OFDM and OFDMA: The Difference

I was curious as to why IEEE 802.16d (fixed service) uses Orthogonal Frequency Division Multiplexing (OFDM). IEEE 802.16e (mobile) uses Orthogonal Frequency Division Multiple Access (OFDMA). So, what’s the difference between the two, and why is there a difference?

Lets first look at FDM:

In FDM system, signals from multiple transmitters are transmitted simultaneously (at the same time slot) over multiple frequencies. Each frequency range (sub-carrier) is modulated separately by different data stream and a spacing (guard band) is placed between sub-carriers to avoid signal overlap.

OFDM is sometimes referred to as discrete multi-tone modulation because, instead of a single carrier being modulated, a large number of evenly spaced subcarriers are modulated using some m-ary of QAM. This is a spread-spectrum technique that increases the efficiency of data communications by increasing data throughput because there are more carriers to modulate. In addition, problems with multi-path signal cancellation and spectral interference are greatly reduced by selectively modulating the “clear” carriers or ignoring carriers with high bit-rate errors.

Like FDM, OFDM also uses multiple sub-carriers but the sub-carriers are closely spaced to each other without causing interference, removing guard bands between adjacent sub-carriers. This is possible because the frequencies (sub-carriers) are orthogonal, meaning the peak of one sub-carrier coincides with the null of an adjacent sub-carrier.

In an OFDM system, a very high rate data stream is divided into multiple parallel low rate data streams. Each smaller data stream is then mapped to individual data sub-carrier and modulated using some sorts of PSK (Phase Shift Keying) or QAM (Quadrature Amplitude Modulation). i.e. BPSK, QPSK, 16-QAM, 64-QAM.

OFDM needs less bandwidth than FDM to carry the same amount of information which translates to higher spectral efficiency. Besides a high spectral efficiency, an OFDM system such as WiMAX is more resilient in NLOS environment. It can efficiently overcome interference and frequency-selective fading caused by multipath because equalizing is done on a subset of sub-carriers instead of a single broader carrier. The effect of ISI (Inter Symbol Interference) is suppressed by virtue of a longer symbol period of the parallel OFDM sub-carriers than a single carrier system and the use of a cyclic prefix (CP).

The OFDM spread-spectrum scheme is used for many broadly used applications, including digital TV broadcasting in Australia, Japan and Europe; digital audio broadcasting in Europe; Asynchronous Digital Subscriber Line (ADSL) modems and wireless networking worldwide (IEEE 802.11a/g).

Like OFDM, OFDMA employs multiple closely spaced sub-carriers, but the sub-carriers are divided into groups of sub-carriers. Each group is named a sub-channel. The sub-carriers that form a sub-channel need not be adjacent. In the downlink, a sub-channel may be intended for different receivers. In the uplink, a transmitter may be assigned one or more sub-channels.

Subchannelization defines sub-channels that can be allocated to subscriber stations (SSs) depending on their channel conditions and data requirements. Using subchannelization, within the same time slot a Mobile WiMAX Base Station (BS) can allocate more transmit power to user devices (SSs) with lower SNR (Signal-to-Noise Ratio), and less power to user devices with higher SNR. Subchannelization also enables the BS to allocate higher power to sub-channels assigned to indoor SSs resulting in better in-building coverage.

Subchannelization in the uplink can save a user device transmit power because it can concentrate power only on certain sub-channel(s) allocated to it. This power-saving feature is particularly useful for battery-powered user devices, the likely case in Mobile WiMAX.

The WiMAX forum established that, initially, OFDM-256 will be used for fixed-service 802.16d (2004). It is referred to as the OFDM 256 FFT Mode, which means there are 256 subcarriers available for use in a single channel. Multiple access on one channel is accomplished using TDMA. Alternatively, FDMA may be used.

On the other hand, OFDMA 128/512/1024/2048 FFT Modes have been proposed for IEEE 802.16e (mobile service). OFDMA 1024 FFT matches that of Korea’s WiBRO. OFDM 256 also is supported for compatibility with IEEE 802.16d (fixed, 2004).

3G in 900MHz band can make 3G a winner

The widespread deployment of 3G networks in the 900MHz GSM spectrum band, as well as the 2100MHz band, could enable an additional 300 million people across Asia, Europe and Africa to enjoy mobile broadband services by 2012, according to a study by the analyst and consulting company Ovum for the GSMA.

Note: HSPA is already being deployed at 900MHz in Finland and trials are underway in a number of other countries, such as France and the Isle of Man. More about this is available here.

In 900MHz, the greater range of radio waves in the lower spectrum band and their ability to provide better coverage in buildings would enable operators to achieve much broader 3G coverage, particularly in rural areas. The study shows that a 3G network in the 900MHz band would achieve up to 40% greater coverage than a 3G network in the 2100MHz band for the same capital expenditure.

The cost-effectiveness of 3G at 900MHz would be of particular significance in developing countries, many of which are looking to HSPA, an evolution of the leading 3G technology, to provide high-speed Internet access in the many regions that lack fixed-line infrastructure. However, Ovum cautions that the level of success of 3G in the 900MHz band will depend on multiple countries making this spectrum band available in a harmonised way, so that equipment manufacturers have a large market to target and can quickly achieve economies of scale, particularly for handsets.

Ovum envisages that operators would use 900MHz to provide widespread 3G coverage, supplemented by 3G at 2100MHz in urban ‘hot-spots’ that need more capacity. The extensive use of both the 900MHz and the 2100MHz bands for 3G in Asia–Pacific countries could lead to 450 million people in the region using 3G by 2012, if all operators chose to deploy 3G and the majority of investment goes into 3G at 900MHz. If 3G were restricted to 2100MHz alone, Ovum forecasts there will be just 200 million people using 3G in the region by 2012.

