Small Cells Enhancements for 3GPP Release-12

The following presentation is by 3GPP in the not so long ago, Small Cells World Summit 2013.

Enhancements for Small Cells in 3GPP Release-12 from Zahid Ghadialy

Related Post:

• Small cell standardization in 3GPP Release 12

Adaptive Video Streaming: Principles, Improvements and Innovation

An Interdigital presentation from last year explains the principle of adaptive streaming very well for those who would not know how it worked.

This process of adaptation could be improved based on the quality of coverage at any particular time.

Interdigital are proposing a further enhancement of improving the adaptation further based on the User behaviour. If for example the user is far away then the quality need not be great on the device. On the other hand if the user is very close-by, the quality should be as good as it can get. They have explained it in a whitepaper for whoever is interested here.

A video showing this method is embedded below:

500 Billion devices by 2030, etc...

Few weeks back in the LTE World Summit 2013, I heard someone from Ericsson mention that internally they think that by 2030 there will be 500 Billion Connected devices on the planet. The population projections for 2030 is somewhere around 8.5 Billion people worldwide. As a result the figure does not come much as a surprise to me.

John Cunliffe from Ericsson is widely credited for making the statement 50 Billion connected devices by 2020. Recently he spoke in the Cambridge Wireless and defended his forecast on the connected devices. He also provided us with the traffic exploration tool to see how the devices market would look up till 2018. Here is one of the pictures using the tool:

In terms of Cellular connectivity, we are looking at 9 Billion devices by 2018. The interesting thing to notice is that in 2017, there are still some 4 Billion feature phones. While in the developed world our focus is completely on Smartphones, its interesting to see new and existing SMS/USSD based services are still popular in the developing world. Some months back I heard about Facebook developing SMS/USSD based experience for Feature phones, I am sure that would attract a lot of users from the developing world.

One thing missing from the above is non-cellular connections which will make bulk of connectivity. Wi-Fi for example is a major connectivity medium for tablets. In fact 90% of the tablets have only WiFi connectivity. Bluetooth is another popular method of connectivity. While its mostly used in conjunction with phones, it is going to be a popular way of connecting devices in the Personal Area Network's (PAN's). So its no surprise that we will see 50 Billion connected devices but maybe not by 2020. My guess would be around 2022-23.

Is it too early to talk '5G'

While LTE/LTE-A (or 4G) is being rolled out, there is already a talk about 5G. Last week in the LTE World Summit in Amsterdam, there was a whole track on what should 5G be without much technical details. Couple of months back Samsung had announced that they have reached 5G breakthrough. In my talk back in May, I had suggested that 5G would be an evolution on the Radio Access but the core will evolve just little. Anyway, its too early to speculate what the access technology for 5G would be.

Ericsson has published a '5G' whitepaper where they talk about the vision and why and what of 5G rather than going into any technical details. It is embedded below:

5G: What is it? from Ericsson

Multi-RAT mobile backhaul for Het-Nets

Recently got another opportunity to hear from Andy Sutton, Principal Network Architect, Network Strategy, EE. His earlier presentation from our Cambridge Wireless event is here. There were many interesting bits in this presentation and some of the ones I found interesting is as follows:

Interesting to see in the above that the LTE traffic in the backhaul is separated by the QCI (QoS Class Identifiers - see here) as opposed to the 2G/3G traffic.

This is EE's implementation. As you may notice 2G and 4G use SRAN (Single RAN) while 3G is separate. As I mentioned a few times, I think 3G networks will probably be switched off before the 2G networks, mainly because there are a lot more 2G M2M devices that requires little data to be sent and not consume lots of energy (which is an issue in 3G), so this architecture may be suited well.

Finally, a practical network implementation which looks different from the text book picture and the often touted 'flat' architecture. Andy did mention that they see a ping latency of 30-50ms in the LTE network as opposed to around 100ms in the UMTS networks.

Mark Gilmour was able to prove this point practically.

Here is the complete presentation:

Timing Accuracy and Phase Performance Requirements in LTE/LTE-A/4G

Nice quick summary videos from Chronos.



If you are interested in learning more on this topic or discussions, I would recommend joining the Phase Ready Linkedin group.

3 Band Carrier Aggregation in Release-12

So it looks like in the latest 3GPP RAN meeting finally more than 2 carriers have been proposed for Carrier Aggregation. The TDoclist has a few items on 3 carriers for CA. In some cases its been specified that there is 1 uplink component carrier (1UL CC) but in other cases its not specified and I have not looked into details. Its good to finally see more than 2 carriers being discussed.

