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CWTEC 2016 - The Quantum Revolution is coming

Showing posts with label Mobile Phones and Devices. Show all posts
Showing posts with label Mobile Phones and Devices. Show all posts

Friday, 17 June 2016

History: 30 years of the mobile phone in the UK


In January 1985 the UK launched its first mobile networks. Now, thirty years on, many people and companies in the UK have been celebrating this enormous achievements and advances that have been made since then and which have seen the mobile evolve from a humble telephone into the multimedia pocket computer which has become such an essential part of modern life. It was simply not possible in 1985 to envisage a country that would be able to boast more active mobile phones than people or to have along the way clocked up several world firsts, and be now leading on the deployment of 4G and shaping the future 5G technologies.

Below is a series of talks in an event organised by University of Salford,



The following talks are part of playlist:

1. Launch of Vodafone – Nigel Linge, on behalf of Vodafone
2. Launch of Cellnet - Mike Short, O2
3. The emergence of GSM - Stephen Temple, 5GIC
4. The launch of Mercury one2one and Orange - Graham Fisher, Bathcube Telecoms
5. From voice to data - Stuart Newstead, Ellare
6. Telepoint - Professor Nigel Linge, University of Salford
7. 3G - Erol Hepsaydir, 3 UK
8. Handset evolution and usage patterns - Julian Divett, EE
9. 4G and onwards to 5G – Professor Andy Sutton, EE  and University of Salford.

For anyone interested in reading about the history of mobile phones in UK, read this book below with more facts and figures


If you have any facts to share, please feel free to add in the comments below.

Saturday, 14 May 2016

4G / LTE by stealth


In the good old days when people used to have 2G phones, they were expensive but all people cared about is Voice & SMS.


The initial 3G phones were bulky/heavy with small battery life, not many apps and expensive. There was not much temptation to go and buy one of these, unless it was heavily subsidised by someone. Naturally it took a while before 3G adoption became common. In the meantime, people had to go out of their way to get a 3G phone.

With 4G, it was a different story. Once LTE was ready, the high end phones started adding 4G in their phones by default. What it meant was that if the operator enabled them to use 4G, these devices started using 4G rather than 3G. Other lower end devices soon followed suit. Nowadays, unless you are looking for a real cheap smartphone, your device will have basic LTE support, maybe not advanced featured like carrier aggregation.

The tweets below do not surprise me at all:



This is what I refer to as 4G or LTE by stealth.

Occasionally people show charts like these (just using this as a reference but not pin pointing anyone) to justify the 5G growth trajectory with 4G in mind. It will all depend on what 5G will mean, how the devices look like, what data models are on offer, what the device prices are like, etc.

I think its just too early to predict if there will be a 5G by stealth.

Thursday, 31 March 2016

Smartphones: It came, It saw, It conquered


Smartphones have replaced so many of our gadgets. The picture above is a witness to how all the gadgets have now been replaced by smartphones. To some extent hardware requirements have been transferred to software requirements (Apps). But the smartphones does a lot more than just hardware to software translation.

Most youngsters no longer have bookshelves or the encyclopedia collections. eBooks and Wikipedia have replaced them. We no longer need sticky notes and physical calendars, there are Apps for them.

Back in 2014, Benedict Evans posted his "Mobile is Eating the world" presentation. His presentation has received over 700K views. I know its not as much as Justin Bieber's songs views but its still a lot in the tech world. He has recently updated his presentation (embedded below) and its now called "Mobile ate the world".

Quite rightly, the job is not done yet. There is still long way to go. The fact that this tweet has over 600 retweets is a witness to this fact. Here are some of the slides that I really liked (and links reltaed to them - opens in a new window).
While we can see how Smartphones are getting ever more popular and how other gadgets that its replacing is suffering, I know people who own a smartphone for everything except voice call and have a feature phone for voice calls. Other people (including myself) rely on OTT for calls as its guaranteed better quality most of the time (at least indoors).

Smartphones have already replaced a lot of gadgets and other day to day necessities but the fact is that it can do a lot more. Payments is one such thing. The fact that I still carry a physical wallet means that the environment around me hasn't transformed enough for it to be made redundant. If I look in my wallet, I have some cash, a credit and debit card, driving license, some store loyalty cards and my business cards. There is no reason why all of these cannot be digital and/or virtual.
A Connected Car is a Smartphone on/with wheels.


A connected drone can be considered as smartphone that flies.
The Smartphones today are more than just hardware/software. They are a complete ecosystem. We can argue if only 2 options for OSs is good or bad. From developers point of view, two is just about right.
Another very important point to remember that smartphones enable different platforms.

While we may just have messaging apps that are acting as platforms, there is a potential for a lot more.

