Multi-Panel UE (MPUE) in 5G and 5G-Advanced

With the introduction of millimetre-wave spectrum in 5G NR, antenna design at the UE became significantly more complicated. At these higher frequencies, increased propagation and penetration losses mean that directional antenna arrays and beamforming are important not only at the base station but also at the device. A single directional antenna array on a smartphone, however, would provide good performance over only part of the surrounding space. Rotate the device, change the direction of the serving cell, or block the antenna with a hand, and the radio link could deteriorate rapidly.

One solution is to place several antenna panels around different parts of the device. This gives rise to the concept of the Multi-Panel User Equipment, or MPUE.

A useful definition appears in a patent on cell reselection for MPUEs. It describes a mobile UE using two or more differently oriented antenna panels, with each providing different angular coverage. Each panel can itself contain multiple closely spaced antenna elements forming an antenna array or antenna module.

In its simplest form, imagine three directional antenna panels positioned around different edges of a smartphone.

Depending on the orientation of the phone, location of the base station and blockage from the user's hand or body, one antenna panel may provide a significantly better radio path than the others.

This type of architecture is particularly interesting for 5G FR2, where directional antenna gain helps compensate for higher path and diffraction losses. Research into MPUE mobility has considered devices with several spatially distinct antenna panels, allowing the UE to exploit antenna directivity while potentially reducing interference arriving from other directions.

An important point is that MPUE should not be thought of simply as a separate type of UE defined by 3GPP.

The antenna-panel implementation has traditionally been largely hidden from the network. In Release 16, for example, antenna panel selection, activation, deactivation and switching were largely left to the UE implementation. Different MPUE hardware architectures can consequently have quite different capabilities and power-consumption characteristics.

Three MPUE assumptions have commonly been used in 3GPP-related work to represent these different hardware capabilities.

• MPUE-Assumption 1 (MPUE-A1): multiple panels are present, but only one panel can be active at a time. Switching between panels therefore introduces some activation or switching delay.
• MPUE-Assumption 2 (MPUE-A2): multiple panels can be active simultaneously, and one or more panels can be used for transmission.
• MPUE-Assumption 3 (MPUE-A3): multiple panels can be active simultaneously for reception and measurements, but only one panel is used for transmission.

These assumptions are useful because having several physical antenna panels does not automatically mean that all of them can measure, receive or transmit simultaneously. The result depends on the RF and baseband architecture inside the device.

This leads to an interesting problem for mobility. If a UE has several antenna panels pointing in different directions, which panel should be used to measure the serving and neighbouring cells?

Research from Nokia and the Vodafone Chair at TU Dresden has looked at this question in multi-beam FR2 networks, particularly comparing MPUE-A1 and MPUE-A3.

With MPUE-A1, only one panel makes measurements at a time. Measurements are therefore effectively obtained sequentially as the UE moves between its available antenna panels.

With MPUE-A3, multiple panels can make measurements simultaneously.

The difference sounds subtle, but it can have an important impact on mobility. Consider a three-panel UE moving through a network. Under MPUE-A3, measurements obtained through all three panels can remain relatively current.

Under MPUE-A1, while Panel 1 is measuring the radio environment, measurements previously obtained through Panels 2 and 3 are getting older. By the time one of those panels is used again, the UE may have moved and the surrounding radio conditions may have changed.

A handover decision can therefore potentially be based on outdated measurements.

The 2022 study Analysis and Performance Evaluation of Mobility for Multi-Panel User Equipment in 5G Networks found that the two MPUE schemes could provide significant mobility-performance gains compared with the reference traditional UE architecture used in the study. It also found that the different MPUE architectures required different mobility-parameter settings to achieve their best performance.

This is an important observation because simply adding more antenna panels does not automatically solve mobility problems. The network procedures and mobility parameters have to take account of how the particular UE actually performs its measurements.

The issue becomes even more interesting when UE-side receive beamforming is added.

Instead of merely selecting one directional antenna panel, the UE can potentially form or steer receive beams within the angular coverage of a panel.

A later study investigated three different UE-side receive-beamforming approaches for an MPUE equipped with three directional panels in a multi-beam FR2 network. In the system-level simulations used in the study, the proposed techniques reduced radio link failures by up to 53% and handover failures by up to 90%. These figures are specific to the assumptions and scenarios used in that research, but they illustrate the potential mobility benefits of combining multiple panels with UE-side beamforming.

There are also interesting implications for interference.

