New Tutorial on 5G Spectrum

We made a new tutorial on 5G spectrum. It's in 2 different formats. Short version (~13 mins) or Long version (~31 mins). Instead of embedding the slides/videos here, I am providing links to the 5G section on 3G4G page below.

Short Version (~13 mins) - click here

Long Version (~31 mins) - click here


Related posts:

• Examples of 5G Use Cases & Applications
• Bandwidth Part (BWP) in 5G New Radio (NR)
• When will 2G & 3G be switched off now that 5G is here?
• Couple of talks by NTT Docomo on 5G and Beyond (pre-6G)
• Slides and Videos from the 1st 6G Wireless Summit - March 2019
• Slides from Parallel Wireless Webinar: 5G at #MWC19

Presentations on Macro Cells and Millimetre-wave Technology from recent CW (Cambridge Wireless) events

CW (Cambridge Wireless) held a couple of very interesting events from 2 very popular groups.

The first one was on "5G wide area coverage: macro cells – the why and the how". This event looked at the design and optimisation of the macro cell layer and its role within future heterogeneous networks. You can access the presentations for limited time on CW website here.

The presentations available are:

• Macro Cell developments that support LTE evolution and 5G deployments by Colin Bryce, Commscope
• Review of current macro network site types and design by Andy Sutton, British Telecommunications
• Smart rollout to maximise ROI by Mike Page, Radio Design
• Strategic planning: an overview of the role of the macro cell by Iris Barcia, Keima
• How massive MIMO can deliver the promise of new 5G Radio Networks by George Grayland, 5GFutures

Related posts that may be of interest:

• Keima: Automated 4G / 5G HetNet Design
• Prof. Andy Sutton: 5G Radio Access Network Architecture Evolution - Jan 2019
• #CWHeritage Talk: The history of synchronisation in digital cellular networks

Commercialising millimetre-wave technology - Presentations from @cambwireless #CWRadioTech event last week available now: https://t.co/PJbrBiJ8UR #4G #5G #Spectrum #Frequencies pic.twitter.com/6naiUSK1qw

— 3G4G (@3g4gUK) May 21, 2019

The second one was on "Commercialising millimetre-wave technology". The event reviewed the commercial opportunities at millimetre-wave frequencies, what bands are available and what licensing is needed. You can access the presentations on CW website for limited time here.

The presentations available are:

• ‘Measurements, Modelling and Testing Millimetre Wave Communication Systems’ by Mark Beach, University of Bristol (Communication Systems & Networks Research Group)
• The Design of a Plastic Packaged Front-end IC for mmWave 5G by Liam Devlin, Plextek RFI
• Design Considerations for the Realisation of Cost-Effective, High-Performance mmWave PCBs by James Henderson, Plextek
• Millimetre wave wireless for improved wireless connectivity in Transport by Mark Barrett, Blu Wireless Technology
• Unlicensed, unlimited: 60GHz mmWave’ by Paul Morris, CCS
• Millimetre-Wave Circuit Simulation Challenges’ by David Morris, Keysight Technologies
• Use Cases & Enabling 5G NR Technologies by Mark Beach, University of Bristol (Communication Systems & Networks Research Group)
• Whitepaper by Paul Holes, Anritsu

We recently made a video to educate people outside our industry about non-mmWave 5G. It's embedded below.

When will 2G & 3G be switched off now that 5G is here?

I wrote this blog post '2G / 3G Switch Off: A Tale of Two Worlds' back in Oct 2017. Since then I have continued to see the same trend in 2G/3G shutdown announcements. Based on that post and also taking the GSMA Mobile Economy Report into account, we have created a short tutorial on 2G/3G switch off and how the trends are affected by the launch of KaiOS based Smart Feature phones. Presentation and video embedded below. Would love to hear your thoughts.

Beginners: When will 2G & 3G be switched off now that 5G is here? from 3G4G

Related posts:

• Operator Watch Blog: Swisscom launched 5G Fast and 5G Wide
• The 3G4G Blog: 2G / 3G Switch Off: A Tale of Two Worlds
• The 3G4G Blog: Can KaiOS accelerate the transition from 2G / 3G to 4G?

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 

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

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

Minimum Bandwidth Requirement for 5G Non-Standalone (NSA) Deployment

I was attending the IEEE 5G World Forum live-stream, courtesy of IEEE Tv and happen to hear Egil Gronstad, Senior Director of Technology Development and Strategy at T-Mobile USA. He said that they will be building a nationwide 5G network that will initially be based on 600 MHz band.

