IMS World Forum 2013 Highlights

For more details, you can read Alan Quayle's summary on his blog here.

Video: Quick summary of 3GPP Release 12 features

Ericsson recently posted a very good summary video of Release-12 features. My comments and more details are posted below the video:


You may have noticed that LTE Release 12 is also referred to as LTE-B as I posted in my blog post here. Unfortunately, this terminology is not supported by 3GPP which refers to all advancements of LTE as LTE-A. See comment on the post I just referred.

The Elevation Beamforming is also referred to as 3D-Beamforming or 3D-MIMO as I show here.

I havent written any posts on Dual connectivity and not exactly sure how it works but there is an interesting presentation on the Small Cells Enhancements in Release-12 on my blog here.

You can learn more about the WiFi and EPC Integration here.

Click on the following Direct Communications, Device to device (D2D) and Public Safety for more information on the topics.

There are many good presentations on Machine Type Communications (MTC) or M2M that are available on this label here.

Finally, I havent seen much about the lean carrier but now that I know, will add some information on this topic soon.

Related links:

• The four C's of Release-12 enhancements
• Quick update on 3GPP Release-12 progress
• 3GPP Release-12 and beyond
• New opportunities for 3GPP in Release-12

NTT Docomo gives another shot to Mobile TV

Couple of news items from earlier this month from Japan about the nottv Mobile TV service. First was that it celebrated its 1st anniversary. The second is that it has racked up 700,000 subscribers; less than a million that it was expecting. I have posted in the past about attempts by various parties on Mobile TV that was unsuccessful. You can read more about that here and here.

One of the ways Mobile TV can provide additional value as compared to the normal TV is through audience participation. NOTTV is working to be able to provide this feature in future. Also it uses the ISDB-Tmm standard for broadcast. Hopefully in future when eMBMS is more popular, it may be used to transmit Mobile TV data as well. A picture showing the difference between the ISDB-T and ISDB-Tmm is shown below (from the presentation here)

A magazine article on NOTTV from the NTT Docomo magazine is embedded as follows:

Service Overview of NOTTV Mobile Multimedia Broadcasting for Smartphones from Zahid Ghadialy

eMBMS Release-11 enhancements

Continuing on the eMBMS theme. In the presentation in the last post, there was introduction to the eMBMS protocols and codecs and mention about the DASH protocol. This article from the IEEE Communications magazine provides insight into the working of eMBMS and what potential it holds.

Evolved Multimedia Broadcast/Multicast Service (eMBMS) in LTE-Advanced: Overview and Rel-11 Enhancements from Zahid Ghadialy

eMBMS rollouts gathering steam in 2013

Its been a while since I last posted something on eMBMS. Its been even longer that we saw anything official from 3GPP on eMBMS. Recently I have seen some operators again starting to wonder if eMBMS makes business sense, while the vendors and standards are still working hard on the technology.

Not so long back, HEVC/H.265 codec was standardised. This codec helps transmission of the video using half the bandwidth. This means that it would be economical to use this for broadcast technologies. No wonder Nokia, Thompson and NTT Docomo are excited.

Interesting picture from a Qualcomm presentation (embedded in the end) shows how different protocols fit in the eMBMS architecture. My guess would be that the HEVC  may be part of the Codecs.

On the operators front, Korea Telecom (KT) has intentions for countrywide rollout. Korea is one of the very few countries where end users have embraced watching video on small form factors. Verizon wireless has already signalled the intention to rollout eMBMS in 2014; its working out a business case. Telenor Sweden is another player to join the band with the intention of adopting Ericsson's Multi screen technology.

One of the main reasons for the lack of support for the 3G MBMS technology was not a compelling business case. Qualcomm has a whitepaper that outlines some of the potential of LTE Broadcast technology here. A picture from this whitepaper on the business case below:

Finally, a presentation from Qualcomm research on eMBMS embedded below:

LTE eMBMS Technology Overview from Zahid Ghadialy

Cell Range Expansion (CRE)

The intention of the Pico Cells is to offload traffic from the Macro cells to increase the system capacity. As a result, when Macro cell becomes overloaded, it would make sense to offload the MUE’s in the vicinity of the Pico cell to it. This can/should be done even if the UE is receiving a better signal from the Macro cell. The expansion of the range of the Pico cell is termed as CRE or Cell Range expansion.

