Showing posts with label LTE. Show all posts
Showing posts with label LTE. Show all posts

Saturday, 16 June 2018

Summary and Analysis of Ericsson Mobility Report 2018

Ericsson Mobility reports always make a fantastic reading. Its been a while since I wrote anything on this topic so I thought lets summarize it and also provide my personal analysis. Please feel free to disagree as this is just a blog post.

Before we start, the official site for the report is here. You can jump directly to the PDF here. Ericsson will also be holding a webinar on this topic on 19 June, you can register here.

A short summary of some of the highlights are in the table above but lets look at more in detail.

Mobile subscriptions 



  • The total number of mobile subscriptions was around 7.9 billion in Q1 2018.
  • There are now 5.5 billion mobile broadband subscriptions.
  • Global subscription penetration in Q1 2018 was 104 percent.
  • The number of LTE subscriptions increased by 210 million during the quarter to reach a total of 2.9 billion.
  • Over the same period, GSM/EDGE-only subscriptions declined by 90 million. Other technologies declined by around 32 million.
  • Subscriptions associated with smartphones now account for around 60 percent of all mobile phone subscriptions.

Many things to note above. There is still a big part of the world which is unconnected and most of the connectivity being talked about is population based coverage. While GSM/EDGE-only subscriptions are declining, many smartphone users are still camped on to GSM/EDGE for significant time.

While smartphones are growing, feature phones are not far behind. Surprisingly, Reliance Jio has become a leader of 4G feature phones.

My analysis from the developing world shows that many users are getting a GSM feature phone as a backup for when smartphone runs out of power.


Mobile subscriptions worldwide outlook


  • 1 billion 5G subscriptions for enhanced mobile broadband by the end of 2023, accounting for 12 percent of all mobile subscriptions.
  • LTE subscriptions continues to grow strongly and is forecast to reach 5.5 billion by the end of 2023
  • In 2023, there will be 8.9 billion mobile subscriptions, 8.3 billion mobile broadband subscriptions and 6.1 billion unique mobile subscribers.
  • The number of smartphone subscriptions is forecast to reach 7.2 billion in 2023.

The report describes "A 5G subscription is counted as such when associated with a device that supports NR as specified in 3GPP Release 15, connected to a 5G-enabled network." which is a good approach but does not talk about 5G availability. My old question (tweet below) on "How many 5G sites does an operator have to deploy so that they can say they have 5G?" is still waiting for an answer.


5G device outlook



  • First 5G data-only devices are expected from the second half of 2018.
  • The first 3GPP smartphones supporting 5G are expected in early 2019.
  • From 2020, when third-generation chipsets will be introduced, large numbers of 5G devices are forecast.
  • By 2023, 1 billion 5G devices for enhanced mobile broadband are expected to be connected worldwide.

Qualcomm has made a good progress (video) on this front and there are already test modems available for 5G. I wont be surprised with the launch. It would remain to be seen what will be the price point and demand for these 5G data-only devices. The Register put it quite bluntly about guinea pigs here. I am also worried about the misleading 5G claims (see here).


Voice over LTE (VoLTE) outlook



  • At the end of 2017, VoLTE subscriptions exceeded 610 million.
  • The number of VoLTE subscriptions is projected to reach 5.4 billion by the end of 2023.
  • VoLTE technology will be the foundation for enabling 5G voice calls.
  • New use cases in a 5G context are being explored, such as augmented reality (AR) and virtual reality (VR).

Back in 2011, I suggested the following (tweet below)
Looks like things haven't changed significantly. There are still many low end devices that do not support VoLTE and many operators dont support VoLTE on BYOD. VoLTE has been much harder than everyone imagined it to be.


Mobile subscriptions worldwide by region



  • Globally, mobile broadband subscriptions now make up 68 percent of all mobile subscriptions.
  • 5G subscriptions will be available in all regions in 2023.
  • In 2023, 48 percent of subscriptions in North America and 34 percent in North East Asia are expected to be for 5G.

