. A recent presentation from Ericsson provides more details.

A nice presentation by Ericsson from #WSTS2018: Sync in 5G: What is really needed? - https://t.co/X3XIokELpe pic.twitter.com/6du5ezFfqE

— 3G4G (@3g4gUK) July 17, 2018

In frequencies below 6GHz (referred to as frequency range 1 or FR1 in standards), there is a probability to use both FDD and TDD bands, especially in case of re-farming of existing bands. In frequencies above 6GHz (referred to as frequency range 2 or FR2 in standards, even though FR2 starts from 24.25 GHz), it is expected that all bands would be TDD.

Interesting to see that the cell phase synchronization accuracy measured at BS antenna connectors is specified to be better than 3 μs in 3GPP TS 38 133. This translates into a network-wide requirements of +/-1.5 microseconds and is applicable to both FR1 and FR2, regardless of the cell size.

Frequency Error for NR specified in 3GPP TS 38.104 states that the base station (BS) shall be accurate to within the following accuracy range observed over 1 ms:
Wide Area BS → ±0.05 ppm
Medium Range BS → ±0.1 ppm
Local Area BS → ±0.1 ppm

The presentation specifies that based on request by some operators, studies in ITU-T on the feasibility of solutions targeting end-to-end time synchronization requirements on the order of +/-100 ns to +/-300 ns

There is also a challenge of how the sync information is transported within the network. The conclusion is that while the current LTE sync requirements would work in the short term, new solutions would be required in the longer term.

If this is an area of interest, you will also enjoy watching CW Heritage SIG talk by Prof. Andy Sutton, "The history of synchronisation in digital cellular networks". Its available here.

Updated 5G Terminology Presentation (Feb 2019)

I made this video before MWC with the intention to educate the attendees about the various architecture options and 5G terminologies being discussed. As always, happy to get feedback on what can be done better. Slides followed by video below.

Beginners: 5G Terminology (Updated - Feb 2019) from 3G4G

Complete list of our training resources are available on 3G4G page here.

Top 10 Blog Posts and Top 5 Videos for 2023

The 3G4G Blog is our most popular blog, running for over 16 years with over 15.5 million views. With 2023 coming to an end, here are the top 10 most viewed posts from 2023 as well as top 5 most viewed videos. These posts/videos were not necessarily posted this year, so I have added the month and year each of them was posted.

1. Network Slicing using User Equipment Route Selection Policy (URSP), Nov. 2021
2. NWDAF in 3GPP Release-16 and Release-17, Feb. 2021
3. New 5G NTN Spectrum Bands in FR1 and FR2, May 2023
4. Non-public networks (NPN) - Private Networks by another name, May 2019
5. How many Cell Sites and Base Stations Worldwide?, Mar. 2023
6. What is RF Front-End (RFFE) and why is it so Important?, Jan. 2022
7. 3GPP Release 17 Description and Summary of Work Items, Dec. 2022
8. Two Types of SMS in 5G, Sep. 2020
9. ATIS Webinar on "3GPP Release 18 Overview: A World of 5G-Advanced", Feb. 2023
10. Prof. Ted Rappaport Keynote at EuCNC & 6G Summit 2023 on 'Looking Towards the 6G Era - What we may expect, and why', Aug. 2023

Here are top 5 videos viewed on our YouTube channel in the last year:

1. Beginners: What is Industrial IoT (IIoT), Feb.2019
2. Beginners: Radio Frequency, Band and Spectrum, July 2017
3. Beginners: Different Types of RAN Architectures - Distributed, Centralized & Cloud, July 2021
4. Beginners: Fixed Wireless Access (FWA), Sep. 2018
5. Beginners: MNO, MVNO, MVNA, MVNE: Different types of mobile operators, Apr. 2018

Let us know about your favourite post and/or video in the comments below.

Related Posts: 

• Free 6G Training: Top 10 Posts for 2023
• Telecoms Infrastructure Blog: Top 5 Posts For 2023
• Connectivity Technology Blog: Top 5 Posts for 2023
• Operator Watch Blog: Top 5 Posts for 2023
• Private Networks Technology Blog: Top 5 Posts for 2023
• The 3G4G Blog: Top Blog Posts of 2022
• The 3G4G Blog: Top 10 Posts for 2021 and Top 5 Videos
• The 3G4G Blog: Top 10 Posts for 2020 and Top 5 Videos 

A Look into 5G Virtual/Open RAN - Part 4: Intra-gNB DU Handover

In the previous posts of this series I described O-RAN interfaces and protocols, connection establishment and connection release procedures. Now it is time to look at handovers.