In light of these findings, the GSMA urges regulators, together with vendors, to plan together for the coordinated refarming of 900/1800MHz spectrum, which is widely used for GSM in Europe, Asia and Africa, and for the availability of compatible and affordable handsets. Such global planning will give investors the confidence to fund the development of 3G/HSPA at 900MHz and 1800MHz as well. There should be no differentiation between the different GSM bands (900/1800/1900) to avoid any distortion of competition among GSM operators. The same benefits would also be achieved by refarming 850MHz spectrum (widely used in US and Latin America).

According to the Inquirer, the GSMA may have fallen into a trap. China has its own flavour of 3G – called TD-SCDMA. One of the benefits of this standard – compared to W-CDMA which the GSMA promotes – is that it shares infrastructure costs with existing GSM equipment. Naturally providing cost savings. So while the GSMA is admitting that standard W-CDMA at 2100 MHz is too expensive for developing economies, China can quite reasonably say, "We know. That's why we've stuck with TD-SCDMA.
A bit of an own goal really.

OMA seeks to ease mobile TV pain

The Open Mobile Alliance's recently-unveiled BCAST Enabler specification is designed to create a 'write once, run anywhere' environment' for broadcasters and other content providers. The spec - if widely adopted - could have significant implications for the concept of mobile TV 'roaming'.

In theory, it means broadcasters will be able to deploy their programming across the whole gamut of broadcast mobile TV platforms - DVB-H, DVB-SH, DMB, DAB-IP, ATSC-M/H etc - with little or no tweaking.

Because it works with any IP-based content delivery technology BCAST Enabler can also be used for the delivery of programming across cellular systems like 3GPP MBMS, 3GPP2 BCMCS and mobile unicast streaming systems, such as 3G streaming.

What benefits will OMA BCAST offer broadcasters and broadcast network operators?

• The specification enables broadcast-only mode for delivering services. It also allows broadcast-only terminals and free-to-air content with service and content protection capability.

• The specification is agnostic to access network meaning that the same service offering can be delivered over broadcast channel, interaction channel or both. Being agnostic to underlying architecture allows integration of the broadcast offering with operators or independent delivery over the interaction channel, which is controlled by broadcaster.

• Service interactivity is well specified and caters for broad range of services including interactive and direct feedback from viewers. Also, the service interactivity is not bound to the cellular channel – WLAN or a similar network can also be used. The use of the interaction channel allows personalization of services and service guides.

• The Service Guide enables the broadcaster to associate broadcast
programming with on-demand content. In addition, it supports both broadcast and on-demand delivery of the Service Guide itself.

What benefits will OMA BCAST offer terminal manufacturers?

• The Mobile TV Enabler specifies features for a common TV & video service layer that are currently not addressed by other specifications but still needed to ensure interoperability for large-scale terminal availability.

• Enables economies of scale by leveraging same technologies for both
broadcast and interactive channels. This means vendors can build an
economically viable terminal base that can be used by operators/carriers or broadcasters or jointly by both.

Certified Wireless USB's and Cablefree USB

This is a copy from my old blog.

While doing some background sstudy of Wireless USB i came acrosss interesting information. Apparently there are two different Wireless USB standards that are being developed and they are not compatible with each other. More information aas follows:

Wireless USB (also known as Cablefree USB)

* Supported by UWB forum (pioneered by Freescale semiconductor)

* Uses DS-UWB (direct sequence)

* It mimics USB 2.0 in its interfaces to host and peripheral devices, handling the wireless issues within device adapters.

* This approach of retaining the USB 2.0 protocol means that developers can quickly offer products that users can simply plug in without making any system changes.

* Existing USB drivers will work

* The current Freescale UWB chipset operates at 114Mbps with a likely throughput of 50Mbps

Certified Wireless USB

* Supported by WiMedia alliance and USB-IF (USB Implementers Forum)

* Uses OFDM-UWB

* Certified Wireless USB employs a new communications protocol, similar but not identical to USB, to address the wireless issues.

* The Certified Wireless approach, on the other hand, required the definition of a new specification. The initial specification, which its developers released in May 2005, received a supplement defining the association's methods in March 2006. The specifications are now under the control of the USB-IF.

* Will need new software and USB drivers

* They operate at 480Mbps like USB 2.0 with probably similar throughput (peak 320Mbps)

2.5 Billion GSM Subscribers Worldwide

Bellevue, WA, June 05, 2007 -
Today, 3G Americas reports that the number of GSM mobile wireless subscribers worldwide has reached 2.5 billion, a stunning 400% increase in GSM subscribers from only six years ago, according to the estimates of Informa's World Cellular Information Service. Every day, there are more than one million new additions to the GSM family of technology users receiving service from one of 700 commercial GSM networks across 218 countries and territories around the world.

“It’s unprecedented for almost any global industry to achieve the growth and success demonstrated by the GSM family of technologies, with an estimated 2.5 billion global customers today,” stated Chris Pearson, President of 3G Americas. “This level of wireless technology growth exceeds that of almost all other lifestyle-changing innovations.”
Looking back, it was almost one hundred years ago when the first so-called "mobile" phone call was made by Lars Ericsson in 1910— although not wireless, as Ericsson attached wires to a telephone pole terminal to make his call while on the road. 2007 marks the 60th anniversary of AT&T and Bell Laboratories' 1947 invention of the cellular phone. Today, it is estimated that more than 37% of the world's 6.6 billion people (US Census Bureau) use GSM technology.

GSM subscribers, including nearly 130 million UMTS/HSDPA subscriptions, currently comprise nearly 85% of the global mobile wireless market. GSM became the dominant Latin American mobile wireless technology in less than a decade since its launch in the region in 1998, acquiring 2 million subscribers by the year 2000, and 200 million by end of year 2006. The GSM family now serves 331 million customers in all the Americas as of 1Q 2007, and is available in every single country. This market leadership is due to the numerous technical and economic benefits of the GSM family of technologies for both operators and their customers.

GSM technologies, including GPRS, EDGE and UMTS/HSPA, offer overwhelming advantages in terms of global scope, scale, international roaming and service that are still unmatched by other mobile wireless technologies. As of May 2007, there are 169 UMTS operators in service across 71 countries, and 117 of those operators in 59 countries have deployed an enhanced version of UMTS called HSDPA. Additionally, nearly all UMTS/HSDPA devices manufactured today include the EDGE technology as the compatible fallback technology, allowing for global roaming and delivery of high-speed wireless data services.
HSPA (HSDPA/HSUPA) technology is poised to be the leading mobile broadband technology for the rest of the decade, outpacing alternative mobile broadband technologies by leveraging on the current installed base of the GSM family of technologies and providing the most efficient solution. It is expected that almost all GSM/EDGE operators will someday migrate to HSPA technology.

Pearson continued, “While other technologies are grabbing attention, HSPA is being rolled out around the world, separating future promise from that which is available today. Building upon the enormous foundation of customers and commercial deployment of GSM, and the broad research and development by vendors, HSPA will continue in its mobile broadband leadership position for years to come.”

For white papers, statistics and more information on the GSM family of technologies, visit http://www.3gamericas.org/.

About 3G Americas: Unifying the Americas through Wireless Technology
The mission of 3G Americas is to promote and facilitate the seamless deployment throughout the Americas of GSM and its evolution to 3G and beyond. The organization fully supports the Third Generation (3G) technology migration strategy to EDGE and UMTS/HSPA adopted by many operators in the Americas. The GSM family of technologies accounts for 85% of wireless mobile customers worldwide. 3G Americas is headquartered in Bellevue, WA with an office for Latin America and the Caribbean in Dallas, TX. For more information, visit our website at http://www.3gamericas.org/.

About Informa Telecoms & Media
Informa Telecoms & Media provides business intelligence and strategic services to the global telecoms and media markets. All of our products and services - from news, trend analysis and forecasting to industry data, face-to-face events and training - are driven by our deep understanding of the markets we serve and by our goal to help our clients make better business decisions. http://www.informatm.com/

Continuous Packet Connectivity (CPC)

Packet-oriented features like HSDPA and HSUPA (HSPA) in UMTS systems provide high data rates forboth downlink and uplink. This will promote the subscribers’ desire for continuous connectivity, where theuser stays connected over a long time span with only occasional active periods of data transmission, andavoiding frequent connection termination and re-establishment with its inherent overhead and delay. Thisis the perceived mode to which a subscriber is accustomed in fixed broadband networks (e.g., DSL) andmay make a significant difference to the user experience.

The Fractional-DPCH feature was introduced in Rel-6 to support a high number of HSDPA users in thecode limited downlink, where effectively a user in the active state, not being transmitted with any data, isconsuming only a very small portion of the downlink capacity.

In the uplink, the limiting factor for supporting a similarly high number of users is the noise rise. For sucha high number of users in the cell it can be assumed that many users are not transmitting any user datafor some time (e.g., for reading during web browsing or in between packets for periodic packettransmission such as VoIP). The corresponding overhead in the noise rise caused by maintained controlchannels will limit the number of users that can be efficiently supported.

Since completely releasing the dedicated connection during periods of traffic inactivity would cause considerable delays for reestablishing data transmission and a correspondingly worse user perception,the Continuous Connectivity for Packet Data Users intends to reduce the impact of control channels onuplink noise rise while maintaining the connections and allowing a much faster reactivation for temporarily inactive users. This is intended to significantly increase the number of packet data users (i.e. HSPA users) in the UMTS FDD system that can stay in the active state (Cell_DCH) over a long time period,without degrading cell throughput. The objective aims also at improving the achievable UL capacity forVoIP users with its inherent periodic transmission through reducing the overhead of the control channels.

Delay optimization for procedures applicable to PS and CS Connections

In Rel-99, UMTS introduced a dedicated channel (DCH) that can be used for CS and PS connectionswhen UE is in CELL_DCH state. In addition to CELL_DCH state, Rel-99 introduced CELL_FACH statewhere signaling and data transmission is possible on common channels (RACH and FACH) andCELL_PCH and URA_PCH states, where the transmission of signaling or user data is not possible butenables UE power savings during inactivity periods maintaining the RRC connection between UE andUTRAN and signaling connection between UE and PS CN. The introduction of the CELL_PCH andURA_PCH states, the need of releasing the RRC connection and moving the UE to Idle mode for PSconnections was removed and thus the Rel-99 UTRAN can provide long living Iu-connection PS services.

On the other hand, when UE is moved to CELL_PCH or URA_PCH state, the start of data transmissionagain after inactivity suffers inherent state transition delay before the data transmission can continue inCELL_DCH state. As new packet-oriented features like HSDPA and HSUPA in Rel-5 and Rel-6 UMTSsystems respectively provide higher data rates for both downlink and uplink in CELL_DCH state, the statetransition delay has been considered to be significant and negatively influencing the end user experience.

In addition to RRC state transition delay, the radio bearer setup delay to activate new PS and CS serviceshas been seen as problematic in UMTS, due to signaling delays on CELL_FACH state where only lowdata rates are available via RACH and FACH, and due to activation time used to synchronize thereconfiguration of the physical and transport channel in CELL_DCH state.