If the serving cell is received strongly through one UE panel while an interfering neighbouring cell lies in a substantially different direction, the directional response of the selected antenna panel can provide some spatial isolation between them.

Research into Fast Conditional Handover has similarly noted that if an MPUE can communicate using panels oriented towards its serving cell, inter-cell interference from neighbouring cells may be significantly suppressed.

A patent from Nokia takes this idea in another direction by proposing the use of spatial separation when performing cell reselection in a network supporting network slicing.

The proposed mechanism considers candidate cells and performs communication-quality measurements using one or more of the UE's antenna panels. It can then consider whether a candidate cell supporting a required network slice is sufficiently spatially separated, or orthogonal, from other candidate cells before selecting it.

It is important to stress that this is a patent proposal rather than functionality defined by current 3GPP cell-reselection procedures.

Cell reselection normally applies when the UE is in RRC_IDLE or RRC_INACTIVE, whereas most of the MPUE mobility research discussed above focuses on connected-mode handover. The patent is interesting precisely because it proposes extending the usefulness of directional MPUE measurements into the cell-reselection problem, particularly where slice availability and intra-frequency interference need to be considered.

The underlying point remains the same: for an MPUE, the radio environment seen by the device can depend not only on where the UE is located, but also on which antenna panel is observing the network and in which direction that panel is looking.

5G-Advanced takes the multi-panel concept another important step forward.

As part of the Release 18 MIMO enhancements, 3GPP introduced support for Simultaneous Transmission with Multi-Panel, or STxMP, for multi-TRP uplink operation.

This allows a capable UE to transmit simultaneously using different antenna panels towards two Transmission/Reception Points, or TRPs.

There are several possibilities.

For single-DCI STxMP Spatial Division Multiplexing (SDM) PUSCH transmission, different spatial layers of one PUSCH are separately transmitted towards the two TRPs.

For single-DCI STxMP Single Frequency Network (SFN) PUSCH transmission, the same layers of one PUSCH are transmitted towards the two TRPs. This provides transmission diversity and can improve robustness.

For multi-DCI STxMP PUSCH+PUSCH transmission, two PUSCH transmissions are transmitted towards the two TRPs.

This distinction is worth making carefully. Separate PUSCH transmissions belong to the multi-DCI PUSCH+PUSCH case; the single-DCI SDM case divides different layers of one PUSCH between the two TRPs.

Release 18 therefore represents an interesting evolution of the MPUE concept.

Initially, multiple antenna panels were largely about giving a highly directional UE better angular coverage and allowing it to select an appropriate panel as its orientation and radio environment changed.

The evolution can roughly be thought of as:

Multiple antenna panels

→ Broader angular coverage
→ Panel selection and switching
→ Panel-aware measurements
→ UE-side beamforming
→ Improved mobility and spatial interference isolation

→ Simultaneous multi-panel transmission

There are, of course, trade-offs.

Supporting several simultaneously active antenna panels may require additional RF chains and baseband processing, increasing hardware complexity and power consumption. MPUE-A1 avoids some of this complexity by using one panel at a time, but sequential measurements can become outdated and panel switching can introduce delay.

More capable architectures can provide fresher measurements and support simultaneous panel operation, but potentially at a higher implementation and energy cost.

The network and UE therefore need to balance radio performance, mobility robustness, measurement freshness, hardware capability and power consumption.

MPUE is consequently much more interesting than simply saying that a 5G smartphone contains several antenna arrays.

At FR2 in particular, the physical orientation and capabilities of those antenna panels can influence how the UE sees the network, how reliably it moves between cells and how effectively it exploits directional beamforming.

With 5G-Advanced Release 18 STxMP, multiple UE panels can now also become part of the simultaneous uplink transmission strategy towards multiple TRPs.

As mobile networks make greater use of beamforming, multi-TRP operation and increasingly sophisticated MIMO techniques, understanding the antennas and RF capabilities inside the UE becomes an increasingly important part of understanding how the overall radio network performs.

Related Posts: 

• The 3G4G Blog: High Power / Performance User Equipment (HPUE)
• The 3G4G Blog: Is 6G Our Last Chance to Make Antennas Great Again?
• Free 6G Training: MediaTek’s Device View of the Road to 6G
• Free 6G Training: 6G Terminal Vision Whitepaper by GSMA and HONOR
• Free 6G Training: Qualcomm Keynote on 'Advancing Wireless Innovations towards 6G — from a Device’s Viewpoint' from B6GS 2023
• The 3G4G Blog: What is RF Front-End (RFFE) and why is it so Important? 