Rohde&Schwarz have explained in one of their whitepapers about the numbering of CA bands.

Now there is a possibility that we may have 2 contiguous bands and 1 band from an Inter-band so the naming would be accordingly. There are also going to be new carrier types (NCT), Band 29 for example. See details here.

Finally, If you want to learn more about Carrier Aggregation (CA) or other LTE-Advanced features, my article from last year, here, would be useful.

Economical M2M using LTE - #LTEWS

In the upcoming LTE World Summit 2013 (programme here), I will be doing a briefing on the topic 'Economical M2M using LTE'. I have some ideas but I would like to hear more on what you think? In fact, is LTE the right technology from the M2M device point of view? Or do they better stick to 2G (I dont think 3G is good enough generally from low data M2M point of view). What other issues can be foreseen? Security? Roaming?

A recent presentation from Telefonica shows how they are partnering with other operators worldwide to create universal solutions. Will this help? Why not use these solutions for everything, not just LTE? LTE is data only technology isn't it?

The presentation is embedded below to draw your own conclusion but I an interested in hearing your thoughts on Twitter or here on the blog.

Telefónica - M2M Global Operator – Strategy of Alliances from Zahid Ghadialy

Five Future Technologies (#FutureTech) we may see soon in our devices!

Remember 'Internet of Everything' rather than 'Internet of Things', here is a recent Cisco video explaining this vision:

You can read more on these topics on Cisco blogs.


Next is the self-healing technology:



Spray-on clothes
These will go very well with phones where you can spray paint phone covers and maybe if its possible to dissolve the skin and re-use it, it would be an added bonus.


Just think how the technology used to design Robots can enable flexible phones and other devices.




With sensors becoming smaller and cheaper, more of them are being put in our devices. Many years back people were saying that breath analysers could be available in mobiles but I guess there wasnt a business case for that. Also many of these sensors have come as part of Bluetooth add-ons to keep the cost/weight/size of the device down. Now there is a possibility of whole new range of sensors coming to our devices.

You can read more details on this here.


Finally, there is always one user who would ask me why is there no mention of LTE in the videos above so here is a **bonus** video.

I have to mention that this didnt sound very convincing to me as a selling point. Its like back in the year 2000, 3G was being sold as an enabler to the must have 'Video calling'.

Summary of Network Security Conference (#NetworkSecurity) 2013

Summary of Network Security Conference (#NetworkSecurity) from 3G4GLtd

3GPP Public Safety focus in Rel-12

Public Safety is still a hot topic in the standards discussion and on this blog as well. Two recent posts containing presentations have been viewed and downloaded like hotcakes. See here and here.

3GPP presented on this topic in the Critical Communications World that took place last month. The following is from the 3GPP press release:

The ’Critical Communications World’ conference, held recently in Paris, has focused largely on the case for LTE standardized equipment to bring broadband access to professional users, by meeting their high demands for reliability and resilience.

Balazs Bertenyi, the 3GPP SA Chair, reported on the latest status of the first 3GPP features for public safety, in particular those covering Proximity services (Direct mode) and Group call. He spoke of the need to strike a balance between more or less customisation, to make use of commercial products while meeting the specific requirements for Public Protection and Disaster Relief (PPDR).

To ensure that these needs are met, Balazs Bertenyi called for the wholehearted participation of the critical communications community in 3GPP groups, by sending the right people to address the technical questions and obstacles that arise during the creation of work items.

A presentation and video from that event is embedded below:

LTE Standards for Public Safety – 3GPP view from Zahid Ghadialy

For more details see here.

New Carrier Type (NCT) in Release-12 and Band 29

One of the changes being worked on and is already available in Release-11 is the Band 29. Band 29 is a special FDD band which only has a downlink component and no uplink component. The intention is that this band is available an an SCell (Secondary cell) in CA (Carrier Aggregation). 

What this means is that if this is only available as an SCell, any UE that is pre-Rel-11 should not try to use this band. It should not read the system information, reference information, etc. In fact the System Information serves little or no purpose as in CA, the PCell will provide the necessary information for this SCell when adding it using the RRC Reconfiguration message. This gives rise to what 3GPP terms as New Carrier Type for LTE as defined here. An IEEE paper published not long back is embedded below that also describes this feature in detail. 

The main thing to note from the IEEE paper is what they have shown as the unnecessary information being removed to make the carrier lean.

China Mobile, in their Rel-12 workshop presentation, have suggested 3 different types/possibilities for the NCT for what they call as LTE-Hi (Hi = Hotspot and Indoor).