I think that for some regions these predictions may be a bit optimistic. Many operators are struggling with finance and revenue, especially as the pricing going down due to intense competition. It would be interesting to see how these numbers hold up next year.

While China has been added to North-East Asia, it may be a useful exercise to separate it. Similarly Middle East should be separated from Africa as the speed of change is going to be significantly different.


Mobile data Traffic Growth and Outlook

  • In Q1 2018, mobile data traffic grew around 54 percent year-on-year.
  • The quarter-on-quarter growth was around 11 percent.
  • In 2023, 20 percent of mobile data traffic will be carried by 5G networks.
  • North America has the highest monthly usage of mobile data per smartphone at 7.2 gigabytes (GB), anticipated to increase to 49GB in 2023.
  • Total mobile data traffic is expected to increase by nearly eight times by the end of 2023.
  • In 2023, 95 percent of total mobile data traffic is expected to be generated by smartphones, increasing from 85 percent today.
  • North East Asia has the largest share of mobile data traffic – set to reach 25EB per month in 2023.

This is one of the toughest areas of prediction as there are a large number of factors affecting this from pricing to devices and applications.

Quiz question: Do you remember which year did data traffic overtake voice traffic? Answer here (external link to avoid spoilers)


Mobile traffic by application category



  • In 2023, video will account for around 73 percent of mobile data traffic.
  • Traffic from social networking is also expected to rise – increasing by 31 percent annually over the next 6 years.
  • The relative share of social networking traffic will decline over the same period, due to the stronger growth of video.
  • Streaming videos in different resolutions can impact data traffic consumption to a high degree. Watching HD video (720p) rather than standard resolution video (480p) typically doubles the data traffic volume, while moving to full HD (1080p) doubles it yet again.
  • Increased streaming of immersive video formats would also impact data traffic consumption.

It would have been interesting if games were a separate category. Not sure if it has been lumped with Video/Audio or in Other segments.


IoT connections outlook


  • The number of cellular IoT connections is expected to reach 3.5 billion in 2023. This is almost double our last forecast, due to ongoing large-scale deployments in China.
  • Of the 3.5 billion cellular IoT connections forecast for 2023, North East Asia is anticipated to account for 2.2 billion.
  • New massive cellular IoT technologies, such as NB-IoT and Cat-M1, are taking off and driving growth in the number of cellular IoT connections.
  • Mobile operators have commercially launched more than 60 cellular IoT networks worldwide using Cat-M1 and NB-IoT.

It is important to look at the following 2 definitions though.

Short-range IoT: Segment that largely consists of devices connected by unlicensed radio technologies, with a typical range of up to 100 meters, such as Wi-Fi, Bluetooth and Zigbee. This category also includes devices connected over fixed-line local area networks and powerline technologies

Wide-area IoT: Segment consisting of devices using cellular connections, as well as unlicensed low-power technologies, such as Sigfox and LoRa

The Wide-area IoT in the table above includes cellular IoT. If you are a regular reader of this blog, you will know that I think LoRa has a bright future and my belief is that this report ignores some of the reasons behind the popularity of LoRa and its growth story. 


Network coverage

  • In 2023, more than 20 percent of the world’s population will be covered by 5G.
  • 5G is expected to be deployed first in dense urban areas to support enhanced mobile broadband.
  • Another early use case for 5G will be fixed wireless access.
  • Today, 3GPP cellular networks cover around 95 percent of the world’s population.

A lot of work needs to be done in this area to improve coverage in rural and remote locations.

I will leave this post at this point. The report also contains details on Network Evolution, Network Performance, Smart Manufacturing, etc. You can read it from the report.

Monday, 21 May 2018

Tutorial on Network In a Box (NIB)


Made a short video explaining what Network In a Box is. Slides and video embedded below.







Tuesday, 1 May 2018

MAMS (Multi Access Management Services) at MEC integrating LTE and Wi-Fi networks

Came across Multi Access Management Services (MAMS) a few times recently so here is a quick short post on the topic. At present MAMS is under review in IETF and is being supported by Nokia, Intel, Broadcom, Huawei, AT&T, KT.

