WebRTC (Web Real-Time Communication) Updates

Its been a while since I last blogged about WebRTC. Things have been progressing as rather fast pace in this area.



WebRTC capabilities have quietly sneaked in our browsers. There is a debate about who would move to WebRTC before, Apple or Microssoft; Tsahi Levent-Levi makes his predictions here.



As per Light Reading, Japanese operator NTT has opened a WebRTC based chatroom recently.



The Korean operator SK Telecom as been showing off its WebRTC interworking with IMS platform.



The problem with WebRTC can be as seen in the slide above. Classic problem of what was promised and whats the reality.

There are 2 interesting presentations that I am embedding below that I found useful:

Additional Reading:

• Alan Quayle: IMS and WebRTC Workshop
• Disruptive Analysis WebRTC Market Status & Forecast Update - March 2014
• Snapchat made a secret acquisition to power its new video chat - Verge

Further enhanced Inter-Cell Interference Coordination (FeICIC)

Recently while delivering a training, I realised that this is a topic that I haven't covered in the blog before, even though I have been talking about it for a while. FeICIC has been introduced in Release-11 and there are a few enhancements as shown above. The main being that instead of an Almost Blank Subframe (ABS) with no other information except for the reference signals, now there is a possibility of reduced power ABS where the data on PDSCH can still be transmitted but on a reduced power level. This would ensure that the capacity of the interferer is not wasted.

Another enhancement on which FeICIC depends on are the advanced receivers (should do a post on it sometime soon). Another feature that allows a better probability of reception is the Transmission Mode 9 (TM9 - see blog post here)

An interesting comment that I received on my Deployments Dilemma Post is also relevant to the discussion here:

The ground reality is generally a lot different than theory. Metrocells often face interference not just from Macrocells but also other Metrocells. The ABS patterns are not just straightforward Macro to pico case but even pico to pico and multiple macros to pico.

Until all the handsets and other dongles could be upgraded with advanced interference cancellation receivers, there would be many scenarios where deployment option 2 may be chaotic. Deployment option 1 can serve the users well in the meantime. 

We can sacrifice efficiency for reliability in the meantime.

I recently posted the Small Cells Research Bible on the Small Cells blog here, the following is the Interference Management part that would help anyone willing to learn more about this feature.

Recent Advances in Wireless Small Cell Networks from Zahid Ghadialy

LTE Deployment Dilemma

Earlier this month during our Cambridge Wireless Small Cells SIG event, I presented a small quiz in the final session. The first part of the quiz was titled "LTE Deployment Dilemma" and it generated lots of interesting discussions. After the event, I did a more detailed writeup of that and Cisco has kindly published it in their SP Mobility Blog. Since many people have told me that they cannot anonymously post comments there, I am now bringing it to this blog. I am interested in hearing what others think.

Here is the complete post

LTE Deployment Dilemma from Cisco Service Provider Mobility

Different flavours of Bluetooth: 4.0, 4.1, Low Energy, Smart, Smart Ready...

Once upon a time, Nokia proposed a standard called Wibree. That standard was good enough to be merged with Bluetooth SIG and then become part of Bluetooth Low Energy (Bluetooth LE or BLE) standards.

The Bluetooth Low Energy standards comes in two different flavours, 'Smart' and 'Smart Ready'

The Smart and Smart Ready were introduced in 2011 to explain which devices will be compatible to what. Here is a table which explains how interoperability would work.

One of the obvious use of Bluetooth Low Energy is in Beacons. Here is an excellent presentation on Bluetooth 4.0:

Bluetooth 4.0: Low Energy from Zahid Ghadialy

Bluetooth 4.1 brings new capabilities in Bluetooth for it to become a challenger for Internet of Things (IoT). Here is an extract from an article in Network Computing:

With 4.1, the Bluetooth SIG is aiming to become a major player in the much-hyped Internet of Things (IOT) market. While 4.0 steps on Wi-Fi’s turf for location-based interaction with client devices, Bluetooth 4.1 looks to leverage Bluetooth's broad name recognition, widespread acceptance, and new low-power capabilities to compete with technologies that also want in on the IOT. These include ZigBee and Near Field Communication, both which are arguably niche technologies that just aren't familiar to many people.

As IoT looms larger for environments of all sizes, Bluetooth 4.1 allows client devices to daisy-chain to each other and multiple devices simultaneously for larger networks that are more Zigbee-like. Perhaps the biggest change for those of us who have to guide our network environments into the future: Bluetooth’s latest version lays the groundwork for dedicated device channels and the use of IPv6 for smart sensors to bridge themselves out of the isolated PAN world and into the IOT. This represents a major and substantial change to the Bluetooth mission, and will absolutely impact the Zigbee market in some substantial way.

Other features with Bluetooth 4.1 make it generally better in its PAN role. Bluetooth has been improved to ensure that nearby LTE radios (frequently under the same device hood) are not interfered with. It has a longer allowable interval between service advertisements, for better battery life and less chatter in the busy 2. GHz band. One of the big gains with 4.1 is the Bulk Transfer feature. For example, the feature would allow my fitness gizmo to auto-transfer all the data it's recorded of my gym activities when I get within range of my cell phone to update the app that tracks my activities.

