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Saturday, 31 October 2009

Over-the-top (OTT) Applications and Services

I keep on hearing about OTT apps everywhere I go nowadays. I know roughly what they mean but I couldnt find a proper definition anywhere. Here is my attampt to write a bit about what OTT means.

Traditionally lots of services like Voice and Television for example is delivered in a conventional way where Voice was transferred via a PSTN or a Mobile network and similarly TV was delivered via Cable, Satellite, DVB-T kind of technology. With Internet becoming common and Broadband access available to everyone, easily and cheaply, new applications are available to deliver Voice and TV kinds of services. The most popular voice app is for example Skype and Youtube is an example of TV (even though its more like Video On Demand)

These apps cause two main problems. The first problem is that the companies using this traditional medium starts losing customers and their cost per person goes up forcing their profits down. At the same time the amount of data traffic for the ISP increases thereby increasing the number of bits/cent (bits/pence). This forces them to upgrade their infrastructure to provide the same quality of service (QoS).

What this would mean is that in future it would not be possible to get flat rate packages for Mobile broadband or there may be restrictions where certain applications wont run unless you pay extra.

The dilemma for carriers is that LTE’s all-IP architecture will create a more open environment for Over The Top (OTT) applications, including third-party VoIP services, which threaten to further commoditize the network. To overcome this threat and realize revenue gains from LTE, carriers will need to partner with content and application providers, develop application store-fronts such as Apple’s App Store, and perhaps deploy APIs that expose LTE’s value-added network capabilities to third-party application and content developers for a fee.

The only way to ensure profitability in this ‘cost-per-bit’ model is to maximise scale. We have seen this clearly in mobile telephony, where a lack of differentiation has led to intense price pressure, flat rate tariffs and a decoupling of the revenues from the costs. The mobile operator suffers the cost of deploying ever increasing bandwidth while the ‘value’ that this bandwidth enables – the access to over the top (OTT) applications and services benefits the OTT providers.

To avoid this commoditisation, service providers need to add intelligence to the way they deliver these bits. Adopting a ’value-per-bit’ strategy ensures that the value added over and above the simple transport of data is seen and desired by the consumer and by any upstream content or application provider.

This creates a tighter coupling between infrastructure costs and the revenue that infrastructure can attract, thereby ensuring a far more sustainable business model for the service provider. It also benefits consumers and application providers by providing them levels of security, performance and reliability appropriate to the transaction being carried out and the subscribed service.

Most of us wouldn’t dream of paying for a customized Internet experience on a tailor-made device from our broadband service provider. But that is the way we used to buy telephone service, and it continues to be the way we do things for mobile and video services. Over time, all of these businesses will follow a similar pattern, breaking down into their component parts so that the best adapted players win in each piece of the business. The only questions are: “Who are the best adapted?” and “How long will it take?”

Further Reading: Making the Network Relevant in an Over-the-Top World

Thursday, 29 October 2009

LTE definitely needed and coming next year...dont mention Voice and SMS please


The unremitting growth in data traffic will bring about a 3G network capacity crisis for some mobile network operators as early as 2010. This dire scenario, according to a new study from Unwired Insight, will only be avoided by the early deployment of LTE, and the acceptance that additional LTE spectrum will be required to satisfy this demand.

With 3G traffic volumes set to increase by a factor of 20 by 2015--driven by many technology factors and also dramatic reductions in mobile data pricing--Alastair Brydon, co-author of the new study, points to the example of mobile broadband pricing that has fallen as low as US$2 per gigabyte, "which is nearly half a million times smaller than the price per gigabyte of an SMS message."

Brydon believes that early LTE will be necessary for the following reasons:

  • As 2G users continue to migrate to 3G services, the available capacity per 3G user will decline rapidly in networks utilising HSPA, to less than 100MB per user per month in some cases. LTE will be essential to counter this decline.
  • While LTE promises peak data rates of over 100Mbps, this is only possible with wide allocations of spectrum, and particularly good radio conditions. Average data rates from practical LTE networks will be nowhere near the peak values.
  • Network operators will have an insatiable appetite for LTE spectrum, to stand any chance of keeping up with forecast traffic demand. For some operators, 10MHz of spectrum will be able to support forecast traffic levels only until 2011. A further 10MHz will be needed by 2012 and another 10MHz in 2013.
Unwired Insight claims LTE's ability to relieve the capacity constraints of HSPA networks will be limited initially, until operators can acquire additional spectrum and seed a sufficient number of LTE devices in the market place. "But, we don't expect to see LTE handsets until 2011," the company warns.

Fourteen operators have committed to LTE rollouts next year, up from 10 in March, the research firm said. It predicts the LTE network gear market will be worth more than $5 billion by 2013, dominated by E-UTRAN macrocell (eNodeB) deployments.

It also expects the LTE customer base to top 72 million by 2013, mostly users with laptops, netbooks or dongles, with the first smartphones expected to hit the market after 2011.

In another forecast, Informa Telecoms and Media said Japan would account for more than half of Asia's 14.4 million LTE subscribers by 2015.

NTT DoCoMo, Japanese rival eMobile and China Mobile will be the first to launch LTE in the region, Informa said, with Hong Kong's CSL likely to follow soon after.

But rollouts in the region may be hindered by delays, as Japan and Hong Kong are so far the only Asian countries to have awarded spectrum for LTE.

Regulators in other nations are scrambling to free up enough spectrum, Informa added. Even in Japan, there is not enough 2100MHz spectrum available to support DoCoMo's full LTE plans, so it will use its newly allocated 1.5GHz for LTE from 2010.

According to news sources in South Korea, LG Telecom (LGT) quietly revealed their intention to migrate to LTE for 4G service in South Korea. LG-Nortel and Samsung will provide the multi-mode base stations which are part of the company's green network upgrade. SKT and KTF (now part of KT), the other two mobile operators in the country, have already announced their LTE migration path for 4G previously. Unlike SKT and KTF who will migrate from HSPA to LTE, LGT will go from EV-DO to LTE, similar to the case of Verizon Wireless.

It was probably a matter of time for LGT to announce the LTE migration plan since it was only running EV-DO network, and this officially puts LGT on the LTE camp. Now, my speculation is that other major EV-DO operators (noticeably, Sprint) who haven't announced such plans will follow the same path down the road since WiMAX does not seem to be a viable migration path for the FDD part of the network.

Wednesday, 28 October 2009

China proposes TD-LTE-Advanced as its candidate for 4G


The International Telecommunication Union (ITU) has recently received six candidate technology submissions, including China's domestically-developed TD-LTE-Advanced for the global 4G (IMT-Advanced) mobile wireless broadband technology.

China's Ministry of Industry and Information Technology (MIIT) said on October 26 that it will fully support TD-LTE-Advanced in competing to be qualified as global 4G standard technology and promote development of related industries.

TD-LTE-Advanced, which is the intellectual property of China, inherits some of the major technical elements of TD-SCDMA, but will be able to offer an extended bandwidth and higher speed for Internet access.

Currently, 3GPP's LTE-advanced and IEEE's 802.16m are the two major 4G technologies. TD-LTE-Advanced was submitted at the ITU meeting as IMT-Advanced candidate technology, which is supported by major telecom operators and network device manufacturers including France Télécom, Deutsche Telekom, AT&T, NTT, KT, China Mobile, Ericsson, Nokia, Huawei and ZTE.

The selected technologies are expected to be accorded the official designation of IMT-Advanced - to qualify as true 4G technologies - in October 2010.

I was unable to locate more information on TD-LTE-Advanced. Will update once I have some more info.

Tuesday, 27 October 2009

Potential "killer apps" for Femtocell in 3G and LTE



Interesting discussion on Linkedin. Too big for me to summarise here but do check it out here.

Sorry, you may have to login :(

Monday, 26 October 2009

African Mobile Market grows 550% in 5 years



Africans are buying mobile phones at a world record rate, with take-up soaring by 550% in five years, research shows.

"The mobile phone revolution continues," says a UN report charting the phenomenon that has transformed commerce, healthcare and social lives across the planet. Mobile subscriptions in Africa rose from 54m to almost 350m between 2003 and 2008, the quickest growth in the world. The global total reached 4bn at the end of last year and, although growth was down on the previous year, it remained close to 20%.

On average there are now 60 mobile subscriptions for every 100 people in the world. In developing countries, the figure stands at 48 – more than eight times the level of penetration in 2000.

In Africa, average penetration stands at more than a third of the population, and in north Africa it is almost two-thirds. Gabon, the Seychelles and South Africa now boast almost 100% penetration. Only five African countries – Burundi, Djibouti, Eritrea, Ethiopia and Somalia – still have a penetration of less than 10 per 100 inhabitants.

Uganda, the first African country to have more mobiles than fixed telephones, is cited as an example of cultural and economic transformation. Penetration has risen from 0.2% in 1995 to 23% in 2008, with operators making huge investments in infrastructure, particularly in rural areas. Given their low incomes, only about a quarter of Ugandans have a mobile subscription, but street vendors offer mobile access on a per-call basis. They also invite those without access to electricity to charge their phones using car batteries.

Popular mobile services include money transfers, allowing people without bank accounts to send money by text message. Many farmers use mobiles to trade and check market prices.

The share of the population covered by a mobile signal stood at 76% in developing countries in 2006, including 61% in rural areas. In sub-Saharan Africa, closer to half the population was covered, including 42% in rural areas.

At the end of 2007, there were eight times as many mobile phones as fixed lines in the least developed countries. The number of fixed lines in the world has essentially been frozen around 1.2bn since 2006 and saw a slight decline in 2008.

But a "digital divide" persists in terms of internet access. Australia, a country with 21 million inhabitants, has more broadband subscribers than the whole of Africa. There is also a huge gap in terms of broadband speed. The report warns: "Urgent attention is needed to address this situation and bring the continent more meaningfully online."

Other developing regions often boast a broadband penetration 10 times higher than in Africa, where Algeria, Egypt, Morocco, South Africa, and Tunisia account for 90% of all subscriptions. Broadband access in Burkina Faso, the Central African Republic and Swaziland is the most expensive in the world, costing more than $1,300 (£780) a month.

The report also found that at the end of 2008 there were an estimated 1.4bn internet users around the world. The growth rate of 15% was slightly lower than in 2007. In developing countries, the number of users grew by a quarter and such countries now account for more than half the world's internet users. But while more than half of the developed world population is now online, the corresponding share is only 15% in developing economies and 17% in "transition" economies.

China hosted the biggest number of users (298 million), followed by the United States (191 million) and Japan (88 million). A little over one fifth of the world's population used the internet in 2008.

Sunday, 25 October 2009

All eyes on China Mobile TD-SCDMA network


China Mobile plans to spend more on 3G terminal subsidies in 2010.

