Sunday 10 May 2015

LTE-Broadcast making a push while Terrestrial broadcast still popular as ever



"TV isn't dying, it's having babies." This quote made my day. I have argued a few times in the past that terrestrial broadcasting will continue working and will be probably the most popular approach for a long time to come. The way things work with it may change. Multi-screen is one possible approach but you may have more interactions like 'red button functionality', etc.
Anyway, in Europe 800MHz spectrum has been cleared for use by Mobile Broadband technologies (LTE mainly). 700MHz is planned to be cleared as well by 2020, as per the suggestion in Lamy report. The other UHF band from 470MHz to 694MHz would be left as it is until 2030, with a review planned in 2025.

This has forced even big players like BBC to start looking at other mechanisms to deliver TV. While BBC3 was moved to online only, BBC is also exploring how to use LTE-Multicast to deliver content. It has been working to have its very popular iPlayer work with eMBMS.

Embedded below is a presentation from Cambridge Wireless CWTEC 2015 conference.




eMBMS is gaining popularity with its presence in lot more chipsets and even more trials. GSA report has shown that there are quite a few trials going on worldwide but the question remains about the business models. Most operators would not like to become content providers and compete with the incumbents in their markets. Having someone like BBC in the UK is helpful but not sure how many such options are available worldwide. Embedded below is the GSA presentation




There were some nice pictures from MWC as can be seen above. Ericsson has a video as well (below) on how the app works.



D-Link is also working on M2M modules that could be used in billboards to dynamically update the ads at very regular intervals. There is a video here that explains this further.

Finally here is a Video from Visteon/Verizon that explains how LTE-Multicast can be used to deliver software updates in the connected car:



Finally, here are couple of presentations that may interest you too:



Monday 4 May 2015

New LTE UE Categories: 11, 12, 13 and 14 in 3GPP Rel-12

While checking 3GPP TS 36.306, I noticed some new LTE categories have been defined. We now have all the way up to category 14. I also noticed that Wikipedia page has up to Category 15, not sure how/where they got it from. 


The LG Space page has some more details for anyone interested in exploring further.

A Qualcomm demo from MWC for LTE Category 11, if interested.



Finally, other related posts:


Saturday 25 April 2015

Mobile Telecoms Technology & Market Disruptions

Sometimes its good to take a step back and look at the new applications and services that are already happening or may be happening sometime soon. Some of these have a possibility to disrupt the existing industries and markets, giving rise to not only new players but a completely new order.

Embedded below is a presentation from Dean Bubley of Disruptive Analysis. While there are a few things that I look at differently, there are many interesting points that the industry should already be looking at.


A good example of disruption would be the SIM card evolution that Apple introduced in iPadAir2 and iPadMini3. While they had great expectations, it didnt work out exactly as they had hoped due to the operators not letting Apple use the feature they wanted. In fact John Legere, T-Mobile US CEO, took to twitter to explain the problem. See here.

Another example is the new MVNO model by Google (Fi) in the USA. The problem in USA compared to Europe is that the operators have monopoly in many areas (fixed and mobile) and they can also get away with charging far higher amounts.




In addition, the problem that the operators have is that they focus on areas where they don't have issues; crying wolf if required. An example is taking advantage of 'data tsunami' and using it to hoard spectrum, as be seen from the tweet below:

Anyway, here is the presentation. Let me know what you think.



Sunday 19 April 2015

3GPP Release-13 work started in earnest


The 3GPP news from some months back listed the main RAN features that have been approved for Release-13 and the work has already started on them. The following are the main features (links contain .zip files):

  • LTE in unlicensed spectrum (aka Licensed-Assisted Access) - RP-150055
  • Carrier Aggregation enhancements - RP-142286
  • LTE enhancements for Machine-Type Communications (MTC) - RP-141865
  • Enhancements for D2D - RP-142311
  • Study Item Elevation Beamforming / Full-Dimension MIMO - RP-141831
  • Study Item Enhanced multi-user transmission techniques - RP-142315
  • Study Item Indoor positioning - RP-141102
  • Study Item Single-cell Point-to-Multipoint (SC-PTM) - RP-142205


Another 3GPP presentation from late last year showed the system features that were being planned for Rel-13 as shown above.

I have also posted a few items earlier relating to Release13, as follows:


Ericsson has this week published a whitepaper on release 13, with a vision for 'Networked Society':
The vision of the Networked Society, where everything that benefits from being connected will be connected, places new requirements on connectivity. LTE is a key component in meeting these demands, and LTE release 13 is the next step in the LTE evolution.
Their whitepaper embedded below:



It should be pointed out that 5G work does not start until Release-15 as can be seen from my tweet

xoxoxo Added Later (26/04/2015) xoxoxo
I came across this presentation from Keysight (Agilent) where Moray Rumney has provided information in much more detail.


Sunday 12 April 2015

LTE-Hetnet (LTE-H) a.k.a. LTE Wi-Fi Link Aggregation (LWA)


We have talked about the unlicensed LTE (LTE-U), re-branded as LTE-LAA many times on this blog and the 3G4G Small Cells blog. In fact some analysts have decided to call the current Rel-12 non-standardised Rel-12 version as LTE-U and the standardised version that would be available as part of Release-13 as LTE-LAA.

There is a lot of unease in the WiFi camp because LTE-LAA may hog the 5GHz spectrum that is available as license-exempt for use of Wi-Fi and other similar (future) technologies. Even though LAA may be more efficient as claimed by some vendors, it would reduce the usage for WiFi users in that particular spectrum.

As a result, some vendors have recently proposed LTE/WiFi Link Aggregation as a new feature in Release-13. Alcatel-Lucent, Ruckus Wireless and Qualcomm have all been promoting this. In fact Qualcomm has a pre-MWC teaser video on Youtube. The demo video is embedded as follows:



The Korean operator KT was also involved in demoing this in MWC along with Samsung and Qualcomm. They have termed this feature as LTE-Hetnet or LTE-H.

The Korean analyst firm Netmanias have more detailed technical info on this topic.

Link aggregation by LTE-H demonstrated at MWC 2015 (Source: Netmanias)

As can be seen the data is split/combined in PDCP layer. While this example above shows the practical implementation using C-RAN with Remote Radio Head (RRH) and BaseBand Unit (BBU) being used, the picture at the top shows LTE Anchor in eNodeB. There would be a need for an ideal backhaul to keep latency in the eNodeB to minimum when combining cellular and WiFi data.

Comparison of link level Carrier Aggregation technologies (Source: Netmanias)

The above table shows comparison between the 3 main techniques for increasing data rates through aggregation; CA, LTE-U/LAA and LTE-H/LWA. While CA has been part of 3GPP Release-10 and is available in more of less all new LTE devices, LTE-U and LTE-H is new and would need modifications in the network as well as in the devices. LTE-H would in the end provide similar benefits to LTE-U but is a safer option from devices and spectrum point of view and would be a more agreeable solution by everyone, including the WiFi community.

A final word; last year we wrote a whitepaper laying out our vision of what 4.5G is. I think we put it simply that in 4.5G, you can use WiFi and LTE at the same time. I think LTE-H fulfills that vision much better than other proposals.

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 15 March 2015

Air-Ground-Air communications in Mission Critical scenarios

In-flight communications have always fascinated me. While earlier the only possibility was to use Satellites, a hot topic for in the last few years has been Air-Ground-Air communications.

Some of you may remember that couple of years back Ericsson showed an example of using LTE in extreme conditions. The video below shows that LTE can work in these scenarios.



Now there are various acronyms being used for these type of communications but the one most commonly used is Direct-Air-to-Ground Communications (DA2GC), Air-to-Ground (A2G) and Ground-to-Air (G2A).


While for short distance communications, LTE or any cellular technology (see my post on Flying Small Cells) may be a good option, a complete solution including communication over sea would require satellite connectivity as well. As I have mentioned in a blog post before, 75Mbps connectivity would soon be possible with satellites.

For those interested in working of the Air-Ground-Air communications, would find the presentation below useful. A much detailed ECC CEPT report from last year is available here.



The next challenge is to explore whether LTE can be used for Mission Critical Air Ground Air communications. 3GPP TSG RAN recently conducted study on the feasibility and the conclusions are as follows:

There is a common understanding from companies interested in the topic that:

  1. Air-to-Ground communications can be provided using the LTE standards (rel-8 and beyond depending on the targeted scenarios).
  2. 3GPP UE RF requirements might need to be adapted
  3. It may be possible to enhance the performance of the communications with some standards changes, but these are in most cases expected to be non-fundamental optimizations
  4. Engineering and implementation adaptations are required depending on the deployment scenario. In particular, the ECC report [1] comments that from implementation point of view synchronization algorithms are to be modified compared to terrestrial mobile radio usage in order to cope with high Doppler frequency shift of the targeted scenario. In addition, some network management adaptations might be needed. From engineering perspective the Ground base station antenna adjustment has to be matched to cover indicated aircraft heights above ground up to 12 km by antenna up-tilt. It is also expected that the inter-site distances would be dominated by the altitudes to be supported [5].
  5. A2G technology using legacy LTE has been studied and successfully trialed covering different kinds of services: Surfing, downloading, e-mail transmission, use of Skype video, audio applications and Video conferencing. Related results can be found in several documents from ECC and from companies [1], [2], [3]. The trials in [1] and [2] assumed in general a dedicated spectrum, and the fact that the communications in the aircraft cabin are using WIFI or GSMOBA standards, while LTE is used for the Broadband Direct-Air-to-Ground connection between the Aircraft station and the Ground base station.
  6. It is understood that it is possible to operate A2G communications over spectrum that is shared with ground communications. However, due to interference it is expected that the ground communications would suffer from capacity losses depending on the deployment scenario. Therefore, it is recommended to operate A2G communication over a dedicated spectrum.
  7. It can be noted that ETSI studies concluded that Spectrum above 6 GHz is not appropriate for such applications [4].
  8. LTE already provides solutions to allow seamless mobility in between cells. Cells can be intended for terrestrial UEs and cells intended for A2G UEs which might operate in different frequencies.
  9. Cell range in LTE is limited by the maximum timing advance (around 100km). Larger ranges could be made possible by means of implementation adaptations. 

Sunday 8 March 2015

LTE Category-0 low power M2M devices


While we have talked about different LTE categories, especially higher speeds, we have not yet discussed Category-0 or Cat-0 for M2M.

A recent news report stated the following:

CAT-1 and CAT-0 are lower speed and power versions of the LTE standard which dramatically extend the addressable market for carriers and chip makers alike. They introduce new IoT targeted features, extend battery operation and lower the cost of adding LTE connectivity.
“While chipsets supporting these lower categories are essential for numerous applications, including wearable devices, smart home and smart metering, there has been an industry development gap that we had anticipated two years ago,” said Eran Eshed, co-founder and vice president of marketing and business development at Altair. “We’ve worked hard to address this gap by being first to market with true CAT-1 and 0 chipsets featuring a power/size/cost combination that is a massive game-changer.”
Ericsson has an interesting presentation that talks about LTE evolution for cellular IoT. While Rel-12 Cat-0 would use the normal allocated bandwidth (upto 20MHz), Rel-13 plans further enhancements to save even more power by reducing the bandwidth to 1.4Mhz. Another possible saving of power comes from the use of Half Duplex (but its optional). There is a very interesting presentation from Mstar semiconductors on half duplex that I have blogged about here. Anyway, the presentation from Ericsson is here:



When we talk about 50 billion M2M devices, a question that I regularly ask is how many of them will be using cellular and how many will use other technologies. Its good to see that my skepticism is shared by others as well, see the tweet below.

Click on the pic.twitter.com/Z7s6wqxkBM to see the actual media.

Nokia has also got an interesting whitepaper on this topic which talks about optimizing LTE and the architectural evolution that will lead cellular LTE to become a compelling technology so that it can be widely adopted. That paper is embedded as well below.



Sunday 1 March 2015

Monday 23 February 2015

Static/Dynamic IP Address Allocation in LTE


I recently came across a discussion on how static and dynamic IP address are allocated in LTE for a UE. Luckily, there is a recent document from Netmanias that discussed this topic. The document is embedded below.



If you enjoyed reading the document (part 1) above, then there is a part 2 here. While in part 1, we saw that IP addresses can be either dynamic or static depending on their allocators, part 2 presents a specific case of IP address allocation – allocation in geographically-separated locations within an LTE network. In case of dynamic allocation, no matter where a user accesses, a dynamically selected P-GW dynamically allocates an IP address to the user for PDN connection. In case of static allocation, however, there is always one specific P-GW and one IP address for a user - the designated P-GW allocates a static IP address for the user’s PDN connection. A case study shows an LTE network that serves two cities as an example to describe different ways and procedures of IP address allocation, and see how they are different from each other.

Sunday 15 February 2015

5G and NFV


In my 5G: A 2020 vision presentation, I argued that some of the technologies that will be necessary for 5G is in fact independent of 5G. One such technology is NFV. Having said that, I also argue that the minimum prototype for 5G would require an NFV based implementation.


Tieto gave an interesting presentation in our last Small Cell SIG event explaining how the network will be implemented based on NFV. The presentation is embedded below:



There is also an interesting paper that expands on this further, available from Slideshare here.

Tuesday 3 February 2015

5G: A 2020 Vision


I had the pleasure of speaking at the CW (Cambridge Wireless) event ‘5G: A Practical Approach’. It was a very interesting event with great speakers. Over the next few weeks, I will hopefully add the presentations from some of the other speakers too.

In fact before the presentation (below), I had a few discussions over the twitter to validate if people agree with my assumptions. For those who use twitter, maybe you may want to have a look at some of these below:







Anyway, here is the presentation.

 

Wednesday 21 January 2015

Voice over WiFi (VoWiFi) technical details

VoWiFi is certainly a hot topic, thanks to the support of VoWiFi on iPhone 6. A presentation from LTE World Summit 2014 by Taqua on this topic has already crossed 13K views. In this post I intend to look at the different approaches for VoWiFi and throw in some technical details. I am by no means an expert so please feel free to add your input in the comments.

Anybody reading this post is not aware of S2a, S2b, Samog, TWAG, ePDG, etc. and what they are, please refer to our whitepaper on cellular and wi-fi integration here (section 3).

There are two approaches to VoWiFi, native client already in your device or an App that could be either downloaded from the app store or pre-installed. The UK operator '3' has an app known as ThreeInTouch. While on WiFi, this app can make and receive calls and texts. The only problem is that it does not handover an ongoing call from WiFi to cellular and and vice versa. Here are a few slides (slides 36-38) from them from a conference last year:



The other operators have a native client that can use Wi-Fi as the access network for voice calls as well as the data when the device is connected on the WLAN.

A simple architecture can be seen from the picture above. As can be seen, the device can connect to the network via a non-3GPP trusted wireless access network via the TWAG or via a non-3GPP untrusted wireless access network via ePDG. In the latter case, an IPSec tunnel would have to be established between the device and the ePDG. The SIM credentials would be used for authentication purposes so that an intruder cannot access ePDG and the core.

Now, I dont want to talk about VoLTE bearers establishment, etc. which I have already done here earlier. In order to establish S2a (trusted) and S2b (untrusted) connection, the AAA server selects an APN among those which are subscribed to in the HLR/HSS. The PDN-GW (generally referred to as PGW) dynamically assigns an IP address out of a pool of addresses which is associated with this APN. This UE IP address is used by the VoWiFi SIP UA (User Agent) as the contact information when registering to the SIP soft switch (which would typically be the operators IMS network).

If for any reason the SIP UA in the device is not able to use the SIM for authentication (needs ISIM?) then a username/password based authentication credentials can be used (SIP digest authentication).

Typically, there would be a seperate UA for VoLTE and VoWiFi. They would both be generally registering to the same IMS APN using different credentials and contact addresses. The IMS network can deal with multiple registrations from the same subscriber but from different IP addresses (see 3GPP TS 23.237 - 'IMS Service Continuity' for details).

Because of multiple UA's, a new element needs to be introduced in order to 'fork' the downstream media streams (RTP/RTCP packets) to different IP addresses over time.

3GPP has defined the Access Transfer Gateway (ATGW) which is controlled by the Access Transfer Control Function (ATCF); the ATCF interfaces to the IMS and Service Centralization and Continuity Application Server (SCC AS). All these are not shown in the picture above but is available in 3GPP TS 23.237. The IMS networks in use today as well as the one being deployed for VoLTE does not have ATGW/ATCF. As a result vendors have to come up with clever non-standardised solutions to solve the problem.

When there is a handover between 3GPP and non-3GPP networks, the UE IP address needs to be preserved. Solutions like MIP and IPSec have been used in the past but they are not flexible. The Release-12 solution of eSAMOG (see 3GPP TS 23.402) can be used but the solution requires changes in the UE. For the time being we will see proprietary solutions only but hopefully in future there would be standardised solutions available.

3GPP TS 23.234 describes more in detail the interworking of 3GPP based system and WLAN. Interested readers can refer to that for further insight.

Wednesday 14 January 2015

IEEE Globecom 2014 Keynote Video: 5G Wireless Goes Beyond Smartphones


Embedded below is a video from the keynote session by Dr. Wen Tong of Huawei. I do not have the latest presentation but an earlier one (6 months old) is also embedded below for reference. It will give you a good idea on the 5G research direction





You may also be interested in this other presentation from Huawei in IEEE Globecom 2014, 5G: From Research to Standardization (what, how, when)

Wednesday 7 January 2015

Enhancing voice services using VoLTE


VoLTE has been a very popular topic on this blog. My overview of the LTE Voice Summit missed out narrowly from the Top 10 posts of 2014 but there were other posts related to VoLTE that made it.

In this magazine article, NTT Docomo not only talks about its own architecture and transition from 3G to 4G for voice and video, it provides some detailed insights from its own experience.

There is also discussion into technical details of the feature and examples of signalling for VoLTE registration and originating/terminating calls (control, session and user plane establishment), SMS, SRVCC, Video over LTE (ViLTE) and voice to video call switching.

The paper is embedded below and available from slideshare to download.



Related links: