DL Modulation support on different radio bands
15 hours ago
Tuesday 18 November 2014
SON Update from 3GPP SA5
Sunday 16 November 2014
Is mobile eating the world?
How Mobile is Enabling Tech to Outgrow the Tech Industry from Andreessen Horowitz on Vimeo.
And a recent interview by Benedict Evans with Bloomberg TV on the same topic as follows:
Tuesday 11 November 2014
New Spectrum Usage Paradigms for 5G
Sometime back I wrote a post that talked about Dynamic Spectrum Access (DSA) techniques for Small Cells and WiFi to work together in a fair way. The Small Cells would be using the ISM bands and Wi-Fi AP's would also be contending for the same spectrum. For those who may not know, this is commonly referred to as LTE-U but the correct term that is being used in standards is LA-LTE, see here for details.
IEEE Comsoc has just published a whitepaper that details how the spectrum should be handled in 5G to make sure of efficient utilisation. The whitepaper covers the following:
Chapter 2 – Introduction, the traditional approach of repurposing spectrum and allocating it to Cellular Wireless systems is reaching its limits, at least below the 6GHz threshold. For this reason, novel approaches are required which are detailed in the sequel of this White Paper.
Chapter 3 - Spectrum Scarcity - an Alternate View provides a generic view on the spectrum scarcity issue and discusses key technologies which may help to alleviate the problem, including Dynamic Spectrum Management, Cognitive Radios, Cognitive Networks, Relaying, etc.
Chapter 4 – mmWave Communications in 5G addresses a first key solution. While spectrum opportunities are running out at below 6 GHz, an abundance of spectrum is available in mmWave bands and the related technology is becoming mature. This chapter addresses in particular the heterogeneous approach in which legacy wireless systems are operated jointly with mmWave systems which allows to combine the advantages of both technologies.
Chapter 5 – Dynamic Spectrum Access and Cognitive Radio: A Current Snapshot gives a detailed overview on state-of-the-art dynamic spectrum sharing technology and related standards activities. The approach is indeed complementary to the upper mmWave approach, the idea focuses on identifying unused spectrum in time, space and frequency. This technology is expected to substantially improve the usage efficiency of spectrum, in particular below the 6GHz range.
Chapter 6 – Licensed Shared Access (LSA) enables coordinated sharing of spectrum for a given time period, a given geographic area and a given spectrum band under a license agreement. In contract to sporadic usage of spectrum on a secondary basis, the LSA approach will guarantee Quality-of-Service levels to both Incumbents and Spectrum Licensees. Also, a clear business model is available through a straightforward license transfer from relevant incumbents to licensees operating a Cellular Wireless network in the concerned frequency bands.
Chapter 7 – Radio Environment Map details a technology which allows to gather the relevant (radio) context information which feed related decision making engines in the Network Infrastructure and/or Mobile Equipment. Indeed, tools for acquiring context information is critical for next generation Wireless Communication systems, since they are expected to be highly versatile and to constantly adapt.
Chapter 8 – D2DWRAN: A 5G Network Proposal based on IEEE 802.22 and TVWS discusses the efficient exploitation of TV White Space spectrum bands building on the available IEEE 802.22 standard. TV White Spaces are indeed located in highly appealing spectrum bands below 1 GHz with propagation characteristics that are perfectly suited to the need of Wireless Communication systems.
Chapter 9 – Conclusion presents some final thoughts.
The paper is embedded as follows:
Chapter 2 – Introduction, the traditional approach of repurposing spectrum and allocating it to Cellular Wireless systems is reaching its limits, at least below the 6GHz threshold. For this reason, novel approaches are required which are detailed in the sequel of this White Paper.
Chapter 3 - Spectrum Scarcity - an Alternate View provides a generic view on the spectrum scarcity issue and discusses key technologies which may help to alleviate the problem, including Dynamic Spectrum Management, Cognitive Radios, Cognitive Networks, Relaying, etc.
Chapter 4 – mmWave Communications in 5G addresses a first key solution. While spectrum opportunities are running out at below 6 GHz, an abundance of spectrum is available in mmWave bands and the related technology is becoming mature. This chapter addresses in particular the heterogeneous approach in which legacy wireless systems are operated jointly with mmWave systems which allows to combine the advantages of both technologies.
Chapter 5 – Dynamic Spectrum Access and Cognitive Radio: A Current Snapshot gives a detailed overview on state-of-the-art dynamic spectrum sharing technology and related standards activities. The approach is indeed complementary to the upper mmWave approach, the idea focuses on identifying unused spectrum in time, space and frequency. This technology is expected to substantially improve the usage efficiency of spectrum, in particular below the 6GHz range.
Chapter 6 – Licensed Shared Access (LSA) enables coordinated sharing of spectrum for a given time period, a given geographic area and a given spectrum band under a license agreement. In contract to sporadic usage of spectrum on a secondary basis, the LSA approach will guarantee Quality-of-Service levels to both Incumbents and Spectrum Licensees. Also, a clear business model is available through a straightforward license transfer from relevant incumbents to licensees operating a Cellular Wireless network in the concerned frequency bands.
Chapter 7 – Radio Environment Map details a technology which allows to gather the relevant (radio) context information which feed related decision making engines in the Network Infrastructure and/or Mobile Equipment. Indeed, tools for acquiring context information is critical for next generation Wireless Communication systems, since they are expected to be highly versatile and to constantly adapt.
Chapter 8 – D2DWRAN: A 5G Network Proposal based on IEEE 802.22 and TVWS discusses the efficient exploitation of TV White Space spectrum bands building on the available IEEE 802.22 standard. TV White Spaces are indeed located in highly appealing spectrum bands below 1 GHz with propagation characteristics that are perfectly suited to the need of Wireless Communication systems.
Chapter 9 – Conclusion presents some final thoughts.
The paper is embedded as follows:
Wednesday 5 November 2014
2015 will finally be the year of Voice over LTE (VoLTE)
On 4th Nov. 2009, the One Voice initiative was published by 12 companies including AT&T, Orange, Telefonica, TeliaSonera, Verizon, Vodafone, Alcatel-Lucent, Ericsson, Nokia Siemens Networks, Nokia, Samsung and Sony Ericsson. These all agreed that the IMS based solution, as defined by 3GPP, is the most applicable approach to meet their consumers expectations for service quality, reliability and availability when moving from existing CS based voice services to IP based LTE services.
On 15th Feb 2010, GSMA announced that it has adopted the work of the One Voice initiative to drive the global mobile industry towards a standard way of delivering voice and messaging services for LTE. The GSMA’s VoLTE initiative was supported by more than 40 organisations from across the mobile ecosystem, including many of the world’s leading mobile communication service providers, handset manufacturers and equipment vendors, all of whom support the principle of a single, IMS-based voice solution for next-generation mobile broadband networks. This announcement was also supported by 3GPP, Next Generation Mobile Networks alliance (NGMN) and the International Multimedia Teleconferencing Consortium (IMTC).
As per GSA: 71 operators are investing in VoLTE studies, trials or deployments, including 11 that have commercially launched HD voice service. The number of HD voice launches enabled by VoLTE is forecast to reach 19 by end-2014 and then double in 2015. In July 2014 GSA confirmed 92 smartphones (including carrier and frequency variants) support VoLTE, including products by Asus, Huawei, LG, Pantech, Samsung and Sony Mobile. The newly-announced Apple iPhone 6 & 6 Plus models support VoLTE.
Things are also moving quickly with many operators who have announced VoLTE launches and are getting more confident day by day. Du, Dubai recently announced Nokia as VoLTE partner. KDDI, Japan is launching au VoLTE in December. Telstra, Australia has already been doing trials and plans to launch VoLTE network in 2015. Finally, Verizon and AT&T will have interoperable VoLTE calls in 2015.
Below is my summary from the LTE Voice Summit 2014. Let me know if you like it.
Saturday 1 November 2014
4G Security and EPC Threats for LTE
Thursday 30 October 2014
Codecs and Quality across VoLTE and OTT Networks
Codecs play an important role in our smartphones. Not only are they necessary and must for encoding/decoding the voice packets but they increase the price of our smartphones too.
A $400 smartphone can have as much as $120 in IPR fees. If you notice in the picture above its $10.60 for the H.264 codec. So its important that the new codecs that will come as part of new generation of mobile technology is free, open source or costs very little.
The new standards require a lot of codecs, some for backward compatibility but this can significantly increase the costs. Its important to make sure the new codecs selected are royalty-free or free license.
The focus of this post is a presentation by Amir Zmora from AudioCodecs in the LTE Voice Summit. The presentation below may not be self-explanatory but I have added couple of links at the bottom of the post where he has shared his thoughts. Its worth a read.
A good explanation of Voice enhancement tools as follows (slide 15):
Adaptive Jitter Buffer (AJB) – Almost all devices today (Smartphones, IP phones, gateways, etc.) have built in jitter buffers. Legacy networks (which were LAN focused when designed) usually have older devices with less sophisticated jitter buffers. When designed they didn’t take into account traffic coming in from networks such as Wi-Fi with its frequent retransmissions and 3G with its limited bandwidth, in which the jitter levels are higher than those in wireline networks. Jitter buffers that may have been planned for, say, dozens of msec may now have to deal with peaks of hundreds of msec. Generally, if the SBC has nothing to mediate (assume the codecs are the same and the Ptime is the same on both ends) it just forwards the packets. But the unexpected jitter coming from the wireless network as described above, requires the AJB to take action. And even if the network is well designed to handle jitter, today’s OTT applications via Smart Phones add yet another variable to the equation. There are hundreds of such devices out there, and the audio interfaces of these devices (especially those of the Android phones) create jitter that is passed into the network. For these situations, too, the AJB is necessary.