I heard about MAMS for the first time at a Small Cell Forum event in Mumbai, slides are here for this particular presentation from Nokia.

As you can see from the slide above, MAMS can optimise inter-working of different access domains, particularly at the Edge. A recent presentation from Nokia (here) on this topic provides much more detailed insight.

From the presentation:

        MAMS (Multi Access Management Services) is a framework for

-            Integrating different access network domains based on user plane (e.g. IP layer) interworking,

-            with ability to select access and core network paths independently

-            and user plane treatment based on traffic types

-            that can dynamically adapt to changing network conditions

-            based on negotiation between client and network
        The technical content is available as the following drafts*



-            MAMS User Plane Specification: https://tools.ietf.org/html/draft-zhu-intarea-mams-user-protocol-02




*Currently under review, Co-authors: Nokia, Intel, Broadcom, Huawei, AT&T, KT,

The slides provide much more details, including the different use cases (pic below) for integrating LTE and Wi-Fi at the Edge.


Here are the references for anyone wishing to look at this in more detail:

Thursday, 12 April 2018

#CWHeritage Talk: The history of synchronisation in digital cellular networks


CW (a.k.a. Cambridge Wireless) held a very interesting event titled 'Time for Telecoms' at the Science Museum in London. I managed to record this one talk by Prof. Andy Sutton, who has also kindly shared slides and some other papers that he mentions in his presentation. You can also see the tweets from the event on Twitter.

The video playlist and the presentation is embedded below.




The papers referred to in the presentation/video available as follows:

Sunday, 25 March 2018

5G Security Updates - March 2018


Its been a while since I wrote about 5G security in this fast changing 5G world. If you are new to 3GPP security, you may want to start with my tutorial here.

3GPP SA3 Chairman, Anand R. Prasad recently mentioned in his LinkedIn post:

5G security specification finalized! Paving path for new business & worry less connected technology use.

3GPP SA3 delegates worked long hours diligently to conclude the specification for 5G security standard during 26 Feb.-2 Mar. Several obstacles were overcome by focussed effort of individuals & companies from around the globe. Thanks and congrats to everyone!

All together 1000s of hours of work with millions of miles of travel were spent in 1 week to get the work done. This took 8 meetings (kicked off Feb. 2017) numerous on-line meetings and conference calls.

Excited to declare that this tremendous effort led to timely completion of 5G security specification (TS 33.501) providing secure services to everyone and everything!

The latest version of specs is on 3GPP website here.

ITU also held a workshop on 5G Security in Geneva, Switzerland on 19 March 2018 (link). There were quite a few interesting presentations. Below are some slides that caught my attention.

The picture in the tweet above from China Mobile summarises the major 5G security issues very well. 5G security is going to be far more challenging than previous generations.

The presentation by Haiguang Wang, Huawei contained a lot of good technical information. The picture at the top is from that presentation and highlights the difference between 4G & 5G Security Architecture.


New entities have been introduced to make 5G more open.


EPS-AKA vs 5G-AKA (AKA = Authentication and Key Agreement) for trusted nodes


EAP-AKA' for untrusted nodes.


Slice security is an important topic that multiple speakers touched upon and I think it would continue to be discussed for a foreseeable future.

Dr. Stan Wing S. Wong from King’s College London has some good slides on 5G security issues arising out of Multi-Tenancy and Multi-Network Slicing.

Peter Schneider from Nokia-Bell Labs had good slides on 5G Security Overview for Programmable Cloud-Based Mobile Networks

Sander Kievit from TNO, a regular participant of working group SA3 of 3GPP on behalf of the Dutch operator KPN presented a view from 3GPP SA3 on the Security work item progress (slides). The slide above highlights the changes in 5G key hierarchy.

The ITU 5G Security Workshop Outcomes is available here.

ETSI Security Week 2018 will be held 11-15 June 2018. 5G security/privacy is one of the topics.

There is also 5GPPP Workshop on 5G Networks Security (5G-NS 2018), being held in Hamburg, Germany on August 27-30, 2018.