To secure future competitiveness of UMTS and enhance the end user experience even further, the delayoptimization for procedures applicable to PS and CS connections work is targeted to reduce both setuptimes of new PS and CS services and state transition delays to, but still enable, excellent UE powersaving provided by CELL_PCH and URA_PCH states.

During the 3GPP Rel-6 time frame, the work was focused on solutions that can be introduced in a fastmanner on top of existing specifications with limited effects to the existing implementations. In addition,the solutions which allow the Rel-6 features to be used in the most efficient manner were considered.The agreed modifications can be summarized as: introduction of enhanced support of defaultconfigurations, reduced effects of the activation time, and utilization of HSPA for signaling. Thus, fromRel-6 onwards, the signaling radio bearers (SRBs) can be mapped on HSDPA and HSUPA immediatelyin RRC connection setup and default configurations can be used in radio bearer setup message and RRCconnection setup message in a more flexible manner.

The utilization of default configuration and mapping of the SRBs on HSDPA and HSUPA will reducemessage sizes, activation times, and introduce faster transmission channels for the signaling procedures,thereby providing significant enhancement to setup times of PS and CS services compared to Rel-99performance.

In the 3GPP Rel-7 time frame, the work will study methods of improving the performance even further,especially in the area of state transition delays. As the work for Rel-7 is less limited in scope of possiblesolutions, significant improvements to both RRC state transition delays and service setups times are expected.

3GPP TR 25.903: Continuous connectivity for packet data users (Release 7)

3G Americas: Mobile Broadband: The Global Evolution of UMTS/HSPA3GPP Release 7 and Beyond

Housam's Technology blog on CPC

Voice call continuity (VCC)

Voice call continuity requires maintaining a voice call when a mobile terminal moves from one cell to another for second generation Global System for Mobile Communications (GSM) digital cellular communications systems. Operational for many years, this technique enables a conversation to continue when the Circuit-Switched (CS) call reroutes to use a new basestation as the mobile moves from one coverage area to another. The parties will perceive no break whatsoever.

Today, the scenario is rather more complicated, with calls being handed over not only from 2G to 2G cells and from 3G to 3G cells, but also between 2G GSM and 3G Universal Mobile Telecommunications System (UMTS) cells. This is relatively easy from an administrative point of view, given that generally the same cellular network is involved throughout.

Earlier work carried out within the 3rd Generation Partnership Project (3GPP) envisaged telephony using packet-switched connections – Voice over Internet Protocol (VoIP) – using either the 3GPP-defined IP Multimedia Subsystem (IMS) on the 3G Universal Terrestrial Access Network (UTRAN), or Wireless Local Area Network (WLAN) radio access technology based on IEEE 802.11, and other standards. This was covered by the WLAN interworking work items.

However, until now, handover between CS and IMS (packet-switched) calls was not addressed. 3GPP is now investigating the problem of handing over a voice (or potentially video or other multimedia conversational service) call between the cellular network and a WLAN, possibly operated by a completely different service provider. Again, for conversational service, the hand-over has to be seamless, with no break in service perceived by either party to the call. Until recently, such handover had only been considered for services that are not real-time, such as file-transfer, where short breaks during the handover process are acceptable and probably go unnoticed by the user.

The approach taken by 3GPP is to have the WLAN operator use the information registered by the home operator for the mobile terminal subscriber in this sequence:

1. Validate the eligibility of the handover to happen at all
2. Manage charging for the call that is effectively transferred from one network operator to another

It is generally, though not necessarily, the case that WLAN hotspots are also well covered by cellular service. Thus, such handover may take place when cellular coverage is reduced to an unacceptable level, yet an adequate WLAN hotspot service is available. The handover is more likely to occur when spare bandwidth exists on the WLAN but where excess demand for cellular channels exists.

The goal is to maintain the conversational service call, thus optimizing the service to the users, which in turn will maximize the revenue accruing to the operator(s). 3GPP embarked on the technical activity required to enable this service by approving a work item on Voice Call Continuity (VCC) in the June 2005 meeting of its Technical Specification Group System Aspects and Architecture (TSG SA). In order to be accepted onto the 3GPP work plan, any work item needs to have the support of at least four supporting member companies, and no sustained opposition. The VCC work item has no fewer than 16 supporters, and its progress
can be tracked on the 3GPP website, www.3gpp.org. It is intended that this work be achieved in the Release 7 time frame.



3GPP TR 23.806: Voice Call Continuity between CS and IMS Study (Release 7)
3GPP TS 23.206: Voice Call Continuity (VCC) between Circuit Switched (CS) and IP Multimedia Subsystem (IMS); Stage 2 (Release 7)
3GPP TS 24.206: Voice Call Continuity between the Circuit-Switched (CS) domain and the IP Multimedia Core Network (CN) (IMS) subsystem; Stage 3 (Release 7)
3GPP TS 24.216: Communication Continuity Management Object (MO) (Release 7)

http://www.compactpci-systems.com/columns/spec_corner/pdfs/2006,04.pdf
http://www.huawei.com/publications/viewRelated.do?id=1146&cid=1802
http://news.tmcnet.com/news/it/2006/06/02/1667856.htm
http://www.tmcnet.com/usubmit/-an-introduction-voice-call-continuity-vcc-/2007/05/02/2577864.htm
http://www.tmcnet.com/wifirevolution/articles/5861-voice-call-continuity-solution-dual-mode-wi-ficdma.htm

IMS strategies: Synopsis from IMS 2.0 world forum

From Ajit's Open Gardens Blog:

IMS 2.0 world forum is a must attend event .. I learnt a lot from it. Here is a brief synopsis of where I see IMS is heading to ..