To make sure that the UE does not fail in the handover process, the Time domain ICIC should be used and Macro cell should use ABS. The UE’s can be configured to do measurements on the Pico when the Macro is using ABS. The MUE now reports the Measurement reports to the Macro and are handed over to the Pico to act as PUE.

Myths and Challenges in Future Wireless Access

Interesting article from the recent IEEE Comsoc magazine. Table 1 on page 5 is an interesting comparison of how different players reach the magical '1000x' capacity increase. Even though Huawei shows 100x, which may be more realistic, the industry is sticking with the 1000x figure. 

Qualcomm is touting a similar 1000x figure as I showed in a post earlier here.

Interference Management in HetNets

Interference Management is a big topic in HetNet's. An earlier blog post here on similar topic was very popular. The above picture shows a Heterogeneous cellular network topology incorporating different forms of small cell deployments as an overlay on the macrocell network. Small cells would generally use secure tunnels back to the core network using existing broadband infrastructure. Whereas in the HCS (Hierarchical Cell Structures), different layers have different frequencies, thereby not causing radio frequency interference, in HetNets same frequencies can be used between different layers. The same frequencies can cause radio frequency Interference and necessitates the use of advanced Interference avoidance techniques.

CTTC has another interesting presentation on Interference Management in HetNets that I am embedding below as slides and video:

Interference Management in Co-Channel Femtocell Deployment from Zahid Ghadialy

The 'Phantom Cell' concept in LTE-B

One of the LTE-B proposals by NTT Docomo is this 'Phantom Cell' concept. A recent article from the IEEE Communications Magazine expands this further:


Phantom Cell Concept — In the current deployments, there are a number of capacity solutions for indoor environments such as WiFi, femtocells, and in-building cells using distributed antenna systems (DAS). However, there is a lack of capacity solutions for high-traffic outdoor environments that can also support good mobility and connectivity. Thus, we propose the concept of macro-assisted small cells, called the Phantom Cell, as a capacity solution that offers good mobility support while capitalizing on the existing LTE network. In the Phantom Cell concept, the C-plane/U-plane are split as shown in Fig. The C-plane of UE in small cells is provided by a macrocell in a lower frequency band, while for UE in macrocells both the C-plane and U-plane are provided by the serving macrocell in the same way as in the conventional system. On the other hand, the Uplane of UE in small cells is provided by a small cell using a higher frequency band. Hence, these macro-assisted small cells are called Phantom Cells as they are intended to transmit UE-specific signals only, and the radio resource control (RRC) connection procedures between the UE and the Phantom Cell, such as channel establishment and release, are managed by the macrocell.

The Phantom Cells are not conventional cells in the sense that they are not configured with cell specific signals and channels such as cell-ID-specific synchronization signals, cell-specific reference signals (CRS), and broadcast system information. Their visibility to the UE relies on macrocell signaling. The Phantom Cell concept comes with a range of benefits. One important benefit of macro assistance of small cells is that control signaling due to frequent handover between small cells and macrocells and among small cells can be significantly reduced, and connectivity can be maintained even when using small cells and higher frequency bands. In addition, by applying the new carrier type (NCT) that contains no or reduced legacy cell-specific signals, the Phantom Cell is able to provide further benefits such as efficient energy savings, lower interference and hence higher spectral efficiency, and reduction in cellplanning effort for dense small cell deployments.

To establish a network architecture that supports the C/U-plane split, and interworking between the macrocell and Phantom Cell is required. A straightforward solution to achieve this is to support Phantom Cells by using remote radio heads (RRHs) belonging to a single macro eNB. This approach can be referred to as intra-eNB carrier aggregation (CA) using RRHs. However, such a tight CA-based architecture has some drawbacks as it requires single-node operation with low-latency connections (e.g., optical fibers) between the macro and Phantom Cells. Therefore, more flexible network architectures should be investigated to allow for relaxed backhaul requirements between macro and Phantom Cells and to support a distributed node deployment with separated network nodes for each (i.e., inter-eNB CA).

LTE for Public Safety Networks

The last presentation on this topic couple of months back has reached nearly 7K views so here is another one from a recent article on the same topic from IEEE Communications Magazine

From M2M Communications to IoT

M2M was again in the news recently when a new report suggested that it would be $1 Trillion industry. Back in december I posted a detailed presentation on M2M that has now crossed over 6K views. This shows that there is an appetite for this topic. So here is a three part presentation on M2M and IoT. In fact as I pointed out in a post last year, it is very often referred to as IoE (Internet of Everything) rather than IoT (Internet of Things). If this is a topic close to your heart then please do come to the Future of Wireless International Conference (FWIC) organised by Cambridge Wireless on 1st and 2nd July 2013. Details here.