An FAQ from the Bluetooth SIG on 4.1 is embedded below:

BLUETOOTH® 4.1 FREQUENTLY ASKED QUESTIONS from Zahid Ghadialy

International LTE Data and VoLTE Roaming - NTT Docomo

Quick recap of the Bearer Architecture: Remember the interface between S-GW and P-GW is known as S5/S8. S5 in case the S-GW and P-GW are part of the same network (non-roaming case) and S8 in case where P-GW belongs to another network than S-GW (roaming case). The S5/S8 interfaces are generally exactly the same. There is a possibility of different types of S5/S8 interfaces like GTP based and PMIP based but lets not discuss that here.

NTT Docomo published an excellent article in their magazine recently showing the different approaches to International Data roaming.

The different scenarios above are based on the guidelines provided in GSMA PRD IR.88. Each operator has to adopt one of the scenarios above, NTT Docomo has selected scenario 4. The Home PLMN (HPLMN) and the Visited PLMN (VPLMN) connect via IP eXchange (IPX).

As can be seen above, the MME in VPLMN communicates with HSS in HPLMN using Diameter Edge Agent (DEA).

Finally, it is well known that NTT Docomo is not launching VoLTE untill 2015. The above is their proposal on how they handle VoLTE while in Japan and when roaming.

The paper is an interesting read, embedded below:

NTT Docomo: Implementing LTE International Data Roaming from Zahid Ghadialy

Another article worth a read is the VoLTE roaming with RAVEL here.

LTE-Broadcast of the operator, by the operator, for the operator!

Heard an insightful talk from EE in the CW event this week. While I agree with the intentions and approaches, I still think there may be too many assumptions in the eMBMS business model. I have made my intentions known all but too well in my earlier blog post here.

Some of the insights that I have gained in the last couple of months with regards to the way operators are planning to use the LTE broadcast is through the OTT Apps. Take for instance an OTT application like iPlayer or Hulu and some popular program is about to be broadcast, that program can be sent using LTE-B. Now some people may watch on the time (linear) and some may watch at a later time (non-linear or time-shifted). The App can be intelligent enough to buffer the program so there is no delay required when the user wants to watch it. This can open all sorts of issues like the user may have watched one episode on his device while the current one is being watched on his digital television. While the program is being buffered the battery and memory of the device is being consumed. How long should a program be stored on the device. There can be many other open issues.

Another question I had was how would the users be billed for these things. Would it be free since the data was received over LTE-B. Matt Stagg from EE said that the users would be billed normally as if they received it in case of streaming. He was more pragmatic though. He clearly said that in the initial phase everything would have to be free. This will ensure that any technical issues are ironed out and at the same time the users become familiar with how all this works.

Finally a point worth remembering, users prefer watching videos on their tablets. Most tablets are WiFi only which means the LTE-Broadcast wont work on it.

The presentation is embedded as follows:

LTE as a TV and Video Distribution Network - EE from Zahid Ghadialy

Some interesting April Fools' Day 2014 Technology Jokes

Its very interesting to see all the companies proposing very interesting concepts on the 1st of April. I was told that not everyone knows what April Fools day means so here is the link to Wikipedia.

Samsung Fly-Fi: Samsung has come up with some interesting ideas, the first being Wi-Fi for everyone powered by Pigeons. They have a website here with Video.




Looks like since we have Pigeons everywhere, so they are always used in one way or the other. The best prank ever in my opinion was the PigeonRank by Google, back in 2002. I spent a few hours that day trying to figure out how they were actually doing it.

Smart Wear was always going to be the big thing. Quite a few smart wearables this year.

Bonobos has done a good job with with TechStyle. See video below:



Samsung has a glove called Samsung Fingers here. The best thing I liked was 'Talk to the Hand'



HTC came up with similar concept called Gluuv



Toshiba's DiGiT is as interesting. See the video:


Virgin Mobile, Canada has come up with SmartKicks. See here.



Roku Watch is not too bad:


Virgin America even convinced Sir Richard Branson to appear in the April Fools ad along with Tony Faddell, the CEO of Nest. Funny Youtube video here.

Sony Power Food was just okay, video here.

Toshiba Spehere is a funny Gaming concept, see here.

Nokia reviewed its most popular phone 3310 with modern day features here. Coloured screen with 41Megapixel camera.

Google wants to Emojify the web here.

Google Japan has a magic hand here.

Selfiebot by Orbotix is a cool concept, here.

Twitter Helmet didnt make me laugh though. See here.

Is there some others that I missed? Please feel free to add it in the comments.

MNO, MVNO, MVNA, MVNE - The different types of operators

A new video and simplified presentation on this topic is available on 3G4G page here.