Seek your thoughts and feedback especially you can identify other Operators with an interesting strategy and / or if you attended this event

As I could gather, there are six broad strategies:
a) Voice call continuity(VCC) / fixed to mobile convergence
b) Blended voice : voice tied contextually to messaging or rich media
c) SIP without IMS (Naked SIP)
d) Strategies from device manufacturers(especially Nokia and Motorola)
e) Real time IMS applications (multiplayer games and other such applications that need near real time blended media interaction within a session)
f) Abstraction of the core network

Most of the focus is around (a) Voice call continuity(VCC) / fixed to mobile convergence

This is a pity – but also understandable Operators are most familiar with voice
In its broadest sense, voice call continuity pertains to roaming within cellular and non cellular networks(such as roaming between cellular and wifi networks). A specific instance of this is Fixed to mobile convergence for instance BT fusion

My personal view is:

a) I don’t quite know if I would be interested in FMC as a customer ..
b) I think its being sold on cost – which is not a good idea
c) I think it fulfils an industry goal(fixed and mobile networks trying to get new subscribers from each other’s networks in mature markets)
d) In general, voice is becoming cheap .. so I am not sure that a pure voice play is a good idea

Blended voice(b) and real time applications(e) are interesting but need device support. Devices supporting IMS fully are conspicuous by their absence!

In contrast, devices supporting SIP(c) - but not IMS are very much here and so are applications – for instance movial

Abstracting the network layer through software APIs(f) – is the most interesting – but I felt very few Operators had the vision to embrace this strategy at the moment. The two big exceptions being TIM and Telia sonera - who are doing some very interesting work.

To recap, by abstracting the network layer, I mean : In an IP world, as the Mobile Internet mirrors the Internet, the Operator should focus on the core of the network and leave the edge of the network to third parties. Specifically, this means – identify the elements that can be performed ONLY in the core and then abstract them through APIs. This approach gets us away from the dichotomy of the ‘pipe’ vs. ‘no pipe’. It also means that the Operator retains control.

Finally, Operators in emerging markets like Globe telecom from Philippines were also impressive i.e. they understood the space, the issues specific to their market and how they could leverage IMS in their markets. Harvey G Libarnes, Head of innovation and incubations program , Globe Telecom, gave a very thorogh presentation

Finally, there are some interesting plays : such as Mobilkom with A1 over IP and France Telecom with IPTV strategy

To conclude:
a) At Operator level, IMS is still largely about voice and a defensive approach(such as FMC)
b) Lack of devices is the key question mark
c) Device manufacturers on the other hand have significant leverage(more on that soon)
d) Some operators are going to be very innovative – TIM and Teliasonera from amongst the attendees

Cognitive radio

Cognitive radio (CR) is a newly emerging technology, which has been recently proposed to implement some kind of intelligence to allow a radio terminal to automatically sense, recognize, and make wise use of any available radio frequency spectrum at a given time. The use of the available frequency spectrum is purely on an opportunity driven basis. In other words, it can utilize any idle spectrum sector for the exchange of information and stop using it the instant the primary user of the spectrum sector needs to use it. Thus, cognitive radio is also sometimes called smart radio, frequency agile radio, police radio, or adaptive software radio,1 and so on. For the same reason, the cognitive radio techniques can, in many cases, exempt licensed use of the spectrum that is otherwise not in use or is lightly used; this is done without infringing upon the rights of licensed users or causing harmful interference to licensed operations.

The only difference with SDR (Software Defined Radio) is that a cognitive radio needs to scan a wide range of frequency spectra before deciding which band to use, instead of a predefined one, as an SDR terminal does. One of the most important characteristic features of an SDR terminal is that its signal is processed almost completely in the digital domain, needing very little analogue circuit. This brings a tremendous benefit to make the terminal very flexible (for a multimode terminal) and ultrasmall size with the help of state-of-the-art microelectronics technology.

More Information at:

http://www.technologyreview.com/read_article.aspx?ch=specialsections&sc=emergingtech&id=16471

http://www.ece.gatech.edu/research/labs/bwn/CR/Projectdescription.html

http://en.wikipedia.org/wiki/Cognitive_radio

AT&T bets on LTE

AT&T says its next-generation roadmap leads to LTE, though it's evaluating the use of WiMAX technology for backhaul according to a report in Wireless Week.

AT&T's Chris Hill, vice president of Government Solutions for Mobility, commented during an interview at the Wireless Communications Association (WCA) conference that, "LTE provides similar throughputs, so we're taking a wait-and-see approach to WiMAX. We just don't see the value proposition for mobile WiMAX."

After reading this i started digging around on who is betting on WiMAX and i found an excellent summary:

Mobile wimax equipment which utilize beam-forming and MIMO technologies will become available towards the end of this year. Broadband wireless deployments using pre-802.16e compliant equipment have already begun. In Korea both KT and SK Telecom have implemented mobile broadband wireless networks in specific locations throughout the country.

Sprint/Nextel are deploying an 802.16e compliant mobile wimax network which will reach 100 million Americans by the end of 2008. BT will bid for 2.5GHz RF spectrum in the Ofcom auctions which will take place towards the end of the year 2007. Gaining such spectrum will allow the incumbent to deploy an efficient wimax service and compete with companies such as Vodafone for triple play services. Cable companies are gradually acquiring spectrum and are looking at distributing their content to mobile devices. Greenfield operators are expected to utilize mobile wimax technology in order to secure a 3G/4G market position by attracting consumers with an early new level of service. Clearwire is such a carrier with operations in the United States, Denmark, Belgium, Ireland and in Mexico (via MVSnet).