The outfit has tripled the amount of subsidies from the current year level and is expected to spend $4.4 billion next year. The huge amounts of cash will enable the outfit to push into the 3G space in the worlds largest economy.

China Mobile has 70 per cent of the Chinese wireless market but has been taking a caning from China Unicom. The outfit uses its own TD-SCDMA 3G standard but with that sort of money to spend it is fairly clear that foreign salesmen will be showing up trying to flog the outfit shedloads of 3G gear.

The company recently launched a line of smartphones dubbed Ophones based on the TD-SCDMA technology which uses Google's Android mobile operating system.

All three carriers have commercially launched their 3G networks over the recent months, but take-up has been slow. Market leader Mobile has been hamstrung by the limited number of handsets for the new TD-SCDMA system.

But now with its device range expanding and the network expected to be rolled out to 238 cities by year-end, the market’s 800-pound gorilla appears ready to assert itself.

Analyst firm BDA says China Mobile plans to spend 120 billion yuan on handset subsidies this year, most of it on TD-SCDMA. It laid out 50 billion on subsidizing phones in the first half of the year, with less than 12% going to TD phones.

Now a China Mobile source told has told website C114 that the company would leverage its financial strengths “to stage a price war to resist Telecom’s and Unicom’s 3G” services.

China Mobile has 503 million users, Unicom 142 million and China Telecom 44 million customers. Of these 3G comprises a tiny fraction - China Mobile has 1.3 million using TD-SCDMA, Unicom 350,000 using W-CDMA and China Telecom 1.3 million on its CDMA EV-DO network.


TD-SCDMA is primed to evolve into a global standard: TD-LTE. Granted, TD-LTE's sales pitch is not all that different from its ancestors - i.e. making use of unpaired spectrum to boost capacity in urban environments where FDD macro networks get overloaded. What is different this time around is a bigger ecosystem of vendors developing it - admittedly for just a single market at the moment, but also the biggest single mobile market in the world.

The other key difference is that TDD has always been primarily a data play. But from 2001 up to 2008, 3G cellcos were still primarily in the voice business, and FDD allowed them to continue milking that cash cow. That worked fine when 3G data usage was still mostly ringtones, wallpapers and other walled-garden content.

Then the iPhone happened. Smartphones got smarter and data usage skyrocketed so high that E1 backhaul links became the new bottlenecks. If ABI Research is to be believed, by 2014 mobile users will be transmitting a total of 1.6 exabytes a month (compared to 1.3 exabytes for all of last year).

Hence all the interest in LTE, as well as related technological tricks to offload data traffic and maximize RAN capacity like spectrum refarming in the 900- and 1800-MHz bands and femtocells. TD-LTE is another tool in the toolbox, and by the time we start hitting monthly exabyte levels in five years, its predecessor in China will have been put through the ringer enough to qualify as "seasoned" if not "mature".

Of course, all that depends on a ton of factors over the next five years. Still, TDD is a lot closer to realizing its potential than it was at the start of the decade.

If nothing else, TD-LTE may have the novel distinction of being the quietest evolution the cellular world has yet seen. That will depend on how much progress Qualcomm and other chipset vendors make with dual-mode FDD/TDD chipsets, but once devices are capable of roaming seamlessly between both, TD-LTE may be the first RAN acronym that won't need to be marketed to end-users who don't give a toss what it's called anyway.

ST-Ericsson is creating a strong foothold in the evolving Chinese 3G market, and is powering the first modem for TD-HSPA, which can take advantage of the fastest speeds offered by China Mobile.

The silicon joint venture is working with Chinese partner Hojy Wireless on modules that will turn up in data cards and dongles early next year. China Mobile will hope these will boost uptake of its new network by heavy duty data users, a market where China Telecom's EV-DO system has so far shone more brightly. The M6718 modem could also be included in notebooks, netbooks and smartphones in future, as the market moves beyond data cards.

Mobile broadband modules, for incorporation in a range of devices, are an important part of the broader ST-Ericsson portfolio, with co-parent Ericsson a key customer as it bolsters its module business in 3G and LTE. The M6718 is a dual-mode TD-HSPA/EDGE device, supporting 2.8Mbps downlink and 2.2Mbps uplink.

LTE: moving from a promising technology to real business

Interesting presentation.

Tuesday, 20 October 2009

IMT-Advanced Proposals by 3GPP and IEEE

The proposals for IMT-Advanced that I mentioned about earlier have been put up on 3G4G website.

The 3GPP proposal for LTE-Advanced is here.

The IEEE proposal for 802.16m is here.

Saturday, 17 October 2009

Vodafone Access Gateway (VAG) femtocell setup

I blogged about ALU and Vodafone Femto earlier. Here is an Interesting Video showing unboxing, setting up and using the Femtocell.

Thursday, 15 October 2009

On Relay Technology in LTE-Advanced and WiMAX standards

I blogged earlier about Relay technology that is part of LTE-Advanced. In the IEEE Communications Magazine, this month there is a complete article on Relay technology. Here is a brief summary from that paper with my own understanding (and words).