To overcome this issue, there is a need for a highly advanced Adaptive Jitter Buffer (AJB) built into the SBC that neutralizes the incoming jitter so that it is handled without problem on the other side. The AJB can handle high and variable jitter rates.
Additionally, the AJB needs to work in what is called Tandem scenarios where the incoming and outgoing codec is the same. This scenario requires an efficient solution that will minimize the added delay. AudioCodes has built and patented solutions supporting this scenario.
Transcoding – While the description above discussed the ability to bypass the need to perform transcoding in the Adaptive Jitter Buffer context, there may very well be a need for transcoding between the incoming and outgoing packet streams. Beyond being able to mediate between different codecs on the different networks on either end of the SBC, the SBC can transcode an incoming codec that is less resilient to packet loss (such as narrowband G.729 or wideband G.722) to a more resilient codec (such as Opus). By transcoding to a more resilient codec, the SBC can lower the effects of packet loss. Transcoding can also lower the bandwidth on the network. Additionally, the SBC can transcode from narrowband (8Khz) to wideband (16Khz) (and vice versa) as well as wideband transcoding, where both endpoints support wideband codecs but are not using the same ones. For example, a wireless network may be using the AMR wideband codec while the wireline network on the other side may be using Opus. Had it not been for the SBC, these two networks would have negotiated a common narrowband codec.
Flexible RTP Redundancy – The SBC can also use RTP redundancy in which voice packets are sent several times to ensure they are received. Redundancy is used to balance networks which are characterized by high packet loss burst. While reducing the effect of packet loss, Redundancy increases the bandwidth (and delay). There are ways to get around this bandwidth issue that are supported by the SBC. One way is by sending only partial packet information (not fully redundant packets). The decoder on the receiving side will know how to handle the partial information. This process is called Forward Error Correction (FEC).
Transrating – Transrating is the process of having more voice payload ‘packed’ into a single RTP packet by increasing the packet intervals, thus changing the Packetization Time or Ptime. Ptime is the time represented by the compression of the voice signals into packets, generally at 20 msec intervals. In combining the payloads of two or more packets into one, the Transrating process causes a reduction in the overhead of the IP headers, lowering the bandwidth and reducing the stress on the CPU resources, however, it increases delay. It thus can be used not only to mediate between two end devices using different Ptimes, but also as a means of balancing the network by reducing bandwidth and reducing CPU pressure during traffic peaks.
Quality-based Routing – Another tool used by the SBC is Quality-based routing. The SBC, which is monitoring all the calls on the network all the time, can decide (based on pre-defined thresholds and parameters) to reroute calls over different links that have better quality.
Further reading:
The new standards require a lot of codecs, some for backward compatibility but this can significantly increase the costs. Its important to make sure the new codecs selected are royalty-free or free license.
The focus of this post is a presentation by Amir Zmora from AudioCodecs in the LTE Voice Summit. The presentation below may not be self-explanatory but I have added couple of links at the bottom of the post where he has shared his thoughts. Its worth a read.
A good explanation of Voice enhancement tools as follows (slide 15):
Adaptive Jitter Buffer (AJB) – Almost all devices today (Smartphones, IP phones, gateways, etc.) have built in jitter buffers. Legacy networks (which were LAN focused when designed) usually have older devices with less sophisticated jitter buffers. When designed they didn’t take into account traffic coming in from networks such as Wi-Fi with its frequent retransmissions and 3G with its limited bandwidth, in which the jitter levels are higher than those in wireline networks. Jitter buffers that may have been planned for, say, dozens of msec may now have to deal with peaks of hundreds of msec. Generally, if the SBC has nothing to mediate (assume the codecs are the same and the Ptime is the same on both ends) it just forwards the packets. But the unexpected jitter coming from the wireless network as described above, requires the AJB to take action. And even if the network is well designed to handle jitter, today’s OTT applications via Smart Phones add yet another variable to the equation. There are hundreds of such devices out there, and the audio interfaces of these devices (especially those of the Android phones) create jitter that is passed into the network. For these situations, too, the AJB is necessary.
To overcome this issue, there is a need for a highly advanced Adaptive Jitter Buffer (AJB) built into the SBC that neutralizes the incoming jitter so that it is handled without problem on the other side. The AJB can handle high and variable jitter rates.
Additionally, the AJB needs to work in what is called Tandem scenarios where the incoming and outgoing codec is the same. This scenario requires an efficient solution that will minimize the added delay. AudioCodes has built and patented solutions supporting this scenario.
Transcoding – While the description above discussed the ability to bypass the need to perform transcoding in the Adaptive Jitter Buffer context, there may very well be a need for transcoding between the incoming and outgoing packet streams. Beyond being able to mediate between different codecs on the different networks on either end of the SBC, the SBC can transcode an incoming codec that is less resilient to packet loss (such as narrowband G.729 or wideband G.722) to a more resilient codec (such as Opus). By transcoding to a more resilient codec, the SBC can lower the effects of packet loss. Transcoding can also lower the bandwidth on the network. Additionally, the SBC can transcode from narrowband (8Khz) to wideband (16Khz) (and vice versa) as well as wideband transcoding, where both endpoints support wideband codecs but are not using the same ones. For example, a wireless network may be using the AMR wideband codec while the wireline network on the other side may be using Opus. Had it not been for the SBC, these two networks would have negotiated a common narrowband codec.
