Introduction to M2M and its developments in LTE

LTE Innovation Summit 2013 - Anandamoy Sen from Rohde & Schwarz on Vimeo.

An interesting video on Introduction to M2M and its developments in LTE from Rohde&Schwarz LTE Innovation Summit 2013.

The presentation is also embedded below and can be downloaded from Slideshare.

Introduction to M2M by Sierra Wireless from Zahid Ghadialy

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:

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.

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

Summary of Network Security Conference (#NetworkSecurity) 2013

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

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:

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

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.

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:

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

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.

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.

LTE evolution: Beyond lte-advanced from Zahid Ghadialy

Future Radio Access, M2M and Grand Societal Challenges from Zahid Ghadialy

Rel-11/12 3GPP Security Update

Here is the latest Security Update from 3GPP, presented in the 8th ETSI Security Workshop Jan 16-17 2013.

3GPP Security Update - Jan. 2013 from Zahid Ghadialy

All presentations are available from here to download.

Related blog posts:

• Quick update on 3GPP Release-12 progress
• The four C's of Release-12 enhancements
• Quick update on LTE Release 11 Work and Study Items
• 3GPP LTE Security Aspects
• Evolution of 3GPP Security
• 2 Presentations on Mobile technology Security

By the way, I will also be present in the Network Security conference in London in May 2013

Public Safety Communications using LTE

Public Safety Communications using LTE from Zahid Ghadialy

2 Presentations on Mobile technology Security

Present and future Standards for mobile internet and smart phone information security from Zahid Ghadialy

Other related posts:

• Evolution of 3GPP Security
• 'Mapped Security' Concept in LTE
• 3GPP LTE Security Aspects
• New Security Algorithms in Release-11
• 6th ETSI Security Workshop

Half Duplex Operation (HD-FDD) in LTE

It was interesting to hear the other day that there is an option for HD-FDD but it is still undergoing investigation and not standardised yet. From what I hear, operators are showing an interest and we may see it coming to an operator near us in the next couple of years.

Complete presentation below:

Half Duplex Operation in Multimode/Multiband/MIMO-capable Handsets from Zahid Ghadialy

The advantages are obvious but probably the only reason this was not standardised actively is probably because then peak rates often quoted when promoting technology will be halved. The economy of scale is also important and we may not see this becoming popular unless many operators decide together to push for this.

Other posts of interest:

• Quick Introduction to LTE-Advanced
• Quick update on 3GPP Release-12 progress
• TD-LTE in China: Progress and Plan

'LTE' and 'Small Cells' specific applications

Some 4 years back, I posted my first presentation here, titled "LTE Femtocells: Stepping stone for 'killer apps' presentation". I had couple of apps in mind that I thought could benefit from both LTE and Small Cells (or Femtocells to be specific).

The first was your phone acting as a Wireless Hard Disk Drive (HDD) that can be used to store things remotely in a server somewhere. This is similar to what is known as the Cloud nowadays.

Picture Source: Dialaphone.

The other day when I read why LTE is suitable for cloud connectivity, I could see that my old idea could start to become a reality. The article is here. Selective abstract as follows:

The LTE network lends itself well to cloud connectivity because it:

• provides high-bandwidth connections
• is IP- and Ethernet-oriented, the technologies used to connect to the cloud and within data centers
• offers tools that operators didn't have in 2G and 3G (such as more granular ability to manage traffic flows and a better, DPI-based view of traffic running on the network)
• features low latency, which is vital to the small flows and sessions that characterize M2M communications.

The rise of both cloud services and LTE creates a virtuous cycle. Cloud services continue to grow, which helps operators sustain their LTE business model. That growth enables them to accelerate LTE investments. Then operators can support new types of enterprise services, including cloud-based applications.

To take full advantage of this opportunity, operators have to deploy the right backhaul infrastructure. In addition to IP awareness and content awareness, the right backhaul network can leverage the technical advantages that LTE presents:

• flattened architecture that helps distribute compute and storage resources
• seamless migration from 2G and 3G for various physical mediums and networking protocols
• an increase in capacity that starts to put mobile connectivity on par with fixed broadband access.

My reasoning for Small Cell here is, in most cases when you are doing operations that require large amounts of data to be transferred, you will be indoors, either at home or in office or in a low mobility scenario. The requirement for high security and at the same time high speed data transfer that should not be affected by other users in the cell (capacity issues) can be easily solved by using a Small cell (Femtocell for indoors, Metrocell for outdoors).


The other application I had in mind was the Home Security System. I read the following on TotalTele the other day:

3UK's wholesale division on Friday detailed plans to capture high-margin machine-to-machine traffic by partnering with service providers that are likely to have higher-than-average bandwidth requirements.

As a 3G-only operator, the company cannot go after high volume, low margin M2M traffic because it typically only requires a 2G connection. However, there are opportunities to use its 3G network to address more data-hungry verticals that will generate higher traffic volumes.

"The margin on one CCTV M2M connection is more than 50 times bigger than the margin on a smart meter connection," claimed Tom Gardner, lead wholesale manager at 3UK, during Breakfast with Total Telecom in London.

"There is one CCTV camera for every 14 people in the U.K.," he said. "If I can put a SIM in every one of them I'll be a very happy man."

3UK, which on Thursday launched its Ericsson-based wholesale M2M platform, sees a big opportunity in CCTV, particularly for mobile and temporary installations at festivals, for instance. Other potentially lucrative sectors it has identified include digital signage, back-up for fixed Internet connections, and backhauling WiFi traffic from public transport.

I am sure some of you may be thinking that '3' UK uses HSPA network, not LTE, which is true. The point here is that it could be done better using LTE and Small Cells.

The reason for using LTE would be to provide higher data rates, meaning that information can be sent faster, with higher resolution and more regularly. This will help identify the problems earlier. If the CCTV is used indoors or in high usage areas, it would make sense that it connects via Small Cell to avoid creating capacity issues in the Macro network.

Here is the embed again, of my old presentation just in case if it interests you:

Lte Femtocells: Stepping stone for killer applications from Zahid Ghadialy

Mobile Broadband Speeds: How is 4G different from 3G?

I wrote this answer on Quora and as of yesterday there were 20+ upvotes. So here is an embed for the same:

Read Quote of Zahid Ghadialy's answer to Mobile Broadband: How is 4G different from 3G? on Quora

CSFB Performance

Here is another presentation from Qualcomm from the '4G World'.

CSFB Performance from Zahid Ghadialy

With regards to SI Tunneling mentioned in the presentation, I found the following in another Qualcomm whitepapers:


With Release 9 Enhanced Release with Redirection—SI Tunneling, the device follows 3GPP release 9, where SIB information can be tunneled from the target Radio Access Network (RAN) via the core network to the source RAN and be included in the redirection message sent to the device. This can avoid reading any SIBs on the target cell. 

The predominant solutions deployed today are based on Release 8 Release with Redirection — SIB Skipping, in order to achieve good call setup times, good reliability, and simplify deployments. It is anticipated that Release 9 Enhanced Release with Redirection will be deployed in the near future. At this time, there is not as much push for handover-based CSFB since both Release 8 Release with Redirection—SIB Skipping and Release 9 Enhanced Release with Redirection—SI Tunneling have largely addressed any call setup time issues that may have existed with the Basic Release with Redirection solution.

I have blogged on this topic before, here.

More on Dual Radio here and SVLTE here.