We have mentioned about IMT-Advanced and LTE-Advanced before. International Mobile Telecommunications-Advanced is going to be the first 4G technology and as i discussed earlier, there are two main technologies vying for the 4G crown. I am sure both are as good and both will succeed. From 3GPP point of view, the standards will be part of Release-10 and should be ready end 2010 or beginning 2011. The understanding is that IMT-Advanced systems will support peak data rates of 100 Mb/s in high mobility environment (up to 350 km/h) and 1 Gb/s in stationary and pedestrian environments (up to 10 km/h). The transmission bandwidth of IMT-Advanced systems will be scalable and can change from 20 to 100 MHz, with downlink and uplink spectrum efficiencies in the ranges of [1.1, 15 b/s/Hz] and [0.7, 6.75 b/s/Hz], respectively. There will be a minimum requirement on voice over IP (VoIP) capacities in high- and low-mobility environments of around 30 and 50 active users/sector/MHz. The latency for control and user planes should be less than 100 ms and 10 ms, respectively, in unloaded conditions.


As I mentioned last week, the 3GPP candidate for IMT-Advanced is LTE-Advanced. On the IEEE front, 802.16j group published the relay-based multihop techniques for WiMAX and IEEE 802.16m has been submitted for the IMT-Advanced approval last week. The normal 802.16 WiMAX standard has been approved as 3G standard by the ITU.

So what exactly are Relays. Relay transmission can be seen as a kind of collaborative communications, in which a relay station (RS) helps to forward user information from neighboring user equipment (UE)/mobile station (MS) to a local eNode-B (eNB)/base station (BS). In doing this, an RS can effectively extend the signal and service coverage of an eNB and enhance the overall throughput performance of a wireless communication system. The performance of relay transmissions is greatly affected by the collaborative strategy, which includes the selection of relay types and relay partners (i.e., to decide when, how, and with whom to collaborate).



There are two different terminology used for Relay's. First is Type-I and Type-II and other is non-transparency and transparency. Specifically, a Type-I (or non-transparency) RS can help a remote UE unit, which is located far away from an eNB (or a BS), to access the eNB. So a Type-I RS needs to transmit the common reference signal and the control information for the eNB, and its main objective is to extend signal and service coverage. Type-I RSs mainly perform IP packet forwarding in the network layer (layer 3) and can make some contributions to the overall system capacity by enabling communication services and data transmissions for remote UE units. On the other hand, a Type-II (or transparency) RS can help a local UE unit, which is located within the coverage of an eNB (or a BS) and has a direct communication link with the eNB, to improve its service quality and link capacity. So a Type-II RS does not transmit the common reference signal or the control information, and its main objective is to increase the overall system capacity by achieving multipath diversity and transmission gains for local UE units.


Different relay transmission schemes have been proposed to establish two-hop communication between an eNB and a UE unit through an RS. Amplify and Forward — An RS receives the signal from the eNB (or UE) at the first phase. It amplifies this received signal and forwards it to the UE (or eNB) at the second phase. This Amplify and Forward (AF) scheme is very simple and has very short delay, but it also amplifies noise. Selective Decode and Forward — An RS decodes (channel decoding) the received signal from the eNB (UE) at the first phase. If the decoded data is correct using cyclic redundancy check (CRC), the RS will perform channel coding and forward the new signal to the UE (eNB) at the second phase. This DCF scheme can effectively avoid error propagation through the RS, but the processing delay is quite long. Demodulation and Forward — An RS demodulates the received signal from the eNB (UE) and makes a hard decision at the first phase (without decoding the received signal). It modulates and forwards the new signal to the UE (eNB) at the second phase. This Demodulation and Forward (DMF) scheme has the advantages of simple operation and low processing delay, but it cannot avoid error propagation due to the hard decisions made at the symbol level in phase one.

Relay starts becoming interesting because according to the 3GPP LTE-Advanced and IEEE 802.16j, an RS can act as the BS for legacy UE units and should have its own physical cell identifier. It should be able to transmit its own synchronization channels, reference symbols and downlink control information. So an RS shall have the full functions of an eNB/BS (except for traffic backhauling), including the capabilities of knowing the radio bearer of received data packets and performing traffic aggregation to reduce signaling overhead. There should be no difference between the cell controlled by an RS and that controlled by a normal eNB.

There are much more details and simulation results in the IEEE article. For those interested, can always get hold of the article and dig deeper.
More information also available in the following:

Monday, 12 October 2009

LTE Stuff

Just added some new material on LTE at 3G4G website. Check the LTE section here. Also started collection FAQ's. See here.

As always, comments, criticisms, suggestions and feedback welcome :)

Sunday, 11 October 2009

Google's strategy for winning in a nutshell

Interesting analysis by Zigurd Mednieks on his blog 4thscreen. Though not directly linked to mobiles, I am sure a similar approach is being taken for mobiles.

Google wants to enable Google applications to run as well as possible as many places as possible. Here is how:

Google applications: Web applications run in browsers, on all kinds of systems. No need to be installed or updated, and hard to block. Anyone with IE, Firefox, Safari, Opera, or, of course, Chrome has access to all the latest applications.

Gears: Web applications run in a sandbox and don't have much access to your system. Gears enables more access. Applications are still in a sandbox, but the Gears-enabled sandbox is bigger, and can persist. This frees Web applications from having to be connected all the time.

GWT: The Google Web Toolkit (GWT) is a radical abstraction of of the browser runtime environment. GWT applications are written in Java and compiled to JavaScript. The GWT library provides fixes for incompatibilities between browsers, as well as a rich UI library.

Chrome: Google's browser. Chrome provides the ideal browser runtime environment for Google applications. Fast JavaScript execution. Separate processes for each Web page.