It took me quite a while trying to understand the different types of operators and the differences between them. Here is a short summary. Please feel free to add more information or correct me where needed


Mobile Network Operator (MNO): The MNO is the most commonly visible mobile network operator. Examples would be the likes of Vodafone, Verizon, T-Mobile, Orange, Telefonica, etc. These MNO's are responsible for creating the mobile network. They have to purchase/lease the spectrum from the regulatory body of the country and then purchase/lease the network equipment from the vendors. They have to then get into an agreement with various handset suppliers, do various testing, etc. They are responsible for the day to day running of the network and would be blamed if there are problems or if the quality of experience is not as expected.

The MNO has to maintain its own Operation Support Systems (OSS) and Business Support Systems (BSS). They are responsible for billing the direct customers and may also be responsible for indirectly billing the customers of MVNO's.


Mobile Virtual Network Operator (MVNO): An MVNO relies on the infrastructure and most other things provided by the MNO. The MNO may have plenty of spare capacity that it may be willing to sell at a cheaper price or a different rate. They wouldn't want to do this themselves as this may dilute the brand. To solve this they may sell the messages, voice minutes and data at a much cheaper price in wholesale to an MVNO. Examples of popular MVNO's include Virgin Mobile, Lyca Mobile, Walmart mobile, Lebara Mobile, etc.

A full fledged MVNO will have its own OSS/BSS software and would be responsible for billing its own customers but a smaller MVNO may rely on the MNO to provide usage information for its customers that it can bill.


Mobile Virtual Network Aggregator (MVNA): Sometimes, it makes little or no sense to have many small MVNO's connected to the MNO. As a result, MNO may decide to only sell the discounted bundles to really big players. An MVNA can aggregate lots of small MVNO's and using the collective might, be able to connect to the operator as a single MVNO. MVNA's will typically not have direct subscribers but only other smaller MVNO's that connect to it. It would typically have to have an own OSS/BSS to be able to provide accurate billing information to the MVNO's.


Mobile Virtual Network Enabler (MVNE): An MNO may decide to outsource all functionality related to virtual networks to an MVNE. The MVNE may do similar functionality like an MVNA or it may even allow MVNA to connect to the MNO via itself. It may allow MVNO's to connect to MNO's through it and in special cases, it may even provide sell services directly to customers. The main reason for it being called an Enabler is because its enables smaller MVNO's to be created. It can provide services to such as billing, network element provisioning, administration, operations, support of OSS/BSS, etc. to MVNOs. An MVNE typically would not have any relationship with end-user customers, instead focussing on providing infrastructure and services to enable MVNO's to offer services and have a relationship with end-user brand, customer loyalty and marketing and leave the back-end enablement to MVNE's.

The MVNO's could be Full or Light MVNO's. The above picture shows different variants but in simple terms a Full MVNO has its own HLR while the Light(er) MVNO's use the HLR of the MNO where it enters the details of its own subscribers. A Full MVNO has considerably more power as it may decide to move to another MNO for service if its not happy with the service provided by an MNO. It would definitely also mean a lot more investment as opposed to the lighter models.

Sometimes MVNOs refer to themselves as Skinny, Thin or Thick as can be seen in the picture above. My guess is that its just another term for Full, Light or Branded resellers.

Finally, we may be in what is being termed as MVNO 3.0. As per this PwC article:

The first generation of MVNOs was spawned during an era of regulatory concerns and rapid growth in the wireless industry. They struggled to compete with the very network owners who were selling them capacity. The second generation, known in some circles as MVNO 2.0, sought to change the playing field by basing customer relationships on innovative devices such as the iPhone and the Jitterbug. Could we be witnessing the end of the era of the branded network operator? Here are four key changes currently underway that could make MVNO 3.0 a reality.

Finally, if you have enough time and patience, there is an interesting list of articles to read on this topic.

Additional reading:

• MVNA MVNE MVNO MNO - SIM Surprise
• WHAT IS AN MVNO, MVNE, MVNA? - http://www.mobile-virtual-network.com/
• InvesTelecom - MVNO, MVNE
• Prospering in a new MVNO hype cycle - Informa
• What do MVNA’s bring? - Cognatel
• Full MVNO and LIght MVNO - Georges-Harald Bernard's blog
• The Coming of MVNO 3.0 - PWC
• Insight: MVNO 3.0
• MVNOs explained

A quick case study on Smartwatches

My presentation from the Cambridge Wireless Connected devices SIG event "On Trend – High Fashion meets High Technology" held today, is embedded below. One of my favourite ads that highlights our fascination with the smart watches has been shown very well in a advert by Samsung mobile USA as follows:



I believe there is an opportunity and a market for the smart wear and smartwatches. There is a need for just the right kind of products to capitalise on the demand.

Securing the backhaul with the help of LTE Security Gateway

An excellent presentation from the LTE World Summit last year, that is embedded below. The slide(s) that caught my attention was the overhead involved when using the different protocols. As can be seen in the picture above, the Ethernet MTU is 1500 bytes but after removing all the overheads, 1320 bytes are left for data. In case you were wondering, MTU stands for 'maximum transmission unit' and is the largest size packet or frame, specified in octets (8-bit bytes), that can be sent in a packet or frame based network such as the Internet.

Anyway, the presentation is embedded below:

Securing the backhaul from 3G4G Blogs

HSPA+ Carrier Aggregation

Came across Qualcomm's HSPA+ Carrier aggregation video (above) and whitepaper. Interesting to see that HSPA/HSPA+ is still growing. As per my earlier post, half of the connections in 2018 would be HSPA/HSPA+.

As can be seen in the picture above, there are quite a few features that may be of interest to the operators. Scalable UMTS is one such feature as I have put in the blog before.

You will notice that upto 4 bands can be aggregated. It would be interesting to see which operators have these bands available and if they would be willing to use HSPA+ CA with upto 4 bands. The presentation by Qualcomm is embedded below and is available to download from here.

Related posts:

• Multipoint HSDPA / HSPA
• HSDPA multiflow data transmission

Mobile World Congress 2014 (#MWC14) Roundups

The worlds largest technology event came to a conclusion just over a week back so here is a summary of reports and roundups written by different people. Feel free to add yours in the comments:

The best way is to start with this Video of different gadgets by Orange (excuse their adverts)


Maravedis-Rethink has an excellent summary from Network point of view:

Now all the carriers have the same devices, and the all-you-can-eat offers are largely gone. This has shifted the competitive race to innovation in pricing and bundling; to services, even over-the-top ones; but most importantly to the one area which is still unique to MNOs, their licensed-spectrum networks. The race to implement more and more advanced features from the 3GPP menu is not just a carrier game of ‘mine’s bigger than yours’, but a truly necessary attempt, at least in the developed mobile markets, to differentiate themselves with the most advanced network capacity and capabilities.

In the network, new battle lines are being drawn, and the players are placing big bets on unproven technologies and new architectures. This is taking place on two levels – the well-understood but highly complex advances in RAN platforms, from the LTE-Advanced standards to small cells to Cloud-RAN; and the shift towards software-driven, if not yet fully software-defined networking, and towards virtualization.

Complete summary here.

Chetan Sharma has written a brilliant summary and covers all different topics:

All the progress that has been on the mobile economy has been on the back of trillions of dollars of investment over the last couple of decades. With declining margins, how long do operators continue to invest and at what pace? What’s the margin profile they are willing to live with? What’s the role of government in building out the infrastructure when high-speed mobile networks are concerned? Japan, Korea, Israel have all based their competitiveness on connected broadband world. Can others follow? The impact of Whatsapp launching voice services and Netflix/Comcast deal were hotly debated in the hallways. It is one thing to put out national broadband plans and it is entirely another reality to have an execution path to deliver on the plan. The broadband investment has much far reaching implications than most people and governments realize.

Complete article here.

Ian Poole from Radio Electronics has done a good job too with the summary and video:

There was a considerable amount of talk about connected cities, connected cars and the like. Many exhibitors at Mobile World Congress were showing their ideas and developments. There is a huge amount of work going on in these areas and this is reflected in the work and products being exhibited.

Said Mike Short, VP Telefonica: “Mobile World Congress is more of a data World Congress . . . . . . . there are many software companies, many special network companies, other companies providing billing and customer care and there are solutions for the whole digital economy”

Talking to a variety of people across Mobile World Congress, it was obvious there is a large amount of work going on.

In terms of the auto mobile industry there is a lot of interest and development. While it is not expected all of the work will come to fruition in the short term, such as mesh networked cars where the networking elements can be used for crash avoidance, etc, there are other areas for in car connectivity that will be implemented in the shorter term.

Qualcomm were even demonstrating an electric racing car that not only used wireless communications technology, but also utilised wireless charging. In this way they were incorporating two developing technologies.

In addition to this, technologies like Weightless – the white space data cellular system have moved forwards. The original aim was for the technology to be used in the television white space to provide low powered data communications particularly for remote sensors and actuators. For these applications, cellular technology is too heavy. Dealing with complex waveforms like OFDM requires considerable processing and this is not conducive to long battery life – some devices ae expected to operate for months or even years from the same battery.

Neul has been working to develop the ideas further. They are now looking at using unlicensed spectrum instead of the TV white space. They have found that in urban areas, little white space often exists. Unfortunately it is often in urban environments where population levels are highest and there will be the greatest need for low power data communications.

In another move announced at Mobile World Congress Orange announced that it is helping start up companies who are developing products for the IoT. Orange states that it wants to help them accelerate development and assist with marketing. This move is possibly a long term move, because it can only be approached with 4G, but with 5G anticipated to be more capable of meeting IoT requirements it should be able to enter the market more strongly when it arrives. It is anticipated that the main areas where IoT will start to grow initially are personal services, healthcare, the connected home and smart cities.

Complete report and the video here.