Equipment manufacturers are becoming increasingly active in mobile wimax. Vendors such as Samsung, Nortel Networks, Alcatel and Nokia-Siemens Networks are all involved in 802.16e projects globally. Motorola have just announced a major deal in Pakistan. Companies that have been heavily involved in operator proprietary broadband wireless implementations such as Alvarion and Proxim are also developing 802.16e compliant platforms. Various chipset providers such as Wavesat, Runcom Technologies and Beceem Communications are developing OFDMA chips and are testing their products for interoperability with solutions from other vendors. Dual mode handsets will be very popular with mobile wimax deployments with GSM/OFDMA and CDMA/OFDMA handsets dominating the market.

But there is confusion. Ericsson believe that by the year 2010 mobile wimax will account for only 5-10% of global broadband wireless revenues and are therefore more focused on broadband cellular technologies. Who is right? Availability of 2.5GHz spectrum is crucial to the success of mobile wimax particularly throughout the western world. In Europe HSPA is dominating the cellular market and this combined with the current unavailability of 2.5GHz spectrum throughout most of the continent is leading to little interest from mobile operators. In the U.S a lot of the 2.5GHz spectrum is owned by Sprint. The carrier will start its deployment by using 10MHz channels to deliver services and could use even larger bandwidths in the future.

Meanwhile in the US, everyone is concentrating on the 700MHz spectrum auction that will be happening soon. The spectrum is in the upper 700 MHz range, not the lower 700 MHz band where companies such as Qualcomm’s MediaFLO already are deploying services. It’s desirable for wireless carriers because at 700 MHz, fewer base stations are required than at higher ranges, making it more economical for buildouts. But numerous other parties also are interested in the spectrum, as evidenced in FCC filings. Everyone from Cyren Call Communications to Frontline Wireless and Google are giving advice on how to use the spectrum.

Among the more neutral players in the cacophony of lobbyists trying to affect the outcome of the auction is Nortel. The company has been sending executives to Washington, D.C., mainly to serve as educators around technologies that could be deployed in the space. Those include OFDM/MIMO and others around WiMAX, as well as evolutions of the GSM and CDMA technologies in long-term evolution (LTE) and ultramobile broadband (UMB), respectively.

“We are keeping a very close eye on where the 700 MHz auction goes,” says Danny Locklear, director of Nortel wireless product marketing. “We see this 700 MHz space as being a very large opportunity for us,” as well as for the overall U.S. market, where it will add more competition and improvements for end-users.

It’s important for companies like Nortel to be involved now, he explains, because typically there is an 18-month cycle from the time standards are developed to the actual product. Delivering products for a new or different band of spectrum is nothing new; vendors know how to do it, but it still takes time, not only in the hardware but software as well.

Discussions over 700 MHz are expected to continue through the coming months, with a final ruling possibly toward the end of the summer and an auction start time anywhere between the third quarter of this year and January of next year. Even then, some of the winners of the spectrum probably won’t be moving in immediately. Analog TV users currently in the spectrum have until the first quarter of 2009 to vacate.

Will WiMAX compete with 3G+

Various reports and discussions have started trying to compare WiMAX and HSPA/LTE and also justifying why WiMAX is better or vice versa. so will WiMAX compete with 3G+? To answer this problem lets go back to the beginning of 3G.

NTT DoComo launched the worlds first 3G system which it called as FOMA. Infact before FOMA it already had i-Mode available which was a revolutionary technology of its time. So instead of being so great and revolutionary, why was it not adopted by everyone. The answer is that it was a closed technology and not an open standard.

WiMAX is comparatively an open standard. Its Specifications are not available freely as is 3G. This gives 3G a definite advantage over WiMAX. Also 3G+ (which includes HSPA, HSPA+, LTE, MIMO, etc) has evolved from 3G which has in turn evolved from GSM. There is an inbuilt facility to move between 3G/GSM and perform Handovers, etc. This would be missing in WiMAX.

You may argue that once IMS is there, these problems wont be big as IMS would allow these handovers to take place. IMS is access agnostic. The problem is that it will take time for IMS to be adopted and for it to be completely functional. When this happens, by that time LTE would already be available. LTE uses the same Radio Technology as WiMAX and since it has evolved ffrom 3G/GSM, it would definitely be preferrred over WiMAX.

There was an article in Financial Express last week comparing WiMAX and 3G. Some important points from that:

But from what we do know, 3G/HSPA has several clear advantages vis-à-vis mobile WiMAX in terms of backward compatibility, standardisation, use of licensed spectrum and availability of infrastructure and terminals giving it an edge over WiMAX in terms of large scale economies leading to better affordability, availability, scalability and overall ruggedness of the 3G/HSPA standard. Further, the pace of adoption of HSPA has been remarkable. HSPA is already commercially available in Africa, America, Asia, Australia, the European Union and the Middle East. There is thus already a large ecosystem of global suppliers of components, subsystems, equipment and network design and implementation services in place for 3G/HSPA.

WiMAX on the other hand faces a number of challenges. Mobile WiMAX standards are still under evaluation. The capex for deploying WiMAX is upto 5-10 times higher than HSDPA because the size of mobile WiMax cells is upto 16 times smaller than the cells in an HSPA system, which would necessitate a larger number of base stations to cover the same geography.

Further, the prices of mobile WiMAX handsets as and when available, will be significantly higher than the cellular terminals, which are being developed in much higher volumes and offered at increasingly lower costs. Also WiMax has fragmented frequency bands. In Europe and the United States, WiMAX operates in 3.5GHz and 5.8GHz while in Asia Pacific it operates in 2.3, 2.5, 3.33 and 5.8GHz. This makes global or even pan-regional roaming rather difficult. Users visiting different countries will have to either hope that the visited country uses the same band or have their devices equipped with multiple modes to enable connectivity to other WiMAX based broadband networks. WiMAX systems also have a lower capacity for voice vis-à-vis 3G/HSPA networks, which will limit the potential market size that WiMAX can cater to.

