Showing posts with label Wi-Fi. Show all posts
Showing posts with label Wi-Fi. Show all posts

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.

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:



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:


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:


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.


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:


Monday 30 June 2014

4.5G: Integration of LTE and Wi-Fi networks


With LTE-A getting ready to meet the IMT-Advanced requirements and fulfilling the role of promised '4G', we believe the next phase of evolution before 5G will be successful interworking of LTE and Wi-Fi networks.


This whitepaper (embedded below) explores this feature, we call 4.5G, in detail.

Understanding WLAN offload in cellular networks by Anritsu

We are very thankful to Anritsu for kindly sponsoring this whitepaper. They have their own whitepaper on this topic which is also worth a read, available here.



Let us know what you think about this.

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 21 May 2014

Connected and Autonomous Car Revolution

Last week we had the Automotive and Transport SIG event in Cambridge Wireless. There is already some good writeup on that event here and here. In this post my interest in looking at the technologies discussed.

R&S (who were the sponsors) gave their introduction presentation quite well highlighting the need and approaches for the connected car. He also introduced the IEEE 802.11p to the group.

As per Wikipedia, "IEEE 802.11p is an approved amendment to the IEEE 802.11 standard to add wireless access in vehicular environments (WAVE), a vehicular communication system. It defines enhancements to 802.11 (the basis of products marketed as Wi-Fi) required to support Intelligent Transportation Systems (ITS) applications. This includes data exchange between high-speed vehicles and between the vehicles and the roadside infrastructure in the licensed ITS band of 5.9 GHz (5.85-5.925 GHz). IEEE 1609 is a higher layer standard based on the IEEE 802.11p."

Back in December, Dr. Paul Martin did an equally useful presentation in the Mobile Broadband SIG and his presentation is equally relevant here as he introduced the different terms live V2X, V2i, V2V, V2P, etc. I have embedded his presentation below:



Roger Lanctot from Strategy Analytics, gave us some interesting facts and figures. Being based in the US, he was able to give us the view of both US as well as Europe. According to him, “LTE is the greatest source of change in value proposition and user experience for the customer and car maker. Bluetooth, Wi-Fi, NFC and satellite connectivity are all playing a role, but LTE deployment is the biggest wave sweeping the connected car, creating opportunities for new technologies and applications.” His officially released presentation is embedded below (which is much smaller than his presentation on that day.



There were also interesting presentations that I have not embedded but other may find useful. One was from Mike Short, VP of Telefonica and the other was from Dr. Ireri Ibarra of MIRA.


The final presentation by Martin Green of Visteon highlighted some interesting discussions regarding handovers that may be required when the vehicle (and the passengers inside) is moving between different access networks. I for one believe that this will not be an issue as there may be ways to work the priorities of access networks out. Anyway, his presentation included some useful nuggets and its embedded below:


Saturday 5 April 2014

Some interesting April Fools' Day 2014 Technology Jokes

Its very interesting to see all the companies proposing very interesting concepts on the 1st of April. I was told that not everyone knows what April Fools day means so here is the link to Wikipedia.

Samsung Fly-Fi: Samsung has come up with some interesting ideas, the first being Wi-Fi for everyone powered by Pigeons. They have a website here with Video.

Power of Pigeons


Looks like since we have Pigeons everywhere, so they are always used in one way or the other. The best prank ever in my opinion was the PigeonRank by Google, back in 2002. I spent a few hours that day trying to figure out how they were actually doing it.

Smart Wear was always going to be the big thing. Quite a few smart wearables this year.

Bonobos has done a good job with with TechStyle. See video below:



Samsung has a glove called Samsung Fingers here. The best thing I liked was 'Talk to the Hand'

Samsung Fingers_Talk to the hand

HTC came up with similar concept called Gluuv



Toshiba's DiGiT is as interesting. See the video:


Virgin Mobile, Canada has come up with SmartKicks. See here.



Roku Watch is not too bad:


Virgin America even convinced Sir Richard Branson to appear in the April Fools ad along with Tony Faddell, the CEO of Nest. Funny Youtube video here.

Sony Power Food was just okay, video here.

Toshiba Spehere is a funny Gaming concept, see here.

Nokia reviewed its most popular phone 3310 with modern day features here. Coloured screen with 41Megapixel camera.

