Showing posts with label NTT DoCoMo. Show all posts
Showing posts with label NTT DoCoMo. Show all posts

Sunday, 26 January 2020

NTT Docomo's Vision on 5G Evolution and 6G


NTT Docomo released a whitepaper on 5G Evolution and 6G. In a press release they announced:

NTT DOCOMO has released a white paper on the topic of 6G, the sixth-generation mobile communications system that the company aims to launch on a commercial basis by 2030. It incorporates DOCOMO's views in the field of 5G evolution and 6G communications technology, areas that the company has been researching since 2018. The white paper summarizes the related technical concepts and the expected diverse use cases of evolving 5G and new 6G communication technologies, as well as the technology components and performance targets.

Mobile communication systems typically evolve into the next generation over a period of roughly ten years; DOCOMO commenced its research into the commercial launch of 5G in 2010. In 2018, the company conducted successful radio wave propagation experiments at frequencies of up to 150 GHz, levels which are expected to enable the much faster and larger-capacity communications that 6G will require.

DOCOMO will continue to enhance the ultra-high-speed, large-capacity, ultra-reliable, low-latency and massive device-connectivity capabilities of 5G technology. It will continue its research into and development of 5G evolution and 6G technology, aiming to realize technological advances including:

  • the achievement of a combination of advances in connectivity, including ultra-high speed, large capacity and low latency
  • the pioneering of new frequency bands, including terahertz frequencies
  • the expansion of communication coverage in the sky, at sea and in space
  • the provision of ultra-low-energy and ultra-low-cost communications
  • the ensuring of highly reliable communications
  • the capability of massive device-connectivity and sensing

Visitors to DOCOMO Open House 2020 will be able to view conceptual displays incorporating DOCOMO's vision of the evolution of 5G technologies into 6G. The event will take place in the Tokyo Big Sight exhibition complex in Tokyo on January 23 and 24. DOCOMO also plans to hold a panel session entitled "5G Evolution and 6G" on January 24.

Videos from Docomo Open House are embedded below, along with a previous talk by Takehiro Nakamura from 6G Summit.


6G has become a hot topic, especially after China announced back in November that they are working on 6G. We have some interesting tweets on 6G as well.

This one from Stefan Pongratz, Dell'Oro group shows the timeline for 5G, Pre-6G and 6G



This one provides a timeline all the way from Release 99 up till 21



Finally, here is a tweet highlighting the 6G research



Finally, the paper acknowledges the 5G challenges and focus areas for 5G evolution, before focusing on 6G.
The mmWave coverage and mobility needs improvement, while the downlink is able to provide very high data rates, the uplink is struggling to be better than 4G. Also, there are some very extreme requirements for industrial use cases, 5G has yet to prove that it can meet them.

Finally, here is another view from iDate Digiworld comparing 5G vs 6G in terms of performance, spectrum and network.



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Wednesday, 27 November 2019

Private 4G / 5G Cellular Networks and Bring Your Own Spectrum


With 4G maturing, private cellular networks are finally getting the attention that they deserve and has been promised for quite a while. In a Industry Analyst event, Nokia announced that they are running 120+ private networks including transportation, Energy, Public sector, Smart cities, manufacturing and logistics, etc. (tweet below). The Enterprise Business division is now accounting for 5% of the revenue.
Ray Le Maistre, Editor-in-Chief at Light Reading, in an opinion on Telecoms.com pointed out:

One of the more immediate revenue stream opportunities right now is wireless private networks, and the good news is that this opportunity doesn’t require 5G. Instead, the potential looks set to be enhanced by the availability of a full set of 5G standards (including the yet-to-be concluded core network specs) and the maturity of associated technology.

In the meantime, 4G/LTE has already been the cellular foundation for an increasingly thriving wireless private networks sector that, according to ABI Research, will be worth $16.3 billion by 2025

Another market sizing prediction, this time by SNS Telecom & IT, pitches annual spending on private 4G and 5G networks at $4.7 billion by the end of 2020 and almost $8 billion by 2023. 

