Tuesday 5 March 2013

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:

Wednesday 27 February 2013

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.



Monday 25 February 2013

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

Saturday 23 February 2013

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.

Monday 18 February 2013

Thursday 14 February 2013

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.

Monday 11 February 2013

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.


Thursday 7 February 2013

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/

Thursday 31 January 2013

Monday 28 January 2013

Overview of 3GPP Release-12 Study Item UPCON

Mobile operators are seeing significant increases in user data traffic. For some operators, user data traffic has more than doubled annually for several years. Although the data capacity of networks has increased significantly, the observed increase in user traffic continues to outpace the growth in capacity. This is resulting in increased network congestion and in degraded user service experience. Reasons for this growth in traffic are the rapidly increasing use of smart phones and tablet like devices, and the proliferation of data applications that they support, as well as the use of USB modem dongles for laptops to provide mobile Internet access using 3GPP networks. As the penetration of these terminals increases worldwide and the interest in content-rich multi-media services (e.g. OTT video streaming services) rises, this trend of rapidly increasing data traffic is expected to continue and accelerate.


Here are couple of presentations on this topic:







Related blog posts:

Wednesday 23 January 2013

LTE-B, LTE-C, ... , LTE-X

Please make sure to read the comment from Kevin Flynn of 3GPP at the end


When I saw this picture above, I started wondering what LTE-B, etc. and started digging a bit deep. Came across this Ericsson presentation (embedded below) that shows the breakdown.

To just be sure that this is not Ericsson specific term, I also found a presentation by NTT Docomo (embedded below)
So I guess using LTE-B, LTE-C, etc. is better than saying 4.1G, 4.2G, etc. as we did in case of 3G/HSPA.


The presentations from Ericsson and NTT Docomo embedded below, available to download from Slideshare.






Tuesday 22 January 2013

LTE / EPC Signalling Training from eXplanoTech

Training is one of the areas we have been focussing on for a long time. Due to lack of bandwidth we have only been offering our training to a selected few customers but we are now expanding further. Here is a sample of LTE / EPS Signalling training

Sunday 13 January 2013

Videos from the CES 2013





Gorilla glass (above) is made by a company called Corning that is much more well known for its futuristic video, see here.











Finally, this Sony Xperia Z has got over 2 million hits, not exactly sure why so I have added the video for this as well

Friday 11 January 2013

The four C's of Release-12 enhancements

Mid last year, I did a post on the LTE Rel-12 workshop and later another post on the progress.  Late last year, 3GPP posted a news item that the Rel-12 will be available by June 2014 and the main areas of focus will be as follows:


Exploiting new business opportunities

  • Public Safety and Critical Communications 
    — Group Communications (GCSE_LTE)
  • Proximity Services, including both Public Safety and Commercial aspects (ProSe)
  • Machine Type Communications 
    — UE Power Consumption, Small Data and Device Triggering (MTCe_UEPCOPMTCe_SDDTE )

WiFi integration

  • Network Selection aspects (WLAN_NS)
  • S2a Mobility with GTP for WLAN (FS_SaMOG)
  • Optimized Offloading to WLAN in 3GPP-RAT mobility (FS_WORM)

System capacity and stability

  • User plane congestion (UPCON)
  • Core Network Overload (FS_CNO)
In addition to those three areas, other features can still be considered for completion in the Release 12 timeframe. The SA2 Working Group - responsible for Architecture - will produce time budgets to see whether further priority could be put on;
  • Pure IMS features that can run in parallel with key items
  • Policy and Charging Control for supporting fixed broadband access networks, PCC for fixed terminals (P4C BB1 and BB2)
  • Application Based Charging (FS_ABC)
  • User Monitoring Control Enhancements (FS_UMONC)
  • LIPA Mobility and SIPTO at the Local Network (LIMONET)
  • Operator Policies for IP Interface Selection (OPIIS)
Working Group SA2 will provide time budgeting information, for the selected features, at the next Plenary meeting - TSG#59, in March 2013.


Nokia Siemens Networks (NSN) has published their own whitepaper on 'LTE Release 12 and Beyond' (available on Slideshare here).

The following is their take on the four C's:


Release 12 enhancements focus on the four areas of Capacity, Coverage, Coordination (between cells), and Cost. Improvements in these areas are based on using several technology enablers: small cell enhancements, macro cell enhancements, New Carrier Type (NCT) and Machine-Type Communications (MTC). These enablers are described in this paper.

Customer experience, capacity and coverage will be improved with small cell enhancements, based on inter-site Carrier Aggregation, LTE-WLAN integration and macro cell enhancements. Small cell enhancements are also known as enhanced local access.

NCT helps achieve the required changes in the physical layer and initially provides base station energy savings, flexibility in deployment and ways to reduce interference in heterogeneous networks (HetNets).

Improvements in capacity and a more robust network performance are achieved by 3D Beamforming/MIMO (Multiple Input Multiple Output), advanced user equipment (UE) receivers and evolved Coordinated Multipoint (CoMP) techniques, as well as through Self-Organizing Networks for small cell deployments.

