Macrocells, Small Cells & Hetnets Tutorial

I blogged about it on the Small Cells blog but cross posting here, just in case you missed it. I am making some videos sharing basic information about mobile technology. Its on YouTube here.

Recently I made some videos looking at all kinds of cellular infrastructure; playlist is embedded below. If you need slides, get it from 3G4G slideshare channel here.

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

5G NR Radio Protocols and Tight Inter-working with LTE

Osman Yilmaz, Team Leader & Senior Researcher at Ericsson Research in Finland gave a good summary of 5G NR at URLLC 2017 Conference (see summary here). His presentation is embedded below:

5G NR radio protocols to support URLLC from 3G4G

Osman, along with Oumer Teyeb, Senior Researcher at Ericsson Research & member of the Ericsson 5G standardization delegation has also published a blog post LTE-NR tight-interworking on Ericsson Research blog.

The post talks about how how signalling and data will work in LTE & New Radio (NR) dual connected devices. In control plane it looks at RRC signalling applicable for this DC devices whereas in user plane it looks at direct and split DRB options.

Further details here.

A practical use of MOCN in ESN

Just came across this slide from recent DAS & Small Cells Congress where EE talked about their ESN network development. Found this particular example interesting as they talk about how the commercial user and ESN user would use the same RAN but a different core.

This ties nicely with a recent tutorial that I did on Mobile Network Sharing options. If you would like to learn more, see here.

Related Post (added 23 March 2019)

• Update on UK's Emergency Services Network (ESN) from BAPCO 2019

Ultra Reliable Low Latency Communications (URLLC) 2017 Conference summary

Picture Source: Martin Geddes

It was a pleasure to attend this conference this week. Not only was the topic of interest but I am always impressed by how well EIE organizes their events. Instead of writing my own summary, here is a story created from tweets, 'The Mobile Network' live blog and a summary write-up from Martin Geddes. I have my takeaways below.

URLLC 2017 (#URLLC2017) conference summary from 3G4G

My takeaway from the conference is that:

• URLLC is going to be challenging but its achievable.
• Ultra-reliable (UR) may have different use cases then low latency communication (LLC). Lumping them together in URLLC is not helpful.
• Extremely low latency may not be achievable in every scenario. In some cases it would make more sense to continue with existing or proprietary solutions.
• URLLC may not happen when 5G is rolled out initially but will happen not long after that. 
• There are many verticals who may be able to take advantage of both the higher data rates that would come as part of eMBB and the low latency and high reliability as part of URLLC. 
• The operators would have to foot the bill for upgrading the networks as there is a relucatnce from the verticals to invest in something they cant see or play with
• There are verticals who invest heavily in alternative solutions that 5G may be able to solve. Some operators believe that this will bring new revenue to the mobile operators
• Slicing has a lot of open questions including Security and SLAs - nobody has a clear cut answer at the moment
• The industry is in a learning phase, figuring things out as they go along. There should be much more clarity next year.
• #URLLC2018 is on 13 & 14 Nov. 2018 in London. Plenty of time to find all the answers 😉

Further reading:

• Conference report: Ultra Reliable Low Latency Communications 2017 - Martin Geddes
• URLLC 2017 LiveBlog: The Mobile Network
• Couple of quick interviews from URLLC 2017 Conference
• 5G Research Presentation on URLLC - Mehdi Bennis

Couple of quick interviews from URLLC 2017 Conference

I tried the Facebook Live feature yesterday at the URLLC 2017 conference and recorded a couple of quick interviews with Martin Geddes and Prof. Andy Sutton. Hope you find them useful.

           

Further Reading:

• Ultra Reliable Low Latency Communications (URLLC) 2017 Conference summary

5G Research Presentation on URLLC

Dr.Mehdi Bennis from Centre for Wireless Communications, University of Oulu, Finland recently did a keynote at The International Conference on Wireless Networks and Mobile Communications (WINCOM'17), November 01-04, 2017, Rabat, Morocco. He has shared his presentation with us. Its embedded below and available to download from Slideshare.

Picture Source: Ericsson

For those who may not be aware, there are 3 main use cases defined for 5G. As shown in the picture above, they are enhanced Mobile BroadBand (eMBB), Ultra-Reliable Low Latency Communications (URLLC) and massive Machine Type Communications (mMTC). You can read the requirements here.

Building the foundations of Ultra-RELIABLE and Low-LATENCY Wireless Communication from 3G4G

Further Reading:

• Couple of quick interviews from URLLC 2017 Conference
• Ultra Reliable Low Latency Communications (URLLC) 2017 Conference summary
• 5G on 3G4G Blog

Quick tutorial on Mobile Network Sharing Options

Here is a quick tutorial on mobile network sharing approaches, looking at site/mast sharing, MORAN, MOCN and GWCN. Slides and video embedded below. If for some reason you prefer direct link to video, its here.