Chrome Frame: Chrome Frame puts the Chrome browser inside Internet Explorer. This shows the lengths Google will go to in order to give Google applications the best possible runtime environment is as many situations as possible.

Android: Android is a Linux-based OS for mobile handsets and other devices. Android has exploded in popularity among handset manufacturers. This is Google's first win in computing platforms, and Google influences the software “stack” all the way down to the hardware. Android has a Webkit-derived browser.

Chrome OS: Chrome OS is meant for things larger than handsets. Chrome will be Google's attempt to bring a Linux-based OS and Web-based applications to netbooks and PCs.

Google's strategy is comprehensive: Control the software all the way down to the hardware where possible, and, if that isn't possible, be compatible, and maximize capabilities, on every possible platform.

Google's strategy is also technologically coherent: Java, Linux, Webkit, SQLite, Eclipse, and other common components are reused across multiple Google products and platforms. You can expect Google to contribute to and influence the development of these key ingredients. You can also see some design philosophy in common across Google products. For example, Android runs Java applications in multiple tasks, and Chrome runs Web pages/apps in multiple tasks to make these systems resilient to apps that crash.

While Google's applications, like Gmail, are proprietary, Android, Chrome, Gears, GWT and many other components of Google's strategy are open source software, many with permissive licensing that would not preclude competitors from using them. Open source builds confidence in Google's partners and in software developers using Google platforms.

Google's strategy has formed recently and moved quickly. It can be hard to perceive the impact. As fast as Google is implementing this strategy, you can expect a similarly fast emergence of an application ecosystem around Google's strategy. This will be one of the most significant developments in software in the coming years.

Meanwhile google has recently added search options to mobiles. You can now search only forums and you can search for posts that were posted within last week. Very powerful feature but shame so many PC users dont even know hot to use them.

Another very interesting feature that has been added is that when you search using desktop, you will be able to see that in your search history in mobiles as well. Google now synchs between your desktop and mobile as long as you have iPhone, Android or Palm phone.

I wonder how will Google surprise us next.

Friday, 9 October 2009

IMT-Advanced Proposals to be discussed next week

Depending on which camp you belong to, you would have read atleast one press release.

The 3GPP Partners, which unite more than 370 leading mobile technology companies, made a formal submission to the ITU yesterday, proposing that LTE Release 10 & beyond (LTE-Advanced) be evaluated as a candidate for IMT-Advanced. Complete press release here.

The IEEE today announced that it has submitted a candidate radio interface technology for IMT-Advanced standardization in the Radiocommunication Sector of the International Telecommunication Union (ITU-R).

The proposal is based on IEEE standards project 802.16m™, the “Advanced Air Interface” specification under development by the IEEE 802.16™ Working Group on Broadband Wireless Access. The proposal documents that it meets ITU-R’s challenging and stringent requirements in all four IMT-Advanced “environments”: Indoor, Microcellular, Urban, and High Speed. The proposal will be presented at the 3rd Workshop on IMT-Advanced in Dresden on 15 October in conjunction with a meeting of ITU-R Working Party 5D. Complete press release here.

The workshop next week will see lots of announcements, discussions and debates about both these technologies. More details on workshop here. My 3G4G page on LTE-Advanced here.
I am sure there is a place for both these technologies and hopefully both of them will succeed :)

Thursday, 8 October 2009

TD-SCDMA Politics!


I posted sometime back about China Mobile standards ready to battle the 3G standards. I read this interesting piece in The IET Magazine:

The wait is over for millions of Chinese mobile phone users. Following several years of delays, the government has finally issued the licences that were necessary for the introduction of third-generation cellular services in the country.

As ordered by the Ministry of Industry and Information Technology, each of the nation’s three main operators will have to build and operate a network based on one of the three different standards that were vying for a share of the world’s largest cellular market.

China Mobile (by far the dominant carrier with over 460 million subscribers) will operate on TD-SCDMA, the 3G technology that was developed entirely in the People’s Republic by the Chinese Academy of Telecommunications Technology in collaboration with Datang and Siemens. China Telecom will run on W-CDMA, while China Unicom gets CDMA2000.

Considering how immature TD-SCDMA technology still is - and how discouraging its build-up trials have proved - China Mobile seems to have landed the worst possible deal.

Then again, that was the whole idea of this so-called reorganisation of the country’s telecoms industry. Let the incumbent cellco work on the many problems that will have to be ironed out before TD-SCDMA can be considered a credible 3G alternative, and that should give the two smaller operators enough time to catch up by taking advantage of proven technologies and an established pool of equipment suppliers.

The Chinese government wants a more balanced, more competitive telecoms market, and this should help do the trick. But the move is also likely to have some strange consequences in the relationship between mobile operators and phone makers.

China Mobile faces two different handset-related challenges when it comes to 3G. The first one is qualitative: existing TD-SCDMA phones are technically inferior to those that subscribers have been using in the rest of the world for well over eight years now. The second is quantitative: only 40 or so TD-SCDMA models exist, while China Mobile says it will need several hundred.

So the company is resorting to some unprecedented behaviour for a cellular operator. At the last Mobile World Congress in Barcelona, Wang Jianzhou, the chairman of China Mobile, met with a group of handset vendors (including Nokia, LG, Samsung, Sony Ericsson and some of the Chinese manufacturers) and offered to pay them part of the R&D costs of developing better TD-SCDMA products.

Handset makers have rarely witnessed such generous attitudes from an operator. Even rarer is the fact that the offer is coming from what is now the world’s largest operator. Add to that the unfavourable financial conditions most of these OEMs are enduring and you could safely assume they’ll go and see what they can do to help China Mobile.

You can also read about what TD-SCDMA is here. More about the current status of TD-SCDMA here.

Wednesday, 7 October 2009

Femtocells Standardization in 3GPP

Femtocells have been around since 2007. Before Femtocells, the smallest possible cell was the picocell that was designed to serve a small area, generally a office or a conference room. With Femtocells came the idea of having really small cells that can be used in houses and they were designed to serve just one home. Ofcourse in my past blogs you would have noticed me mentioning about Super Femtos and Femto++ that can cater for more users in a small confined space, typically a small office or a meeting room but as far as the most common definition is concerned they are designed for small confined spaces and are intended to serve less than 10 users simultaneously.

This blog post is based on IEEE paper on "Standardization of Femtocells in 3GPP" that appeared in IEEE Communications Magazine, September 2009 issue. This is not a copy paste article but is based on my understanding of Femtos and the research based on the IEEE paper. This post only focusses on 3GPP based femtocells, i.e., Femtocells that use UMTS HSDPA/HSPA based technology and an introduction to OFDM based LTE femtocells.

The reason attention is being paid to the Femtocells is because as I have blogged in the past, there are some interesting studies that suggest that majority of the calls and data browsing on mobiles originate in the home and the higher the frequency being used, the less its ability to penetrate walls. As a result to take advantage of the latest high speed technologies like HSDPA/HSUPA, it makes sense to have a small cell sitting in the home giving ability to the mobiles to have high speed error free transmission. In addition to this if some of the users that are experiencing poor signal quality are handed over to these femtocells, the overall data rate of the macro cell will increase thereby providing better experience to other users.

Each technology brings its own set of problems and femocells are no exception. There are three important problems that needs to be answered. They are as follows:

Radio interference mitigation and management: Since femtocells would be deployed in adhoc manner by the users and for the cost to be kept down they should require no additional work from the operators point of view, they can create interference with other femtocells and in the worst possible scenario, with the macro cell. It may not be possible initially to configure everything correctly but once operational, it should be possible to adjust the parameters like power, scrambling codes, UARFCN dynamically to minimise the interference.

Regulatory aspects: Since the mobiles work in licensed spectrum bands, it is required that they follow the regulatory laws and operate in a partcular area in a band it is licensed. This is not a problem in Europe where the operators are given bands for the whole country but in places like USA and India where there are physical boundaries within the country for the allocation of spectrum for a particular operator. This brings us to the next important point.

Location detection: This is important from the regulatory aspect to verify that a Femtocell can use a particular band over an area and also useful for emergency case where location information is essential. It is important to make sure that the user does not move the device after initial setup and hence the detection should be made everytime the femto is started and also at regular intervals.

3GPP FEMTOCELLS STANDARDIZATION

Since the femtocells have been available for quite a while now, most of them do not comply to standards and they are proprietary solutions. This means that they are not interoperable and can only work with one particular operator. To combat this and to create economy of scale, it became necessary to standardise femtocells. Standardized interfaces from the core network to femtocell devices can potentially allow system operators to deploy femtocell devices from multiple vendors in a mix-and-match manner. Such interfaces can also allow femtocell devices to connect to gateways made by multiple vendors in the system operator’s core network (e.g., home NodeB gateway [HNB-GW] devices).

In 2008, Femto Forum was formed and it started discussion on the architecture. From 15 different proposals, consensus was reached in May over the Iuh interface as shown below.

There are two main standard development organizations (SDOs) shaping the standard for UMTS-related (UTRAN) femto technology: 3GPP and The Broadband Forum (BBF).
More about 3GPP here. BBF (http://www.broadbandforum.org) was called the DSL Forum until last year. As an SDO to meet the needs of fixed broadband technologies, it has created specifications mainly for DSL-related technologies. It consists of multiple Working Groups. The Broadband Home WG in particular is responsible for the specification of CPE device remote management. The specification is called CPE wide area network (WAN) Management Protocol (CWMP), which is commonly known by its document number, TR-069.

There are several other important organisations for femto technology. The two popular ones are the Femto Forum (www.femtoforum.org) and Next Generation Mobile Network (NGMN).

3GPP has different terminology for Femtocells and components related to that. They are as follows:

Generic term: Femtocell
3GPP Term: home NodeB (HNB)
Definition: The consumer premises equipment (CPE) device that functions as the small-scale nodeB by interfacing to the handset over the standard air interface (Uu) and connecting to the mobile network over the Iuh interface.

Generic term: FAP Gateway (FAP-GW) or Concentrator
3GPP Term: home NodeB gateway (HNB-GW)
Definition: The network element that directly terminates the Iuh interface with the HNB and the existing IuCS and IuPS interface with the CN. It effectively aggregates a large number of HNBs (i.e., Iuh interface) and presents it as a single IuCS/PS interface to the CN.

Generic term: Auto-Configuration Server (ACS)
3GPP Term: home NodeB management system (HMS)
Definition: The network element that terminates TR-069 with the HNB to handle the remote management of a large number of HNBs.