Google wants to Emojify the web here.

Google Japan has a magic hand here.

Selfiebot by Orbotix is a cool concept, here.

Twitter Helmet didnt make me laugh though. See here.

Is there some others that I missed? Please feel free to add it in the comments.

Saturday 8 March 2014

Mobile World Congress 2014 (#MWC14) Roundups

The worlds largest technology event came to a conclusion just over a week back so here is a summary of reports and roundups written by different people. Feel free to add yours in the comments:

The best way is to start with this Video of different gadgets by Orange (excuse their adverts)


Maravedis-Rethink has an excellent summary from Network point of view:

Now all the carriers have the same devices, and the all-you-can-eat offers are largely gone. This has shifted the competitive race to innovation in pricing and bundling; to services, even over-the-top ones; but most importantly to the one area which is still unique to MNOs, their licensed-spectrum networks. The race to implement more and more advanced features from the 3GPP menu is not just a carrier game of ‘mine’s bigger than yours’, but a truly necessary attempt, at least in the developed mobile markets, to differentiate themselves with the most advanced network capacity and capabilities.

In the network, new battle lines are being drawn, and the players are placing big bets on unproven technologies and new architectures. This is taking place on two levels – the well-understood but highly complex advances in RAN platforms, from the LTE-Advanced standards to small cells to Cloud-RAN; and the shift towards software-driven, if not yet fully software-defined networking, and towards virtualization.

Complete summary here.

Chetan Sharma has written a brilliant summary and covers all different topics:

All the progress that has been on the mobile economy has been on the back of trillions of dollars of investment over the last couple of decades. With declining margins, how long do operators continue to invest and at what pace? What’s the margin profile they are willing to live with? What’s the role of government in building out the infrastructure when high-speed mobile networks are concerned? Japan, Korea, Israel have all based their competitiveness on connected broadband world. Can others follow? The impact of Whatsapp launching voice services and Netflix/Comcast deal were hotly debated in the hallways. It is one thing to put out national broadband plans and it is entirely another reality to have an execution path to deliver on the plan. The broadband investment has much far reaching implications than most people and governments realize.

Complete article here.

Ian Poole from Radio Electronics has done a good job too with the summary and video:

There was a considerable amount of talk about connected cities, connected cars and the like. Many exhibitors at Mobile World Congress were showing their ideas and developments. There is a huge amount of work going on in these areas and this is reflected in the work and products being exhibited.
Said Mike Short, VP Telefonica: “Mobile World Congress is more of a data World Congress . . . . . . . there are many software companies, many special network companies, other companies providing billing and customer care and there are solutions for the whole digital economy”
Talking to a variety of people across Mobile World Congress, it was obvious there is a large amount of work going on.
In terms of the auto mobile industry there is a lot of interest and development. While it is not expected all of the work will come to fruition in the short term, such as mesh networked cars where the networking elements can be used for crash avoidance, etc, there are other areas for in car connectivity that will be implemented in the shorter term.
Qualcomm were even demonstrating an electric racing car that not only used wireless communications technology, but also utilised wireless charging. In this way they were incorporating two developing technologies.
In addition to this, technologies like Weightless – the white space data cellular system have moved forwards. The original aim was for the technology to be used in the television white space to provide low powered data communications particularly for remote sensors and actuators. For these applications, cellular technology is too heavy. Dealing with complex waveforms like OFDM requires considerable processing and this is not conducive to long battery life – some devices ae expected to operate for months or even years from the same battery.
Neul has been working to develop the ideas further. They are now looking at using unlicensed spectrum instead of the TV white space. They have found that in urban areas, little white space often exists. Unfortunately it is often in urban environments where population levels are highest and there will be the greatest need for low power data communications.
In another move announced at Mobile World Congress Orange announced that it is helping start up companies who are developing products for the IoT. Orange states that it wants to help them accelerate development and assist with marketing. This move is possibly a long term move, because it can only be approached with 4G, but with 5G anticipated to be more capable of meeting IoT requirements it should be able to enter the market more strongly when it arrives. It is anticipated that the main areas where IoT will start to grow initially are personal services, healthcare, the connected home and smart cities.
Complete report and the video here.