In the meantime, please feel free to add your comments & suggestions below.


Related Posts & Further Reading:

Tuesday, 13 March 2018

LoRa is quietly marching on...


During the mobile world congress, I was pleasantly surprised to see how LoRa ecosystem keeps getting larger. There was also an upbeat mood within the LoRa vendor community as it keeps winning one battle after another. Here is my short take on the technology with an unbiased lens.


To start with, lets look at this short report by Tom Rebbeck from Analysys Mason. The PDF can be downloaded after registering from here.

As can be seen, all major IoT technologies (LoRa, NB-IoT, Sigfox & LTE-M) gained ground in 2017. Most of the LoRa and all of Sigfox networks are actually not deployed by the mobile operators. From the article:

These points lead to a final observation about network deployments – many operators are launching multiple technologies. Of the 26 operators with publicly-announced interest in LTE-M networks, 20 also have plans for other networks;
• 14 will combine it with NB-IoT
• four will offer LTE-M and LoRa and
• two, Softbank and Swisscom, are working with LoRa, LTE-M and NB-IoT.

We are not aware of operators also owning Sigfox networks, though some, such as Telefónica, are selling connectivity provided by a Sigfox network operator.

The incremental cost of upgrading from NB-IoT or LTE-M to both technologies is relatively small. Most estimates put the additional cost at less than an additional 20% – and sometimes considerably less. For many operators, the question will be which technology to prioritise, and when to launch, rather than which to choose.

The reasons for launching multiple networks appear to be tactical as much as strategic. Some operators firmly believe that the different technologies will match different use cases – for example, LoRa may be better suited to stationary, low bandwidth devices like smart meters, while LTE-M, could meet the needs of devices that need mobility, higher bandwidth and support for voice, for example a personal health monitor with an emergency call button.

But, a fundamental motive for offering multiple networks is to hedge investments. While they may not admit it publicly, operators do not know which technology will gain the most traction. They do not want to lose significant, lucrative contracts because they have backed the wrong technology. Deploying both LTE-M and NB-IoT – or LoRa – adds little cost and yet provides a hedge against this risk. For operators launching LoRa, there has been the added benefit of being early to market and gaining experience of what developers want and need from LPWA networks. This experience should help them when other technologies are deployed at scale.

The following is from MWC 2018 summary by ABI Research:

LPWA network technologies continue to gather momentum with adoption from a growing ecosystem of communications service providers (CSPs), original equipment manufacturers (OEMs) and IoT solution providers. LPWA networks are central to the connectivity offerings from telcos with support for NB-IoT, LTE-M, LoRaWAN, and SIGFOX. Telefonica highlighted SIGFOX as an important network technology along with NB-IoT and Cat M in its IoT connectivity platform. Similarly, Orange and SK Telecom emphasized on their continued support for LoRaWAN along with Cat M in France and South Korea. On the other hand, Vodafone and Deutsche Telekom, while aggressively pursuing deployment of NB-IoT networks, currently have mostly large scale POCs on their networks. 

...
Smart meters — Utilities are demanding that meter OEMs and technology solution providers deliver product design life of at least 15 years for battery operated smart water and gas meters. LPWA technologies, such as NB-IoT, LoRaWAN, SIGFOX and wireless M-bus, that are optimized for very low-power consumption and available at low cost are clearly emerging as the most favored LPWA solutions.

The following picture is from Ovum post MWC-2018 Webinar:

Here is a short video from MWC by yours truly looking at LoRa Gateways


There are also few announcements / news from LoRa world just to highlight how the ecosystem is thriving:


Source: SenRa

So someone recently asked me is LoRa is the new WiMax? The answer is obviously a big NO. Just look at the LoRa alliance members in the picture above. Its a whole ecosystem with different players having different interests, working on a different part of the ecosystem.

NB-IoT & LTE-M will gain ground in the coming years but there will always be a place for other LPWA technologies like LoRa.