Flexible RTP Redundancy – The SBC can also use RTP redundancy in which voice packets are sent several times to ensure they are received. Redundancy is used to balance networks which are characterized by high packet loss burst. While reducing the effect of packet loss, Redundancy increases the bandwidth (and delay). There are ways to get around this bandwidth issue that are supported by the SBC. One way is by sending only partial packet information (not fully redundant packets). The decoder on the receiving side will know how to handle the partial information. This process is called Forward Error Correction (FEC).
Transrating – Transrating is the process of having more voice payload ‘packed’ into a single RTP packet by increasing the packet intervals, thus changing the Packetization Time or Ptime. Ptime is the time represented by the compression of the voice signals into packets, generally at 20 msec intervals. In combining the payloads of two or more packets into one, the Transrating process causes a reduction in the overhead of the IP headers, lowering the bandwidth and reducing the stress on the CPU resources, however, it increases delay. It thus can be used not only to mediate between two end devices using different Ptimes, but also as a means of balancing the network by reducing bandwidth and reducing CPU pressure during traffic peaks.
Quality-based Routing – Another tool used by the SBC is Quality-based routing. The SBC, which is monitoring all the calls on the network all the time, can decide (based on pre-defined thresholds and parameters) to reroute calls over different links that have better quality.
Thursday 23 October 2014
Detailed whitepaper on Carrier Aggregation by 4G Americas
Two very important features that have come as part of CA enhancements were the multiple timing advance values that came as a part of Release-11 and TDD-FDD joint operation that came part of Release-12
Anyway, here is the 4G Americas whitepaper.
LTE Carrier Aggregation Technology Development and Deployment Worldwide from Zahid Ghadialy
You can read more about the 4G Americas whitepaper in their press release here.
You can read more about the 4G Americas whitepaper in their press release here.
Sunday 19 October 2014
What is (pre-5G) 4.5G?
Before we look at what 4.5G is, lets look at what is not 4.5G. First and foremost, Carrier Aggregation is not 4.5G. Its the foundation for real 4G. I keep on showing this picture on Twitter
I am sure some people much be really bored by this picture of mine that I keep showing. LTE, rightly referred to as 3.9G or pre-4G by the South Korean and Japanese operators was the foundation of 'Real' 4G, a.k.a. LTE-Advanced. So who has been referring to LTE-A as 4.5G (and even 5G). Here you go:
So lets look at what 4.5G is.
Back in June, we published a whitepaper where we referred to 4.5G as LTE and WiFi working together. When we refer to LTE, it refers to LTE-A as well. The standards in Release-12 allow simultaneous use of LTE(-A) and WiFi with selected streams on WiFi and others on cellular.
Some people dont realise how much spectrum is available as part of 5GHz, hopefully the above picture will give an idea. This is exactly what has tempted the cellular community to come up with LTE-U (a.k.a LA-LTE, LAA)
In a recent event in London called 5G Huddle, Alcatel-Lucent presented their views on what 4.5G would mean. If you look at the slide above, it is quite a detailed view of what this intermediate step before 5G would be. Some tweets related to this discussion from 5G Huddle as follows:
While in Alcatel-Lucent slide, I could visualise 4.5G as our vision of LTE(-A) + WiFi + some more stuff, I am finding it difficult to visualise all the changes being proposed by Huawei. How are we going to see the peak rate of 10Gbps for example?
I have to mention that I have had companies that have told me that their vision of 5G is M2M and D2D so Huawei is is not very far from reality here.
We should keep in mind that this 4G, 4.5G and 5G are the terms we use to make the end users aware of what new cellular technology could do for them. Most of these people understand simple terms like speeds and latency. We may want to be careful what we tell them as we do not want to make things confusing, complicated and make false promises and not deliver on them.
xoxoxo Added on 2nd January 2015 oxoxox
Chinese vendor ZTE has said it plans to launch a ‘pre-5G’ testing base station in 2015, commercial use of which will be possible in 2016, following tests and adjustment. Here is what they think pre-5G means:
I am sure some people much be really bored by this picture of mine that I keep showing. LTE, rightly referred to as 3.9G or pre-4G by the South Korean and Japanese operators was the foundation of 'Real' 4G, a.k.a. LTE-Advanced. So who has been referring to LTE-A as 4.5G (and even 5G). Here you go:
Got 4G? Wake up, grandad. We're doing 4.5G LTE-A in London - EE chief: And get a load of our gleaming voice system! … http://t.co/78HSHlyPuA
— The Register (@TheRegister) March 5, 2014
Voda UK PR says: "The new technology, called Carrier Aggregation but also referred to as LTE Advanced or 4.5G" 4.5G?