Navigating the Airwaves: The Future of Spectrum in Wi-Fi and Cellular Networks

Peter Rysavy is the president of Rysavy Research LLC, the consulting firm that he has led since 1993, focusing on computer networking, wireless technology, and mobile computing. Recently he did a presentation for Oregon Chapter of IEEE Communications Society (ComSoc). The abstract of the talk states:

Wireless communication is fundamental to our digital society, with radio spectrum the key enabling resource. Understanding the critical role of spectrum provides deep insight into how wireless technologies function and how they will evolve. This enlightening talk delves into the ingenious advancements in Wi-Fi and cellular networks to harness spectrum, including increasing efficiency, deploying new bands, aggregating channels, and dynamically sharing spectrum. Despite huge progress, formidable challenges remain in meeting soaring demands for capacity, achieving global harmonization, and ensuring coexistence with existing services. 

Key takeaways:

• There is increasing demand for wireless spectrum from technologies like WiFi and 5G cellular networks, but the amount of usable spectrum is finite.
• Different spectrum bands have tradeoffs between coverage, capacity, and ability to support new technologies. The mid-band spectrum between 2 and 6 GHz is well-suited for 5G.
• Technologies are evolving to use spectrum more efficiently through techniques like carrier aggregation, advanced modulation, massive MIMO, and puncturing in WiFi 7.
• The US lacks a clear long-term national spectrum strategy and roadmap, putting it at a disadvantage compared to countries like China, which plan spectrum allocations years in advance.
• Spectrum sharing is complex with no one-size-fits-all solution, though approaches like beamforming, dynamic spectrum access databases, and sensing show promise if challenges are addressed.
• Harmonizing spectrum use globally through conferences helps drive economies of scale in devices and supports roaming, though the US diverges in some bands like 6 GHz assigned solely to WiFi.

The video of the talk is embedded below:

The slides are available here.

Related Posts: 

• The 3G4G Blog: Prof. Ted Rappaport Keynote at EuCNC & 6G Summit 2023 on 'Looking Towards the 6G Era - What we may expect, and why'
• The 3G4G Blog: New 5G NTN Spectrum Bands in FR1 and FR2
• Free 6G Training: Recent Advances on Terahertz (THz) communications
• The 3G4G Blog: New Tutorial on 5G Spectrum
• Telecoms Infrastructure Blog: Ericsson's Massive MIMO Handbook(s)
• Telecoms Infrastructure Blog: Samsung and Ericsson Talks Massive MIMO
• Free 6G Training: Can Ultra Massive MIMO deliver Terabit/s Broadband Connectivity in 6G?
• The 3G4G Blog - 6G: Above 100 GHz and Terahertz (THz) Frequencies
• Connectivity Technology Blog: The Evolution of Wi-Fi 7 (IEEE 802.11be EHT) to Wi-Fi 8 (IEEE 802.11bn UHR) 

Radio Design Webinar: Optimising Your 700 MHz Deployments

 

Radio Design, the award-winning market leader in the provision of wireless infrastructure sharing solutions and RF filter systems, hosted a webinar last week focused on the deployment of the 700 MHz frequency band. This new 700 MHz spectrum is in great demand across the world, mainly due to its long anticipated use as low band 5G spectrum. The webinar explores the potential of this band, as well as how to prepare for potential challenges when deploying.

For people who are familiar with our trainings, we divide the spectrum into three layers, the coverage layer, the capacity layer and the high-throughput layer. 700 MHz is the most popular coverage layer spectrum worldwide.

The slide above from the webinar talks of the recent Austrian 5G Spectrum auction that we blogged about. See tweet below for details

Operator Watch Blog: Austria Gets New 5G Spectrum - https://t.co/jN3sdIeci8 featuring tweets from @JimStLeger @tefficient #3G4G5G #OperatorWatch #Spectrum #4G #5G #Austria #Europe #RTR #H3A #Drei #TMobile #TMA #A1 pic.twitter.com/FAPAZsIGnl

— 3G4G (@3g4gUK) October 3, 2020

In the webinar, slides and video embedded below, Radio Design’s founder – Eric Hawthorn – kicks things off by analysing the benefits of deploying the 700 MHz band in the real world, before passing over to Global Engineering Director – Steve Shaw – who explores some of the technical problems which can arise, as well as some of the solutions. Last but not least, COO and co-owner of Keima – Iris Barcia – provides her insight into the benefits of deploying the 700 MHz band.

