Tuesday, 19 November 2019

Cell-free Massive MIMO and Radio Stripes


I wrote about "Distributed Massive MIMO using Ericsson Radio Stripes" after MWC 2019 here. I found it a very interesting concept and it will certainly take a few years before it becomes a reality.

Emil Björnson, Associate Professor at Linköping University have produced couple of videos on this topic. I am embedding both of them below for anyone who may be interested.

"A New Look at Cell-Free Massive MIMO" - based on technical paper from PIMRC 2019 on how to design Cell-free Massive MIMO systems that are both scalable and achieve high performance.



Worth noting the following about this video (based on video comments):
  • There are some minor issues with the sudio
  • Cell-free Massive MIMO is particularly for stadiums, streets, and places with many users or where it is hard to provide sufficient network quality with other methods.
  • This concept is still 4-5 years away from being ready to be practically deployed. It should be ready for later part of 5G, probably 5.5G

"Reinventing the Wireless Network Architecture Towards 6G: Cell-free Massive MIMO and Radio Stripes" looks at the motivation behind Cell-free Massive MIMO and how it can be implemented in 6G using radio stripes.



Worth noting the following on this video (based on video comments):

  • It may be possible that multiple frequency bands can be handled in the same radio stripe. If it is found to be possible then every other antenna  processing unit could manage a different band.
  • In principle, you can make the stripe as long as you need. But you probably need to divide it into segments since the power is supplied from one end of a stripe and it will only reach a limited distance (roughly up to 1 km). There are many implementation ideas and it remains to be seen what works out well in practice.

I am looking forward to see it work as it can solve coverage issues in many tricky scenarios.

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Thursday, 7 November 2019

Introduction to 5G ATSSS - Access Traffic Steering, Switching and Splitting


Last month we made a short tutorial on 5G and Fixed-Mobile Convergence (FMC). One of the features covered in that was ATSSS. It deserved a bit more detail so we made a short tutorial on this feature.

Access Traffic Steering, Switching and Splitting or ATSSS for short is being standardized as part of 3GPP Rel-16 and allows traffic steering across multiple accesses at a finer granularities than a PDU session.  It is an optional feature both on the UE and the 5GC network. ATSSS introduces the notion of Multi Access PDU session, a PDU session for which the data traffic can be served over one or more concurrent accesses (3GPP access, trusted non-3GPP access and untrusted non-3GPP access). The simplest way to visualize it is as shown below:


The presentation and video is embedded below:







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Sunday, 27 October 2019

R&S Webinar on LTE-A Pro and evolution to 5G


Rohde & Schwarz recently uploaded a webinar video on their YouTube channel. I found it really useful. It's embedded below.

Topics covered:

  • LTE-M / NB-IoT
    • feMTC
    • UE Category M2
    • OTDOA based positioning
  • UE Categories
  • Unlicensed Spectrum Overview
  • LTE in Unlicensed Spectrum
    • LWA, LWIP
    • LAA, eLAA
    • Wi-Fi
    • LBT
    • LWA mobility
  • Carrier Aggregation Enhancements
  • Multi-user superposition transmission (MUST)
  • Single cell - point to multipoint transmission (SC-PTM)
    • SC-PTM Channel Structure
    • SC-PTM Channel Flow
  • Massive MIMO
  • V2X Overview
    • eNB scheduling - transmission mode 3
    • Distributed scheduling - transmission mode 4
    • Direct communication
  • LTE Advanced Pro (Release 15)
    • Further NB-IoT Enhancements
    • Even further enhanced MTC - eMTC4 (Rel-15)



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Tuesday, 22 October 2019

From traditional RAN to Open RAN - O-RAN: Goals and Challenges


My Open RAN tutorial has recently gained popularity with recent announcements from Altiostar, Mavenir, Parallel Wireless, Telefonica and Vodafone. With TIP Summit in few weeks time, I am hoping for a lot more curious people to discover that blog post and video.

Olivier Simon, Director, Radio Innovation, Orange spoke about "O-RAN: Goals and Challenges" at Open Networking Summit Europe 2019. In his presentation, he explained how O-RAN will trigger more intelligence and openness in the RAN domain. He talked about which use cases will require this new architecture and why O-RAN is coming at the right time. Major architectural change are necessary in the next years in order to improve E2E latency and benefit from the flexibility of virtualized network functions. O-RAN will provide the right framework in order to perform this transformation in an open manner and keeping at the same time economies of scale thanks to a global adoption.


The presentation also touches on O-RAN Software Community. The O-RAN Alliance recently partnered with the Linux Foundation to establish the O-RAN-Software Community (O-RAN-SC), to provide that open source software application layer to the RAN. O-RAN-SC will foster development of an open source infrastructure platform for running 5G RAN solutions.

The key aspects of ORAN-SC are:
  • New Open Community focused on RAN Software in collaboration with O-RAN Alliance
  • Set up for collaboration across OPNFV, ONAP, Akraino and other Open Source projects

Here is the video of the conference embedded below:



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Tuesday, 15 October 2019

Summary of #CWTEC 2019 Conference: 5G, Satellites & Magic MIMO

I was involved in helping organise yet another CW TEC conference this year. The topic was quite interesting and we had some brilliant speakers. Some of the excellent presentations were shared too, links below. Here is a very quick summary of the event, linking also to couple of excellent summaries below.