However this plays out, there’s clear anticipation of growing investment. What’s particularly interesting, though, is which organizations might pocket that investment. That’s because enterprises and/or organizations looking to benefit from having a private wireless network have a number of options once they decide to move ahead with a private network – here are three permutations that look most likely to me:
  1. Build and run it themselves – technology vendors get some sales in this instance
  2. Outsource the network planning, construction and possibly even the day-to-day. management of the network to a systems integrator (SI) – the SI and some vendors get the spoils. It’s possible here, of course, that the SI could be a technology vendor.
  3. Outsource to a mobile network operator – the operator and some vendors will get some greenbacks.
For sure there will be other permutations, but it shows how many different parts of the ecosystem have some skin in the game, which is what makes this sector so interesting.

What’s also interesting, of course, is what the enterprises do with their private networks: Does it enhance operations? Help reduce costs? Create new business opportunities? All of the above?

Let’s not forget the role of the regulators in all of this. In the US the private wireless sector has been given a shot in the arm by the availability of CBRS (Citizens Broadband Radio Service) shared spectrum in the currently unlicensed 3.5 GHz band: This has given rise to numerous trials and deployments in locations such as sports stadiums, Times Square and even prisons.

In Germany, the regulator has set aside 100MHz of 5G spectrum for private, industrial networks has caused a storm and even led to accusations from the mobile operators that the move ramped up the cost of licenses in the spectrum auction held earlier this year.

In the UK, Ofcom is making spectrum available in four bands:
  • the 1800 MHz and 2300 MHz shared spectrum bands, which are currently used for mobile services;
  • the 3.8-4.2 GHz band, which supports 5G services, and
  • the 26 GHz band, which has also been identified as one of the main bands for 5G in the future.
Slide shared by Mansoor Hanif, CTO, Ofcom at TIP Summit 2019

The process to enable companies and organizations (Ofcom has identified manufacturers, business parks, holiday/theme parks and farms as potential users) in the UK to apply for spectrum will go live before the end of this year, with Ofcom believing that thousands of private networks could be up and running in the coming years.

Dean Bubley from Disruptive Analysis recently spoke about BYOSpectrum – Why private cellular is a game-changer at TAD Summit. The talk is embedded below and is definitely worth listening:



TelecomPaper reported:

The German Federal Ministry for Economic Affairs and Energy said that companies can start to apply to use 5G frequencies in the 3.7-3.8 GHz range on industrial campuses. Local frequencies enable firms to build their own private networks, rather than rely on telecommunications providers to build networks. 

The Automotive Industry Association (VDA) and other industry associations including the VCI, VDMA and ZVEI have welcomed the allocation of frequencies for industrial campuses. According to VDA, several dozen companies have already registered their interest in such frequencies with the Federal Network Agency. 

The firms believe that 5G can replace existing networks, including WLAN, provide improved coverage of entire company premises, enable full control over company data and reduce disruption to public mobile networks.

The spectrum licences will be allocated based on the applicant's geographic footprint and use of a certain area. Prices also take account the area covered by the network, as well as the amount of bandwidth used and duration of the licence.

The formula for the prices is very interesting as shown in the tweet below



In Japan, NTT Docomo is working in co-operation with industry partners to help them to create their own private 5G networks. More announcements on this are expected at MWC next year.



Finally, I am running an Introduction to Private 4G /5G Networks Workshop with Dean Bubley on 04 Feb 2020. If this is an area of interest, consider attending it.



Related Posts:

Sunday, 2 June 2019

Couple of talks by NTT Docomo on 5G and Beyond (pre-6G)


The Japanese operator, NTT Docomo is a very bold MNO. Not only do they do interesting research but they are very open about what they have been doing and share it publicly. For example, last month they announced development of a safe, blade-free drone propelled by Ultrasonic Vibrations (tweet). This was just amazing as it has a potential to use drones in many new areas where the conventional drones are deemed too dangerous. This is why I was very pleased to see couple of talks by Docomo available online.

The first one is by Takehiro Nakamura, SVP and General Manager of the 5G Laboratories in NTT DOCOMO, Inc. at the 6G Summit in Finland. Slides available here. Video embedded below




The next one is by Seizo Onoe, Chief Technology Architect, NTT DOCOMO, INC. and President, DOCOMO Technology, Inc. from Brooklyn 5G Summit. Unfortunately the slides are not shared but the video is worth a watch below.