Radio Design Webinar: Optimising Your 700 MHz Deployments from 3G4G

Related Posts:

• Operator Watch Blog: Hungary Allocates 5G Spectrum in 700 MHz, 2.1 GHz and 3.6 GHz
• Operator Watch Blog: Austria Gets New 5G Spectrum
• Operator Watch Blog: Finland now has Ideal 5G Spectrum Allocation
• Operator Watch Blog: Italy's 5G Spectrum Auction Controversy
• Operator Watch Blog: Bhutan improving 2G, 3G & 4G coverage while preparing for arrival of 5G in 2022
• Operator Watch Blog: Malaysia Decides on Innovative Approach for 5G Spectrum
• The 3G4G Blog: Automated 4G / 5G HetNet Design
• The 3G4G Blog: 700 MHz Spectrum - Google: Loser or Winner? 

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.

Related Posts:

• Distributed Massive MIMO using Ericsson Radio Stripes
• Antenna evolution: From 4G to 5G

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.

#CWTEC is underway with a thorough breakfast briefing from @CambConsultants. What is 5G NR? What is #MassiveMIMO? How about #beamforming? Delegates get up to speed with the day’s subject area before talks kick off at 10AM. We can’t wait! pic.twitter.com/lGELOWeZk2

— Cambridge Wireless (@cambwireless) September 26, 2019

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)

Anvar Tuknanov from ⁦⁦@bt_uk⁩ showing improvement in communications capacity as technology has evolved to 5G M-MIMO. ⁦@cambwireless⁩ #CWTEC ⁦@CGI_UKNEWS⁩ #ExperienceCGI pic.twitter.com/IZXJk2n6u4

— Andrew Palmer (@AndrewPalmerCGI) September 26, 2019

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)

A fantastic technical in-depth session on Non-Terrestrial Networks (NTN) by Yinan Qi, Samsung. Loved it @TMGB
#CWTEC pic.twitter.com/QUpxA3wKj9

— Zahid Ghadialy (@zahidtg) September 26, 2019

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)

We loved @zahidtg’s #OpenRAN diagrams in his session at #CWTEC this afternoon. Good explanation of why OpenRAN matters and how it actually works. #5G @Parallel_tw pic.twitter.com/DTna4pC7bA

— Cambridge Wireless (@cambwireless) September 26, 2019

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)

3GPP Release - Technology
99 - UMTS (3G)
4
5 - HSDPA (3.5G)
6 - HSUPA
7 - HSPA+
8 - LTE (3.9G)
9
10 - LTA-A (4G)
11
12
13 - LTE-A Pro (4.5G)
14
15 - 5G
16
17
18 - 5.5G?
19
20
21 - 6G?#CWTEC #3G4G5Gpic.twitter.com/vQi5Dhfsno

— 3G4G (@3g4gUK) October 8, 2019

And my personal highlight was that I launched World's first coloured 5G tie

Did I mention I am launching my World's First Coloured 5G Tie that caters for all different implementations of 5G 😁 #CWTEC@cambwireless @3g4gUK @Parallel_tw @3GPPLive @IBTwi @AndrewPalmerCGI @alainmouradUK pic.twitter.com/j0ebPnSxaB

— Zahid Ghadialy (@zahidtg) September 26, 2019

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


Related Articles:

• CW Technology & Engineering Conference Review by CW (Cambridge Wireless)
• CWTEC: 5G, Massive MIMO and Satellites by David Chambers, ThinkSmallCell
• Dean Bubley made a nice Twitter Thread on CWTEC here.
• All the information about the conference is available here.

Distributed Massive MIMO using Ericsson Radio Stripes

One of the interesting things that caught my attention in MWC 2019 was the Ericsson Radio Stripes.

Emil Björnson explains it nicely in his blog as to how this works.

Distributed MIMO deployments combine the best of two worlds: The beamforming gain and spatial interference suppression capability of conventional Massive MIMO with co-located arrays, and the bigger chance of being physically close to a service antenna that small cells offer. Coherent transmission and reception from a distributed MIMO array is not a new concept but has been given many names over the years, including Distributed Antenna System and Network MIMO. Most recently, in the beyond-5G era, it has been called ubiquitous Cell-free Massive MIMO communications and been refined based on insights and methodology developed through the research into conventional Massive MIMO.

One of the showstoppers for distributed MIMO has always been the high cost of deploying a large number of distributed antennas. Since the antennas need to be phase-synchronized and have access to the same data, a lot of high-capacity cables need to be deployed, particularly if a star topology is used. 
...