Arthur D. Little and Altran Telecoms & Media have also produced a report for GSM Association comparing HSPA and Mobile WiMax for Mobile Broadband Wireless Access (MBWA). According to them:

HSPA is likely to account for the majority of investment in global mobile broadband networks over the next five years, finds a new study by Arthur D. Little. By comparison mobile WiMax will be a niche technology within the overall
global mobile broadband wireless access market, likely to account for at most 15% of this network equipment market and perhaps 10% of mobile broadband wireless subscribers by 2011-2012.

HSDPA (including HSUPA and HSPA+) is taking the lead as it is a natural migration path for a large number of GSM and UMTS operators already operating commercial networks in 3G spectrum. This will give rise to significant economies
of scale on handsets and user devices and a large ecosystem of global suppliers of components, subsystems, equipment and network design and implementation services. Hence this is the least risky and best understood route to offering broadband mobile services which can offer speeds comparable to first generation fixed DSL services.

According to a report in Broadband Wireless Exchange Magazine:

The results of Arthur D. Little's modeling work shows that WiMax systems are expected to achieve significantly greater theoretical peak data transfer rates when deployed than today's commercial HSPA networks deliver now, such as theoretical speeds of e.g. 16.8 Mbps in urban areas vs 2-3 Mbps for HSPA. However, the coverage a WiMax base station can achieve, is substantially lower than HSPA, hence HSPA operators will be able to deploy a smaller number of base stations and sites to cover the same geography. Indications are that radio access network capex for current WiMax technology can significantly exceed HSDPA capex.

Another consequence of this characteristic of these two technologies is that an HSPA operator will be able to match its growing investment more clearly to the development of demand than mobile WiMax operators who will have to install more cell sites at the beginning to ensure coverage.

Arthur D. Little acknowledges that in the longer term, well into the second decade of this century, mobile broadband wireless systems will be characterized by technologies such as OFDMA and MIMO. Development of these technologies is being pursued by the 3G/HSPA ecosystem within the framework of 3G LTE as well as by WiMax. The long term future relative roles of 3G LTE and mobile WiMax, both of which face major development hurdles before they achieve the full promise of new, so-called 4G systems, is uncertain and will be influenced by continuing expected shifts in the priorities and competitive alignments of major players in the wireless industry which has undergone a number of consolidations in recent months.

In contrast to many other reports on HSPA, mobile WiMax and other broadband wireless technologies, the Arthur D. Little study highlights and assesses all the factors - strategic, competitive, commercial, regulatory and political as well as technological that influence operators' choices of wireless network technology.

Evidence for the potential complementary nature of HSPA and WiMax can be seen in the increased interest in multi-mode user devices and roaming capabilities across the technologies. This development, which reflects the widespread anticipation of the central role of OFDMA and other technologies involved in WiMax and 3G LTE in all eventual future broadband wireless networks, is a welcome change from the provocative and misleading headlines that have appeared over the past two years which imply that mobile WiMax threatens the viability of today's HSPA and related technologies

With Intel promising WiMAX chips on all its laptops in future, only time will tell how far WiMAX will and if this comparison holds true.

Cellular Multi-Mode Madness

From Geekzone, New Zealand

At the moment you can get most places with UMTS2100 including limited coverage on Vodafone NZ. The future looks a lot more difficult. With the Telecom announcement today NZ will be getting what is called an E-GPRS network operating at 850MHz. This will offer GSM/GPRS/EDGE. For real 3G as in HSDPA you will still need 2100MHz but as we all know this frequency is limited in what it can offer in terms of coverage and in-building penetration.

It has been rumored that Vodafone are trialling a UMTS900 network in NZ which certainly makes sense. With this 3G band Vodafone needs 60% less cells sites for the same coverage footprint currently offered on their UMTS2100 network. They can also use the same antennas and feeders currently used for GSM900 but the downside is that they will need to give up at least 2.6MHz of their existing GSM spectrum to act as a guard band between GSM and UMTS. It doesn't sound like much but it does cut into voice capacity.

UMTS900 is very new and only this year have the first tests calls been completed in Europe. Being new means a lack of devices which is a similar position Telstra found themselves in with their NextG network. NextG operates at 850MHz but this is UMTS (HSDPA) and not the same as the Telecom E-GPRS network. Same frequency different technology.

Over the last year more and more data devices have been appearing to support UMTS850. These devices are tri-mode as in they support UMTS850/1900/2100MHz so they work on Telstra (850), Cingular (850/1900) and the 'rest of the world' (2100).

In NZ Vodafone is adding a new spin by playing with UMTS900. At this stage there are no UMTS850/900/2100MHz devices and I am not sure what (if any) radio issues will be faced with building such a product. Given that UMTS900 has been trialled in Europe and that 900 is the dominant global GSM band it is quite feasible that 900/2100MHz will rule supreme with 850/1900MHZ relegated to side frequencies operating in different pockets around the world. Although, as voice usage grows carriers are running out of 900MHz spectrum. But then again they could also choose UMTS800 (not to be confused with UMTS850) and IP Wireless (the company that supplies technology to Woosh) is tinkering with UMTS450 which has traditionally been used for CDMA450. On top of that we have UMTS1700, UMTS2600, UMTS1800 and now talk of UMTS2500.

Will add some more details on this soon.

IMT Advanced = 4G

In this story on Telecom TV, is says:

Working under a mandate to address "systems beyond 3G", the working party has now come up with a name for the future mobile systems. Thankfully, they are veering away from 4G and are calling it 'IMT-Advanced'.