During the Q&A, Egil mentioned that because of the way the USA has different markets, on average they have 31 MHz of 600 MHz (Band 71). The minimum is 20 MHz and the maximum is 50 MHz.

So I started wondering how would they launch 4G & 5G in the same band for nationwide coverage? They have a good video on their 5G vision but that is of course probably going to come few years down the line.

In simple terms, they will first deploy what is known as Option 3 or EN-DC. If you want a quick refresher on different options, you may want to jump to my tutorial on this topic at 3G4G here.

The Master Node (recall dual connectivity for LTE, Release-12. See here) is an eNodeB. As with any LTE node, it can take bandwidths from 1.4 MHz to 20 MHz. So the minimum bandwidth for LTE node is 1.4 MHz.

The Secondary Node is a gNodeB. Looking at 3GPP TS 38.101-1, Table 5.3.5-1 Channel bandwidths for each NR band, I can see that for band 71

	NR band / SCS / UE Channel bandwidth
NR Band	SCS kHz	5 MHz	101,2 MHz	152 MHz	202 MHz	252 MHz	30 MHz	40 MHz	50 MHz	60 MHz	80 MHz	90 MHz	100 MHz
n71	15	Yes	Yes	Yes	Yes
	30		Yes	Yes	Yes
	60

The minimum bandwidth is 5MHz. Of course this is paired spectrum for FDD band but the point I am making here is that you need just 6.4 MHz minimum to be able to support the Non-Standalone 5G option.

I am sure you can guess that the speeds will not really be 5G speeds with this amount of bandwidth but I am looking forward to all these kind of complaints in the initial phase of 5G network rollout.

I dont know what bandwidths T-Mobile will be using but we will see at least 10MHz of NR in case where the total spectrum is 20 MHz and 20 MHz of NR where the total spectrum is 50 MHz.

If you look at the earlier requirements list, the number being thrown about for bandwidth was 100 MHz for below 6 GHz and up to 1 GHz bandwidth for spectrum above 6 GHz. Don't think there was a hard and fast requirement though.

Happy to hear your thoughts.

Terahertz and Beyond 100 GHz progress

There seems to be a good amount of research going on in higher frequencies to see how a lot more spectrum with a lot more bandwidth can be used in future radio communications. NTT recently released information about "Ultra high-speed IC capable of wireless transmission of 100 gigabits per second in a 300 GHz band". Before we discuss anything, lets look at what Terahertz means from this article.

Terahertz wave: Just as we use the phrase ‘kilo’ to mean 103 , so we use the term ‘giga’ to mean 109 and the term ‘tera’ to mean 1012 . “Hertz (Hz)” is a unit of a physical quantity called frequency. It indicates how many times alternating electric signals and electromagnetic waves change polarity (plus and minus) per second. That is, one terahertz (1 THz = 1,000 GHz) is the frequency of the electromagnetic wave changing the polarity by 1 × 1012 times per second. In general, a terahertz wave often indicates an electromagnetic wave of 0.3 THz to 3 THz.

While there are quite a few different numbers, this is the one that is most commonly being used. The following is the details of research NTT did.

In this research, we realized 100 Gbps wireless transmission with one wave (one carrier), so in the future, we can extend to multiple carriers by making use of the wide frequency band of 300 GHz band, and use spatial multiplexing technology such as MIMO and OAM. It is expected to be an ultra high-speed IC technology that enables high-capacity wireless transmission of 400 gigabits per second. This is about 400 times the current LTE and Wi-Fi, and 40 times 5G, the next-generation mobile communication technology. It is also expected to be a technology that opens up utilization of the unused terahertz wave frequency band in the communications field and non-communication fields.

Complete article and paper available here.

NTT Docomo has been doing 5G Field Testing of Ultra-high-speed, Long-distance Transmission Using mmWave in 28, 39 GHz in collaboration with @Huawei . Achieved high speed communication over distances exceeding 1 km with mmWave - https://t.co/a03SdqVhI7 pic.twitter.com/rlsqRAJ5YC

— 3G4G (@3g4gUK) July 2, 2018

Huawei has also been doing research in W (92 - 114.5 GHz) and D (130 - 174.5 GHz) bands.

A recent presentation by Debora Gentina, ETSI ISG mWT WI#8 Rapporteur at the UK Spectrum Policy Forum is embedded below.

This presentation can be downloaded from UK SPF site here. Another event on beyond 100GHz that took place last year has some interesting presentations too. Again, on UKSPF site here.