Mobile Network Sharing from 3G4G

See also:

• Telecoms Infrastructure Blog: Passive and Active Infrastructure Sharing
• Telecoms Infrastructure Blog: Small Cells Network Sharing
• The 3G4G Blog: Network Sharing is becoming more relevant with 5G
• The 3G4G Blog: A practical use of MOCN in ESN

RRC states in 5G

Looking back at my old post about UMTS & LTE (re)selection/handovers, I wonder how many different kinds of handovers and (re)selection options may be needed now.

In another earlier post, I talked about the 5G specifications. This can also be seen in the picture above and may be easy to remember. The 25 series for UMTS mapped the same way to 36 series for LTE. Now the same mapping will be applied to 38 series for 5G. RRC specs would thus be 38.331.

A simple comparison of 5G and LTE RRC states can be seen in the picture above. As can be seen, a new state 'RRC Inactive' has been introduced. The main aim is to maintain the RRC connection while at the same time minimize signalling and power consumption.

Looking at the RRC specs you can see how 5G RRC states will work with 4G RRC states. There are still for further studies (FFS) items. Hopefully we will get more details soon.

3GPP TS 22.261, Service requirements for the 5G system; Stage 1 suggests the following with regards to inter-working with 2G & 3G

5.1.2.2 Legacy service support
The 5G system shall support all EPS capabilities (e.g., from TSs 22.011, 22.101, 22.278, 22.185, 22.071, 22.115, 22.153, 22.173) with the following exceptions:
- CS voice service continuity and/or fallback to GERAN or UTRAN,
- seamless handover between NG-RAN and GERAN,
- seamless handover between NG-RAN and UTRAN, and
- access to a 5G core network via GERAN or UTRAN.

5G Forecasts and 5G Deployed Claim

Source: GSA

5G forecasts have been arriving steadily with many different figures. Here are some numbers:

Date	Predicted by	Number of Connections	Year	Any other comments
23-Aug-16	Strategy Analytics	690 million	2025	"690M Connections and 300M Handset Shipments"
15-Nov-16	Ericsson	500 million	2022	"North America will lead the way in uptake of 5G subscriptions, where a quarter of all mobile subscriptions are forecast to be for 5G in 2022."
30-Nov-16	ABI Research	500 million	2026	"500 Million 5G cmWave and mmWave Subscribers Will Bring $200 Billion in Service Revenue through 2026" - what about non mmWave/cmWave 5G subs?
12-Apr-17	CCS Insight	100 million	2021	"Smartphones sales will rise to 1.90 billion in 2021, when smartphones will account for 92 percent of the total mobile phone market."
26-Apr-17	GSMA	1.1 billion	2025	"5G connections are set to reach 1.1 billion by 2025, accounting for approximately one in eight mobile connections worldwide by this time."
16-May-17	Ovum	389 million	2022	"Ovum now forecasts that there will be 111 million 5G mobile broadband subscriptions at end-2021, up more than fourfold from Ovum’s previous forecast of 25 million 5G subscriptions at end-2021"
14-Aug-17	Juniper Research	1.4 billion	2025	"an increase from just 1 million in 2019, the anticipated first year of commercial launch. This will represent an average annual growth of 232%."
17-Oct-17	GSMA	214 million in Europe	2025	"30 per cent of Europe’s mobile connections will be running on 5G networks by 2025"
23-Oct-17	CCS Insight	2.6 billion	2025	"1 Billion Users of 5G by 2023, with More Than Half in China", "broadly similar path to 4G LTE technology...more than one in every five mobile connections."

If we just look at 2025/2026, the estimates vary from 500 million to 2.6 billion. I guess we will have to wait and see which of these figures comes true.

I wrote a post earlier titled '4G / LTE by stealth'. Here I talked about the operators who still had 3G networks while most people had 4G phones. The day the operator switched on the 4G network, suddenly all these users were considered to be on 4G, even if they didn't have 4G coverage just yet.

I have a few questions about what 5G features are necessary for the initial rollout and when can an operator claim they have 5G? In fact I asked this question on twitter and I got some interesting answers.

Question: How many 5G sites does an operator have to deploy so that they can say they have 5G?