Finally, an excellent summary on Small Cells and related by ThinkSmallCell:

The official Small Cell conference track was pretty tame - Vodafone have deployed 300K Small Cells in total, KT (Korea Telecom) and Radisys spoke of 18K LTE deployed in mostly indoor metropolitan areas. Vodafone said they continue to drive vendors to deliver multi-technology small cell and backhaul products with high operational efficiency and look for added value to help the business case. By contrast, the Small Cell Forum booth hosted extensive and popular presentations and is perhaps outgrowing its booth format.

A key network equipment vendor theme was SDN (Software Defined Network) and NFV (Network Function Virtualisation). We can expect next year to see this evolving to orchestration - better methods of managing and manipulating these virtualised software components, but in the short term it means slightly less or cheaper hardware. Frankly, I was more impressed to see Huawei now supporting any of 2G, 3G or LTE (FDD&TDD) on the same physical macrocell radio hardware modules - true software definable radio. We are beginning to see that capability for Small Cells too, but it's not quite as mature yet.

Most of the Small Cell activity is around 3G indoor (Enterprise) and LTE outdoor (Urban), with 3G still important indoors (for voice) and LTE HetNets seen as the longer term solution for capacity. At least four DAS vendors announced lower cost, simpler products intended to address larger buildings and stadia - highlighting the growing demand for in-building cellular solutions. Many new LTE Small Cell vendors are appearing on the scene. Residential femtocells still have a place in the market especially where integrated into a broadband modem or set-top box, driven by a different business case than before. There were some signs that the radical approach of Free France, who are shipping many 10Ks of femtocells a month, may be emulated by others.

Complete report here.

Ronald Gruia from Frost&Sullivan has created a summary presentation on Slideshare that is embedded below:

Other Summaries worth reading:

• GiffGaff Blog
• SONLTE
• Alan Quayle Blog
• Cisco SP 360 Blog
• Frank Rayal Blog
• Mobile OS Summary from MWC 2014
• Informa T&M Day 1, Day 2 and Day 3
• CCS Insight Day 0, Day 1 and Day 2

There was also a Carrier Wi-Fi Summit going on in parallel to the main MWC. A summary of that is available on the WBA website here: Day 1, Day 2, Day 3 and Day 4.



Claus Hetting has also added an excellent summary of the Carrier Wi-Fi Summit on his blog here.

LTE Radar - LTE proximity services

Last year, DT gave an interesting presentation on what they termed as 'LTE Radar'. Here is the video to explain the motivation:


The picture below summarises how this will work:

It is interesting to note that these problems are already being solved using Apps and other technologies. Once the 3GPP standard is finalised, it would be a challenge to get this to mass adoption. An example would be Bluetooth based Beacons that I blogged about earlier here. Nevertheless, it would be interesting to see how compelling the use cases would be once this is standardised. The complete DT presentation is embedded below:

LTE proximity services from Zahid Ghadialy

Mobile, Context and Discovery - Ben Evans

An Interesting presentation and Video from Benedict Evans, both embedded below:

There is an interesting Q&A at the end of the talk in the video. You can directly jump to 27:30 marker for the Q&A. One of the interesting points highlighted by him, that I always knew but was not able to convey it across is there is no real point comparing Google and Apple. I am too lazy to type down so please jump to 45:10. One of the comment on the Youtube summarises it well:

"Google is a vast machine learning engine... and it spent 10-15 years building that learning engine and feeding it data"

So true. It is not Apple vs Google; it is not about the present. It is about the future (see Google's recent acquisitions for context). As Benedict says, if Google creates beautiful, meaningful and unique experiences for users, why would they do it only for Android, they would also have it on Apple devices. 

In the end, comparing Apple and Google is like comparing Apple(s) and Oranges :)

Beacons, Bluetooth, NFC and WiFi

Not sure if you have heard about some kind of Beacons that will be used to guide us everywhere. There are Bluetooth Beeacons, iBeacon, Paypal Beacon, probably more. So here is an attempt to understand some of these things.

The first is this introductory presentation which seems to be extremely popular on Slideshare:

Once we understand the concept of Beacons, there is another presentation that helps us understand iBeacons and Paypal Beacons as follows:

Bluetooth Beacons vs Wifi vs NFC is an interesting article comparing the Beacons with WiFi & NFC. Read it here

Why Beacons may be NFC killer, GigaOm has a good answer here:

iBeacon could be a NFC killer because of its range. NFC tags are pretty cheap compared to NFC chips, but NFC tags are required on each product because NFC works only in very close proximity. In theory, NFC range is up to 20cm (7.87 inches), but the actual optimal range is less than 4cm (1.57 inches). Also, mobile devices need to contain a NFC chip that can handle any NFC communications. On the other hand, iBeacons are a little expensive compared to NFC chips, but iBeacons range is up to 50 meters. Not all phones have NFC chips, but almost all have Bluetooth capability.

Many years back there was a proximity marketing craze using Bluetooth. Then the craze died down and everyone started focussing on other approaches for LBS. I also suggested a Small Cells based approach here. Its good to see that we are going to use a new Bluetooth based approach for similar functions.