Ericsson has an interesting article in Technology Review, looking at beyond 100GHz from backhaul point of view. Its available here.

If 5G is going to start using the frequencies traditionally used by backhaul then backhaul will have to start looking at other options too.

Happy to listen to your thoughts and insights on this topic.

100 Gbps wireless transmission using Orbital Angular Momentum (OAM) multiplexing

From a press release by NTT Group:

Nippon Telegraph and Telephone Corporation (NTT, Head Office: Chiyoda-ku, Tokyo, President and CEO: Hiroo Unoura) has successfully demonstrated for the first time in the world 100 Gbps wireless transmission using a new principle — Orbital Angular Momentum (OAM) multiplexing — with the aim of achieving terabit-class wireless transmission to support demand for wireless communications in the 2030s. It was shown in a laboratory environment that dramatic leaps in transmission capacity could be achieved by an NTT devised system that mounts data signals on the electromagnetic waves generated by this new principle of OAM multiplexing in combination with widely used Multiple-Input Multiple-Output (MIMO) technology. The results of this experiment revealed the possibility of applying this principle to large-capacity wireless transmission at a level about 100 times that of LTE and Wi-Fi and about 5 times that of 5G scheduled for launch. They are expected to contribute to the development of innovative wireless communications technologies for next-generation of 5G systems such as connected cars, virtual-reality/augmented-reality (VR/AR), high-definition video transmission, and remote medicine.


NTT is to present these results at Wireless Technology Park 2018 (WTP2018) to be held on May 23 – 25 and at the 2018 IEEE 87th Vehicular Technology Conference: VTC2018-Spring, an international conference sponsored by the Institute of Electrical and Electronics Engineers (IEEE) to be held on June 3 – 6.

For more technical details look at the bottom of this link.

Related Post:

• 'Twisted Radio Waves': Could they be the way out of Spectrum Crunch?

Connectivity on Planes

I recently made a video explaining how connectivity works on planes and how its about to change. The video and slides are embedded below.

Beginners: Connectivity in Planes from 3G4G

Related posts:

• In-flight broadband connectivity service with speeds up to 75Mbps
• Deutsche Telekom: Media kit European Aviation Network
• European Aviation Network (EAN) Explained with Ground Based Mast Example
• An Introduction to Non-Terrestrial Networks (NTN)

5G and CBRS Hype?

The dissenting voices on 5G and CBRS are getting louder. While there are many analysts & operators who have been cautioning against 5G, its still moving ahead with a rapid pace. In the recent Huawei Mobile Broadband forum for example, BT's boss admitted that making case for 5G is hard. Bruno Jacobfeuerborn, CTO of Deutsche Telekom on the other hand is sitting on the fence. Dean Bubley's LinkedIn post is interesting too.

Vodafone CTO asked yesterday: "Will 5G be like 2G and 4G, or like 3G?". Now, it's like 3G, designing use cases and apps that nobody knows if they will be successful (e.g. 3G video calling).
2G and 4G were all about letting users/developers create their own. #HWMBBF

— Dimitris Mavrakis (@dmavrakis) November 16, 2017

. @BJacobfeuerborn says the forthcoming glut of sporting events in Asia (three Olympics, winter and summer, in next five years) will give them a 5G headstart. "If you want to do massive infrastructure investment, you need events." #HWMBBF

— Mobile Europe (@mobileeurope) November 16, 2017

Anyway, we have storified most of the tweets from Huawei Mobile Broadband Forum here.

Signals Research Group recently published their Signals Flash report, which is different from the more detailed Signals Ahead reports looking at 5G and CBRS, in addition to other topics. I have embedded the report below (with permission - thanks Mike) but you can download your own copy from here.

The summary from their website will give a good idea of what that is about:

CBRS – Much Ado About Not Very Much.  The FCC is heading in the right direction with how it might regulate the spectrum. However, unless you are a WISP or a private entity looking to deploy a localized BWA service, we don’t see too many reasons to get excited.

Handicapping the 5G Race.  Millimeter wave networks will be geographically challenged, 600 MHz won’t scale or differentiate from LTE, Band 41 may be the most promising, but this isn’t saying much. Can network virtualization make a winner?

It makes no Cents! Contrary to widespread belief,  5G won’t be a new revenue opportunity for operators – at least in the near term. The vertical markets need to get on board while URLLC will lag eMBB and prove far more difficult to deploy.

This Fierce Wireless article summarises the issues with CBRS well.