— Zahid Ghadialy (@zahidtg) October 18, 2017

Just having a few 5G NR (new radio) sites enough for an operator to claim that they have deployed 5G? Would all the handsets with 5G compatibility then be considered to be on 5G? What features would be required in the initial rollouts? In case of LTE, operators initially only had Carrier Aggregation deployed, which was enough to claim they supported LTE-A. Would 100MHz bandwidth support be enough as initial 5G feature?

Please let me know what you think.

5G Architecture Options for Deployments?

I have blogged earlier about the multiple 5G Architecture options that are available (see Deutsche Telekom's presentation & 3G4G video). So I have been wondering what options will be deployed in real networks and when.

The 3GPP webinar highlighted that Option-3 would be the initial focus, followed by Option 2.

Last year AT&T had proposed the following 4 approaches as in the picture above. Recall that Option 1 is the current LTE radio connected to EPC.

ZTE favours Deployment option 2 as can be seen in the slide above

Huawei is favoring Option 3, followed by Option 7 or 2 (& 5)

Going back to the original KDDI presentation, they prefer Option 3, followed by Option 7.

If you are an operator, vendor, analyst, researcher, or anyone with an opinion, what options do you prefer?

Evolution of SON in 3GPP

A good list of 3GPP Evolution of SON features. Whitepaper available here. You may also like the earlier post here.

See also: Self-Organizing Networks / Self-Optimizing Networks (SON) - 3G4G Homepage

3GPP Sidelink and its proposed extensions

In an earlier post I discussed briefly about the sidelink: V2V communications are based on D2D communications defined as part of ProSe services in Release 12 and Release 13 of the specification. As part of ProSe services, a new D2D interface (designated as PC5, also known as sidelink at the physical layer) was introduced and now as part of the V2V WI it has been enhanced for vehicular use cases, specifically addressing high speed (up to 250Kph) and high density (thousands of nodes).

Before going further, lets just quickly recap the different V2x abbreviations:

• V2X = Vehicle-to-Everything
• V2V = Vehicle-to-Vehicle
• V2I = Vehicle-to-Infrastructure 
• V2P = Vehicle-to-Pedestrian 
• V2H = Vehicle-to-Home
• eV2X = enhanced Vehicle-to-Everything

I came across this interesting presentation from ITRI that provides lot more details on sidelink and its proposed extension to other topics including eV2X and FeD2D (Further enhanced Device-to-Device).

There are quite a few references in the document that provides more details on sidelink and its operation and extension to other devices like wearables.

There are also details on synchronization and eV2X services.

There is also a very nice D2D overview presentation by Orange that I am embedding below (download from slideshare)

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

Smartphone Wi-Fi Analytics for Travel Route Optimisations

Transport for London (TFL), the local government body responsible for transport in London, which also runs the London Underground (known as Tubes) has been using smartphone Wi-Fi data to work out how people travel on the stations.

They did the trial and collected data in 2016 and have also openly talked about it (see this talk for example), they have now published their findings which is available here. One of the interesting findings for example is that 18 different routes taken by customers between King's Cross St Pancras and Waterloo - and many people don't use the shortest route changing Tube lines

Its interesting to think that because many people do not have their Wi-Fi switched on while outside and many others who put their phone in plane more while in the underground (no mobile coverage, in case you are wondering), this data is probably not as detailed as it could have been.

Nevertheless, there is a talk of bringing Mobile connectivity into the underground network. Once its there, the combination of data could be far more valuable.

5G Dual Connectivity, Webinar and Architecture Overview

One of the things that will come as a result of NSA (Non-StandAlone) architecture will be the option for Dual Connectivity (DC). In fact, DC was first introduced in LTE as part of 3GPP Release 12 (see 3G4G Small Cells blog entry here). WWRF (Wireless World Research Forum) has a good whitepaper on this topic here and NTT Docomo also has an excellent article on this here.

A simple way to understand the difference between Carrier Aggregation (CA) and Dual Connectivity (DC) is that in CA different carriers are served by the same backhaul (same eNB), while in DC they are served by different backhauls (different eNB or eNB & gNB).


We have produced a short video showing different 5G architectures, looking mainly at StandAlone (SA) and Non-StandAlone (NSA) architectures, both LTE-Assisted and NR-Assisted. The video is embedded below:

Finally, 3GPP has done a short webinar with the 3GPP RAN Chairman Balazs Bertenyi explaining the outcomes from RAN#77. Its available on BrightTalk here. If you are interested in the slides, they are available here.

Related posts:

• 5G Core Network, System Architecture & Registration Procedure
• 5G: Architecture, QoS, gNB, Specifications - April 2017 Update
• 5G Security Updates - July 2017
• Enhanced 5G Security via IMSI Encryption
• 5G – Beyond the Hype
• Network Sharing is becoming more relevant with 5G