Here is the presentation, worth reflecting on each slide:



If you haven't heard Benedict Evans speak, you can refer to a recent video by him on this topic:



Related posts on the web:



Monday, 29 February 2016

The Internet of Me: It’s all about my screens - Bob Schukai


I had the pleasure of attending the IET Turing lecture last week and listening to Robert Schukai. He gave a brilliant talk on how Smartphones are changing the way we do things. Its a very interesting talk but its nearly 87 minutes long. Slides are not available but the video is embedded below.


Wednesday, 13 January 2016

Interesting gadgets from CES 2016

Here are some gadgets from the recently concluded Consumer Electronics Show (CES) 2016. These are all collected from the tweets and there is a Youtube video below if you are interested. There are just too many interesting things to list but do let me know which ones are your favourites.





Sunday, 7 June 2015

Nuggets from Ericsson Mobility Report


Ericsson mobility report 2015 was released last week. Its interesting to see quite a few of these stats on devices, traffic, usage, etc. is getting released around this time. All of these reports are full of useful information and in the old days when I used to work as an analyst, I would spend hours trying to dig into them to find gold. Anyway, some interesting things as follows and report at the end.

The above chart, as expected, data will keep growing but voice will get flatter and maybe go down, if people start moving to VoIP

Application volume shares, based on the data plan. This is interesting. If you are a heavy user, you may be watching a lot of videos and if you are a light user then you are watching just a few of them.

How about device sizes, does our behaviour change based on the screen size?

What about the 50 Billion connected devices, was it too much? Is the real figure more like 28 billion?

Anyway, the report is embedded below.



Friday, 3 April 2015

Some interesting April Fools' Day 2015 Technology Jokes

Here is a quick roundup of some interesting tech #AprilFools day jokes from the web. Click on the links to learn more

Samsung Galaxy Blade Edge - Chef's edition




Selfie Shoes by Miz Mooz - Shoefie



com.google - You can try it in chrome browser, it was working


Smartbox by Inbox: the mailbox of tomorrow, today - by Google




HTC Re-Sok - the "world's first truly smart sock"






Bing's Palm Search technology




Introducing #MotoSelfieStick - By Motorola



Twitter’s Twelfie Stick



Domino’s Domi-No-Driver Service

Iltasanomat news on April 1st 2015 (source not available): Finnish Police is having their own air forces with 250 seagulls with TETRA radio and camera


And finally, these old style pranks still work :-)

If you like them, you will enjoy the last year ones too. Here.

Saturday, 28 March 2015

Report on Spectrum Usage and Demand in the UK


Last week at work, we released a report titled "UK Spectrum Usage & Demand". The only time most people hear about spectrum is when there are some auctions going on. Often a small chunk of spectrum gets sold off for billion(s) of dollars/pounds and these surely make a headline. As I recently found out, 50% of spectrum in UK is shared and 25% is license exempt.

Anyway, this first edition of the report focuses on Public Mobile, Utilities, Business Radio and Space/Satellites. Space is becoming an important area of focus here as it is a significant contributor to the UK economy.

Anyway, the report is embedded below and is available to download from here:



Sunday, 16 November 2014

Is mobile eating the world?

Another interesting and thought provoking presentation by Ben Evans. His earlier presentation which was very popular as well, is here. The video and slides are embedded below.


How Mobile is Enabling Tech to Outgrow the Tech Industry from Andreessen Horowitz on Vimeo.




And a recent interview by Benedict Evans with Bloomberg TV on the same topic as follows:


Saturday, 11 October 2014

A quick update on Antennas

There were couple of very interesting and useful presentations from the LTE World Summit 2014 that I have been thinking for a while to embed in the blog. The first is a market overview from Signals Research Group. The research is focussed more on the US market but it has some very interesting insights. The slideset is embedded below:



The other presentation is from Commscope on Base Station Antennas (BSA) for capacity improvement. I really liked the simplicity of the diagrams. Anyone interested in studying more indepth on the antennas are encouraged to check out my old post here. The complete slideset is below:



Thursday, 2 October 2014

Envelope Tracking for improving PA efficiency of mobile devices

I am sure many people would have heard of ET (Envelope Tracking) by now. Its a technology that can help reduce the power consumption by our mobile devices. Less power consumption means longer battery life, especially with all these new features coming in the LTE-A devices.
As the slide says, there are already 12 phones launched with this technology, the most high profile being iPhone 6/6 Plus. Here is a brilliant presentation from Nujira on this topic:



For people who are interested in testing this feature may want to check this Rohde&Schwarz presentation here.