“While (some) issues are being addressed, the FCC can’t solve how to carve up 150 MHz of spectrum between everyone that wants a piece of the pie, while also ensuring that everyone gets a sufficient amount of spectrum,” the market research firm said in a report. “The 150 MHz is already carved up into 7- MHz for PAL (Priority Access License) and 80 MHz for GAA (General Authorized Access). The pecking order for the spectrum is incumbents, followed by PAL, and then by GAA…. 40 MHz sounds like a lot of spectrum, but when it comes to 5G and eMBB, it is only somewhat interesting, in our opinion. Further, if there are multiple bidders going after the PAL licenses then even achieving 40 MHz could be challenging.”

Signals said that device compatibility will also be a significant speed bump for those looking to leverage CBRS. Manufacturers won’t invest heavily to build CBRS-compatible phones until operators deploy infrastructure “in a meaningful way,” but those operators will need handsets that support the spectrum for those network investments to pay dividends. So while CBRS should prove valuable for network operators, it may not hold as much value for those who don’t own wireless infrastructure.

“The device ecosystem will develop but it is likely the initial CBRS deployments will target the more mundane applications, like fixed wireless access and industrial IoT applications,” the firm said. “We believe infrastructure and devices will be able to span the entire range of frequencies—CBRS and C-Band—and the total amount of available spectrum, combined with the global interest in the C-Band for 5G services, will make CBRS more interesting and value to operators. Operators will just have to act now, and then wait patiently for everything to fall into place.”

While many parts of the world are focusing on using frequencies around and above 3.5GHz for 5G, USA would be the only country using it for 4G. I suspect that many popular devices may not support CBRS but could be good for Fixed Wireless Access (FWA). It remains to be seen if economy of scale would be achieved.

Signals Flash Nov 2017: 5G in Americas | Signals Research Group from 3G4G

2G / 3G Switch Off: A Tale of Two Worlds

Source: Wikipedia

2G/3G switch off is always a topic of discussion in most conferences. While many companies are putting their eggs in 4G & 5G baskets, 2G & 3G is not going away anytime soon.

Based on my observations and many discussions that I have had over the past few months, I see a pattern emerging.

In most developed nations, 2G will be switched off (or some operators may leave a very thin layer) followed by re-farming of 3G. Operators will switch off 3G at earliest possible opportunity as most users would have moved to 4G. Users that would not have moved to 4G would be forced to move operators or upgrade their devices. This scenario is still probably 6 - 10 years out.

As we all know that 5G will need capacity (and coverage) layer in sub-6GHz, the 3G frequencies will either be re-farmed to 4G or 5G as 2G is already being re-farmed to 4G. Some operators may choose to re-balance the usage with some lower frequencies exchanged to be used for 5G (subject to enough bandwidth being available).


On the other hand, in the developing and less-developed nations, 3G will generally be switched off before 2G. The main reason being that there are still a lot of feature phone users that rely on 2G technologies. Most, if not all, 3G phones support 2G so the existing 3G users will be forced onto 2G. Those who can afford, will upgrade to newer smartphones while those who cant will have to grudgingly use 2G or change operators (not all operators in a country will do this at the same time).

Many operators in the developing countries believe that GSM will be around until 2030. While it may be difficult to predict that far in advance, I am inclined to believe this.

For anyone interested, here is a document listing 2G/3G switch off dates that have been publicly announced by the operators.

2G/3G Switch off Dates from 3G4G

Let me know what you think.

Further reading:

• 2G Network Decommissioning, Ready? - Russell Lundberg, Bangkok Beach Telecom

Second thoughts about LTE-U / LAA

Its been a while since I wrote about LTE-U / LAA on this blog. I have written a few posts on the small cells blog but they seem to be dated as well. For anyone needing a quick refresher on LTE-U / LAA, please head over to IoTforAll or ShareTechNote. This post is not about the technology per se but the overall ecosystem with LTE-U / LAA (and even Multefire) being part of that.

Lets recap the market status quickly. T-Mobile US has already got LTE-U active and LAA was tested recently. SK Telecom achieved 1Gbps in LAA trials with Ericsson. AT&T has decided to skip the non-standard LTE-U and go to standards based LAA. MTN & Huawei have trialled LAA for in-building in South Africa. All these sound good and inspires confidence in the technology however some observations are worrying me.

Couple of years back when LTE-U idea was conceived, followed by LAA, the 5GHz channels were relatively empty. Recently I have started to see that they are all filling up.