Ericsson, in their Rel-12 whitepaper mention the following with regards to NCT:

Network energy efficiency is to a large extent an implementation issue. However, specific features of the LTE technical specifications may improve energy efficiency. This is especially true for higher-power macro sites, where a substantial part of the energy consumption of the cell site is directly or indirectly caused by the power amplifier.

The energy consumption of the power amplifiers currently available is far from proportional to the power-amplifier output power. On the contrary, the power amplifier consumes a non-negligible amount of energy even at low output power, for example when only limited control signaling is being transmitted within an “empty” cell.

Minimizing the transmission activity of such “always-on” signals is essential, as it allows base stations to turn off transmission circuitry when there is no data to transmit. Eliminating unnecessary transmissions also reduces interference, leading to improved data rates at low to medium load in both homogeneous as well as heterogeneous deployments.

A new carrier type is considered for Release 12 to address these issues. Part of the design has already taken place within 3GPP, with transmission of cell-specific reference signals being removed in four out of five sub frames. Network energy consumption can be further improved by enhancements to idle-mode support.

The IEEE paper I mentioned above is as follows:

Everything you wanted to know on Cloud Encryption

Cloud has been in the news recently for not the right reasons. The main worry with cloud is not just where your data is located and who can have access to it but also if some rogue person or institution gets access what they will do with your data. Then there is also an issue of which third party programs are allowed to access your data and they may not be as strict in complying with the security requiremenys as the original cloud platform.

I like Dropbox (even though I am still a free user) but it is used as an example in many case studies for security related to cloud. A quick search on Google and some useful links summarising the issues with Dropbox security here, here and here.

A user on slideshare recently uploaded many presentations from the Cloud Asia 2013 in Singapore here. One of the presentations that I really liked is embedded below.

The two main things from the presentation that I really want to highlight is the Worldwide compliance which can be a bit of an issue once you want to offer your service universally and the other is the different level of encryption that is required to keep the data secure. Pictures of both as follows:

Enjoy the presentation:

Friday rant: OTT, Viber, Roaming, etc.

The same old story, mobile operators are seeing that their revenue is not growing, even though they are upgrading their networks and introducing new features / technologies. The following is from Total Telecom:

The global telecom services market generated revenue of €1.12 trillion in 2012, although at 2.7% growth was slower than in the previous year, according to the 2013 DigiWorld Yearbook published by IDATE on Thursday.

The "DigiWorld" as a whole - which also includes telecoms hardware, software and computer services, computer hardware, TV services, consumer electronics and Internet services – recorded revenues of €3.17 trillion last year, up 2.8% on 2011. By 2016 that figure will have risen to €3.66 trillion, IDATE predicts, with telecoms services contributing €1.25 trillion (see chart).

Telecoms operators are experiencing flat growth, while over-the-top (OTT) providers are seeing revenues increase by 15% a year, Vincent Bonneau, head of IDATE's Internet business unit, told attendees at the DigiWorld Yearbook launch in London earlier this month.

Another interesting piece of news was that Viber has launched a desktop application which means it can now rival Skype fully.

Guess what, I would think that operators have more to worry from this news than Skype. I have stopped using Skype for some time now due to many issues I have with it and have moved to Viber for a few months.   If you are a regular reader to this blog then you would have read my recent post complaining about the global roaming rates. When I am travelling abroad, I make sure there is WiFi and use Viber as a substitute for Voice and SMS. In fact I can send MMS and emoticons using Viber which would cost a fortune over cellular otherwise.

Sometimes it feels like the operators are sleepwalking into their own destruction by not innovating enough and fast to be a challenge for these OTT services. Not entirely sure what the solutions are but there are quite a few ideas around to start thinking in that direction. An interesting presentation by Dean Bubley I posted here is a good starting point. Another one from him and Martin Geddes is embedded below, which is quite interesting and intutive.

Enough of my rants, what do you think about this?

Internet Trends by Mary Meeker at #D11

The last time I posted the presentation by Mary Meeker was back in 2011 but the things have moved on and its amazing to see some of the things that have changed. I think the slide that summarises what I mean is as follows:

Nomophobia and FOMO are a big problem and I see this day in day out working in this industry.

The slide pack which was actually posted yesterday has already crossed 550K as I write this, in just 1 day. So you can understand how eagerly awaited event this has become every year.

To download the above, click on the Slideshare icon and then you can save from Slideshare site.

If you want to watch the video of her presentation, its available on All things digital website here.