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Thursday, 3 January 2019

Nice short articles on 5G in 25th Anniversary Special NTT Docomo Technical Journal

5G has dominated the 3G4G blog for last few years. Top 10 posts for 2018 featured 6 posts on 5G while top 10 posts for 2017 featured 7. In makes sense to start 2019 posting with a 5G post.

A special 25th Anniversary edition of NTT Docomo Technical Journal features some nice short articles on 5G covering RAN, Core, Devices & Use cases. Here is some more details for anyone interested.

Radio Access Network in 5G Era introduces NTT Docomo's view of world regarding 5G, scenarios for the deployment of 5G and also prospects for further development of 5G in the future. The article looks at the main features in 5G RAN that will enable eMBB (Massive MIMO), URLLC (short TTI) and mMTC (eDRX).

Interested readers should also check out:

Core network for Social Infrastructure in 5G Era describes the principal 5G technologies required in the core network to realise new services and applications that will work through collaboration between various industries and businesses. It also introduces initiatives for more advanced operations, required for efficient operation of this increasingly complex network.

This article also goes in detail of the Services Based Architecture (SBA). In case you were wondering what UL CL and SSC above stands for; UpLink CLassifiers (UL CL) is a technology that identifies packets sent by a terminal to a specific IP address and routes them differently (Local Breakout) as can be seen above. It is generally to be used to connect to a MEC server. Session and Service Continuity (SSC) is used to decide if the IP address would be retained when the UE moves to a new area from the old one.

Interested readers should also check out:
Evolution of devices for the 5G Era discusses prospects for the high-speed, high-capacity, low-latency, and many-terminal connectivity features introduced with 5G, as well as advances in the network expected in the future, technologies that will be required for various types of terminal devices and the services, and a vision for devices in 2020 and thereafter.

According to the article, the medium term strategy of R&D division of NTT Docomo has three main themes: 5G, AI and Devices. In simple terms, devices will collect a lot of data which will become big data, 5G will be used to transport this data and the AI will process all the collected Big Data.

NTT Docomo has also redefined the devices as connecting through various technologies including cellular, Wi-Fi, Bluetooth & Fixed communications.

Interested readers should also check out:

The final article on 5G, Views of the Future Pioneered by 5G: A World Converging the Strengths of Partners looks at field trials, partnerships, etc. In fact here the embedded video playlist below shows some of these use cases described in the article



In addition there are other articles too, but in this post I have focused on 5G only.

The 25th Anniversary Special Edition of NTT Docomo Technical Journal is available here.

Friday, 14 September 2018

End-to-end Network Slicing in 5G

I recently realised that I have never written a post just on Network slicing. So here is one on the topic. So the first question asked is, why do we even need Network Slicing? Alan Carlton from Interdigital wrote a good article on this topic. Below is what I think is interesting:

Network slicing is a specific form of virtualization that allows multiple logical networks to run on top of a shared physical network infrastructure. The key benefit of the network slicing concept is that it provides an end-to-end virtual network encompassing not just networking but compute and storage functions too. The objective is to allow a physical mobile network operator to partition its network resources to allow for very different users, so-called tenants, to multiplex over a single physical infrastructure. The most commonly cited example in 5G discussions is sharing of a given physical network to simultaneously run Internet of Things (IoT), Mobile Broadband (MBB), and very low-latency (e.g. vehicular communications) applications. These applications obviously have very different transmission characteristics. For example, IoT will typically have a very large number of devices, but each device may have very low throughput. MBB has nearly the opposite properties since it will have a much smaller number of devices, but each one will be transmitting or receiving very high bandwidth content. The intent of network slicing is to be able to partition the physical network at an end-to-end level to allow optimum grouping of traffic, isolation from other tenants, and configuring of resources at a macro level.