As mentioned in one of the earlier posts the gNB-CU CP will be in charge of controlling hundreds of gNB-DUs in a similar way like the 3G RNC was in charge of controlling hundreds of UMTS NodeBs. As a result the most common 5G SA intra-system handovers will be intra-gNB handovers. These handovers can further be classified into intra-gNB-DU handovers (inter- as well as intra-frequency) and inter-gNB-DU handovers.

Due to the virtualization of RAN network functions we will also find another form of switching transmission path, which is a change of the gNB-CU UP during the call without mobility of the UE. This scenario I will discuss later in a separate blog post.

Today I want to focus on the intra-gNB DU handover. Here the UE moves from one cell to another one within the same distributed unit as shown in the figure below.

A prerequisite is the successful establishment of a NR RRC connection and a F1AP UE Context between the gNB-DU and the gNB-CU CP.

The F1AP transports all RRC messages between these two entities. Indeed, it transports the PDCP blocks and the gNB-DU is not aware that these PDCP blocks contain RRC messages. However, for better illustration I have not shown the PDPC part in the ladder diagram.

What we see in step 1 is a NR RRC Reconfiguration message that contains RRC measurement configurations to be enabled on the UE side. A typical trigger event for intra-frequency handovers is the A3 event that is already known from LTE RRC.

Once the UE detects a better neighbor cell meeting the A3 criteria it sends a RRC Measurement Report to the gNB-CU CP (step 2).

In step 3 the gNB-CU CP orders the gNB-DU to perform a F1AP UE Context Modification. The purpose is to allocate radio resources for the UE in the target cell and to prepare the cell change.

The gNB-DU replies with F1AP UE Context Modification Response. This messages contains the new C-RNTI and a large block of lower layer configuration parameters (e.g. for RLC and MAC layer) that need to be sent to the UE and thus, need to be transported to the gNB-CU CP before, because it is the only RAN function capable to communicate with the UE using the RRC protocol.

Hence, in step 5 we see another downlink RRC message transfer. This time it is used to transport the handover command towards the UE. The handover command is a NR RRC Reconfiguration message and it contains the new C-RNTI (new UE identity within the cell) as well as the physical cell ID of the target cell and the full set of lower layer configuration parameters previously provided by the gNB-DU.

When the gNB-CU CP receives the RRC Reconfiguration Complete message sent by the UE in step 6 the handover is successfully completed and the UE is now served by the cell with NR PCI 2.

As mentioned before there is neither XnAP (communication between two neighbor gNBs) nor NGAP (communication between gNB and AMF) involved in this handover procedure.

Related Posts:

• A Look into 5G Virtual/Open RAN - Part 5: Inter-gNB DU Handover
• 3G4G: Open RAN, OpenRAN and O-RAN

LiFi can be a valuable tool for densification

LiFi has been popping up in the news recently. I blogged about it (as LED-Fi) 10 years back. While the concept has remained the same, many of the limitations associated with the technology has been overcome. One of the companies driving LiFi is Scottish startup called pureLiFi.

I heard Professor Harald Haas at IEEE Glasgow Summit speak about how many of the limitations of LiFi have been overcome in the last few years (see videos below). This is a welcome news as there is a tremendous amount of Visible Light Spectrum that is available for exploitation.

While many discussions on LiFi revolve round its use as access technology, I think the real potential lies in its use as backhaul for densification.

For 5G, when we are looking at small cells, every few hundred meters, probably on streetlights and lamp posts, there is a requirement for alternative backhaul to fiber. Its difficult to run fiber to each and every lamp post. Traditionally, this was solved by microwave solutions but another option available in 5G is Integrated Access and Backhauling (IAB) or Self-backhauling.

A better alternative could be to use LiFi for this backhauling between lamp posts or streetlights. This can help avoid complications with IAB when multiple nodes are close by and also any complications with the technology until it matures. This approach is of course being trialed but as the picture above shows, rural backhaul is just one option.

LiFi is being studied as part of IEEE 802.11bb group as well as its potential is being considered for 5G.

Here is a vieo playlist explaining LiFi technology in detail.




Further reading:

• O2 uses light to transmit data in latest network trial
• IEEE Task Force Works on Standard for Light Communications
• Learn How Li-Fi Works from Its Inventor, Harald Haas
• Light Communications for Wireless Local Area Networking
• LiFi can bring enhanced connectivity to your workspace, while also enhancing data security

Bluetooth 5 for IoT

Bluetooth 5 (not 5.0 - to simplify marketing messages and communication) was released last year. The main features being 2x Faster, 4x Range (Bluetooth 4 - 50m outdoors, 10m Indoors; Bluetooth 5 - 200m outdoors, 40m indoors) & 8x Data.

I like this above slide by Robin Heydon, Qualcomm from a presentation he gave in CW (Cambridge Wireless) earlier this year. What is highlights is that Bluetooth 5 is Low Energy (LE) like its predecessor 4.0.For anyone interested, a good comparison of 5 vs 4.2 is available here.