NEC on 'Radio Access Network' (RAN) Sharing

Its been a while we looked at anything to do with Network Sharing. The last post with an embed from Dr. Kim Larsen presentation, has already crossed 11K+ views on slideshare. Over the last few years there has been a raft of announcements about various operators sharing their networks locally with the rivals to reduce their CAPEX as well as their OPEX. Even though I understand the reasons behind the network sharing I believe that the end consumers end up losing as they may not have a means of differentiating between the different operators on a macro cell.

Certain operators on the other hand offer differentiators like residential femtocells that can enhance indoor coverage or a tie up with WiFi hotspot providers which may provide them wi-fi access on the move. The following whitepaper from NEC is an interesting read to understanding how RAN sharing in the LTE would work.

“NEC’s Approach towards Active Radio Access Network Sharing” from Zahid Ghadialy

Future proofing with LTE-Advanced

Future Proofing With LTE-Advanced from Zahid Ghadialy

Is the Global Mobile Roaming model broken?

Yesterday, I noticed some heavyweights discussing roaming prices on Twitter. It is embedded below using the new Twitter embed feature:

I really don't understand why Google Maps still failsin this way twitter.com/BenedictEvans/…
— Benedict Evans (@BenedictEvans) May 18, 2013

@benedictevans it might be the Vodafone connectivity on your phone. Try O2 :)
— Carlos Domingo (@carlosdomingo) May 18, 2013

@carlosdomingo you'll have to match their roaming pricing first ;)
— Benedict Evans (@BenedictEvans) May 18, 2013

@benedictevans I am sure @ronandunneo2 will be interested in looking at it.
— Carlos Domingo (@carlosdomingo) May 18, 2013

@carlosdomingo @benedictevans ours is a fixed rate of just £1.99 a day for data and #TUGo for IP calling to anyone
— Ronan Dunne (@ronandunneo2) May 18, 2013

@ronandunneo2 @carlosdomingo not in New York, as far as I can see
— Benedict Evans (@BenedictEvans) May 18, 2013

@benedictevans @ronandunneo2 Hi Benedict, you can find our latest rates by selecting USA from the drop down list here j.mp/ML2Xzy
— O2 in the UK (@O2) May 18, 2013

@o2 @ronandunneo2 O2 in the USA: £6 per meg. Vodafone in the USA: £25 for 100 meg a day. Sorry, but that's an easy choice.
— Benedict Evans (@BenedictEvans) May 18, 2013

Those who follow me on Twitter may have noticed me ranting about the roaming prices recently so I thought that this is a perfect opportunity to put my thoughts down.

As being discussed above, I went on the websites of two UK operators and found out about their roaming rates to India and The USA and they are as follows:

 It should be noted that there is a better rate available with some kind of bundle opt-in from both the operators and I have not shown about the other UK operators but they offer a similar sort of rate so I am not trying to single out O2 and/or Vodafone.

Since LTE is 'All-IP' network my interest is more from Data point of view rather than the voice point of view. A colleague who went to India recently decided that enough is enough and he bought a SIM in India locally. Apparently is just a bit too difficult to get SIM in India if you are not an Indian resident, nevertheless he somehow managed it. The rates as shown below was INR 24 for 100 MB of data.

Rs. 24 is something like $0.50 or £0.35. You see my problem regarding the data rates? People may be quick to point out here that India has the cheapest data rates in the world. On the other hand we look at US, the rates are as follows:

Even if we assume $15 / 1GB data, its far cheaper than the roaming rate which may be something like,  £3/MB = £3000/GB or £6/MB = £6000/GB.

I blogged about all the interesting developments that have been happening in LTE World Summit regarding the roaming solutions but what is the point of having all these solutions if the operators cant work out a way to reduce these costs. Or is it that they do not want to reduce these costs as they are a good source of income?

The operators complain that the OTT services are taking business away from them and turning them into dumb data pipes but to a lot of extent its their fault. People like me who travel often dont want to spend loads of cash on data and have worked out a way around it. Most of the places I visit have WiFi, most of my work is not urgent enough and I can wait till I am in a WiFi coverage area. In some parts of the world, still I have to buy an expensive WiFi access but compared to the roaming rates, its still cheap so I have stopped complaining about it. My decision to book a hotel depends of reviews, free breakfast and free WiFi. Some of our clients who give us their phone to use abroad strictly inform us that data should not be turned on unless its a matter of life and death.

If the operators dont change their strategies and work out a better solution for the roaming rates I am afraid that their short term gains will only lead to long term pains.

Do you have an opinion? I am interested in hearing.

Access Class Barring in LTE using System Information Block Type 2

As per 3GPP TS 22.011 (Service accessibility):

All UEs are members of one out of ten randomly allocated mobile populations, defined as Access Classes (AC) 0 to 9. The population number is stored in the SIM/USIM. In addition, UEs may be members of one or more out of 5 special categories (Access Classes 11 to 15), also held in the SIM/USIM. These are allocated to specific high priority users as follows. (The enumeration is not meant as a priority sequence):
Class 15 - PLMN Staff;
 -"-  14 - Emergency Services;
 -"-  13 - Public Utilities (e.g. water/gas suppliers);
 -"-  12 - Security Services;
 -"-  11 - For PLMN Use.

Now, in case of an overload situation like emergency or congestion, the network may want to reduce the access overload in the cell. To reduce the access from the UE, the network modifies the SIB2 (SystemInformationBlockType2) that contains access barring related parameters as shown below:

For regular users with AC 0 – 9, their access is controlled by ac-BarringFactor and ac-BarringTime. The UE generates a random number
– “Rand” generated by the UE has to pass the “persistent” test in order for the UE to access. By setting ac-BarringFactor to a lower value, the access from regular user is restricted (UE must generate a “rand” that is lower than the threshold in order to access) while priority users with AC 11 – 15 can access without any restriction

For users initiating emergency calls (AC 10) their access is controlled by ac-BarringForEmergency – boolean value: barring or not

For UEs with AC 11- 15, their access is controlled by ac-BarringForSpecialAC - boolean value: barring or not.

The network (E-UTRAN) shall be able to support access control based on the type of access attempt (i.e. mobile originating data or mobile originating signalling), in which indications to the UEs are broadcasted to guide the behaviour of UE. E-UTRAN shall be able to form combinations of access control based on the type of access attempt e.g. mobile originating and mobile terminating, mobile originating, or location registration.  The ‘mean duration of access control’ and the barring rate are broadcasted for each type of access attempt (i.e. mobile originating data or mobile originating signalling).

Another type of Access Control is the Service Specific Access Control (SSAC) that we have seen here before. SSAC is used to apply independent access control for telephony services (MMTEL) for mobile originating session requests from idle-mode.

Access control for CSFB provides a mechanism to prohibit UEs to access E-UTRAN to perform CSFB. It minimizes service availability degradation (i.e. radio resource shortage, congestion of fallback network) caused by mass simultaneous mobile originating requests for CSFB and increases the availability of the E-UTRAN resources for UEs accessing other services.  When an operator determines that it is appropriate to apply access control for CSFB, the network may broadcast necessary information to provide access control for CSFB for each class to UEs in a specific area. The network shall be able to separately apply access control for CSFB, SSAC and enhanced Access control on E-UTRAN.

Finally, we have the Extended Access Barring (EAB) that I have already described here before.

Around the World with Mobile Global Insights - via @TomiAhonen

Next month we will reach the milestone where the number of active Mobile devices is equal to the number of people in the world. There are many people with more than one active mobile device and there are others who have no devices so the number of active devices will still keep rising for some time to come.

Embedded below is a presentation by Tomi Ahonen in MMAF 2013, you can see all the presentations from the event on Slideshare here.

eMBMS Physical layer aspects from T&M point of view

Based on the success of the recent posts on eMBMS, here and here, this final post on this topic is a look at physical layer perspective from Test and Measurement point of view. Slides kindly provided by R&S

eMBMS: Broadcast and Multicast in LTE from Zahid Ghadialy

A video of this is also available on Youtube, embedded below:

IMS World Forum 2013 Highlights

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

Video: Quick summary of 3GPP Release 12 features

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


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

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

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

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

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

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

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

Related links:

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

NTT Docomo gives another shot to Mobile TV

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

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

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

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

eMBMS Release-11 enhancements

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

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

eMBMS rollouts gathering steam in 2013

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

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

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

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

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

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

LTE eMBMS Technology Overview from Zahid Ghadialy

Cell Range Expansion (CRE)

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

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

Myths and Challenges in Future Wireless Access

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

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

Interference Management in HetNets

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

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

Interference Management in Co-Channel Femtocell Deployment from Zahid Ghadialy

The 'Phantom Cell' concept in LTE-B

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


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

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

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

LTE for Public Safety Networks

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

From M2M Communications to IoT

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

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

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


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

WebRTC Technical Overview and Introduction from Zahid Ghadialy

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

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

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

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

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

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

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

Picture source: The IET

Recently I read something interesting from IDG here:

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

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

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

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

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

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

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

Complete article is available here.

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

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

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




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

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

802.11u, Passpoint and Hotspot 2.0 (HS 2.0)

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




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


Related posts:

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

Mobile Service status and Trends in the USA - 2012

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

Mobile Status and Trends in the US from Zahid Ghadialy