For those who cannot attend MWC, further conceptual details can be found in a recent overview paper on Cell-free Massive MIMO. An even more detailed description of radio stripes can be found in Ericsson’s patent application from 2017.

The paper explains the Radio stripe system design and also lists the advantages of such a system:

The radio stripe system facilitates a flexible and cheap cell-free Massive MIMO deployment. Cheapness comes from many aspects: (i) deployment does not require highly qualified personnel. Theoretically, a radio stripe needs only one (plug and play) connection either to the front-haul network or directly to the CPU; (ii) a conventional distributed massive MIMO deployment requires a star topology, i.e., a separate cable between each APs and a CPU, which may be economically infeasible. Conversely, radio stripe installation complexity is unaffected by the number of antenna elements, thanks to its compute-and-forward architecture. Hence, cabling becomes much cheaper; (iii) maintenance costs are cut down as a radio stripe system offers increased robustness and resilience: highly distributed functionality offer limited overall impact on the network when few stripes being defected; (iv) low heat-dissipation makes cooling systems simpler and cheaper. While cellular APs are bulky, radio stripes enable invisible installation in existing construction elements as exemplified in Fig. below. Moreover, a radio stripe deployment may integrate for example temperature sensors, microphones/speakers, or vibration sensors, and provide additional features such as fire alarms, burglar alarms, earthquake warning, indoor positioning, and climate monitoring and control.

According to the Ericsson post:

One of the inventors and researchers behind the concept, Jan Hederén, Strategist at Ericsson 4G5G Development, says: 

"Although a large-scale installation of distributed MIMO can provide excellent performance, it can also become an impractical and costly "spaghetti-monster" of cables in case dedicated cables are used to connect the antenna elements.

To be easy to deploy, we need to connect and integrate the antenna elements inside a single cable. We call this solution the "radio stripe" which is an easy way to create a large scale distributed, serial, and integrated antenna system." Says, also inventors and researcher behind the concept."

This visionary concept is an extension of how to build and enhance the capability of current networks. The Radio Stripe systems offers, so to say, new colors and flavors in how we increase the performance of mobile networks.

The Radio Stripe vision is focused on improvements to the reach and quality of radio connectivity in the access part of the mobile network. It shares all other resources (transport, baseband, management, core) with current mobile solutions.

I am looking forward to reading a lot more about this kind of approach in the future and probably some deployment videos too.

Related post:

• Drones at Mobile World Congress 2019 and my upcoming webinar on 5G at #MWC19 

5G Top-10 Misconceptions

Here is a video we did a few weeks back to clear the misconceptions about 5G. The list above summarizes the topics covered.



The video is nearly 29 minutes long. If you prefer a shorter version or are bored of hearing me 😜 then a summary version (just over 3 minutes) is in 3G4G tweet below.

Based on the comments received, here is our shorter version of "5G: Top 10 Misconceptions" video #UK5G #HWMBBFhttps://t.co/7lxE3ekDPM

— 3G4G (@3g4gUK) November 21, 2018

The slides can be downloaded from our Slideshare channel as always.

As always, we love your feedback, even when you strongly disagree.

Other interesting recent posts on 5G:

• 5G NR Radio Protocols Overview
• Overview 3GPP 5G NR Physical Layer
• 5G Development and Progress in Singapore
• 5G Network Architecture Options (Updated)
• Automated 4G / 5G HetNet Design
• Optus launching commercial 5G Fixed Wireless Access services in January 2019
• Benefits and Challenges of Applying Device-Level AI to 5G networks
• 5G New Radio Standards and other Presentations
• Base Station Antenna Considerations for 5G
• End-to-end Network Slicing in 5G
• ITU 'Network 2030': Initiative to support Emerging Technologies and Innovation looking beyond 5G advances

5G New Radio Standards and other Presentations

A recent Cambridge Wireless event 'Radio technology for 5G – making it work' was an excellent event where all speakers delivered an interesting and insightful presentation. These presentations are all available to view and download for everyone for a limited time here.

I blogged about the base station antennas last week but there are other couple of presentations that stood out for me.

The first was an excellent presentation from Sylvia Lu from u-Blox, also my fellow CW Board Member. Her talk covered variety of topics including IoT, IIoT, LTE-V2X and Cellular positioning, including 5G NR Positioning Trend. The presentation is embedded below and available to download from Slideshare

Overview of standardisation status and 3GPP technology evolution trend from 3G4G

The other presentation on 5G NR was one from Yinan Qi of Samsung R&D. His presentation looked at variety of topics, mainly Layer 1 including Massive MIMO, Beamforming, Beam Management, Bandwidth Part, Reference Signals, Phase noise, etc. His presentation is embedded below and can be downloaded from SlideShare.