By the end of the year we will hopefully know if this is a new hype or a successful technology. Issues with battery drains, security, interoperability, etc. will need to be sorted asap for its success.

The Rise and Rise or '4G' - Update on Release-11 & Release-12 features

A recent GSMA report suggests that China will be a significant player in the field of 4G with upto 900 million 4G users by 2020. This is not surprising as the largest operator, China Mobile wants to desperately move its user base to 4G. For 3G it was stuck with TD-SCDMA or the TDD LCR option. This 3G technology is not as good as its FDD variant, commonly known as UMTS.

This trend of migrating to 4G is not unique to China. A recent report (embedded below) by 4G Americas predicts that by the end of 2018, HSPA/HSPA+ would be the most popular technology whereas LTE would be making an impact with 1.3 Billion connected devices. The main reason for HSPA being so dominant is due to the fact that HSPA devices are mature and are available now. LTE devices, even though available are still slightly expensive. At the same time, operators are taking time having a seamless 4G coverage throughout the region. My guess would be that the number of devices that are 4G ready would be much higher than 1.3 Billion.

It is interesting to see that the number of 'Non-Smartphones' remain constant but at the same time, their share is going down. It would be useful to breakdown the number of Smartphones into 'Phablets' and 'non-Phablets' category.

Anyway, the 4G Americas report from which the information above is extracted contains lots of interesting details about Release-11 and Release-12 HSPA+ and LTE. The only problem I found is that its too long for most people to go through completely.

The whitepaper contains the following information:

3GPP Rel-11 standards for HSPA+ and LTE-Advanced were frozen in December 2012 with the core network protocols stable in December 2012 and Radio Access Network (RAN) protocols stable in March 2013. Key features detailed in the paper for Rel-11 include:

HSPA+:

• 8-carrier downlink operation (HSDPA)
• Downlink (DL) 4-branch Multiple Input Multiple Output (MIMO) antennas
• DL Multi-Flow Transmission
• Uplink (UL) dual antenna beamforming (both closed and open loop transmit diversity)
• UL MIMO with 64 Quadrature Amplitude Modulation (64-QAM)
• Several CELL_FACH (Forward Access Channel) state enhancements (for smartphone type traffic) and non-contiguous HSDPA Carrier Aggregation (CA)

LTE-Advanced:

• Carrier Aggregation (CA)
• Multimedia Broadcast Multicast Services (MBMS) and Self Organizing Networks (SON)
• Introduction to the Coordinated Multi-Point (CoMP) feature for enabling coordinated scheduling and/or beamforming
• Enhanced Physical Control Channel (EPDCCH)
• Further enhanced Inter-Cell Interference Coordination (FeICIC) for devices with interference cancellation

Finally, Rel-11 introduces several network and service related enhancements (most of which apply to both HSPA and LTE):

• Machine Type Communications (MTC)
• IP Multimedia Systems (IMS)
• Wi-Fi integration
• Home NodeB (HNB) and Home e-NodeB (HeNB)

3GPP started work on Rel-12 in December 2012 and an 18-month timeframe for completion was planned. The work continues into 2014 and areas that are still incomplete are carefully noted in the report.  Work will be ratified by June 2014 with the exception of RAN protocols which will be finalized by September 2014. Key features detailed in the paper for Rel-12 include:

HSPA+:

• Universal Mobile Telecommunication System (UMTS) Heterogeneous Networks (HetNet)
• Scalable UMTS Frequency Division Duplex (FDD) bandwidth
• Enhanced Uplink (EUL) enhancements
• Emergency warning for Universal Terrestrial Radio Access Network (UTRAN)
• HNB mobility
• HNB positioning for Universal Terrestrial Radio Access (UTRA)
• Machine Type Communications (MTC)
• Dedicated Channel (DCH) enhancements

LTE-Advanced:

• Active Antenna Systems (AAS)
• Downlink enhancements for MIMO antenna systems
• Small cell and femtocell enhancements
• Machine Type Communication (MTC)
• Proximity Service (ProSe)
• User Equipment (UE)
• Self-Optimizing Networks (SON)
• Heterogeneous Network (HetNet) mobility
• Multimedia Broadcast/Multicast Services (MBMS)
• Local Internet Protocol Access/Selected Internet Protocol Traffic Offload (LIPA/SIPTO)
• Enhanced International Mobile Telecommunications Advanced (eIMTA) and Frequency Division Duplex-Time Division Duplex Carrier Aggregation (FDD-TDD CA)

Work in Rel-12 also included features for network and services enhancements for MTC, public safety and Wi-Fi integration, system capacity and stability, Web Real-Time Communication (WebRTC), further network energy savings, multimedia and Policy and Charging Control (PCC) framework.

