WiMAX Network reference model

Continuing from yesterdays post.

The WiMAX network architecture is designed to meet the requirements while maximizing the use of open standards and IETF protocols in a simple all-IP architecture. Among the design requirements are supports for fixed and mobile access deployments as well as unbundling of access, connectivity, and application services to allow access infrastructure sharing and multiple access infrastructure aggregation.

The baseline WiMAX network architecture can be logically represented by a network reference model (NRM), which identifies key functional entities and reference points over which the network interoperability specifications are defined. The WiMAX NRM differentiates between network access providers (NAPs) and network service providers (NSPs). The NAP is a business entity that provides WiMAX radio access infrastructure, while the NSP is the business entity that provides IP connectivity and WiMAX services to WiMAX subscribers according to some negotiated service level agreements (SLAs) with one or more NAPs. The network architecture allows one NSP to have a relationship with multiple NAPs in one or different geographical locations. It also enables NAP sharing by multiple NSPs. In some cases the NSP may be the same business entity as the NAP.

The WiMAX NRM, as illustrated in Fig. 3, consists of several logical network entities: MSs, an access service network (ASN), and a connectivity service network (CSN), and their interactions through reference points R1–R8. Each MS, ASN, and CSN represents a logical grouping of functions as described in the following:

• Mobile station (MS): generalized user equipment set providing wireless connectivity between a single or multiple hosts and the WiMAX network. In this context the term MS is used more generically to refer to both mobile and fixed device terminals.

• Access service network (ASN): represents a complete set of network functions required to provide radio access to the MS. These functions include layer 2 connectivity with the MS according to IEEE 802.16 standards and WiMAX system profile, transfer of auathentication, authorization, and accounting (AAA) messages to the home NSP (HNSP), preferred NSP discovery and selection, relay functionality for establishing layer 3 (L3) connectivity with MS (i.e., IP address allocation), as well as radio resource management. To enable mobility, the ASN may also support ASN and CSN anchored mobility, paging and location management, and ASN-CSN tunneling.

• Connectivity service network (CSN): a set of network functions that provide IP connectivity services to WiMAX subscriber(s). The CSN may further comprises network elements such as routers, AAA proxy/ servers, home agent, and user databases as well as interworking gateways or enhanced broadcast services and location-based services.

A CSN may be deployed as part of a green field WiMAX NSP or part of an incumbent WiMAX NSP. The following are some of the key functions of the CSN:–IP address management–AAA proxy or server–QoS policy and admission control based on user subscription profiles–ASN-CSN tunneling support –Subscriber billing and interoperator settlement–Inter-CSN tunneling for roaming–CSN-anchored inter-ASN mobility–Connectivity to Internet and managed WiMAX services such as IP multimedia services (IMS), location-based services, peer-to-peer services, and broadcast and multicast services –Over-the-air activation and provisioning of WiMAX devices

• Base station (BS): a logical network entity that primarily consists of the radio related functions of an ASN interfacing with an MS over-the-air link according to MAC and PHY specifications in IEEE 802.16 specifications subject to applicable interpretations and parameters defined in the WiMAX Forum system profile. In this definition each BS is associated with one sector with one frequency assignment but may incorporate additional implementation-specific functions such as a DL and UL scheduler.

• ASN gateway (ASN-GW): a logical entity that represents an aggregation of centralized functions related to QoS, security, and mobility management for all the data connections served by its association with BSs through R6t. The ASN-GW also hosts functions related to IP layer interactions with the CSN through R3 as well as interactions with other ASNs through R4 in support of mobility.

Typically multiple BSs may be logically associated with an ASN. Also, a BS may be logically connected to more than one ASN-GW to allow load balancing and redundancy options. The WiMAX network specification defines a single decomposed ASN profile (ASN C) with an open R6 interface as well as an alternative ASN profile B that may be implemented as an integrated or a decomposed ASN in which R6 is proprietary or not exposed. The normative definitions of intra-ASN reference points (R6 and R8) are only applicable to profile C. Note that in release 1.5 profile A has been removed to reduce the number of implementation options and create a better framework for network interoperability.

Reference: Overview of Mobile WiMAX Technology and Evolution - Kamran Etemad, Intel Corporation

Mobile WiMAX technology and network evolution roadmap.

The Mobile WiMAX Release 1.0 System Profile, based on 802.16e or 802.16-2005, was completed in late 2006, and the radio-level certification of products began in 2007. The certification follows a phased approach to address deployment priorities and vendor readiness. System Profile Release 1.0 includes all 802.16-2005 mandatory features, and also requires some of the optional features needed for enhanced mobility and QoS support. This system profile is based on OFDMA, and enables downlink and uplink multiple-input multipleoutput (MIMO) as well as beamforming (BF) features. The release 1.0 system profile is defined only for the TDD mode of operation, with more focus on 5 and 10 MHz bandwidths in several band classes in 2.3 GHz, 2.5 GHz ,and 3.5 GHz bands, but it also includes 8.75 MHz specifically for Korea.