5G NR: Key features and enhancements from 3G4G

Related Posts:

• Base Station Antenna Considerations for 5G
• Introduction to Fixed Wireless Access (FWA)
• 5G Network Architecture Options (Updated)
• Automated 4G / 5G HetNet Design

Base Station Antenna Considerations for 5G

I first mentioned Quintel in this blog three years back for their innovations in 4T8R/8T8R antennas. Since then they have been going strength to strength.

I heard David Barker, CTO of Quintel at Cambridge Wireless event titled "Radio technology for 5G – making it work" talking about the antennas consideration for 5G. There are quite a few important areas in this presentation for consideration. The presentation is embedded below:

Base Station Antenna needs for the 5G RAN from 3G4G

Related Posts:

• Using 8T8R Antennas for TD-LTE
• Antenna evolution: From 4G to 5G
• The Art of Disguising Cellular Antennas
• AT&T Blog: "Providing Connectivity from Inside a Cactus"
• Automated 4G / 5G HetNet Design

The Art of Disguising Cellular Antennas

When I did a blog post 'Disguising Small Cells in Rural areas' last year, many people were surprised to see these things. So here is another post showing how the antennas looks like and how they have to be disguised to blend in with the environment.

The above pictures shows fake date trees (with dates) near Koutoubia mosque, Marrakech, designed to blend in with the surroundings. In fact I have been told that these fake date trees are common in the Middle East and North African countries.

The above picture is from Dubai, showing similar palm tree. Source unknown.

The above picture, courtesy of Andy Sutton on Twitter shows a cell site near Blandford Forum. I hope you can spot the fake tree on top right.

Another one, courtesy of Andy Sutton on Twitter shows a cell site between motorway M56, J10 & 11 in Cheshire. Single operator but could be shared, single frequency band, x-pole with 3 cell sectors. Only two of the possible 3 cell sectors connected here. Pointing up and down motorway hence 4 feeders.

A multi-technology cell site blending in with lighting columns in the area #industrialarchaeology #urbanlife #4GLTE pic.twitter.com/GLeickD3Em

— Andy Sutton (@960sutton) January 23, 2016

A unique looking tower #cellular #microwave #radio industrial archaeology, documenting the communications revolution pic.twitter.com/HPuqQUhdSt

— Andy Sutton (@960sutton) December 18, 2015

This is the infrastructure that keeps our smartphones connected. pic.twitter.com/H1ZemnrgYL

— Nigel Linge (@NigelLinge) December 12, 2015

Another one courtesy of Andy Sutton on Twitter. Its been disguised to not look out of place unless someone is observing very carefully.

Three cellular tree sites, powering the 4th industrial revolution. #ruralbroadband #historyoftechnology #mobilephone pic.twitter.com/ApvCyqMdao

— Andy Sutton (@960sutton) August 31, 2015

All three are fake trees and each is a separate cellular installation. The location is Lancashire, off the A6 between Slyne and Bolton-le-Sands. They are all different operators, left to right, O2, T-Mobile, Orange - although two will become one as part of EE of course.

Modern Art and Cellular Antenna, courtesy of Andy Sutton on Twitter.

What will happen when we transition to 5G, where we will have a lot more antennas because of MIMO (massive or not). China Mobile is researching into Smart Tiles, which are antennas that can be hidden inside Chinese characters. See the following for example:

With more antennas becoming commonplace in the urban environment, operators and vendors will have to keep up coming with innovative ways to disguise the antennas and hope no one notices.

See Also:

• Cellular Mobile Communications Heritage - The Association for Industrial Archaeology
• Awkward Trees - CBS News

Updates from the 3GPP RAN 5G Workshop - Part 2

I have finally got round to having a look at some more presentations on 5G from the recently concluded 3GPP RAN 5G Workshop. Part 1 of the series is here.

Panasonic introduced this concept of Sub-RAT's and Cradle-RAT's. I think it should be obvious from the picture above what they mean but you can refer to their presentation here for more details.

Ericsson has provided a very detailed presentation (but I assume a lot of slides are backup slides, only for reference). They have introduced what they call as "NX" (No compatibility constraints). This is in line to what other vendors have referred to as well that above 6GHz, for efficiency, new frame structures and waveforms would serve best. Their slides are here.



Nokia's proposal is that in the phase 1 of 5G, the 5G Access point (or 5G NodeB) would connect to the 4G Evolved Packet Core (EPC). In phase 2, both the LTE and the 5G (e)NodeB's would connect to the 5G core. Their presentation is available here.

Before we move on to the next one, I should mention that I am aware of some research that is underway, mostly by universities where they are exploring an architecture without a centralised core. The core network functionality would be distributed and some of the important data would be cached on the edge. There will be challenges to solve regarding handovers and roaming; also privacy and security issues in the latter case.

I quite like the presentation by GM research about 5G in connected cars. They make a very valid point that "Smartphones and Vehicles are similar but not the same. The presentation is embedded below.

Qualcomm presented a very technical presentation as always, highlighting that they are thinking about various future scenarios. The picture above, about phasing is in a way similar to the Ericsson picture. It also highlights what we saw in part 1, that mmW will arrive after WRC-19, in R16. Full presentation here.

The final presentation we are looking is by Mitsubishi. Their focus is on Massive MIMO which may become a necessity at higher frequencies. As the frequency goes higher, the coverage goes down. To increase the coverage area, beamforming can be used. The more the antennas, the more focused the beam could be. They have also proposed the use of SC-FDMA in DL. Their presentation is here and also embedded below.

Using 8T8R Antennas for TD-LTE

People often ask at various conferences if TD-LTE is a fad or is it something that will continue to exist along with the FDD networks. TDD networks were a bit tricky to implement in the past due to the necessity for the whole network to be time synchronised to make sure there is no interference. Also, if there was another TDD network in an adjacent band, it would have to be time synchronised with the first network too. In the areas bordering another country where they might have had their own TDD network in this band, it would have to be time synchronised too. This complexity meant that most networks were happy to live with FDD networks.

In 5G networks, at higher frequencies it would also make much more sense to use TDD to estimate the channel accurately. This is because the same channel would be used in downlink and uplink so the downlink channel can be estimated accurately based on the uplink channel condition. Due to small transmit time intervals (TTI's), these channel condition estimation would be quite good. Another advantage of this is that the beam could be formed and directed exactly at the user and it would appear as a null to other users.

This is where 8T8R or 8 Transmit and 8 Receive antennas in the base station can help. The more the antennas, the better and narrower the beam they can create. This can help send more energy to users at the cell edge and hence provide better and more reliable coverage there.  



How do these antennas look like? 8T8R needs 8x Antennas at the Base Station Cell, and this is typically delivered using four X-Polar columns about half wavelength apart. I found the above picture on antenna specialist Quintel's page here, where the four column example is shown right. At spectrum bands such as 2.3GHz, 2.6GHz and 3.5GHz where TD-LTE networks are currently deployed, the antenna width is still practical. Quintel’s webpage also indicates how their technology allows 8T8R to be effectively emulated using only two X-Polar columns thus promising Slimline antenna solutions at lower frequency bands. China Mobile and Huawei have claimed to be the first ones to deploy these four X-Pol column 8T8R antennas. Sprint, USA is another network that has been actively deploying these 8T8R antennas.

There are couple of interesting tweets that show their kit below:

Sprint's John Saw showing of TD-LTE 8T8R and Network Vision. Room for expansion. pic.twitter.com/Mydzasg3F6

— Walt Piecyk (@WaltBTIG) June 23, 2014

Sprint's 8T8R antenna (on left) is actually smaller than 4T2R on 1.9 GHz and 1T2R for 800MHz.(on right) #tdlte $S pic.twitter.com/q26IhZmDie

— Walt Piecyk (@WaltBTIG) June 23, 2014

In fact Sprint has very ambitious plans. The following is from a report in Fierce Wireless:

Sprint's deployment of 8T8R (eight-branch transmit and eight-branch receive) radios in its 2.5 GHz TDD LTE spectrum is resulting in increased data throughput as well as coverage according to a new report from Signals Research. "Thanks to TM8 [transmission mode 8] and 8T8R, we observed meaningful increases in coverage and spectral efficiency, not to mention overall device throughput," Signals said in its executive summary of the report.

The firm said it extensively tested Sprint's network in the Chicago market using Band 41 (2.5 GHz) and Band 25 (1.9 GHz) in April using Accuver's drive test tools and two Galaxy Note Edge smartphones. Signals tested TM8 vs. non-TM8 performance, Band 41 and Band 25 coverage and performance as well as 8T8R receive vs. 2T2R coverage/performance and stand-alone carrier aggregation.

Sprint has been deploying 8T8R radios in its 2.5 GHz footprint, which the company has said will allow its cell sites to send multiple data streams, achieve better signal strength and increase data throughput and coverage without requiring more bandwidth.

The company also has said it will use carrier aggregation technology to combine TD-LTE and FDD-LTE transmission across all of its spectrum bands. In its fourth quarter 2014 earnings call with investors in February, Sprint CEO Marcelo Claure said implementing carrier aggregation across all Sprint spectrum bands means Sprint eventually will be able to deploy 1900 MHz FDD-LTE for uplink and 2.5 GHz TD-LTE for downlink, and ultimately improve the coverage of 2.5 GHz LTE to levels that its 1900 MHz spectrum currently achieves. Carrier aggregation, which is the most well-known and widely used technique of the LTE Advanced standard, bonds together disparate bands of spectrum to create wider channels and produce more capacity and faster speeds.

Alcatel-Lucent has a good article in their TECHzine, an extract from that below:

Field tests on base stations equipped with beamforming and 8T8R technologies confirm the sustainability of the solution. Operators can make the most of transmission (Tx) and receiving (Rx) diversity by adding in Tx and Rx paths at the eNodeB level, and beamforming delivers a direct impact on uplink and downlink performance at the cell edge.

By using 8 receiver paths instead of 2, cell range is increased by a factor of 1.5 – and this difference is emphasized by the fact that the number of sites needed is reduced by nearly 50 per cent. Furthermore, using the beamforming approach in transmission mode generates a specific beam per user which improves the quality of the signal received by the end-user’s device, or user equipment (UE). In fact, steering the radiated energy in a specific direction can reduce interference and improves the radio link, helping enable a better throughput. The orientation of the beam is decided by shifting the phases of the Tx paths based on signal feedback from the UE. This approach can deliver double the cell edge downlink throughput and can increase global average throughput by 65 per cent.

These types of deployments are made possible by using innovative radio heads and antenna solutions.  In traditional deployments, it would require the installation of multiple remote radio heads (RRH) and multiple antennas at the site to reach the same level of performance. The use of an 8T8R RRH and a smart antenna array, comprising 4 cross-polar antennas in a radome, means an 8T8R sector deployment can be done within the same footprint as traditional systems.



Anyone interested in seeing pictures of different 8T8R antennas like the one above, see here. While this page shows Samsung's antennas, you can navigate to equipment from other vendors.

Finally, if you can provide any additional info or feel there is something incorrect, please feel free to let me know via comments below.

3GPP Release-13 work started in earnest

The 3GPP news from some months back listed the main RAN features that have been approved for Release-13 and the work has already started on them. The following are the main features (links contain .zip files):

• LTE in unlicensed spectrum (aka Licensed-Assisted Access) - RP-150055
• Carrier Aggregation enhancements - RP-142286
• LTE enhancements for Machine-Type Communications (MTC) - RP-141865
• Enhancements for D2D - RP-142311
• Study Item Elevation Beamforming / Full-Dimension MIMO - RP-141831
• Study Item Enhanced multi-user transmission techniques - RP-142315
• Study Item Indoor positioning - RP-141102
• Study Item Single-cell Point-to-Multipoint (SC-PTM) - RP-142205

Another 3GPP presentation from late last year showed the system features that were being planned for Rel-13 as shown above.

I have also posted a few items earlier relating to Release13, as follows:

• LTE Category-0 low power M2M devices
• Update on Public Safety and Mission Critical communications
• 3GPP Rel-12 and Future Security Work
• Elevation Beamforming / Full-Dimension MIMO
• LA-LTE and LAA
• LTE-Hetnet (LTE-H) a.k.a. LTE Wi-Fi Link Aggregation (LWA)

Ericsson has this week published a whitepaper on release 13, with a vision for 'Networked Society':

The vision of the Networked Society, where everything that benefits from being connected will be connected, places new requirements on connectivity. LTE is a key component in meeting these demands, and LTE release 13 is the next step in the LTE evolution.

Their whitepaper embedded below:

It should be pointed out that 5G work does not start until Release-15 as can be seen from my tweet

Nice picture of "5G Radio Interface development timeline" by @alainmouradUK pic.twitter.com/ANFfujJGS5
— Zahid Ghadialy (@zahidtg) April 4, 2015

xoxoxo Added Later (26/04/2015) xoxoxo
I came across this presentation from Keysight (Agilent) where Moray Rumney has provided information in much more detail.