Source: ITU presentation, see below

The key differentiator of the network slicing approach is that it provides a holistic end-to-end virtual network for a given tenant. No existing QoS-based solution can offer anything like this. For example, DiffServ, which is the most widely deployed QoS solution, can discriminate VoIP traffic from other types of traffic such as HD video and web browsing. However, DiffServ cannot discriminate and differentially treat the same type of traffic (e.g. VoIP traffic) coming from different tenants.

Also, DiffServ does not have the ability to perform traffic isolation at all. For example, IoT traffic from a health monitoring network (e.g. connecting hospitals and outpatients) typically have strict privacy and security requirements including where the data can be stored and who can access it. This cannot be accomplished by DiffServ as it does not have any features dealing with the compute and storage aspects of the network. All these identified shortfalls of DiffServ will be handled by the features being developed for network slicing.

I came across this presentation by Peter Ashwood-Smith from Huawei Technologies who presented '5G End to-end network slicing Demo' at ITU-T Focus Group IMT-2020 Workshop and Demo Day on 7 December 2016. Its a great presentation, I wish a video of this was available as well. Anyway, the presentation is embedded below and the PPT can be downloaded from here.



The European Telecommunications Standards Institute (ETSI) has established a new Industry Specification Group (ISG) on Zero touch network and Service Management (ZSM) that is working to produce a set of technical specifications on fully automated network and service management with, ideally, zero human intervention. ZSM is targeted for 5G, particularly in network slice deployment. NTT Technical review article on this is available here.

Finally, here is a presentation by Sridhar Bhaskaran of Cellular Insights blog on this topic. Unfortunately, not available for download.


Related Posts:

Tuesday, 3 July 2018

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.

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.

Wednesday, 16 May 2018

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:

Wednesday, 7 March 2018

Quick summary of Mobile World Congress 2018 (#MWC18)


This year at MWC, I took the time out to go and see as many companies as I can. My main focus was looking at connectivity solutions, infrastructure, devices, gadgets and anything else cool. I have to say that I wasn't too impressed. I found some of the things later on Twitter or YouTube but as it happens, one cannot see everything.

I will be writing a blog on Small Cells, Infrastructure, etc. later on but here are some cool videos that I have found. As its a playlist, if I find any more, it will be added to the same playlist below.



The big vendors did not open up their stands for everyone (even I couldn't get in ðŸ˜‰) but the good news is that most of their demos is available online. Below are the name of the companies that had official MWC 2018 websites. Will add more when I find them.

Operators

Network Equipment Vendors

Handset Manufacturers

Chipset Manufacturers

Did I miss anyone? Feel free to suggest links in comments.


MWC Summary from other Analysts:


Tuesday, 26 September 2017

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:

Sunday, 21 May 2017

Research on Unvoiced Speech Communications using Smartphones and Mobiles

A startup on kickstarter is touting world's first voice mask for smartphones. Having said that Hushme has been compared to Bane from Batman and Dr. Hannibal Lecter. Good detail of Hushme at Engadget here.

This is an interesting concept and has come back in the news after a long gap. Even though we are well past the point of 'Peak Telephony' because we now use text messages and OTT apps for non-urgent communications. Voice will always be around though for not only urgent communications but for things like audio/video conference calls.


Back in 2003 NTT Docomo generated a lot of news on this topic. Their research paper "Unvoiced speech recognition using EMG - mime speech recognition" was the first step in trying to find a way to speak silently while the other party can hear voice. This is probably the most quoted paper on this topic. (picture source).


NASA was working on this area around the same time. They referred to this approach as 'Subvocal Speech'. While the original intention of this approach was for astronauts suits, the intention was that it could also be available for other commercial use. Also, NASA was effectively working on limited number of words using this approach (picture source).

For both the approaches above, there isn't a lot of recent updated information. While it has been easy to recognize certain characters, it takes a lot of effort to do the whole speech. Its also a challenge to play your voice rather than a robotic voice to the other party.

To give a comparison of how big a challenge this is, look at the Youtube videos where they do an automatic captions generation. Even though you can understand what the person is speaking, its always a challenge for the machine. You can read more about the challenge here.

A lot of research in similar areas has been done is France and is available here.