In addition, Mesh support is now available for Bluetooth. I assume that this will work with Bluetooth 4.0 onwards but it would probably only make sense from Bluetooth 5 due to support for reasonable range.

The Bluetooth blog has a few posts on Mesh (see here, here and here). I like this simple introductory video below.


This recent article by Geoff Varral on RTT says the following (picture from another source):

Long distance Bluetooth can also be extended with the newly supported mesh protocol.

This brings Bluetooth into direct competition with a number of other radio systems including 802.15,4 based protocols such as Zigbee, LoRa, Wireless-M (for meter reading), Thread and 6 LowPAN (IPV6 over local area networks. 802.11 also has a mesh protocol and long distance ambitions including 802.11ah Wi-Fi in the 900 MHz ISM band. It also moves Bluetooth into the application space targeted by LTE NB IOT and LTE M though with range limitations.

There are some interesting design challenges implied by 5.0. The BLE specification is inherently less resilient to interference than Classic or EDR Bluetooth. This is because the legacy seventy eight X 1 MHz channels within the 20 MHz 2.4 GHz pass band are replaced with thirty nine two MHz channels with three fixed non hopping advertising channels in the middle and edge of the pass band.

These have to withstand high power 20 MHz LTE TDD in Band 40 (below the 2.4 GHz pass band) and high power 20 MHz LTE TDD in band 41 above the pass band (and Band 7 LTE FDD). This includes 26 dBm high power user equipment.

The coexistence of Bluetooth, Wi-Fi and LTE has been intensively studied and worked on for over ten years and is now managed with surprising effectiveness within a smart phone through a combination of optimised analogue and digital filtering (SAW and FBAR filters) and time domain interference mitigation based on a set of  industry standard wireless coexistence protocols.

The introduction of high power Bluetooth however implies that this is no longer just a colocation issue but potentially a close location issue. Even managing Bluetooth to Bluetooth coexistence becomes a non-trivial task when you consider that +20 dBm transmissions will be closely proximate to -20 dBm or whisper mode -30 dBm transmissions and RX sensitivity of -93 dBm, potentially a dynamic range of 120dB. Though Bluetooth is a TDD system this isolation requirement will be challenging and vulnerable to ISI distortion. 

More broadly there is a need to consider how ‘5G Bluetooth’ couples technically and commercially with 5G including 5G IOT

Ericsson has a whitepaper on Bluetooth Mesh Networking. The conclusion of that agrees that Bluetooth may become a relevant player in IoT:

Bluetooth mesh is a scalable, short-range IoT technology that provides flexible and robust performance. The Bluetooth Mesh Profile is an essential addition to the Bluetooth ecosystem that enhances the applicability of Bluetooth technology to a wide range of new IoT use cases. Considering the large Bluetooth footprint, it has the potential to be quickly adopted by the market. 

With proper deployment and configuration of relevant parameters of the protocol stack, Bluetooth mesh is able to support the operation of dense networks with thousands of devices. The building automation use case presented in this white paper shows that Bluetooth mesh can live up to high expectations and provide the necessary robustness and service ratio. Furthermore, the network design of Bluetooth mesh is flexible enough to handle the introduction of managed operations on top of flooding, to further optimize behavior and automate the relay selection process.

Moreover, another Ericsson article says that "smartphones with built-in Bluetooth support can be part of the mesh, may be used to configure devices and act as capillary gateways."

A capillary network is a LAN that uses short-range radio-access technologies to provide groups of devices with wide area connectivity. Capillary networks therefore extend the range of the wide area mobile networks to constraint devices. Figure above illustrates the Bluetooth capillary gateway concept.

Once there are enough smartphones and Bluetooth devices with Bluetooth 5 and Mesh support, It would be interesting to see how developers use it. Would also be interesting to see if it will start encroaching LoRa and Sigfox markets as well.

5G and Industry 4.0

Telefónica published an infographic on 'Benefits of 5G in Industry 4.0' last week. You can download it on their website here. This reminded me that we have now completed the third video in our series of IoT.

1. The beginners guide to M2M, MTC & IoT is discussed here and video is available here.
2. Industrial IoT (IIoT) vs IoT is discussed here.
3. This blog post with with embedded video / slide looks at Industrie 4.0 (a.k.a. I4.0 or I4)

Internet of Things (IoT), Industrial IoT (IIoT) and Industry 4.0

Video in works #3G4G5G #I40 pic.twitter.com/zwavdn1dpL

— 3G4G (@3g4gUK) February 8, 2020

Slides and Video is embedded below, let us know what you think.

Beginners: Industry 4.0 & 5G from 3G4G

Related Posts and Links:

• 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)