Finally, an excellent summary on Small Cells and related by ThinkSmallCell:

The official Small Cell conference track was pretty tame - Vodafone have deployed 300K Small Cells in total, KT (Korea Telecom) and Radisys spoke of 18K LTE deployed in mostly indoor metropolitan areas. Vodafone said they continue to drive vendors to deliver multi-technology small cell and backhaul products with high operational efficiency and look for added value to help the business case. By contrast, the Small Cell Forum booth hosted extensive and popular presentations and is perhaps outgrowing its booth format.
A key network equipment vendor theme was SDN (Software Defined Network) and NFV (Network Function Virtualisation). We can expect next year to see this evolving to orchestration - better methods of managing and manipulating these virtualised software components, but in the short term it means slightly less or cheaper hardware. Frankly, I was more impressed to see Huawei now supporting any of 2G, 3G or LTE (FDD&TDD) on the same physical macrocell radio hardware modules - true software definable radio. We are beginning to see that capability for Small Cells too, but it's not quite as mature yet.
Most of the Small Cell activity is around 3G indoor (Enterprise) and LTE outdoor (Urban), with 3G still important indoors (for voice) and LTE HetNets seen as the longer term solution for capacity. At least four DAS vendors announced lower cost, simpler products intended to address larger buildings and stadia - highlighting the growing demand for in-building cellular solutions. Many new LTE Small Cell vendors are appearing on the scene. Residential femtocells still have a place in the market especially where integrated into a broadband modem or set-top box, driven by a different business case than before. There were some signs that the radical approach of Free France, who are shipping many 10Ks of femtocells a month, may be emulated by others.

Complete report here.

Ronald Gruia from Frost&Sullivan has created a summary presentation on Slideshare that is embedded below:



Other Summaries worth reading:


There was also a Carrier Wi-Fi Summit going on in parallel to the main MWC. A summary of that is available on the WBA website here: Day 1, Day 2, Day 3 and Day 4.

SKTelecom2

Claus Hetting has also added an excellent summary of the Carrier Wi-Fi Summit on his blog here.

Tuesday 25 February 2014

Beacons, Bluetooth, NFC and WiFi


Not sure if you have heard about some kind of Beacons that will be used to guide us everywhere. There are Bluetooth Beeacons, iBeacon, Paypal Beacon, probably more. So here is an attempt to understand some of these things.

The first is this introductory presentation which seems to be extremely popular on Slideshare:



Once we understand the concept of Beacons, there is another presentation that helps us understand iBeacons and Paypal Beacons as follows:



Bluetooth Beacons vs Wifi vs NFC is an interesting article comparing the Beacons with WiFi & NFC. Read it here


Why Beacons may be NFC killer, GigaOm has a good answer here:
iBeacon could be a NFC killer because of its range. NFC tags are pretty cheap compared to NFC chips, but NFC tags are required on each product because NFC works only in very close proximity. In theory, NFC range is up to 20cm (7.87 inches), but the actual optimal range is less than 4cm (1.57 inches). Also, mobile devices need to contain a NFC chip that can handle any NFC communications. On the other hand, iBeacons are a little expensive compared to NFC chips, but iBeacons range is up to 50 meters. Not all phones have NFC chips, but almost all have Bluetooth capability.
Many years back there was a proximity marketing craze using Bluetooth. Then the craze died down and everyone started focussing on other approaches for LBS. I also suggested a Small Cells based approach here. Its good to see that we are going to use a new Bluetooth based approach for similar functions.

By the end of the year we will hopefully know if this is a new hype or a successful technology. Issues with battery drains, security, interoperability, etc. will need to be sorted asap for its success.

Tuesday 12 November 2013

Mobile Video Offload using Wi-Fi is the only solution in the coming years

A very interesting infographic from Skyfire some months back highlighted some very valid issues about Video on mobiles.


Personally, I do watch quite a bit of video on my phone and tablet but only when connected using Wi-Fi. Occasionally when I am out, if someone sends me video clip on Whatsapp or some link to watch Video on youtube, I do try and see it. Most of the time the quality is too disappointing. It could be because my operator has been rated as the worst operator in UK. Anyway, as the infographic above suggests, there needs to be some kind of an optimisation done to make sure that end users are happy. OR, the users cn offload to Wi-Fi when possible to get a better experience.