The WiMAX certification for the release 1.0 profile started with a Wave 1 subset, excluding MIMO and a few optimization features, to enable early market deployments. This was followed by Wave 2, which progressively adds more and more feature tests over time based on vendors and testing tool availability. The early phases of certification were also limited to MAC and PHY layer conformance and interoperability testing, which will be expanded to add networklevel testing.

Meanwhile, the development of WiMAX Forum Network Release 1.0 was completed in 2007, based on which the specific network-level device conformance testing as well as infrastructure interoperability testing projects were initiated. The goal was to ensure e2e interoperability of WiMAX devices with networks and also ensure multivendor plug and play network infrastructure deployments. Release 1.0 defines the basic architecture for IP-based connectivity and services while supporting all levels of mobility. Based on operators’ requirements for advanced services and new market opportunities to be more competitive with evolved 3G systems, the WiMAX Forum initiated interim releases for both the system profile and network without major modifications to the IEE 802.16 standard. The work on network release 1.5 network specifications was started in parallel, aimed primarily at enabling dynamic QoS and provisioning of open retail device and support for advanced network services as well as commercial grade VoIP.

The release 1.5 system profile work item was initiated to enable mobile WiMAX in new spectrum including frequency-division duplex (FDD) bands, address a few MAC efficiency improvements needed for technology competitiveness, and align the system profile with advanced network services supported by network release 1.5. All required fixes and minor enhancements needed to support release 1.5 are incorporated in IEEE 802.16 REV2, which combines the IEEE 802.16-2004 base standard plus IEEE 802.16e/f/g amendments and related corrigenda into one specification document.

Following Release 1.5, the next major release mobile WiMAX, Release 2.0, will be based on the next generation of IEEE 802.16, which is being developed in the 16m technical group (TGm) of 802.16. WiMAX Release 2 targets major enhancements in spectrum efficiency, latency, and scalability of the access technology to wider bandwidths in challenging spectrum environments. Currently the expected timeline for the formal completion of 802.16m and WiMAX Certification of Release 2 products are early 2010 and early 2011, respectively.

In parallel with developments in IEEE on the stage 2 system-level description of 802.16m, the requirements for network release 2.0 are being discussed in the WiMAX Forum, where stage 2/3 specifications are expected to be completed by 2010.

Reference: Overview of Mobile WiMAX Technology and Evolution - Kamran Etemad, Intel Corporation

Wavesecure: Helping track lost phones

Siliconindia organized Mobile Applications Conference (MAC) on October 31, where 25 mobile companies exhibited their applications and presented their business plans in NIMHANS (National Institute of Mental Health and Neuro Sciences) convention center, Bangalore, in front of around 400 people and entrepreneurs. Industry leaders within the mobile space also put some light on where the industry is headed and how entrepreneurs and developers can take advantage.

TenCube, whose anchor product, WaveSecure, is the market leading mobile security suite recognized by customers and analysts, won the best mobile application award. TenCube was the unanimous choice of judges as well as the audience. It got 71 votes followed by Eterno Infotech and Divium, which got 37 and 36 votes respectively. Originally developed for police and military use in Singapore, WaveSecure has become Nokia's preferred mobile security product, chosen to be bundled into millions of premium Nokia devices. It is also the preferred security service selected by leading operators like Telenor and SingTel for their subscribers.

Very interesting FAQ's for those interested.

See Demo below:

30 years for the first commercial mobile network in Dec.

Tomi recently posted a blog on Birthdays and how the first commercial network will complete 30 years. It was first of December 1979, that the world's first commercial cellular automated (and 'modern') mobile telecoms network went live in Tokyo Japan, launched by NTT.ANd yes the mobile phone subscriber count will hit 4.6 billion by the end of the year. We passed a billion users in 2002, so it only took 23 years to hit a billion mobile phones on the planet.

While looking for the photo of the original phone, I came across one of the earliest phones used by Martin Cooper of Motorola. He is known to have made the first public call in USA over36 years back. Wikipedia has a section on the Motorola DynaTAC in the picture above.

Here is the comparison of DynaTAC with the earlier model of iPhone.

And last but by no means least, the mobile internet is 10 years old. Launched by NTT DoCoMo of Japan in 1999, its iconic iMode mobile internet was the first mobile-optimized internet service and spawned countless copies and today counting all the WAP users etc, has over a billion users. That in only ten years.. Domo Arigato, NTT DoCoMo, you have invented the fastest technology to spread to a billion users.

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

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.

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.

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 :(

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.

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.