Finally, here is a slide deck (embedded below) that I really like. The picture above very nicely illustrates that LoRaWAN and Cellular complement each other well. Maybe that is the reason that Orange is a big supporter of LoRa.



So for operators who are just starting their IoT journey or smaller operators who are unsure of the IoT potential, may want to start their journey with LoRa to play around and understand the business cases, etc. In the meantime LTE-M and NB-IoT ecosystem will mature with prices coming down further and battery time improving. That may be the right time to decide on the way forward.


Further Reading:

Thursday, 4 January 2018

Introduction to 3GPP Security in Mobile Cellular Networks


I recently did a small presentation on 3GPP Security, looking at the how the security mechanism works in mobile cellular networks; focusing mainly on signaling associated with authentication, integrity protection and ciphering / confidentiality. Its targeted towards people with basic understanding of mobile networks. Slides with embedded video below.



You can also check-out all such videos / presentations at the 3G4G training section.

Friday, 22 December 2017

The small detail about 5G you may have missed...


While going through the latest issue of CW Journal, I came across this article from Moray Rumney, Lead Technologist, Keysight. It highlights an interesting point that I missed out earlier that 5G also includes all LTE specifications from Release 15 onwards.

I reached out to our CW resident 3GPP standards expert Sylvia Lu to clarify and received more details.
There is a whole lot of detail available in RP-172789.zip. Here RIT stands for Radio Interface Technology and SRIT for Set of RIT.

In fact at Sylvia clarified, NB-IoT and Cat-M will also be part of the initial IMT-2020 submissions early next year. Thanks Sylvia.


There is also this nice presentation by Huawei in ITU (here) that describes Requirements, Evaluation Criteria and Submission Templates for the development of IMT-2020. It is very helpful in understanding the process.

Coming back to the question I have often asked (see here for example),
1. What features are needed for operator to say they have deployed 5G, and
2. How many sites / coverage area needed to claim 5G rollout

With LTE Release-15 being part of 5G, I think it has just become easy for operators to claim they have 5G.

What do you think?

Monday, 18 December 2017

Control and User Plane Separation of EPC nodes (CUPS) in 3GPP Release-14


One of the items in 3GPP Rel-14 is Control and User Plane Separation of EPC nodes (CUPS). I have made a video explaining this concept that is embedded below.

In 3G networks (just considering PS domain), the SGSN and GGSN handles the control plane that is responsible for signalling as well as the user plane which is responsible for the user data. This is not a very efficient approach for deployment.

You can have networks that have a lot of signalling (remember signaling storm?) due to a lot of smartphone users but not necessarily consuming a lot of data (mainly due to price reasons). On the other hand you can have networks where there is not a lot of signalling but lot of data consumption. An example of this would be lots of data dongles or MiFi devices where users are also consuming a lot of data, because it’s cheap.

To cater for these different scenarios, the control plane and user plane was separated to an extent in the Evolved Packet Core (EPC). MME handles the control plane signalling while S-GW & P-GW handles the user plane

CUPS goes one step further by separating control & user plane from S-GW, P-GW & TDF. TDF is Traffic Detection Function which was introduced together with Sd reference point as means for traffic management in the Release 11. The Sd reference point is used for Deep Packet Inspections (DPI) purposes. TDF also provides the operators with the opportunity to capitalize on analytics for traffic optimization, charging and content manipulation and it works very closely with Policy and charging rules function, PCRF.

As mentioned, CUPS provides the architecture enhancements for the separation of S-GW, P-GW & TDF functionality in the EPC. This enables flexible network deployment and operation, by using either distributed or centralized deployment. It also allows independent scaling between control plane and user plane functions - while not affecting the functionality of the existing nodes subject to this split.

As the 3GPP article mentions, CUPS allows for:
  • Reducing Latency on application service, e.g. by selecting User plane nodes which are closer to the RAN or more appropriate for the intended UE usage type without increasing the number of control plane nodes.
  • Supporting Increase of Data Traffic, by enabling to add user plane nodes without changing the number of SGW-C, PGW-C and TDF-C in the network.
  • Locating and Scaling the CP and UP resources of the EPC nodes independently.
  • Independent evolution of the CP and UP functions.
  • Enabling Software Defined Networking to deliver user plane data more efficiently.