Friday, 29 August 2014

Wireless Charging: A must-have technology with maturing standards


Wireless charging has been in news recently with the discovery that Apple has found a brilliant way to wireless charge iPhones, iPads and iWatches. While we continue to wait for the details of that one, I thought its worth providing a bit of round up from the LTE World Summit not so long back. A summary of market by IHS is embedded as follows:



Qi (pronounced Chee), probably the most well known standard, not just because its already available in devices like Google Nexus 5 phone and Nexus 7 tablet  but also because its 1.2 standard allows devices to be charged from some distance away. They had an excellent presentation outlining their progress and technology as follows:





Finally, any discussion on Wireless Charging wont be complete without the mention of other big player, Alliance For Wireless Power (A4WP). The above shows a comparison between different standards and the presentation from A4WP is as follows:




Finally, if you haven't seen our concept of futuristic 'Smart Batteries' (crossed 10K+ views) then check it out here.

Thursday, 26 June 2014

LTE-Broadcast: Reality check


When I wrote my blog post about why the 'Cellular Broadcast may fail again' for the Cisco SP Mobility blog, I did not realise that this would become so popular and there would be so many people writing to me to tell me why and how my assumptions are wrong and how they plan to succeed. I have not yet received a successful reasoning on why people disagree with my article and where I am wrong.

In the Video Over LTE Summit just concluded, I did not get a chance to see all the LTE-B presentations but the ones that I saw, were not convincing enough, except for one by Erol Hepsaydir, of '3' UK, that I explain in the end.

Here is my presentation from that event:



The conclusion is not self-explanatory so here it is in my own words.


I am not opposed to the operators trying LTE-B out. I wish more operators do try and hopefully we can have a model where the technology can succeed. When operators succeed in a new technology, it benefits the whole mobile ecosystem directly or indirectly. The operators have to be prepared that they may not see any return. This should not discourage them because the learnings from this may benefit in something else. The customer and their loyalty is more important. We should try and provide them with a value addition rather than think of this as a new source of revenue. People are not interested in watching the same stuff they watch on the terrestrial TV on their small devices; unique and maybe tailored content would help. Finally, don't make the billing model too complex so the users shy away from trying this new technology.

The final presentation of the event was delivered by Erol Hepsaydir of the UK operator '3'. He said that from their point of view, they are trying to have eMBMS to create additional capacity in the network. If they know that many people watch news on different apps and websites, they can offer this as a free service over broadcast. What this means is that they have gained customer loyalty and also free up the capacity for other users who are doing other data related activities. I think this is a very clever approach. He did mention though that they are only in the simulation stages and have not tried it out practically. 

Sunday, 1 June 2014

Internet Trends 2014, by Mary Meeker



Its June, time for the Internet Trends update by Mary Meeker, KPCB. Last year's update has crossed 3 million views on Slideshare. So many interesting slides, difficult to pick up some of the best ones to add here. I have selected a few that I really liked. The first being the growth in Smartphones and Tablets, as compared to PC's and Television's.



The other very interesting point to highlight is that the number of SMS's are decreasing and the number of OTT messages are rising. Just two days back, BITKOM, Germany released the news that SMS's are declining drastically in Germany. OTT's are taking over, rightly so.



Finally, with people doing too much multi-tasking, the above slide highlights what people are doing while watching TV.

Here is the complete set of slides:



Related news on the web:

  • Forbes: Are We In A Tech Bubble? Not Really, According To Mary Meeker's Latest Report
  • Business Insider: Mary Meeker's Stunning 2014 Presentation On The State Of The Web
  • Quartz: Mary Meeker’s 2014 internet trends report: all the slides plus highlights
  • Forbes: Mary Meeker's Web Video Love Affair
  • Guardian: Mary Meeker: 2015 will be about 'findable data' and mobile sensors
  • Business Insider, Australia: In 3 Big Slides, Here's Why Mary Meeker Is Optimistic About The Future Of American Healthcare
  • Tech2: What Mary Meeker’s 2014 trends report says about India’s Internet usage


Thursday, 27 March 2014

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.



Saturday, 8 March 2014

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:


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.

SKTelecom2

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

Saturday, 1 March 2014

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 :)



Tuesday, 18 February 2014

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.


Saturday, 8 February 2014

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. I have collected all the presentations and merged them into one and embedded them below. All presentations can be downloaded individually from CW website here. A combined one is available from Slideshare.

Presentations are:

  • Colin Smithers, Chairman, Plextek - 1914 to 1934: The wireless wave
  • Geoff Varrall, Director, RTT Online - 1934 to 1945: The wireless war
  • Steve Haseldine, Chairman, Deaf Alerter - 1945 to 1974: The cold war - radio goes underground
  • Prof Nigel Linge, Professor of Telecommunications, University of Salford - 1974 to 1994
  • Andy Sutton, Principal Network Architect, EE and Visiting Professor, University of Salford - 1994 to 2014: Mass consumer cellular and the mobile broadband revolution - Broadband radio, digital radio, smart phone and smart networks



Thursday, 30 January 2014

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.