What is WebRTC and where does it fit with LTE and IMS

This simple video from MWC should give an idea on what WebRTC is and can do:


So what exactly WebRTC is in technical terms. Here is a recent presentation from WebRTC Conference and Expo

WebRTC Technical Overview and Introduction from Zahid Ghadialy

And here is another presentation that explains where it fits in with the LTE Architecture.

Extending 4G Communications with WebRTC IMS and WebRTC from Zahid Ghadialy

Dean Bubley from Disruptive Analysis has writted extensively on this topic and his recent post "Is the telephony "threat" from VoIP & WebRTC about competition or contextualisation?" is an interesting read.

Iain Sharp from Netovate recently pointed out that 3GPP have 'nearly' approved a work item for WebRTC access to IMS.

It would be interesting to see how operators will view WebRTC. As an opportunity or as a threat. Please feel free to air your opinions via comments.

DAS or 'Small Cells' and What is DAS anyway?

Its been a while I posted something on DAS (a.k.a. Distributed Antenna System). The articles I have posted have been mainly from AT&T and are here, here and here.

Picture source: The IET

Recently I read something interesting from IDG here:

According to Rob Bruce, Chief Operating Officer at distributed antenna system (DAS) vendor Axell Networks, a building is an asset, and that asset wants to deliver all the services it can in the simplest and most economical way.

"You wouldn't put five separate lighting systems into a building because there are five separate tenants in that building. You would put one in, and it becomes a utility for that building," Bruce told Techworld.

"Our view of life is it's the same for cellular coverage. You put one system in which covers the building. That is then a utility for the building, and operators can then connect into that infrastructure - that's how a DAS system works."

Bruce said that small cells are very good for single operator environments, when a single operator wants to add some capability into a particular area. But if they want to put multiple technologies into that environment then they have to put in multiple small cells.

So if a company in the UK wants to put GSM, UMTS and LTE into an office block, it has to install three small cells. If it wants to make that truly operator agnostic, it will probably have to put in 12 units, because each of the four operators uses at least three spectrum bands.

Axell Wireless recently installed a multi-operator DAS in The Shard in London, using 20 remote units to cover the whole building. Bruce claimed that, if the same thing had been done using small cells, it would involve over 100 units.

"So the building owner is saying I've got 100 lumps of intelligent electronics gadgetry that is scattered all over my building, and there's 4 different operators wanting access to all those different things in private flats, hotels and offices - it's just an operational nightmare," said Bruce.

Complete article is available here.

This is an interesting point because the Small Cells are still not evolved enough so that a single one can serve multiple operators, etc. Note that I am differentiating the closed residential femtocells from the public access small cells. Maybe a service such as FaaS or 'Femto as a Service' can help solve this problem. Based on my previous sentences, some of you may say that it should be called Small Cell as a Service (SCaaS) rather than FaaS but unfortunately that term has come to mean something else as can be seen here.

While initially the in-building solutions were mainly for coverage reasons, this may no longer be the only reason. Capacity is also an issue, especially in-building. Small cells can certainly help in the capacity area much more than DAS. Fortunately as most new phones are coming with inbuilt Wi-Fi chipsets and WiFi is available indoors in plenty, the capacity issue may no longer be a problem indoors. Again this is an area where we can have lots of discussions and each party with a vested interest can argue their case.

Here are couple of interesting videos from youtube that explain DAS:




There is also an interesting presentation by NEC in the Small Cell Americas event, embedded below:

Optimising Small Cells Architectures for In-Building Solutions from Zahid Ghadialy

802.11u, Passpoint and Hotspot 2.0 (HS 2.0)

Came across this interesting Video on Youtube explaining 802.11u that is embedded below.




A bit more detailed presentation on the same topic by Ruckus is also embedded below:


Related posts:

• Wi-Fi & Packet Core (EPC) Integration
• Hotspot 2.0, Next Generation Hotspot (NGH), etc.
• Cellular-Wi-Fi Integration - technology and standardization roadmap

Mobile Service status and Trends in the USA - 2012

This is an update to the presentation from 2011 that I blogged here.

Mobile Status and Trends in the US from Zahid Ghadialy

Technologies from Mobile World Congress 2013 (#MWC13)

If you liked the Gadgets roundup from yesterday then you would like this one as well:



You can read more about this topic here.