The topic was a bit unusual and it rhymed very well with the attendees which were from many different backgrounds, from 5G, communications, satellites, electronics, T&M companies, etc. Here is the opening video that will show you the motivations behind this



The day started with a breakfast briefing from Cambridge Consultants that looked at how Massive MIMO is the key to unlocking 5G User Experiences. Presentations available here.


Session 1 was titled "What has Massive MIMO ever done for us?". The narrative for the session was as follows:
Clearly the desire for more and more capacity in cellular networks has driven the industry to find more and more novel techniques. The work done over the years and boosted by Tom Marzetta’s article titled “Noncooperative Cellular Wireless with Unlimited Numbers of Base Station Antennas” has set high expectations for this emergent technology, so much so the term Magic MIMO has been coined. However, how significant is it into today’s early 5G rollout and what can we expect over the coming years? Are there still further enhancements we should expect to see?

There were 3 talks as follows:
  • Sync Architectures for 5G NR by Chris Farrow, Technical Manager, Chronos Technology (slides)
  • Three UK’s RAN transformation: Spectrum, RAN architecture strategy, Why? by Dr Erol Hepsaydir, Head of RAN and Devices Strategy and Architecture, Three UK (slides)
  • Active antenna systems in RAN: performance, challenges and evolution by Anvar Tukmanov, Wireless Research Manager, BT (slides)


Session 2 looked at "Non-Terrestrial & Hybrid Networks". The narrative for the session was as follows:
There are different initiatives underway to make satellite and other non-terrestrial networks as part of 5G. In addition, many different mobile operators have demonstrated compelling use-cases with drones, balloons and other aerostats. Other innovative approaches like European Aviation Network uses a hybrid-network using terrestrial network supported by a satellite connection as a backhaul for in-flight Wi-Fi. In addition to latency, what other challenges are stopping mass adoption of Non-terrestrial and Hybrid networks? What about advanced features like slicing, etc.?

There were 3 talks as follows:

  • Opportunities for blending terrestrial and satellite technologies by Dr Jaime Reed, Director, Consulting, Space, Defence and Intelligence, CGI (slides)
  • Non-terrestrial Networks: Standardization in 5G NR by Dr Yinan Qi, Senior 5G Researcher, Samsung R&D Institute UK (slides)
  • Satellites and 5G: A satellite operator’s perspective by Simon Watts, Principal Consultant, Avanti Communications (slides)


Session 3 looked at "5G: A Catalyst for Network Transformation". The narrative was as follows:
5G has set high expectations in the user as well as operator community. While eMBB can be supported with an upgrade of existing 4G infrastructure, URLLC and mMTC may require massive change in the network architecture. Operators have already started the transformation process with backhaul upgrades, new data centers, distributed core and cloud rollouts, etc. How are networks evolving to accommodate these deep changes? What other changes will be required in the network to support the growth until the next new generation arrives?
This session featured 3 talks as well
  • An Introduction to Open RAN Concept by Zahid Ghadialy, Senior Director, Strategic Marketing, Parallel Wireless UK & EMEA (slides)
  • Powering the successful deployment of 5G infrastructure by David George, Vice President of EMEA and APAC, Sitetracker (slides)
  • The 5G transformation: no sweet without sweat by Antonella Faniuolo, Head of Network Strategy, Planning, Digital & Optimisation, Vodafone (slides)


The final session topic was "Getting ready for Beyond-5G Era". The narrative was as follows:
Many technologies like Full duplex, etc. that were originally intended to be part of 5G were not able to make it into the standards. Along with these, what other revolutionary changes are needed to make Beyond-5G technologies not only fulfil the vision, ambition and use-cases that were originally envisaged for 5G but to take it a step further and make it a game changer.
This session featured 3 talks as well, as follows:
  • Thinking Beyond 5G: Projects and Initiatives by Alan Carlton, Vice President, InterDigital Europe (slides not available)
  • 5G Evolution: Progressive enhancement and new features for new markets by Matthew Baker, Head of Radio Physical Layer and Coexistence Standardization, Nokia (slides)
  • Why 6G’s design goals need far more than just radio & core innovation by Dean Bubley, Analyst & Futurist, Disruptive Analysis (slides not available)
And my personal highlight was that I launched World's first coloured 5G tie


Hopefully you found the presentations shared as useful. Please also read the summaries of CWTEC provided below.


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Monday, 7 October 2019

Exploiting Possible 5G Vulnerabilities


The standards can try their best to ensure that the next generation of protocols is more secure than the previous one but there is always some way in which the protocols can be exploited. This is where researchers play an important role in finding such vulnerabilities before they can be exploited by hackers. Frankly I am quite sure that only a handful of these vulnerabilities are found and hackers always have something that may never be found.