In addition, there is a security gateway (SeGW) that establishes IPsec tunnel to HNB. This ensures that all the Iuh traffic is securely protected from the devices in home to the HNB-GW.
The HNB-GW acts as a concentrator to aggregate a large number of HNBs which are logically represented as a single IuCS/IuPS interface to the CN. In other words, from the CN’s perspective, it appears as if it is connected to a single large radio network controller (RNC). This satisfies a key requirement from 3GPP system operators and many vendors that the femtocell system architecture not require any changes to existing CN systems.

The radio interface between HNB and UE is the standard RRC based air interface but has been modified to incude HNB specific changes like the closed subscriber group (CSG) related information.

Two new protocols were defined to address HNB-specific differences from the existing Iu interface protocol to 3GPP UMTS base stations (chiefly, RANAP at the application layer).

HNB Application Protocol (HNBAP): An application layer protocol that provides HNB-specific control features unique to HNB/femtocell deployment (e.g., registration of the HNB device with the HNBGW).

RANAP User Adaptation (RUA): Provides a lightweight adaptation function to allow RANAP messages and signaling information to be transported directly over Stream Control Transport Protocol (SCTP) rather than Iu, which uses a heavier and more complex protocol stack that is less well suited to femtocells operating over untrusted networks from home users (e.g., transported over DSL or cable modem connections).


Figure above is representation of the protocol stack diagram being used in TS 25.467.

Security for femtocell networks consists of two major parts: femtocell (HNB) device authentication, and encryption/ciphering of bearer and control information across the untrusted Internet connection between the HNB and the HNB-GW (e.g., non-secure commercial Internet service). The 3GPP UMTS femtocell architecture provides solutions to both of these problems. 3GPP was not able to complete the standardization of security aspects in UMTS Release 8; however, the basic aspects of the architecture were agreed on, and were partially driven by broad industry support for a consensus security architecture facilitated in discussions within the Femto Forum. All security specifications will be completed in UMTS Release 9 (targeted for Dec. 2009).

FEMTOCELL MANAGEMENT

Management of femtocells is a very big topic and very important one for the reasons discussed above.

The BBF has created CWMP, also referred to as TR-069. TR-069 defines a generic framework to establish connection between the CPE and the automatic configuration server (ACS) to provide configuration of the CPE. The messages are defined in Simple Object Access Protocol (SOAP) methods based on XML encoding, transported over HTTP/TCP. It is flexible and extensive enough to incorporate various types of CPE devices using various technologies. In fact, although TR-069 was originally created to manage the DSL gateway device, it has been adopted by many other types of devices and technologies.

The fundamental functionalities TR-069 provides are as follows:
• Auto-configuration of the CPE and dynamic service provisioning
• Software/firmware management and upgrade
• Status and performance monitoring
• Diagnostics

The auto-configuration parameters are defined in a data model. Multiple data model specifications exist in the BBF in order to meet the needs of various CPE device types. In fact, the TR-069 data model is a family of documents that has grown over the years in order to meet the needs of supporting new types of CPE devices that emerge in the market. In this respect, femtocell is no exception. However, the two most common and generic data models are:
TR-098: “Internet Gateway Device Data Model for TR-069”
TR-106: “Data Model Template for TR-069-Enabled Devices”

HAND-IN AND FEMTO-TO-FEMTO HANDOVERS

The 3GPP specifications focused on handovers in only one direction initially — from femtocell devices to the macrocellular system (sometimes called handout). A conscious decision was made to exclude handover from the macrocellular system to the femtocell devices (sometimes called macro to femtocell hand-in). This decision was driven by two factors:
• There are a number of technical challenges in supporting hand-in with unmodified mobile devices and core network components.
• The system operator requirements clearly indicate that supporting handout is much more important to end users.
Nonetheless, there is still a strong desire to develop open, interoperable ways to support handin in an efficient and reliable manner, and the second phase of standards in 3GPP is anticipated to support such a capability.

NEXT-G EFFORTS

3GPP Release 8 defines the over-the-air radio signaling that is necessary to support LTE femtocells. However, there are a number of RAN transport and core network architecture, interface, and security aspects that will be addressed as part off 3GPP’s Release 9 work efforts. While it is preliminary as of the publication of this article, it seems highly likely that all necessary RAN transport and core network work efforts for LTE femtocells will be completed in 3GPP Release 9 (targeted for completion by the end of 2009).