— Keith Dyer (@keithdyer) October 15, 2014
5G wireless technology LTE-Advanced is now running in the Philippines' largest and strongest network. | http://t.co/g8u3lJ8sLV #Smart5G
— Smart Communications (@SMARTCares) August 14, 2014
So lets look at what 4.5G is.
Some people dont realise how much spectrum is available as part of 5GHz, hopefully the above picture will give an idea. This is exactly what has tempted the cellular community to come up with LTE-U (a.k.a LA-LTE, LAA)
Good points: 4.5G as necessary step: CA, VoLTE & WebRTC, CoMP & coordination, NFV & cloud. But that can do everything we need #5GHuddle
— Real Wireless (@real_wireless) September 23, 2014
So 5G will be evolution of 4.5G using DC & CA - but much better signalling, more energy efficient as new air interface for IoT
— Real Wireless (@real_wireless) September 23, 2014
Finally, in a recent GSMA event, Huawei used the term 4.5G to set out their vision and also propose a time-frame as follows:While in Alcatel-Lucent slide, I could visualise 4.5G as our vision of LTE(-A) + WiFi + some more stuff, I am finding it difficult to visualise all the changes being proposed by Huawei. How are we going to see the peak rate of 10Gbps for example?
I have to mention that I have had companies that have told me that their vision of 5G is M2M and D2D so Huawei is is not very far from reality here.
We should keep in mind that this 4G, 4.5G and 5G are the terms we use to make the end users aware of what new cellular technology could do for them. Most of these people understand simple terms like speeds and latency. We may want to be careful what we tell them as we do not want to make things confusing, complicated and make false promises and not deliver on them.
xoxoxo Added on 2nd January 2015 oxoxox
Chinese vendor ZTE has said it plans to launch a ‘pre-5G’ testing base station in 2015, commercial use of which will be possible in 2016, following tests and adjustment. Here is what they think pre-5G means:
Tuesday 14 October 2014
'Real' Full Duplex (or No Division Duplex - NDD?)
One of the technologies being proposed for 5G is referred to as Full Duplex. Here, the transmitter and the receiver both transmit and receive at the same frequency. Due to some very clever signal processing, the interference can be cancelled out. An interesting presentation from Kumu networks is embedded below:
Saturday 11 October 2014
A quick update on Antennas
Thursday 2 October 2014
Envelope Tracking for improving PA efficiency of mobile devices
For people who are interested in testing this feature may want to check this Rohde&Schwarz presentation here.
Saturday 27 September 2014
Elevation Beamforming / Full-Dimension MIMO
Four major Release-13 projects have been approved now that Release-12 is coming to a conclusion. One of them is Full dimension MIMO. From the 3GPP website:
Leveraging the work on 3D channel modeling completed in Release 12, 3GPP RAN will now study the necessary changes to enable elevation beamforming and high-order MIMO systems. Beamforming and MIMO have been identified as key technologies to address the future capacity demand. But so far 3GPP specified support for these features mostly considers one-dimensional antenna arrays that exploit the azimuth dimension. So, to further improve LTE spectral efficiency it is quite natural to now study two-dimensional antenna arrays that can also exploit the vertical dimension.
Also, while the standard currently supports MIMO systems with up to 8 antenna ports, the new study will look into high-order MIMO systems with up to 64 antenna ports at the eNB, to become more relevant with the use of higher frequencies in the future.
Details of the Study Item can be found in RP-141644.
There was also an interesting post by Eiko Seidel in the 5G standards group:The idea is to introduce carrier and UE specific tilt/beam forming with variable beam widths. Improved link budget and reduced intra- and inter-cell interference might translate into higher data rates or increased coverage at cell edge. This might go hand in hand with an extensive use of spatial multiplexing that might require enhancements to today’s MU-MIMO schemes. Furthermore in active antenna array systems (AAS) the power amplifiers become part of the antenna further improving the link budget due to the missing feeder loss. Besides a potentially simplified installation the use of many low power elements might also reduce the overall power consumption.
At higher frequencies the antenna elements can miniaturized and their number can be increased. In LTE this might be limited to 16, 32 or 64 elements while for 5G with higher frequency bands this might allow for “massive MIMO”.
WG: Primary RAN1 (RP-141644)
started 06/2014 (RAN#64), completion date 06/2015 (RAN#68)
work item might follow the study with target 12/2015 (RAN#70)
Supporting companies
Samsung/NSN, all major vendors and operators
Based on RAN1 Rel.12 Study Item on 3D channel model (TR36.873)
Objectives
Phase 1: antenna configurations and evaluation scenarios Rel.12 performance evaluation with 3D channel model
Phase 2: study and simulate FD-MIMO enhancement identify and evaluate techniques, analyze specification impact performance evaluation for 16, 32, 64 antenna elements enhancements for SU-/MU-MIMO (incl. higher dimension MU-MIMO) (keep the maximum number of layer per UE unchanged to 8)
An old presentation from Samsung is embedded below that will provide more insight into this technology:
Related post:
Sunday 21 September 2014
NFV and 5G compatibility issues
There was an interesting discussion on Twitter that has been storified by Keith Dyer. Lets start by having a quick look at the C-RAN architecture that features in the discussion.
There are couple of excellent C-RAN presentations for anyone interested. This one by EE (with 9K+ views) and this from Orange (with 19K+ views).
Anyway, here is the story:
For anyone interested in exploring the discussion further, The Mobile Network has a more detailed comments here.
There are also an interesting article worth reading:
There are couple of excellent C-RAN presentations for anyone interested. This one by EE (with 9K+ views) and this from Orange (with 19K+ views).
Anyway, here is the story:
For anyone interested in exploring the discussion further, The Mobile Network has a more detailed comments here.
There are also an interesting article worth reading:
Thursday 18 September 2014
Update on Public Safety and Mission Critical communications
Its been a while since I wrote about Public Safety and Mission Critical communications, so here is a quick summary.
Iain Sharp have a good overview of whats happening in the standards in the LTE World Summit back in June. Embedded below is his complete presentation.
There is another slightly older presentation that I also thought was worthwhile adding here.
There is a lot of discussion centred around the use of commercial networks for mission critical communications, mainly die to cost. While this may make sense to an extent, there should be procedures put in place to give priority to public safety in case of emergency.
We are planning to run a one day training in Jan 2015 on public safety. If this is of interest to you then please get in touch with me for more details.
x-o-x-o-x-o-x-o-x-o-x-o-x
After the post someone brought these links to my attention so I am adding them below:
Iain Sharp have a good overview of whats happening in the standards in the LTE World Summit back in June. Embedded below is his complete presentation.
There is another slightly older presentation that I also thought was worthwhile adding here.
We are planning to run a one day training in Jan 2015 on public safety. If this is of interest to you then please get in touch with me for more details.
x-o-x-o-x-o-x-o-x-o-x-o-x
After the post someone brought these links to my attention so I am adding them below:
Tuesday 9 September 2014
LTE Device-to-device (D2D) Use Cases
Device-to-device is a popular topic. I wrote a post, back in March on LTE-Radar (another name) which has already had 10K+ views. Another post in Jan, last year has had over 13K views. In the LTE World Summit, Thomas Henze from Deutsche Telekom AG presented some use cases of 'proximity services via LTE device broadcast'
While there are some interesting use cases in his presentation (embedded below), I am not sure that they will necessarily achieve success overnight. While it would be great to have a standardised solution for applications that rely on proximity services, the apps have already come up with their own solutions in the meantime.
The dating app Tinder, for example, finds a date near where you are. It relies on GPS and I agree that some people would say that GPS consumes more power but its already available today.
Another example is "Nearby Friends" from Facebook that allows to find your friends if they are nearby, perfect for a day when you have nothing better to do.
With an App, I can be sure that my location is being shared only for one App. With a standardised solution, all my Apps have info about location that I may not necessarily want. There are pros and cons, not sure which will win here.
Anyway, the complete presentation is embedded below:
For anyone interested in going a bit more in detail about D2D, please check this excellent article by Dr. Alastair Bryon, titled "Opportunities and threats from LTE Device-to-Device (D2D) communication"
Do let me know what you think about the use cases.
While there are some interesting use cases in his presentation (embedded below), I am not sure that they will necessarily achieve success overnight. While it would be great to have a standardised solution for applications that rely on proximity services, the apps have already come up with their own solutions in the meantime.
The dating app Tinder, for example, finds a date near where you are. It relies on GPS and I agree that some people would say that GPS consumes more power but its already available today.
Another example is "Nearby Friends" from Facebook that allows to find your friends if they are nearby, perfect for a day when you have nothing better to do.
With an App, I can be sure that my location is being shared only for one App. With a standardised solution, all my Apps have info about location that I may not necessarily want. There are pros and cons, not sure which will win here.
Anyway, the complete presentation is embedded below:
For anyone interested in going a bit more in detail about D2D, please check this excellent article by Dr. Alastair Bryon, titled "Opportunities and threats from LTE Device-to-Device (D2D) communication"
Do let me know what you think about the use cases.
Friday 29 August 2014
Wireless Charging: A must-have technology with maturing standards
Wireless charging has been in news recently with the discovery that Apple has found a brilliant way to wireless charge iPhones, iPads and iWatches. While we continue to wait for the details of that one, I thought its worth providing a bit of round up from the LTE World Summit not so long back. A summary of market by IHS is embedded as follows:
Finally, any discussion on Wireless Charging wont be complete without the mention of other big player, Alliance For Wireless Power (A4WP). The above shows a comparison between different standards and the presentation from A4WP is as follows:
Finally, if you haven't seen our concept of futuristic 'Smart Batteries' (crossed 10K+ views) then check it out here.
Sunday 24 August 2014
New LTE-A UE Category 9 and 10 in Rel-11
Its been a while since we saw any new UE categories coming but then I noticed some new categories came earlier this year for Release-11. The latest 3TPP TS 36.306 have these new Category 9 and Category 10 as follows.
For those who are aware of the categories of the UE's being used in practice may be aware that the most common ones have been 'Category 3' with 100Mbps max in DL and 50Mbps max in UL. The new 'Cat. 4' devices are becoming more common as more manufacturers start bringing these devices to the market. They support 150Mbps max in DL and 50Mbps max in UL. Neither of them supports Carrier Aggregation.
Having said that, a lot of Cat. 4 devices that we may use in testing actually supports carrier aggregation. The next most popular devices soon to be hitting the market is Cat. 6 UE's with 300Mbps max in DL and 50Mbps max in UL. Category 6 UE's support 2 x 20MHz CA in downlink hence you can say that they can combine 2 x Cat. 4 UE's in DL but they do not support CA in uplink hence the UL part remains the same as Cat. 4 device.
Cat. 9 and 10 are interesting case as Car. 8 was already defined earlier to meet IMT-A requirement as shown below.
To meet IMT-A requirements of peak data rates of 1Gbps in UL and DL, LTE-A had to define category 8 with 5 band CA and 8x8 MIMO to be able to provide 3Gbps max in DL and 1.5Gbps max in UL. No one sees this device becoming a reality in the short term.
The new categories will have to be defined from Cat. 9 onwards.
Cat. 9 allows 3 x Cat. 4 device CA in the downlink to have the maximum possible downlink data rates of 450Mbps but there is no CA in the uplink. As a result, the UL is still 50Mbps max. Cat. 10 allows carrier aggregation in the uplink for upto 2 bands which would result in 100Mbps max in UL.
The LG space website gives a better representation of the same information above which is shown below:
A UE category 9 transmits Rel 11 category 9 + Rel 10 category 6 + Rel 8 category 4
With Release-12 due to be finalised later in the year, we may see new UE categories being defined further.
Having said that, a lot of Cat. 4 devices that we may use in testing actually supports carrier aggregation. The next most popular devices soon to be hitting the market is Cat. 6 UE's with 300Mbps max in DL and 50Mbps max in UL. Category 6 UE's support 2 x 20MHz CA in downlink hence you can say that they can combine 2 x Cat. 4 UE's in DL but they do not support CA in uplink hence the UL part remains the same as Cat. 4 device.
Cat. 9 and 10 are interesting case as Car. 8 was already defined earlier to meet IMT-A requirement as shown below.
To meet IMT-A requirements of peak data rates of 1Gbps in UL and DL, LTE-A had to define category 8 with 5 band CA and 8x8 MIMO to be able to provide 3Gbps max in DL and 1.5Gbps max in UL. No one sees this device becoming a reality in the short term.
The new categories will have to be defined from Cat. 9 onwards.
Cat. 9 allows 3 x Cat. 4 device CA in the downlink to have the maximum possible downlink data rates of 450Mbps but there is no CA in the uplink. As a result, the UL is still 50Mbps max. Cat. 10 allows carrier aggregation in the uplink for upto 2 bands which would result in 100Mbps max in UL.
The LG space website gives a better representation of the same information above which is shown below:
A UE category 9 transmits Rel 11 category 9 + Rel 10 category 6 + Rel 8 category 4
With Release-12 due to be finalised later in the year, we may see new UE categories being defined further.
Saturday 9 August 2014
Multi-Frequency Band Indicator (MFBI)
I am sure we all know that LTE bands have been growing, every few months. All the 32 bands for FDD have now been defined. The 33rd band is where TDD bands start. What if we now want to have more FDD bands? Well, we will have to wait to fix that problem.
Picture Source: LG Space
Anyway, as can be seen in the above picture, some of the frequency bands overlap with each other. Now you may have a UE thats camped onto one frequency that is overlapping in different bands. Wouldn't it be useful to let the UE know that you are camped in more than one band and you can change it to another frequency which may be a different band but you were already on it in the first place (it may sound confusing).
An example could be Sprint that used Band 38 TDD (BW 50MHz) for its legacy devices but is now able to use Band 41 (BW 194MHz) as well. The legacy devices may not work on Band 41 but the new devices can use much wider band 41. So the transmission would still say Band 38 but the new devices can be informed of Band 41 using the System Information Block Type 1. AT&T has a similar problem with Band 12 and 17.
Even though this was implemented in Release-8, it came as a part of Late Non-critical extensions. Its a release independent feature but not all UE's and Network have implemented it. The UE indicates the support for MFBI using the FGI (Feature Group Indicator) bits.
Saturday 26 July 2014
Observed Time Difference Of Arrival (OTDOA) Positioning in LTE
Its been a while I wrote anything on Positioning. The network architecture for the positioning entities can be seen from my old blog post here.
Sunday 20 July 2014
LA-LTE and LAA
Recently came across a presentation by Ericsson where they used the term LA-LTE. I asked a few colleagues if they knew or could guess what it means and they all drew blank. I have been blogging about Unlicensed LTE (a.k.a. LTE-U) on the Small Cells blog here. This is a re-branding of LTE-U
LA-LTE stands for 'Licensed Access' LTE. In fact the term that has now been adopted in a recent 3GPP workshop (details below) is Licensed Assisted Access (LAA).
Couple of months back I blogged in detail about LTE-U here. Since then, 3GPP held a workshop where some of the things I mentioned got officially discussed. In case you want to know more, details here. I have to mention that the operator community is quite split on whether this is a better approach or aggregating Wi-Fi with cellular a better approach.
The Wi-Fi community on the other hand is unhappy with this approach. If cellular operators start using their spectrum than it means less spectrum for them to use. I wrote a post on the usage of Dynamic Spectrum Access (DSA) Techniques that would be used in such cases to make sure that Wi-Fi and cellular usage does not happen at the same time, leading to interference.
Here is a presentation from the LTE-U workshop on Use cases and scenarios, not very detailed though.
Finally, the summary presentation of the workshop. As it says on the final slide "The current SI proposal focuses on carrier aggregation operations and uses the acronym LAA (Licensed Assisted Access)", you would be seeing more of LAA.
Sunday 13 July 2014
Case Study: LTE for real time news gathering by Sky News
Back in May, I had the pleasure of listening to a talk by Richard Pattison from Sky News where he talked about how they have managed to start replacing their Satellite trucks (which are extremely expensive to own and run) with the new solutions using LTE.
One of the advantage of LTE over 3G/HSPA+ is that the uplink is as good as the downlink which wasn't really the case in earlier generations. What this means is that you can use your phone to do a live video call and use that for broadcasting of real time information. The Sky News Tech team has some interesting tweets on this.
An example of the video quality could be seen from this clip here:
The Dejero App is an interesting one that can allow bonding of Cellular + WiFi and provide a combined data rate.
I was having a discussion yesterday on Twitter because we term this bonded cellular and WiFi as 4.5G. There are many proprietary solutions available for using them together but the standardised one is coming in standards soon.
Sky news have managed to set up new standards by having 12 feeds simultaneously broadcasting (all based on Iphones and Ipads) during the European elections.
All this has been possible due to an amazing 4G network by EE and being able to negotiate a 500GB (0.5TB) data package.
Anyway, you can read the complete paper below:
One of the advantage of LTE over 3G/HSPA+ is that the uplink is as good as the downlink which wasn't really the case in earlier generations. What this means is that you can use your phone to do a live video call and use that for broadcasting of real time information. The Sky News Tech team has some interesting tweets on this.
We're broadcasting live from a Bradford City supporters bus on the M1 using a smartphone. Here's my view. pic.twitter.com/i2MXtXNht8
— Nick Martin (@NickMartinSKY) February 24, 2013
An example of the video quality could be seen from this clip here:
The Dejero App is an interesting one that can allow bonding of Cellular + WiFi and provide a combined data rate.
I was having a discussion yesterday on Twitter because we term this bonded cellular and WiFi as 4.5G. There are many proprietary solutions available for using them together but the standardised one is coming in standards soon.
Sky news have managed to set up new standards by having 12 feeds simultaneously broadcasting (all based on Iphones and Ipads) during the European elections.
All this has been possible due to an amazing 4G network by EE and being able to negotiate a 500GB (0.5TB) data package.
In case you've ever wondered, this is what 500GB of mobile data looks like... #EE #4GEE pic.twitter.com/7v27RncK
— Sky News Tech Team (@skynewstech) February 19, 2013
Anyway, you can read the complete paper below:
Thursday 10 July 2014
Taking 5G from vision to reality
All presentations from the Future of Wireless International Conference (FWIC) are available here.
Friday 4 July 2014
Cell capacity and Opportunistic Use of Unlicensed and Shared Spectrum
If you don't know about Dynamic Spectrum Access Schemes, I wrote a post on the Small Cells blog here. The slide above is quite interesting as it shows the possibility of a 'Generalized' Carrier Aggregation in 3GPP Release-13. Personally, we believe that LTE + WiFi working together will be far more successful than LTE + LTE-U (unlicensed). As the blog readers would be aware, we have been pushing our vision of LTE + Wi-Fi working together; which we are calling as 4.5G. In case if you have not seen, our whitepaper is here.
The presentation is embedded below for reference:
Wednesday 2 July 2014
Case Study: Migrating from WiMAX to TD-LTE
I was glad to hear this case study by Mike Stacey where they have a WiMAX network already deployed and are in process of moving to TD-LTE. Along with the technical issues there are also business and customer issues that need to be taken into account while doing this technology swap. Surprisingly 3.5GHz is also not a very popular band because there are very few deployments in this spectrum. On the other hand, most of the companies worldwide that have been able to get their hands on this spectrum, generally got a big chunk (60-100MHz) so they would be able to do CA easily (bar the technical issues of Intra-band interference).
Anyway, the presentation is embedded below. Hope you find it useful. If you know of similar experiences, please feel free to add them in the comments.
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