In the recent HITBSecConf or the Hack In The Box Security Conference Altaf Shaik presented "4G to 5G: New Attacks". He along with Ravishankar Borgaonkar has been working to find out issues with security in cellular networks. In fact in the GSMA Mobile Security Hall of Fame, they both appear twice, individually.

From the talk narrative:

5G raises the security bar a level above 4G. Although IMSI exposure is prevented in 5G, we found new vulnerabilities to attack devices and subscribers. In this talk we expose a set of vulnerabilities in the 5G/4G protocols that are found in network operators equipment and also consumer devices such as phones, routers, latest IoT sensors, and even car modems. Our vulnerabilities affect several commercial applications and use cases that are active in 4G networks and are expected to take off in 5G networks. We developed automated tools to exploit the exposed cellular information and share some of our research traces and data sets to the community. We demonstrate a new class of hijacking, bidding down and battery draining attacks using low cost hardware and software tools. We did a rigorous testing worldwide to estimate the number of affected base stations and are surprised by the results. Finally our interactions with various vendors and standard bodies and easy fixes to prevent our attacks are discussed.

Slides and Video is embedded below






Slides and Whitepaper can be downloaded from here.

Further Reading:

Friday, 4 October 2019

CW Seminar: The present, the future & challenges of AR/VR (#CWFDT)


One of my roles is as a SIG champion of the CW (Cambridge Wireless) Future Devices & Technologies Group. We recently organised an event on "The present, the future & challenges of AR/VR". The CW team has kindly even summarised it here. I have also tried to collect all the tweets from the day here.

Why is this important? Most of the posts on this blog is about the mobile technology and I am guessing most of the readers are from that industry too. While we are focussed too much on connectivity, it's the experience that makes the difference for most of the consumers. On the operator watch blog, I wrote recently about South Korea and the operator LG Uplus. Average data usage by 5G users in Korea is as high as 18.3GB, and average 4G users use 9GB in the same period, according to MSIT in May 2019. 5G data is about 2 times than that of 4G. This remarkable traffic growth is driven by UHD and AR/VR contents. According to the operator LG Uplus, new services featuring AR and VR functions are proving popular and already account for 20% of 5G traffic, compared with 5% for 4G.

Coming back to the CW event, some of the presentations were shared and they are available here for a limited time. There were so many learnings for me, it's difficult to remember and add all of them here.

Our newest SIG champ Nadia Aziz covered many different topics (presentation here) including how to quickly start making your own AR/VR apps and how AR apps will be used more and more for social media marketing in future.


Mariano Cigliano, Creative Developer at Unit9 (presentation here) discussed the journey of their company and what they have learned along the way whilst developing their solution to disrupt the design process through integrating immersive technologies.


Aki Jarvinen from Digital Catapult (presentation here) explained about Brown-boxing and Bodystorming. Both very simple techniques but can help get the app designers story straight and save a lot of time, effort and money while creating the app.


James Watson from Immerse (presentation here) talked about VR training. So many possibilities if done correctly and can be more interactive than the online or classroom training's.



Schuyler Simpson, Vice President - Strategic Partnerships & Operations at Playfusion (presentation here) discussed the reality of enhanced reality, diving deep into the challenges about creating an experience that resonates best with audiences. In his own words, "Enhanced Reality blends visual, audio, haptic, and intelligent components to create highly personalized, immersive, and most importantly, valuable experiences for organizations and their audiences."

The most valuable learning of the day was to create an AR/VR app (just in theory), assuming there is no technology limitation. The whole journey consisted of:

  • Brainstorming of the Use Case
  • Key Pain Points
  • Sort the pain points in priority and select top 3 or 5
  • Map customer journey
  • Define persona for which the app is being designed
  • Map their journey
  • Touch points
  • What can be improved on those touch points 
  • Design a VR/AR application for the defined problem 
  • Storyboarding AR/VR use case
  • UX design considerations – spatial, emotional.. 
  • Scribe a prototype 
  • Playback to others.


Thanks to everyone who helped make this whole event possible, from the SIG champs to the CW team and the host & sponsors NTT Data. Special thanks to our newest SIG champ, Nadia Aziz for tirelessly working to make this event a success.

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Tuesday, 24 September 2019

When does your 5G NSA Device Show 5G Icon?


After I wrote about the 5G Icon Display back in February, I received lots of other useful and related materials, mostly from 3GPP standards delegates. Based on this updated information, I created a presentation and video called 'The 5G Icon Story'. Only recently did I realize that I didn't add it to the blog. So here it is.

And for people who are impatient and directly want to jump to the main point, it's UpperLayerIndication in SIB 2 as can be seen above.

The slides and video is embedded below.





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Sunday, 15 September 2019

5G and Fixed-Mobile Convergence (FMC)


We recently made a new video looking at how 5G architecture caters for Trusted and Untrusted Wireless Access as well as Wireline Access. The presentation discusses:
  • Untrusted non-3GPP access networks;
  • Trusted non-3GPP access networks (TNAN);
  • Wireline access networks;
  • Non-5G-Capable over WLAN (N5CW);
  • Access Traffic Steering, Switching and Splitting (ATSSS)

Slides and video embedded below.





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