Motorola has gone a step further and patented an e-Tattoo that can be emblazoned over your vocal cords to intercept subtle voice commands — perhaps even subvocal commands, or even the fully internal whisperings that fail to pluck the vocal cords when not given full cerebral approval. One might even conclude that they are not just patenting device communications from a patch of smartskin, but communications from your soul. Read more here.


Another term used for research has been 'lip reading'. While the initial approaches to lip reading was the same as other approaches of attaching sensors to facial muscles (see here), the newer approaches are looking at exploiting smartphone camera for this.

Many researchers have achieved reasonable success using cameras for lip reading (see here and here) but researchers from Google’s AI division DeepMind and the University of Oxford have used artificial intelligence to create the most accurate lip-reading software ever.
Now the challenge with smartphones for using camera for speech recognition will be high speed data connectivity and ability to see lip movement clearly. While in indoor environment this can be solved with Wi-Fi connectivity and looking at the camera, it may be a bit tricky outdoors or not looking at the camera while driving. Who knows, this may be a killer use-case for 5G.

By the way, this is not complete research in this area. If you have additional info, please help others by adding it in the comments section.

Related links:



Saturday, 27 August 2016

Dedicated Core Networks (DCN) for different traffic types

Looking at a paper (embedded below) from NTT Docomo technical journal where they talk about Dedicated Core Network (DCN) for handling different traffic type (M2M/IoT for example). Note that this approach is different from NFV based network sliced architecture. For the latter, the network functions should have been virtualized.


There will be some signalling overhead in the core network to handle the new core and reroute the traffic according destined for the new dedicated core. I would still hope that this would be minuscule in the grand scheme of things. Anyway, let me know what you think about the paper below.



Sunday, 17 April 2016

NTT Docomo's 5G Treasure Trove


NTT Docomo's recent technical journal has quite a few interesting 5G articles. While it is well known that 5G will be present in Japan in some or the other shape by 2020, for the summer Olympics, NTT Docomo started studying technologies for 5G in 2010. Some of these have probably ended in 4.5G, a.k.a. LTE-Advanced Pro.

While there are some interesting applications and services envisioned for 5G, I still think some of these can be met with LTE-A and some of them may not work with the initial versions of 5G

As far as 5G timetable is concerned, I recently posted a blog post on this topic here. Initial versions of 5G will have either little or no millimetre wave (mmWave) bands. This is because most of these would be finalised in 2019 after WRC-19 has concluded. It may be a touch challenge to move all the existing incumbents out of these bands or agree of a proper sharing mechanism.

'5G+' or '5G phase 3' will make extensive use of these higher frequency bands extensively in addition to the low and mid frequency bands. For anyone not familiar with different 5G phases, please see this earlier post here.

Enhanced LTE (or eLTE) is probably the same as LTE-Advanced Pro. Docomo believes that the initial 5G deployment would include new RAT but existing 4G core network which would be enhanced later for 5G+. Some of this new RAT technologies are discussed as well.

Core Network evolution is another interesting area. We looked at a possible architecture evolution here. To quote from the magazine:

The vision for future networks is shown in Figure 3. A future network will incorporate multiple radio technologies including LTE/LTE-Advanced, 5G New Radio Access Technology (RAT), and Wi-Fi, and be able to use them according to the characteristics of each service.

Utilizing virtualization technologies, network slices optimized for service requirements such as high efficiency or low delay can be created. Common physical devices such as general-purpose servers and Software Defined Network (SDN) transport switches will be used, and these networks will be provided to service providers. Network slices can be used either on a one service per network basis to increase network independence for originality or security, or with multiple services on one slice to increase statistical multiplexing gain and provide services more economically.

The specific functional architecture and the network topology for each network slice are issues to be studied in the future, but in the case of a network slice accommodating low latency services, for example, GateWay (GW) functions would need to be relatively close to radio access, service processing would be close to terminals, and routing control capable of finding the shortest route between terminals would be necessary to reduce latency. On the other hand, a network slice providing low volume communications to large numbers of terminals, such as with smart meters, would need functionality able to transmit that sort of data efficiently, and such terminals are fixed, so the mobility function can be omitted. In this way, by providing network slices optimized according to the requirements of each service, requirements can be satisfied while still reducing operating costs.

The magazine is embedded below and available to download from here:





See Also:

Sunday, 1 November 2015

Quick Summary of LTE Voice Summit 2015 (#LTEVoice)

Last year's summary of the LTE voice summit was very much appreciated so I have created one this year too.

The status of VoLTE can be very well summarised as can be seen in the image above.
‘VoLTE network deployment is the one of the most difficult project ever, the implementation complexity and workload is unparalleled in history’ - China Mobile group vice-president Mr.Liu Aili
Surprisingly, not many presentations were shared so I have gone back to the tweets and the pictures I took to compile this report. You may want to download the PDF from slideshare to be able to see the links. Hope you find it useful.



Related links:

Saturday, 10 October 2015

VoLTE Roaming: LBO, S8HR or HBO

There was an interesting discussion on different roaming scenarios in the LTE Voice Summit on 29th, 30th Sep. in London. The above picture provides a brief summary of these well known options. I have blogged about LBO/RAVEL here and S8HR here. A presentation by NTT Docomo in a GSMA webinar here provides more details on these architectures (slide 29 onwards - though it is more biased towards S8HR).

Ajay Joseph, CTO, iBasis gave an interesting presentation that highlighted the problems present in both these approaches.

In case of LBO, the biggest issue is that the home operator need to do a testing with each roaming partner to make sure VoLTE roaming works smoothly. This will be time consuming and expensive.

In case of S8HR, he provided a very good example. Imagine a VoLTE subscriber from USA is visiting Singapore. He now needs to make a phone call to someone in Indonesia (which is just next to Singapore). The flow of data would be all the way from Singapore to USA to Indonesia and back. This can introduce delays and impact QoE. The obvious advantage of S8HR is that since the call setup and media go to Home PMN (Public Mobile Network), no additional testing with the Visited PMN is required. The testing time is small and rollouts are quicker.

iBasis are proposing a solution called Hub Breakout (HBO) which would offer the best of LBO and S8HR. Each VoLTE operator would need to test their interoperability only with iBasis. Emergency calls and lawful intercept that does not work with S8HR would work with the HBO solution.

While I agree that this is a good solution, I am sure that many operators would not use this solution and there may be other solutions proposed in due course as well. Reminds me of this XKCD cartoon:


Anyway, here is the iBasis presentation:



Sunday, 12 July 2015

S8HR: Standardization of New VoLTE Roaming Architecture

VoLTE is a very popular topic on this blog. A basic VoLTE document from Anritsu has over 40K views and my summary from last years LTE Voice summit has over 30K views. I assume this is not just due to the complexity of this feature.

When I attended the LTE Voice summit last year, of the many solutions being proposed for roaming, 'Roaming Architecture for Voice over LTE with Local Breakout (RAVEL)' was being touted as the preferred solution, even though many vendors had reservations.

Since then, GSMA has endorsed a new VoLTE roaming architecture, S8HR, as a candidate for VoLTE roaming. Unlike previous architectures, S8HR does not require the deployment of an IMS platform in VPLMN. This is advantageous because it shortens time-to-market and provides services universally without having to depend on the capability of VPLMN.



Telecom Italia has a nice quick summary, reproduced below:

S8HR simplicity, however, is not only its strength but also its weakness, as it is the source of some serious technical issues that will have to be solved. The analysis of these issues is on the Rel13 3GPP agenda for the next months, but may overflow to Rel14. Let’s see what these issues are, more in detail:


Regulatory requirements - S8HR roaming architecture needs to meet all the current regulatory requirements applicable to voice roaming, specifically:
  • Support of emergency calls - The issues in this context are several. For example, authenticated emergency calls rely on the existence if an IMS NNI between VPLMN and HPLMN (which S8HR does not provide); conversely, the unauthenticated emergency calls, although technically feasible in S8HR, are allowed only in some Countries subject to the local regulation of VPLMN. Also, for a non-UE-detectable IMS Emergency call, the P-CSCF in the HPLMN needs to be capable of deciding the subsequent action (e.g. translate the dialed number and progress the call or reject it with the indication to set up an emergency call instead), taking the VPLMN ID into account. A configuration of local emergency numbers per Mobile Country Code on P-CSCF may thus be needed.
  • ­Support of Lawful Interception (LI) & data retention for inbound roamers in VPLMN -  S8HR offers no solution to the case where interception is required in the VPLMN for inbound roamers. 3GPP is required to define a solution that fulfill such vital regulatory requirement, as done today in circuit switched networks. Of course VPLMN and HPLMN can agree in their bilateral roaming agreement to disable confidentiality protection to support inbound roamer LI but is this practice really viable from a regulatory point of view?
Voice call continuity – The issue is that when the inbound roamers lose the LTE coverage to enter into  a 2G/3G CS area, the Single Radio Voice Call Continuity (SRVCC) should be performed involving the HPLMN in a totally different way than current specification (i.e. without any IMS NNI being deployed).
Coexistence of LBO and S8HR roaming architectures will have to be studied since an operator may need to support both LBO and S8HR VoLTE roaming architecture options for roaming with different operators, on the basis of bilateral agreement and depending on the capability.
Other issues relate to the capability of the home based S-CSCF and TAS (Telephony Application Server) to be made aware about the VPLMN identity for charging purposes and to enable the TAS to subsequently perform communication barring supplementary services. Also, where the roaming user calls a geo-local number (e.g. short code, or premium numbers), the IMS entities in HPLMN must do number resolution to correctly route the call.
From preliminary discussions held at Working Group level in SA2 (architecture) and SA3 (security) in April, it was felt useful to create a new 3GPP Technical Report to perform comprehensive technical analysis on the subject. Thus it is expected that the discussions will continue in the next months until the end of 2015 and will overheat Release 13 agenda due to their commercial and “political” nature. Stay tuned to monitor the progress of the subject or contact the authors for further information!
NTT Docomo also did some trials back in February and got some brilliant results:

In the trials, DOCOMO and KT achieved the world's first high-definition voice and video call with full end-to-end quality of service. Also, DOCOMO and Verizon achieved the world's first transoceanic high-definition VoLTE roaming calls. DOCOMO has existing commercial 3G and 4G roaming relations with Verizon Wireless and KT.
The calls were made on an IP eXchange (IPX) and network equipment to replicate commercial networks. With only two months of preparation, which also proved the technology's feasibility of speedy commercialization, the quality of VoLTE roaming calls using S8HR architecture over both short and long distances was proven to be better than that of existing 3G voice roaming services.


In fact, NTT Docomo has already said based on the survery from GSMA's Network 2020 programme that 80% of the network operators want this to be supported by the standards and 46% of the operators already have a plan to support this.


The architecture has the following technical characteristics:
(1) Bearers for IMS services are established on the S8 reference point, just as LTE data roaming.
(2) All IMS nodes are located at Home Public Land Mobile Network (HPLMN), and all signaling and media traffic for the VoLTE roaming service go through HPLMN.
(3) IMS transactions are performed directly between the terminal and P-CSCF at HPLMN. Accordingly, Visited Public Land Mobile Network (VPLMN) and interconnect networks (IPX/GRX) are not service-aware at the IMS level. The services can only be differentiated by APN or QoS levels.

These three technical features make it possible to provide all IMS services by HPLMN only and to minimize functional addition to VPLMN. As a result, S8HR shortens the time-to-market for VoLTE roaming services.

Figure 2 shows the attach procedure for S8HR VoLTE roaming. From Steps 1 to 3, there is no significant difference from the LTE data roaming attach procedure. In Step 4, HSS sends an update location answer message to MME. In order for the MME to select the PGW in HPLMN (Step 5), the MME must set the information element VPLMN Dynamic Address “Allowed,” which is included in the subscribed data, to “Not Allowed.” In Step 6, the bearer for SIP signaling is created between SGW and PGW with QCI=5. MME sends an attach accept message to the terminal with an IMS Voice over PS Session Support Indication information element, which indicates that VoLTE is supported. The information element is set on the basis of the MME’s internal configuration specifying whether there is a VoLTE roaming agreement to use S8HR. If no agreement exists between two PLMNs, the information element will not be set.

The complete article from the NTT Docomo technical journal is embedded