Finally, new spectrum footprint and new business will be opened up by optimizing the system for Machine-Type Communications, as well as by, for example, using LTE for public safety.


The whitepaper is available on Slideshare here.

Tuesday 8 January 2013

VoLTE, Battery Issues and Solutions


Sometime back we had news about how VoLTE is battery killer and how it would suck our 4G phones dry. Well, I agree. I am no fan of VoLTE and think that CSFB solution can suffice in mid-term. Having said that, there is a solution which would be soon available to sort this battery issue during VoLTE call. I had a post on this topic earlier titled SPS and TTI Bundling. I am not sure about exactly how much saving would occur if either of the features are implemented.

ST Ericsson has recently released a whitepaper on this topic that is embedded below. If you have more idea on this, please add it in comments.



Sunday 6 January 2013

Dumbphones, Featurephones, Smartphones, Superphones...

Looks like there is still a lot of confusion in the different types of phones around so here is my take. Please feel free to correct me and I will update accordingly.

Dumb phones: The dumb phones were the original mobile phones whose intention was to allow voice and SMS initially and then later on some kind of data transfer using WAP.

Pic source: iPhaze

A typical dumbphone is as shown above. Dumb phones are no longer available but they can still be used if they are in the working order. Dumbphones were always pre-3G. It wouldnt make sense to have a 3G dumbphone but it is very much possible to have a 2G Featurephone/Smartphone.

Feature Phones: These came next. They allowed more stuff than the basic phones.

Pic source: Gadgetsteria

Featurephones (above) can do much more stuff, for example they may have camera to take photos, they may allow facebook to share the photos, they can have Skype to call, they can even have WiFi for access. Different people have different way of describing the difference between them and smartphones. Some distinguish Featurephones by suggesting that they have a closed operating system (OS) but this may not be necessarily true. Some others suggest that featurephones do not have touch screens while smartphones do, again this may no longer be considered true. There are featurephones available with basic touch functionality. I think an agreeable way to consider a phone a feature phone, in today's terms, can be based on a combination of processor speeds (less than 400MHz), screen size (less than 2inches), presence of physical buttons and pricepoint (less than $50).

Contrary to popular belief, featurephones are still popular and are going strong. See the chart below for example.
Pic source: Seeking Alpha

There is a good article that explains why Feature phone is 'Still the undisputed King' here to interested readers. The main reason according to me is that the reception is much better on Featurephones rather than Smartphones and they consume less battery power in general as compared to the smartphones.

Smartphones: Wikipedia suggests that the term smartphone was used as early as 1997 but what may have been considered as smartphone then is more like a featurephone of today. As per my knowledge, the first true modern smartphone were the Nokia communicators. If you look at the specs now, they may be classified as low end featurephones but they were the foundation for the smartphones.

Picture Source: Droid techy news

The first true modern smartphone that change the mobiles forever is undisputedly the original iPhone. On reflecting back, people had no idea what a phone could do until the arrival of the iPhone. This was soon followed by the iPhone clones and now we have many different ecosystems like Android, Bada, Windows mobile, Blackberry OS, etc. that gives its own flavour to the smartphones.

Superphones: The marketing industry is always thinking of using new terms to sell the products and while there has been terms like smarter-phones, super-smartphones, intelligent phones, etc. being thrown about, I think the industry has now converged on to use Superphones for the next generation devices. Some of the readers may be aware that 'Superphone' is used in Dr. Who series.


Again, there is no defined standards but looks like the superphone should have Quad core and its screen size should be more than 4.1inch. Samsung Galaxy S3 would qualify to be a superphone but its not referred to as one.

Phablets, Tabphones and Phonetabs: So what do you call a hybrid (or a cross between) Tablet and Smartphone? The answer could be any of the terms Phablets, Tabphones or Phonetabs. Again, there is no standard term but people have decided to use whichever term they feel like. Phablet is the most commonly used term.

Pic Source: CNet

Samsung Galaxy Note 2 is a good example of Phablet. One of the suggestions is that to qualify for Phablet, the screen size should be between 5 inches and 7 inches. Some of the users who have braved to buy one of the phablets, swear by it and in most cases vow to never go back to just a phone.

Picture Source: FT

FT has an interesting article that suggests the shipment of phablets could be around 200 million by 2015. It should be noted that according to me, WiFi only devices should not be considered as phablets as the phone part is missing. They are just mini-tablets. In case of 7 inch devices capable of phone and tablet functionality, it is a bit of a fuzzy area in cases where the user does not use the SIM card, thereby making the phone part unusable. For simplicity we can consider a device as phablet as long as the mobile functionality is embedded.

Friday 4 January 2013

Energy-efficient femtocell implementation

In an earlier post, we saw an idea on how to have energy efficient Femtocell. Here is a practical implementation from ALU on energy efficient Femtocell.