3GPP STANDARDS ON FEMTOCELLS

[1] 3GPP TS 25.331: RRC
[2] 3GPP TS 25.367: Mobility Procedures for Home NodeB (HNB); Overall Description; Sage 2
[3] 3GPP TS 25.467: UTRAN Architecture for 3G Home NodeB; Stage 2
[4] 3GPP TS 25.469: UTRAN Iuh Interface Home NodeB (HNB) Application Part (HNBAP) Signaling
[5] 3GPP TS 25.468: UTRAN Iuh Interface RANAP User Adaption (RUA) Signaling
[6] 3GPP TR 3.020: Home (e)NodeB; Network Aspects -(http://www.3gpp.org/ftp/tsg_ran/WG3_Iu/R3_internal_TRs/R3.020_Home_eNodeB/)
[7] 3GPP TS 25.104: Base Station (BS) Radio Transmission and Reception (FDD)
[8] 3GPP TS 25.141: Base Station (BS) Conformance Testing (FDD)
[9] 3GPP TR 25.967: FDD Home NodeB RF Requirements
[10] 3GPP TS 22.011: Service Accessibility
[11] 3GPP TS 22.220: Service Requirements for Home NodeB (HNB) and Home eNodeB (HeNB)
[12] 3GPP TR 23.830: Architecture Aspects of Home NodeB and Home eNodeB
[13] 3GPP TR 23.832: IMS Aspects of Architecture for Home NodeB; Stage 2
[14] 3GPP TS 36.300: E-UTRA and E-UTRAN; Overall Description; Stage 2
[15] 3GPP TR 33.820: Security of H(e)NB 3GPP TR 32.821: Telecommunication Management; Study of Self-Organizing Networks (SON) Related OAM Interfaces for Home NodeB
[16] 3GPP TS 32.581: Telecommunications Management; Home Node B (HNB) Operations, Administration, Maintenance and Provisioning (OAM&P); Concepts and Requirements for Type 1 Interface HNB to HNB Management System (HMS)
[17] 3GPP TS 32.582: Telecommunications Management; Home NodeB (HNB) Operations, Administration, Maintenance and Provisioning (OAM&P); Information Model for Type 1 Interface HNB to HNB Management System (HMS)
[18] 3GPP TS 32.583: Telecommunications Management; Home NodeB (HNB) Operations, Administration, Maintenance and Provisioning (OAM&P); Procedure Flows for Type 1 Interface HNB to HNB Management System (HMS)
[19] 3GPP TS 32.584: Telecommunications Management; Home NodeB (HNB) Operations, Administration, Maintenance and Provisioning (OAM&P); XML Definitions for Type 1 Interface HNB to HNB Management System (HMS)
I would strongly recommend reading [3] and [6] for anyone who wants to gain better understanding of how Femtocells work.

Monday, 5 October 2009

Industry's first LTE Comformance test submitted for approval


Anite has submitted the first LTE test case 8.1.2.1 based on the conformance test specification 36.523-1. The test case was debugged using the LG Electronics LE03 UE.

This is in a way good news as the industry is moving forward at an amazing speed. The Release-8 of LTE was finalised in reality in March 09 (or Dec. 08 for some specs).

Anite has partnered with Agilent for the conformance testing and this release of TC's is a good way forward towards proving industry leadership.

Looking at the latest test cases that have been submitted, it seems another couple of tests 7.1.1.1 and 8.1.1.1 have been submitted as well.

People who are interested in technical details can look at the logs submitted and get the details of the messages that I have specified in the message flow earlier here.

====== Edited after post =====

Here is their press release which seems to have come after my blog :)

Anite, a global leader in testing technology for the wireless industry, and LG Electronics (LG), a global leader and technology innovator in mobile communications, today announced the successful verification of the industry’s first LTE protocol conformance test cases. Anite and LG Electronics have made the results from their groundbreaking work available to the members of the 3GPP standards body, so that the entire mobile industry may benefit from this milestone achievement.

Conformance testing is fundamental in leading-edge technologies, such as LTE, because it ensures that new handsets and data cards deliver both the applications and services anticipated by the end user and the ability to work seamlessly with existing users and networks. LG uses Anite’s LTE solution – which provides a suite of development tools for UE designers – to develop their devices in advance of LTE networks being available, ensuring these meet the industry’s rigorous certification requirements during the earliest stages of their development cycle.

The new tests build upon Anite’s comprehensive portfolio for all leading 3GPP protocol technologies from GSM through EDGE and WCDMA to the latest HSPA+ standards. Anite’s unique blend of software-only host and target test solutions for 2G, 3G and LTE technologies allows developers to adopt a total end-to-end test philosophy for all of their wireless testing needs, reducing both their time and cost to market.

"LTE device certification is essential in ensuring that next generation LTE wireless devices meet customer expectations. Working with LG is speeding the availability of the first LTE test cases to LTE developers, enabling the wireless industry to deploy the technology successfully and more quickly," said Paul Beaver, 3GPP Director, Anite. “Our customers can be confident that investing in Anite’s products will meet their conformance testing needs, maximising their test system utilisation and return on investment.”

Twitter could be very useful ;)


Friday, 2 October 2009

Thursday, 1 October 2009

Interesting stats from Tomi Ahonen's talk on 'the next 4 Billion Mobile Subscribers'


Tomi has posted an interesting blog titled "What do I mean, by 'next four billion'?". Its an interesting read. As usual there are lots of interesting facts that i am posting here for my own reference :)
  • 4 Billion: Global count of mobile subscribers at the start of 2009
  • 480 million newspapers printed daily
  • 800 million automobiles registered on the planet
  • 1.1 billion personal computers including all desktops, laptops, notebooks and netbooks
  • 1.2 billion fixed landine phones
  • 1.4 billion internet users
  • 1.5 billion TV sets
  • 1.7 billion unique holders of a credit card of any type
  • 2.1 billion unique holders of a banking account of any kind
  • Total FM Radio worldwide: 3.9 Billion units
  • Total human population: 6.7 Billion
  • Out of 4 billion total mobile subscribers at the end of last year, 3.1 billion were unique phone owners, and the remaining 900 million were second and third subscriptions
  • Europe today is at 115% penetration rate
  • USA is past 90% penetratation rate per capita
  • Hong Kong, Italy, Israel, Portugal and Singapore are past 130% penetration levels - and still growing
  • The planet is at 64% penetration rate now
  • The UN estimates that the amount of illiterate people on the planet is 800 million
  • SMS has 3.1 billion active users
  • MMS has 1.4 billion active users with over 3 billion phones that can receive MMS messages

Thank you Tomi for these interesting facts