Whitepaper: 4G Mobile Broadband Evolution: 3GPP Release 11 & Release 12 and Beyond from Zahid Ghadialy

VoLTE Roaming with RAVEL (Roaming Architecture for Voice over IMS with Local Breakout)

Voice over LTE or VoLTE has many problems to solve. One of the issues that did not have a clear solution initially was Roaming. iBasis has a whitepaper on this topic here, from which the above picture is taken. The following is what is said above:

The routing of international calls has always been a problem for mobile operators. All too often the answer—particularly in the case of ‘tromboning’ calls all the way back to the home network—has been inelegant and costly. LTE data sessions can be broken out locally, negating the need for convoluted routing solutions. But in a VoIMS environment all of the intelligence that decides how to route the call resides in the home network, meaning that the call still has to be routed back.

The industry’s solution to this issue is Roaming Architecture for Voice over LTE with Local Breakout (RAVEL). Currently in the midst of standardisation at 3GPP, RAVEL is intended to enable the home network to decide, where appropriate, for the VoIMS call to be broken out locally. 

Three quarters of respondents to the survey said they support an industry-wide move to RAVEL for VoLTE roaming. This is emphatic in its enthusiasm but 25 per cent remains a significant share of respondents still to be convinced. Just over half of respondents said they plan to support VoIMS for LTE roaming using the RAVEL architecture, while 12.3 per cent said they would support it, but not using RAVEL.

Until RAVEL is available, 27.4 per cent of respondents said they plan to use home-routing for all VoLTE traffic, while just under one fifth said they would use a non-standard VoLTE roaming solution.

Well, the solution was standardised in 3GPP Release-11. NTT Docomo has an excellent whitepaper (embedded below) explaining the issue and the proposed solution.

In 3GPP Release 11, the VoLTE roaming and interconnection architecture was standardized in cooperation with the GSMA Association. The new architecture is able to implement voice call charging in the same way as circuit-switched voice roaming and interconnection models by routing both C-Plane messages and voice data on the same path. This was not possible with the earlier VoLTE roaming and interconnection architecture.

Anyway, here is the complete whitepaper

NTT Docomo: VoLTE Roaming and Interconnection Standard Technology from Zahid Ghadialy

100 years of Wireless History

Recently attended the Cambridge Wireless Inaugural Wireless Heritage SIG event, “100 years of radio”. Some very interesting presentations and discussions on the wireless history. 

Each of the presenters touched on a double-decade period and focussed on the lessons that can be learnt from that time and their relevance today. Focusing on 20 year timeframes, the event walked us through the exciting rise and evolution of wireless technology from 1914 to present day, while showcasing live demos from each age.

Presentations were heard from:

• Colin Smithers, Chairman, Plextek "1914-1934: The wireless wave" - The Wireless Telegraphy Handbook of 1913 speculated on the future use of Continuous Waves and sets a benchmark against which fundamental trends in the industry can be measured and predicted including data costs and technology and transmission standard life spans. (PDF)
• Geoff Varrall, Director, RTT Online "1934 - 1945: The wireless war" - In his controversial book The Origins of the Second World War the revisionist historian AJP Taylor argues that the Second World War was not caused by Hitler but was the result of a combination of factors including the rapid growth of broadcasting technology. So was this the wireless war? (PDF)
• Steve Haseldine, CEO, Deaf Alerter, "1945 to 1974: The cold war - radio goes underground" - The National Communication Radio System, spy and clandestine radio, preparing for the Third World War (PDF)
• Nigel Linge, Professor of Telecommunications,  School of Computing, Science and Engineering, University of Salford "1974 to 1994" - The transistor comes of age, the role of radio in consumer electronics and cellular radio (PDF)
• Andy Sutton, Principal Network Architect, EE "1994 to 2014: Mass consumer cellular and the mobile broadband revolution" - Broadband radio, digital radio, smart phone and smart networks (PDF)

All presentations can be downloaded individually from CW website here. 

5G and the ‘Millimeter-Wave' Radios

There were quite a few interesting talks in the Cambridge Wireless Radio Technology SIG event last week. The ones that caught my attention and I want to highlight here are as follows.

The mobile operator EE and 5GIC centre explained the challenges faced during the Practical deployments. Of particular interest was the considerations during deployments. The outdoor environments can change in no time with things like foliage, signage or even during certain festivals. This can impact the radio path and may knock out certain small cells or backhaul. The presentation is available to view and download here.

Another interesting presentation was from Bluwireless on the 60GHz for backhaul. The slide that was really shocking was the impact of regulation in the US and the EU. This regulation difference means that a backhaul link could be expensive and impractical in certain scenarios in the EU while similar deployments in the US would be considerably cheaper. This presentation is available here.

Finally, the presentation from Samsung highlighted their vision and showed the test results of their mmWave prototype. The presentation is embedded below and is available here.

Vision and Key Features for 5th Generation (5G) Cellular - Samsung from Zahid Ghadialy

Finally, our 5G presentation summarising our opinion and what 5G may contain is available here. Dont forget to see the interesting discussion in the comments area.

Multi-SIM: The Jargon

I had been having some discussions regarding Multi-SIM phones and there is a bit of misunderstanding so here is my clarification about them. Anyway, a lot of information is just an understanding so feel free to correct any mistakes you think I may have made.