You can read more about this here.











You can read more about this here.


Finally:

Gadgets from Mobile World Congress 2013 (#MWC13)

Finally, if you have enough patience, here is Nokia keynote:



Related blog post:

• Dumbphones, Featurephones, Smartphones, Superphones...
• Videos from the CES 2013
• Future mobile technology with Graphene
• 5 videos showing futuristic technologies that can be used with Mobiles
• Mobile Device Testing and its Path to Commercialization

Wi-Fi & Packet Core (EPC) Integration

Yesterday I wrote a blog post on whether Wi-Fi is the third RAN in the Metrocells blog. Today I am posting this excellent presentation that details how this Wi-Fi integration with EPC will be done.

Wi-Fi & packet core integration from Zahid Ghadialy

LTE-A: Downlink Transmission Mode 9 (TM-9)

When LTE was introduced in Release-8 it had 7 transmission modes that were increased to 8 in Release-9. Earlier, I posted an R&S whitepaper on the different Transmission modes (10K+ views already) that listed transmission modes till TM 8. In Release-10 (LTE-A) 3GPP Introduced a new transmission mode, TM 9. TM9 is designed to help reduce interference between base stations to maximise signal stability and boost performance. The new TM-9 enables the enhancement of network capabilities and performance with minimum addition of overhead. TM9 is designed to combine the advantages of high spectrum efficiency (using higher order MIMO) and cell-edge data rates, coverage and interference management (using beamforming). Flexible and dynamic switching between single-user MIMO (SU-MIMO) and an enhanced version of multi-user MIMO (MU-MIMO) is also provided.

A new Downlink Control Information (DCI) format - known as format 2C - is used for TM9 data scheduling. Two new reference signals are defined in TM9: Channel State Information Reference Signal (CSI-RS) and Demodulation Reference Signal (DMRS). The first is used from the UE to calculate and report the CSI feedback (CQI/PMI/RI), while the latter is an evolution - providing support for more layers - of the UE specific reference signal that is already used for beamforming in Rel-9, and is used for signal demodulation. TM-9 is particularly smart as it can detect when a mobile device is being used and send a different type of signal that is optimal for a mobile device (variable DM-RS – demodulation reference signals). This maximises the efficient use of the base station and guarantee’s a decent data rate for users.

Early results in SK Telecom press release are positive with a claimed 10-15% increase in data rates in locations where there was known inter-cell interference.

I also looked into couple of books and here is one explanation from An Introduction to LTE by Chris Cox.

To use eight layer spatial multiplexing, the base station starts by configuring the mobile into a new transmission mode, mode 9. This supports both single user and multiple user MIMO, so the base station can quickly switch between the two techniques without the need to change transmission mode.

The base station schedules the mobile using a new DCI format, 2C. In the scheduling command, it specifies the number of layers that it will use for the data transmission, between one and eight. It does not have to specify the precoding matrix, because that is transparent to the mobile. The base station then transmits the PDSCH on antenna ports 7 to 7 + n, where n is the number of layers that the mobile is using. The maximum number of codewords is two, the same as in Release 8.

The mobile still has to feed back a precoding matrix indicator, which signals the discrepancy between the precoding that the base station is transparently providing and the precoding that the mobile would ideally like to use. Instead of using the PMI, however, the mobile feeds back two indices, i1 and i2. Both of these can vary from 0 to 15, which provides more finely-grained feedback than the PMI did and in turn improves the performance of the multiple user MIMO technique. The base station can then use these indices to reconstruct the requested precoding matrix.

Embedded below is an extract from Google books for Lte-Advanced Air Interface Technology By Xincheng Zhang, Xiaojin Zhou

Google Glasses - take two

Picture source: Guardian

So nearly after a year of my Google Glass post, looks like Google is ready to ship some of these glasses to some competition winners for $1500. Even the Facebook founder Mark Zuckerberg is excited and cant wait to get his hands on it.

There is also this new video showing 'How it Feels' wearing Glass and everytime I go back to youtube, the count increases by 100K. Embedded below:


My two main concerns are that I have to speak loudly to the glass which may not be convenient in public places or in front of others and the other being that when many people will have these devices, my Glass may pickup command from another user.

Sometime back there was a discussion on 'Bone conduction audio'. This will allow the user to hear from the Glass without the need of a headphone or speakers, I guess a similar kind of technology is needed in place of a mic. The Glass can sense that the user who is wearing it is talking instead of someone else. It should also solve the need to speak to speak loudly to the Glass.

Small cell standardization in 3GPP Release 12

A presentation looking at Small Cell Standardisation in 3GPP Rel-12.

Small cell standardization in 3GPP Release 12 from Zahid Ghadialy

Diameter, Signalling and LTE

Last year, I blogged about Signalling storm and Diamater here and here. Embedded below is a similar sort of presentation from the Fokus Fuseco Forum 2012.

What kind of signalling issues have to be solved by introducing LTE? from Zahid Ghadialy

M2M Standardization and its Role for Emerging Smart Cities

Interesting presentation from FOKUS Fuseco forum 2012.

Global M2M Standardization and its Role for Emerging Smart Cities from Zahid Ghadialy

Related presentation on slideshare here.

Scalable UMTS (S-UMTS) to accelerate GSM Refarming

Looks like a good idea from LTE will possibly be applied to UMTS/HSPA and it will also help accelerate the re-farming of GSM spectrum. A recent presentation from Qualcomm below:

Available to download from here.

Revisiting Coordinated Multi-point (CoMP) Technology

Looks like I re-visit CoMP every Q1 of the year. Couple of years back, I had posted a primer on CoMP here and last year I had a slide on schemes and deployments here. With Release-11 out of the door and  Release-12 getting in full swing in the standards, its time to re-visit this topic in a bit more detail. There are couple of presentations, one completely devoted to this topic and one that has a section on it. Both of them can be downloaded from slideshare.

CoMP and Interference Management Tech in 3GPP from Zahid Ghadialy

3GPP LTE Standards Update: Release 11, 12 and Beyond from Zahid Ghadialy

The story of Femtocells, Small Cells and Metrocells

Femtocells were introduced many years back as a residential, closed group, small base station. The intention was to provide coverage at home for high speed data (primary) and voice (secondary). It was more for coverage than capacity. In these good old days smart phones were far and few and feature phones were many. WiFi on the phone made it expensive and power hungry so cellular was the way to go.

There were many opportunities for Femtocells to take the centre stage as the concept is technologically sound but the operators have been not very willing to deploy it soon enough. Some operators were more willing to give it a try to fix their own issues, for example Softbank which gave free femtocells, in open access mode, to improve its coverage issues. Femtozone services that promised value addition provided with the Femtocells, never took off. Other promises of exclusive broadcast content using Femtocells for example never materialised due to lack of availability of the handsets and content.

Lot has changed since then. The smartphones and tablets have taken over the market, all of them have inbuilt WiFi that is generally more efficient than the cellular radio, coverage issues have become secondary and capacity issues are a bigger concern. Femtocell players have realised that except for the publicity, there isn't much to gain from the Femtocells. As a result Femtocells were replaced by the term Small cells that represents much more than the old Femtocells. The residential Femtocells have been reduced to being just voice boosters.

The different types of Small cells can be seen in the picture above. Except for the residential, the other types of small cells operate in either the open mode or the hybrid mode. Personally, I differentiate closed Femtocells from the other Small Cells. Metrocell is the upcoming type of Small cell that I believe everyone is focussing on. They operate always in the open mode and have been chosen as the promised one to solve the two major problems of capacity and coverage.

According to the Small Cell Forum introductory whitepaper, Metrocells would see an increased growth in the next few years when the operators start deploying more of them and less of the Macrocells.

So for those of you who don't know, and would like to learn more, an introductory presentation on Metrocells is available here.

If this is an area of interest and you are interested in having and in-depth understanding then we invite you to attend our Metrocells Masterclass which is a one day workshop explaining ins and outs of Metrocell. 

If you are a big organisation and would like us to provide you with a private workshop, please feel free to contact us for details.

We have also started the Metrocells Blog that I will use to post information related to Small Cells and Metrocells in future. Please feel free to take a look at: http://metrocells.blogspot.com/

Interference avoidance for in-device coexistence (IDC)

I posted on this topic couple of years back, so here is a quick update. There is also an article in IEEE Comsoc magazine if you can get hold of it.

Here is the updated 3GPP document

Study on signalling and procedure for interference avoidance for in-device coexistence from Zahid Ghadialy

Ten things Wi-Fi had in common with public toilets!

Interesting perspective from a presentation by Agilent in Cambridge Wireless Small Cells SIG.