This is one of the main reasons why operators are actively considering offloading to Wi-Fi and have carrier WiFi solutions in place. The standards are actively working in the same direction. Two of my recent posts on the topic of 'roaming using ANDSF' and 'challenges with seamless cellular/Wi-Fi handover' have been quite popular.



Recently I attended a webinar on the topic of 'Video Offload'. While the webinar reinforced my beliefs about why offload should be done, it did teach me a thing or two (like when is a Hotspot called a Homespot - see here). The presentation and the Video is embedded below. Before that, I want to show the result of a poll conducted during the webinar where the people present (and I would imagine there were quite a few people) were asked about how they think MNO will approach the WiFi solution in their network. Result as follows:



Here is the presentation:



Here is the video of the event:


Monday 4 November 2013

Key challenges with automatic Wi-Fi / Cellular handover

Recently in a conference I mentioned that the 3GPP standards are working on standards that will allow automatic and seamless handovers between Cellular and Wi-Fi. At the same time operators may want to have a control where they can automatically switch on a users Wi-Fi radio (if switched off) and offload to Wi-Fi whenever possible. It upset quite a few people who were reasoning against the problems this could cause and the issues that need to be solved.

I have been meaning to list the possible issues which could be present in this scenario of automatically handing over between Wi-Fi and cellular, luckily I found that they have been listed very well in the recent 4G Americas whitepaper. The whitepaper is embedded below but here are the issues I had been wanting to discuss:

In particular, many of the challenges facing Wi-Fi/Cellular integration have to do with realizing a complete intelligent network selection solution that allows operators to steer traffic in a manner that maximizes user experience and addresses some of the challenges at the boundaries between RATs (2G, 3G, LTE and Wi-Fi).
Figure 1 (see above) below illustrates four of the key challenges at the Wi-Fi/Cellular boundary.
1) Premature Wi-Fi Selection: As devices with Wi-Fi enabled move into Wi-Fi coverage, they reselect to Wi-Fi without comparative evaluation of existing cellular and incoming Wi-Fi capabilities. This can result in degradation of end user experience due to premature reselection to Wi-Fi. Real time throughput based traffic steering can be used to mitigate this.
2) Unhealthy choices: In a mixed wireless network of LTE, HSPA and Wi-Fi, reselection may occur to a strong Wi-Fi network, which is under heavy load. The resulting ‘unhealthy’ choice results in a degradation of end user experience as performance on the cell edge of a lightly loaded cellular network may be superior to performance close to a heavily loaded Wi-Fi AP. Real time load based traffic steering can be used to mitigate this.
3) Lower capabilities: In some cases, reselection to a strong Wi-Fi AP may result in reduced performance (e.g. if the Wi-Fi AP is served by lower bandwidth in the backhaul than the cellular base station presently serving the device). Evaluation of criteria beyond wireless capabilities prior to access selection can be used to mitigate this.
4) Ping-Pong: This is an example of reduced end user experience due to ping-ponging between Wi-Fi and cellular accesses. This could be a result of premature Wi-Fi selection and mobility in a cellular environment with signal strengths very similar in both access types. Hysteresis concepts used in access selection similar to cellular IRAT, applied between Wi-Fi and cellular accesses can be used to mitigate this.
Here is the paper:



Tuesday 29 October 2013

ANDSF: Evolution and Roaming with Hotspot 2.0


Access Network Discovery and Selection Function (ANDSF) is still evolving and with the introduction of Hotspot 2.0 (HS 2), there is a good possibility to provide seamless roaming from Cellular to Wi-Fi, Wi-Fi to Wi-Fi and Wi-Fi to Cellular.


There is a good paper (not very recent) by Alcatel-Lucent and BT that explains these roaming scenarios and other ANDSF policies related information very well. Its embedded below:




Monday 15 July 2013

What's next with 802.11!


From another brilliant presentation by R&S from their LTE Summit 2013. Last year I had a similar overview from Agilent here. This one is much more detailed on what's coming next for WiFi.



Friday 8 March 2013

802.11u, Passpoint and Hotspot 2.0 (HS 2.0)

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




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


Related posts:


Wednesday 27 February 2013

Wi-Fi & Packet Core (EPC) Integration

Yesterday I wrote a blog post on whether Wi-Fi is the third RAN in the Metrocells blog. Today I am posting this excellent presentation that details how this Wi-Fi integration with EPC will be done.