The following high-level principles were also adopted for the CUPS:
  • The CP function terminates the Control Plane protocols: GTP-C, Diameter (Gx, Gy, Gz).
  • A CP function can interface multiple UP functions, and a UP function can be shared by multiple CP functions.
  • An UE is served by a single SGW-CP but multiple SGW-UPs can be selected for different PDN connections. A user plane data packet may traverse multiple UP functions.
  • The CP function controls the processing of the packets in the UP function by provisioning a set of rules in Sx sessions, i.e. Packet Detection Rules for packets inspection, Forwarding Action Rules for packets handling (e.g. forward, duplicate, buffer, drop), Qos Enforcement Rules to enforce QoS policing on the packets, Usage Reporting Rules for measuring the traffic usage.
  • All the 3GPP features impacting the UP function (PCC, Charging, Lawful Interception, etc) are supported, while the UP function is designed as much as possible 3GPP agnostic. For example, the UPF is not aware of bearer concept.
  • Charging and Usage Monitoring are supported by instructing the UP function to measure and report traffic usage, using Usage Reporting Rule(s). No impact is expected to OFCS, OCS and the PCRF.
  • The CP or UP function is responsible for GTP-u F-TEID allocation.
  • A legacy SGW, PGW and TDF can be replaced by a split node without effecting connected legacy nodes.
CUPS forms the basis of EPC architecture evolution for Service-Based Architecture for 5G Core Networks. More in another post soon.

A short video on CUPS below, slides available here.



Further reading:


Tuesday, 12 December 2017

5G Patents Progress

More than 23,500 patents have been declared essential to the GSM & 3G as shown in the picture above. I am assuming this includes 4G as well. Anyway, its been a while I looked into this subject. The last time I was looking, 4G patent pools were beginning to form.

For LTE, indeed there is no one-stop shop for licensing. The only company that has tried is VIA Licensing, with their patent pool, but they don’t have licenses for the big players like Ericsson, Qualcomm, Huawei, ZTE, Samsung, etc. The same will probably apply for 5G.


This old picture and article from Telecom TV (link) is an interesting read on this topic.



This official WIPO list shows ZTE, Huawei, and Qualcomm at the top of the list for international patent filers worldwide in 2016 [PDF].

Back in 2015, NGMN alliance was also looking for creation of some kind of patent pool but it probably didn't go anywhere (link)

(Can't recall the source for this one) In March, Ericsson announced plans to license 5G for $5 per device and possibly as low as $2.50 in emerging markets. In November, Qualcomm announced plans to license 5G IP at the same rates established by the NDRC for 4G/LTE phones sold into China: 2.275% for single mode essential patents / 4.0% for the entire portfolio or 3.25% for multimode essential patents / 5.0% for the entire portfolio. All rates are based on the wholesale price of the phone.

Qualcomm also announced that the previously undisclosed $500 price cap will apply to all phones. Qualcomm also announce a rate of less than $5 for 5G for automotive applications and $0.50 for NB-IoT based IoT applications.

Ericsson has filed patent application for its end-to- end 5G technology. Ericsson has incorporated its numerous 5G and related inventions into a complete architecture for the 5G network standard. The patent application filed by the leading telecom vendor combines the work of 130 Ericsson inventors.

Dr. Stefan Parkvall, Principal Researcher at Ericsson, said, “The patent application contains Ericsson’s complementary suite of 5G inventions.” Stefan added, “It contains everything you need to build a complete 5G network. From devices, the overall network architecture, the nodes in the network, methods and algorithms, but also shows how to connect all this together into one fully functioning network. The inventions in this application will have a huge impact on industry and society: they will provide low latency with high performance and capacity.

This will enable new use cases like the Internet of Things, connected factories and self-driving cars.” Ericsson is involved with leading mobile operators across the world for 5G and Pre-5G research and trials. The patent application is likely to further strengthen its position in the 5G race.

More details on E/// 5G patents on their official website here.

Mobile world live has some good details on Qualcomm 5G NR royalty terms.

Smartphone vendors will have to pay as much as $16.25 per device to use Qualcomm’s 5G New Radio (NR) technology under new royalty guidelines released by the company.

Qualcomm said it will implement a royalty rate of 2.275 per cent of the selling price for single-mode 5G handsets and a higher rate of 3.25 per cent for multi-mode smartphones with 3G, 4G and 5G capabilities.

So for a $200 multi-mode device, for instance, Qualcomm noted a vendor would have to pay $6.50 in royalties per device. Royalties are capped at a $500 device value, meaning the maximum amount a smartphone vendor would have to pay would be $16.25 per handset.

The company added it will also offer access to its portfolio of both cellular standard essential patents and non-essential patents at a rate of 4 per cent of the selling price for single-mode devices and 5 per cent for multi-mode devices.

Qualcomm’s rates are notably higher than those announced by Ericsson in March. The Swedish company said it would charge a flat royalty fee of $5 per 5G NR multimode handset, but noted its fee could go as low as $2.50 per device for handsets with low average selling prices.

The official Qualcomm 5G royalty terms [PDF] are available here.

Further reading:


Thanks to Mike Saji for providing inputs on 4G patent landscape. Thanks to Keith Dyer for interesting tweets on this topic.

Thursday, 23 November 2017

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:



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.

Sunday, 5 November 2017

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.

Wednesday, 20 September 2017

A quick starter on 4G voice (for beginners)


I recently did a 4G voice presentation for beginners after realizing that even though so many years have passed after VoLTE was launched, people are still unsure how it works or how its different from CS Fallback.

There are many other posts that discuss these topics in detail on this blog (follow the label) or on 3G4G website. Anyway, here is the video:


The slides are available on 3G4G Slideshare account here. More similar training videos are available here.

Friday, 8 September 2017

Debugging Problem: Same Phones With Different Signal Levels?

I have discussed this problem in past, based on questions asked on various fora (example). Here is a video I made some weeks back. Will be interested to know what other reasons people can come up with 😊.


Friday, 7 July 2017

Wireless Smart Ubiquitous Network (Wi-SUN) - Another IoT Standard


While we have been discussing IoT these last few weeks, here is another one that I came across. This picture above from a recent Rethink research shows that Wi-SUN is going to enjoy more growth than LoRaWAN or Sigfox. Another recent report by Mobile Experts also makes a mention of this IoT technology.

I am sure most of the readers have not heard of Wi-SUN, so what exactly is Wi-SUN technology?


From Rethink Research, The Wi-SUN Alliance was formed in 2011 to form an organization to push adoption of the IEEE 802.15.4g standard, which aimed to improve utility networks using a narrowband wireless technology. The peer-to-peer self-healing mesh has moved from its initial grid focus to encompass smart city applications (especially street lighting), and we spoke to its Chairman, Phil Beecher, to learn more.

Beecher explained that the non-profit Alliance set about defining subsets of the open standards, testing for interoperability, and certifying compatible products, and soon developed both a Field Area Network (FAN) and a Home Area Network (HAN), which allowed it to move into Home Energy Management Systems (HEMS) in Japan – a country that is leading the curve in HEMS deployments and developments.


As can be seen in the picture above:

  • Develops technical specifications of Physical Layer (PHY) and Medium Access Control (MAC) layers, with Network layer as required
  • Develop Interoperability test programs to ensure implementations are interoperable
  • Physical layer specification is based on IEEE802.15.4g/4u/4v
  • MAC layer may use different options depending on the application
  • Profile specifications are categorized based on application types

Picture source for the last three pics, Wi-SUN presentation here.


A new whitepaper from Wi-SUN Alliance provides comparison of Wi-SUN, LoRaWAN and NB-IoT.

A recent presentation by Dr. Simon Dunkley in Cambridge Wireless is embedded below:



Further reading: