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Showing posts with label LTE World Series. Show all posts
Showing posts with label LTE World Series. Show all posts

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:

Saturday, 11 October 2014

A quick update on Antennas

There were couple of very interesting and useful presentations from the LTE World Summit 2014 that I have been thinking for a while to embed in the blog. The first is a market overview from Signals Research Group. The research is focussed more on the US market but it has some very interesting insights. The slideset is embedded below:

The other presentation is from Commscope on Base Station Antennas (BSA) for capacity improvement. I really liked the simplicity of the diagrams. Anyone interested in studying more indepth on the antennas are encouraged to check out my old post here. The complete slideset is below:

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.

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.

Image iTunes

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:

Qi (pronounced Chee), probably the most well known standard, not just because its already available in devices like Google Nexus 5 phone and Nexus 7 tablet  but also because its 1.2 standard allows devices to be charged from some distance away. They had an excellent presentation outlining their progress and technology 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.

Friday, 4 July 2014

Cell capacity and Opportunistic Use of Unlicensed and Shared Spectrum

One very interesting presentation from the LTE World Summit was about Improving the cell capacity by using unlicensed and shared spectrum opportunistically. Kamran Etemad is a senior advisor to FCC & UCMP and even though he was presenting this in his personal capacity, it reflected some interesting views that are quite prevalent in the USA.

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.

Saturday, 28 June 2014

EE: The Implications of RAN Architecture Evolution for Transport Networks

Here is a presentation by Andy Sutton, EE from the recent LTE World Summit 2014. Unfortunately the event was too big to be present in all presentations but in his own words, "As always the bullet points don’t tell the full story as there’s considerable narrative that goes with this, however it does stress some major themes."

Slides embedded below, can be downloaded from Slideshare:

Friday, 27 June 2014

Voice over WiFi (VoWiFi)

One of the changes that I have noticed in the last year is that some of the operators who have been opposed to WiFi in the past have not only embraced it but are now trying to monopolise the same WiFi spectrum they billed as interference prone. Personally, I think the future of Wi-Fi is not just offloading but also working together with LTE. We are billing this as 4.5G and have recently produced a whitepaper, available here.

There has been a flurry of activity on Voice over Wi-Fi in the last few months. Recently the UK operators '3' and EE announced that they are both allowing WiFi calling and SMS. While '3' customers will have to use an OTT app for the time being, EE customers will experience this seamlessly.

I heard Taqua in the recent LTE World Summit talking about their solution and have offered to share their slides (embedded below). It was interesting to find out while having a discussion with them that their solution supports 'hand-in' and 'hand-out'. This takes away a major advantage that Small Cells offered, seamless roaming. Anyway, feel free to let me know of you have any opinion on this topic

Thursday, 26 June 2014

LTE-Broadcast: Reality check

When I wrote my blog post about why the 'Cellular Broadcast may fail again' for the Cisco SP Mobility blog, I did not realise that this would become so popular and there would be so many people writing to me to tell me why and how my assumptions are wrong and how they plan to succeed. I have not yet received a successful reasoning on why people disagree with my article and where I am wrong.

In the Video Over LTE Summit just concluded, I did not get a chance to see all the LTE-B presentations but the ones that I saw, were not convincing enough, except for one by Erol Hepsaydir, of '3' UK, that I explain in the end.

Here is my presentation from that event:

The conclusion is not self-explanatory so here it is in my own words.

I am not opposed to the operators trying LTE-B out. I wish more operators do try and hopefully we can have a model where the technology can succeed. When operators succeed in a new technology, it benefits the whole mobile ecosystem directly or indirectly. The operators have to be prepared that they may not see any return. This should not discourage them because the learnings from this may benefit in something else. The customer and their loyalty is more important. We should try and provide them with a value addition rather than think of this as a new source of revenue. People are not interested in watching the same stuff they watch on the terrestrial TV on their small devices; unique and maybe tailored content would help. Finally, don't make the billing model too complex so the users shy away from trying this new technology.

The final presentation of the event was delivered by Erol Hepsaydir of the UK operator '3'. He said that from their point of view, they are trying to have eMBMS to create additional capacity in the network. If they know that many people watch news on different apps and websites, they can offer this as a free service over broadcast. What this means is that they have gained customer loyalty and also free up the capacity for other users who are doing other data related activities. I think this is a very clever approach. He did mention though that they are only in the simulation stages and have not tried it out practically. 

Wednesday, 25 June 2014

Diamater: Market Status, Roaming, NFV and Case Studies

Some more interesting presentations from the Signalling Focus Day of LTE World Summit. Good overview of market by Greg Collins of Exact ventures is embedded below.

A good presentation by Tieto where they presented some good case studies for Diameter Interworking. Presentation embedded below:

The final presentation by Diametriq is very interesting because they presented interesting way of mining the control plane. Thee case study presented was of a 'silent roamer' who is not going to spend money while roaming because he is not sure how much money is spent. This can be exploited by the operator to offer flat packages, 1 day pass, etc. to get some revenue from these roamers. Their presentation included some animations that cannot be shown while being embedded. Please download the PPT from Slideshare to view them.

Monday, 23 June 2014

LTE Roaming using IPX

A very interesting presentation from Raphaël Glatt of Bics in the Signalling Focus Day of LTE World Summit 2014. IPX is probably the most popular solution as its already being used by many operators for roaming agreements. Anyway, his presentation was the most detailed one I have come across and he was happy to share it with me for this blog. His complete presentation is embedded below:

Monday, 9 June 2014

European Regulations for 'Decoupling of SIM' and 'International Roaming'

The following is an extract from an article from Capana:

From the 1st of July 2014, the new EU Roaming Regulations III will become active.

The new EU Roaming regulations set by the European Commission, will allow retail mobile customers to purchase roaming services (such as voice, SMS and data) from an Alternative Roaming Provider (ARP) separate from their domestic service provider (DSP), without affecting either mobile number or device.
The general idea behind the regulations is to promote the interests of European citizens by increase competition between European operators, provide greater transparency, reduce bill shocks, and ultimately provide a greater roaming experience and higher quality of service for consumers.
European Commission President Jose Manuel Barosso said in a press release:
“Further substantial progress towards a European single market for telecoms is essential for Europe’s strategic interests and economic progress. For the telecoms sector itself and for citizens who are frustrated that they do not have full and fair access to internet and mobile services.”
Vice President Neelie Kroes, the Digital Agenda Commissioner responsible for package then continued in the same press release by saying:
“The legislation proposed today is great news for the future of mobile and internet in Europe. The European Commission says no to roaming premiums, yes to net neutrality, yes to investment, yes to new jobs. Fixing the telecoms sector is no longer about this one sector but about supporting the sustainable development of all sectors.”
The process of selecting an ARP and its services while abroad within EU is more commonly known as decoupling or separate sale of roaming services. BEREC (the body of European Regulators for Electronic Communications) have provided the European Commission with their recommendations of two decoupling models that should be supported; Local breakout (LBO, which is the local provisioning of data services by a visited network operator, or Single IMSI solution where the ARP acts as a reseller of the DSPs service offerings.
Decoupling using Single IMSI
With the Single IMSI solution the ARP will engage in agreements with each domestic operator providing domestic services, then the ARP will act as a reseller of these services to the roaming subscriber. This type of solution is applicable for all types of service providers such as mobile network operators, MVNOs or VSPs. From a subscriber standpoint, they will have a roaming agreement with the ARP regardless of the DSP and the DSP is required to activate services within one working day.
Decoupling using Local Breakout
The Local breakout model refers to local provisioning of data services only, where the services is provided directly on the visited network and traditional SMS and voice traffic is supplied by the home operator in traditional roaming manner. By using the 3GPP option for local breakouts, the VPMN will be able to act as ARP for internet access and other data services.
With these new regulatory changes, there is a higher demand on flexibility in billing systems. Support for more complex multi-partner business models for ARP and MVNO is necessary for both billing and financial settlement activities.

Raymond Bouwman from Rabion Consultancy did an excellent presentation last year in the LTE World Summit, here is his presentation explaining more about the EU Roaming Regulations III

Wednesday, 28 May 2014

Case Study: RAN Sharing in Poland

The last post on Network sharing by NEC was surprisingly popular so I thought its worth doing a case study by Orange in Poland on how they successfully managed to share their network with T-Mobile. Full presentation embedded as follows:

Sunday, 23 March 2014

Securing the backhaul with the help of LTE Security Gateway

An excellent presentation from the LTE World Summit last year, that is embedded below. The slide(s) that caught my attention was the overhead involved when using the different protocols. As can be seen in the picture above, the Ethernet MTU is 1500 bytes but after removing all the overheads, 1320 bytes are left for data. In case you were wondering, MTU stands for 'maximum transmission unit' and is the largest size packet or frame, specified in octets (8-bit bytes), that can be sent in a packet or frame based network such as the Internet.

Anyway, the presentation is embedded below:

Tuesday, 22 October 2013

Korea Telecom ‘Route Decision System’ for midnight buses

Interesting presentation from Korea Telecom in LTE Asia 2013 about how they use Big Data to decide the night bus routes. Here are two pics which are self explanatory

We will soon start seeing operators using the data being collected from users and this can also be a nice little earner for them.

Monday, 12 August 2013

C-RAN Architecture and Challenges

I have blogged about Cloud RAN or C-RAN in the Metrocells blog here and am looking forward to more discussions on this topic in the SON conference later this year.

I came across this interesting presentation from Orange in the LTE World Summit this year where the authors have detailed the C-RAN architecture and also discussing the fronthaul challenges faced by C-RAN. The presentation is embedded as follows. Please feel free to add your comments with your opinions.

Thursday, 8 August 2013

2 Factor and 3 Factor Authentication (2FA / 3FA)

Found an interesting slide showing 2 Factor Authentication in picture from a presentation in LTE World Summit

You can also read more about this and Multi-factor Authentication (MFA) on Wikipedia here.

Friday, 19 July 2013

Nice way of showing HetNets, by Cisco #LTEWS

This is from a presentation by Akram Awad of Cisco in the LTE World Summit 2013 in Amsterdam. I really like the way HetNets are explained