The 5GHz spectrum is already getting congested, how will #MulteFire fit in this? #WGCLon pic.twitter.com/cqNkBwJZN4

— Zahid Ghadialy (@zahidtg) May 10, 2017

Any malls, hotels, service stations or even big buildings I go to, they all seem to be occupied. While supplemental downlink channels are 20MHz each, the Wi-Fi channels could be 20MHz, 40MHz, 80MHz or even 160MHz.

On many occasions I had to switch off my Wi-Fi as the speeds were so poor (due to high number of active users) and go back to using 4G. How will it impact the supplemental downlink in LTE-U / LAA? How will it impact the Wi-Fi users?

On my smartphone, most days I get 30/40Mbps download speeds and it works perfectly fine for all my needs. The only reason we would need higher speeds is to do tethering and use laptops for work, listen to music, play games or watch videos. Most people I know or work with dont require gigabit speeds at the moment.

Once a user that is receiving high speeds data on their device using LTE-U / LAA creates a Wi-Fi hotspot, it may use the same 5GHz channels as the ones that the network is using for supplemental downlink. How do you manage this interference? I am looking forward to discussions on technical fora where users will be asking why their download speeds fall as soon as they switch Wi-Fi hotspot on.

The fact is that in non-dense areas (rural, sub-urban or even general built-up areas), operators do not have to worry about the network being overloaded and can use their licensed spectrum. Nobody is planning to deploy LTE-U / LAA in these areas. In dense and ultra-dense areas, there are many users, many Wi-Fi access points, ad-hoc Wi-Fi networks and many other sources of interference. In theory LTE-U / LAA can help significantly but as there are many sources of interference,its uncertain if it would be a win-win for everyone or just more interference for everyone to deal with.

Further reading:

• Unlicensed LTE Explained – LTE-U vs. LAA vs. LWA vs. Multefire
• LTE-U(LTE-Unlicensed) / LAA / LWA / MultiPath / MulteFire /LTE-R (LTE-Railway)
• Ruckus Wireless LTE Operation in Unlicensed Spectrum [Video]
• 160 MHz channels in 802.11ac wave 2
• MulteFire: A double-edged sword

Latest on 5G Spectrum - March 2017

In an earlier post I mentioned that there will be three different types of spectrum that would be needed for 5G; coverage layer, capacity layer and high throughput layer. There is now a consensus within the industry for this approach.

In a 5G seminar, back in Jan, there were a few speakers who felt that there is an informal agreement about the frequencies that will be used. One such slide from Ofcom could be seen in the picture above. Ofcom has also recently released a report expanding on this further.

Analysys Mason has nicely summarized the bands suggested by Ofcom and possibly available in the UK for 5G in the picture above.

Global mobile Suppliers Association (GSA) has also nicely summarised the bands under investigations and trials as follows:

Coverage Layer: 600 MHz, 700 MHz, 800 MHz, 900 MHz, 1.5 GHz, 2.1 GHz, 2.3 GHz and 2.6 GHz

Capacity Layer:

Europe                     3400 – 3800 MHz (awarding trial licenses)

China                       3300 – 3600 MHz (ongoing trial), 4400 – 4500 MHz, 4800 – 4990 MHz

Japan                       3600 – 4200 MHz and 4400-4900 MHz

Korea                       3400 – 3700 MHz

USA                          3100 – 3550 MHz (and 3700 – 4200 MHz)

High Throughput Layer:

USA:      27.5 – 28.35 GHz and 37 – 40 GHz pre-commercial deployments in 2018

Korea:   26.5 – 29.5 GHz trials in 2018 and commercial deployments in 2019

Japan:   27.5 – 28.28 GHz trials planned from 2017 and potentially commercial deployments in 2020

China:    Focusing on 24.25 – 27.5 GHz and 37 – 43.5 GHz studies

Sweden: 26.5 – 27.5 GHz awarding trial licenses for use in 2018 and onwards

EU:        24.25 – 27.5 GHz for commercial deployments from 2020

Finally, as a reminder, list of bands originally approved for IMT-2020 (5G) as follows:

Another potential band, not being mentioned above is the 66-76GHz spectrum. This band is adjacent to the 60 GHz Wi-Fi (57 GHz - 66 GHz). Lessons learned from that band can be applied to the 5G band too.

Related links:

• How much spectrum would 5G need?
• IMT-2020 (5G) Requirements
• Ofcom: Update on 5G spectrum in the UK - Feb 2017 [PDF]
• Analysys Mason: A spectrum roadmap towards 5G - Mar 2017
• GSA: 5G Spectrum Bands - Feb 2017