This post is about multiple SIM cards, physical UICC cards rather than single UICC with multiple SIM applications. We will look at Dual IMSI later on in the post. In case you do not know about the multiple SIM applications in a UICC, see this old post here. In this post, I will refer to UICC cards as SIM cards to avoid confusion.

Back in the old days, the Dual-SIM phones allowed only one SIM on standby at any time. The other SIM was switched off. If someone would call the number that was switched off, a message saying that the number is switched off would come or it would go in the voicemail. To make this SIM in standby, you would have to select it from the Menu. The first SIM is now switched off. The way around it was to have one SIM card calls forwarded the other when switched off. This wasn't convenient and efficient, money wise. The reason people use multiple SIM phones is to have cheaper calls using different SIMs. So in this case forwarding calls from one SIM to another wont be cost effective. These type of phones were known as Dual SIM Single Standby or DSSS. These devices had a single transceiver.

So as the technology got cheaper and more power efficient, the new multi-SIM devices could incorporate two receivers but only one transmitter was used. The main reason being that using two transmitters would consume much more power. As a result, these devices can now have both the SIM's on standby at the same time. These kind of devices were known as Dual SIM Dual Standby or DSDS. Wikipedia also calls then Dual SIM Standby or DSS. This concept could be extended further to Triple SIM Triple Standby or TSTS in case of the device with three SIM cards and Quad SIM Quad Standby or QSQS in case of four SIM cards. One thing to remember is that when a call is received and a SIM becomes active, the other SIM cards become inactive for the duration of the call. A workaround for that situation is to forward the call to the other SIM card in case if its unavailable. Though this will work for DSDS, it may not be that straightforward in case of TSTS and QSQS due to more than two SIM cards being present.

Another category of devices that are now available are the Dual SIM Dual Active or DSDA. In this case there are two transceivers in the device. Both the SIM cards are active at the same time so each SIM card can handle the call independently of each other. It would even be possible to conference both these calls.

With the prices of calls falling, there is no longer a real need for multiple SIM cards. One SIM card is generally sufficient. It may be useful though to have multiple IMSI on the SIM card. The different IMSI would have different country and network code. For example, a person in in UK can have one IMSI with the home network code and one with say a US operator IMSI. This IMSI could only be programmed by the home operator. When the person is in UK he could receive calls on his UK number or on the US number which would be routed to his UK number. For a person in US calling the US number, this is a national call rather than an international one. When the person is roaming in the US, his US IMSI would behave like non-roaming case while the calls to the UK number would be forwarded to the US number.

Security and other development on the Embedded SIM

Its no surprise that GSMA has started working on Embedded SIM specifications. With M2M getting more popular every day, it would make sense to have the SIM (or UICC) embedded in them during the manufacturing process. The GSMA website states:

The GSMA’s Embedded SIM delivers a technical specification to enable the remote provisioning and management of Embedded SIMs to allow the “over the air” provisioning of an initial operator subscription and the subsequent change of subscription from one operator to another.

The Embedded SIM is a vital enabler for Machine to Machine (M2M) connections including the simple and seamless mobile connection of all types of connected vehicles. In the M2M market the SIM may not easily be changed via physical access to the device or may be used in an environment that requires a soldered connection, thus there is a need for ‘over the air’ provisioning of the SIM with the same level of security as achieved today with traditional “pluggable” SIM. It is not the intention for the Embedded SIM to replace the removable SIM currently used as the removable SIM still offers many benefits to users and operators in a number of different ways – for example, the familiarity of the form factor, easy of portability, an established ecosystem and proven security model.

The last time I talked about embedded SIM was couple of years back, after the ETSI security workshop here. Well, there was another of these workshops recently and an update to these information.

The ETSI presentation is not embedded here but is available on Slideshare here. As the slide says:

An embedded UICC is a “UICC which is not easily accessible or replaceable, is not intended to be removed or replaced in the terminal, and enables the secure changing of subscriptions” (ETSI TS 103 383)

Finally, Embedded SIM should not be confused with Soft-SIM. My last post on Soft-SIM, some couple of years back here, has over 15K views which shows how much interest is there in the soft SIM. As the slide says:

Soft or Virtual SIM is a completely different concept that does not use existing SIM hardware form factors and it raises a number of strong security issues:

• Soft SIM would store the Operator secret credentials in software within the Mobile device operating system - the same system that is often attacked to modify the handset IMEI, perform SIM-Lock hacking and ‘jail-break’ mobile OS’s
• Operators are very concerned about the reduction in security of their credentials through the use of Soft SIM. Any SIM approach not based on a certified hardware secure element will be subject to continual attack by the hacking community and if compromised result in a serious loss of customer confidence in the security of Operator systems
• Multiple Soft SIM platforms carrying credentials in differing physical platforms, all requiring security certification and accreditation would become an unmanageable overhead – both in terms of resource, and proving their security in a non-standardised virtual environment

The complete GSMA presentation is as follows:

GSMA Embedded SIM from Zahid Ghadialy

You may also like my old paper:

• M2M, Cellular and Small Cells