A simple search on Google returned some useful information from Telecom ABC:

International Mobile Telecommunications - Advanced (IMT-Advanced) is a concept from the ITU for mobile communication systems with capabilities which go further than that of IMT-2000. IMT-Advanced was previously known as “systems beyond IMT-2000”.

It is foreseen that the development of IMT-2000 will reach a limit of around 30 Mbps. In the vision of the ITU, there may be a need for a new wireless access technology to be developed around the year 2010 capable of supporting even higher data rates with high mobility, which could be widely deployed around the year 2015 in some countries. The new capabilities of these IMT-Advanced systems are envisaged to handle a wide range of supported data rates according to economic and service demands in multi-user environments with target peak data rates of up to approximately 100 Mbit/s for high mobility such as mobile access and up to approximately 1 Gbit/s for low mobility such as nomadic/local wireless access.

To support this wide variety of services, it may be necessary for IMT-Advanced to have different radio interfaces and frequency bands for mobile access for highly mobile users and for new nomadic/local area wireless access.

Together with the introduction of the name IMT-Advanced, the ITU introduced the generic root name IMT. The generic root name IMT covers the capabilities of IMT-2000, including future development of IMT-2000, and IMT-Advanced.

Meanwhile a story in ChinaTechNews is suggesting that Datang Telecom has already written a Draft on 4G and is working on 3G&4G convergence. Cannot find much more on this right now.

For more on 4G technologies, either read this story on Network World or 3G4G website.

Things our phone will do in next 10 years

Interesting article in Cnet on "10 things your mobile will do in next 10 years"

1. Wallet: This would be quite cool when available. Have been hearing about this for years now. Apparently very popular in Japan and S.Korea where people are not using credit cards anymore and instead using Phones.

A much better idea would be to have a universal recognition kind of chip which i can use as Credit card, Smart Card for Trains (In london we have Oyester cards) and then i can use this for accessing company door, garage door , etc. This would be a real killer app but doesnt look like will happen in near (or far) future

2. Internet: In December, ABI Research said that almost 50 million people used social-networking sites on their mobile phones. That number is expected to grow to 174 million by 2011. It would be cool to be able to browse using your phone. Mosst of the sites i use (including mine) are not mobile friendly and this is the thing that is turning people off the net.

3. Location: Already too many phones supporting GPS and A-GPS. The chips are becoming cheaper with cost of around $5 so the manufacturers should have no problem. In future we will get disscounted packages where we will have to receive adverts which would be location specific. Nokia has some applications which can compete with TomTom for getting directions, etc.

4. Search: Hardly anything needs to be mentioned for this.

5. TV: Have written enough on Mobile TV already. IMS Research forecasts that by 2011 there will be more than 30 million mobile TV subscribers in the United States. The firm also predicts that almost 70 million handsets capable of receiving mobile TV will be shipped in the U.S. in 2011.

6. Simplified surfing: From the Cnet article

Ever notice how many clicks it takes to find the one thing you're looking for on your phone? It's worse than counting how many licks it takes to get to the center of a Tootsie Roll Pop. But handset makers and mobile operators are
hard at work trying to make phones easier to navigate and simpler to use.

The upcoming iPhone from Apple is a perfect example of how user interfaces will be improved. Apple fans are confident that the company has come up with another slick and intuitive
design, just as it did for the iPod.

One aspect of the iPhone's interface that has been publicized is its use of sensory technology to detect when the device is rotated. This allows the phone to automatically render pictures on the screen in portrait (vertical) or landscape (horizontal) format. That allows the user to determine which format is best for viewing whatever is on the screen, be
it a Web page, video, or photo.

In the future, motion-sensing technology, similar to that used in the Nintendo Wii game console, will also allow people to navigate their cell phone menus or the mobile Internet
with a flick of their wrists.

But motion sensing is just one piece of the puzzle. Operators such as Verizon Wireless are redesigning their content menus
to reduce the number of clicks users must endure to find what they want. Ryan Hughes, vice president of digital media programming for Verizon Wireless, said he believes that user interfaces will be customizable so that users can decide
for themselves which applications will be displayed on their phones most prominently.

Motorola is already offering a customizable interface on the
Razr 2, which the company claims will make searching for contacts, accessing applications, and messaging much easier.

7. Brainier radios: Maybe in future SDRs (Software Defined Radios) may become more common and popular and yes the technology will become feasible. Also multiple radios on the chpset would mean Handovers will be possible from 3G to WiMax, Wifi, etc.

8. Personal Cell: Everyone seems to be talking of Femtocell. Where we will have a small 3G base station in our home. We could use it for Voice or High Speed data. No need for the POTS and use mobile for everything. This will still take some time as the operators dont fully understand the benefits of offering cheap data.

9. Perfect Camera: Today roughly 41 percent of American households own a camera phone. In fact, you'd be hard-pressed to buy a phone today that doesn't have a camera. By 2010 more than 1 billion mobile phones in the world will ship with an embedded camera, up from the 589 million camera phones that are expected to be sold in 2007, according to market research firm Gartner.

10. More music on the phone: Mobile phone users around the globe are expected to spend $32.2 billion on music for their handsets by 2010, up from $13.7 billion in 2007, according to Gartner. This can only happen when Music Video/Audio becomes cheaper though. Personally i would prefer listening to FM Radio rather than music but i am not sure how much demand there would be and ofcourse the operators dont gain anything.

Mobile TV in Top Ten of mobile services

From the Nokia N-Series Blog:

In a report published by Analysis, the global advisers on telecoms, IT and media, Mobile TV shows up in the Top ten most used non voice services on mobile phones.

This new report identifies the top ten services from a large number of non-voice services worldwide, and provides detailed case studies and analysis of these leading services to help others replicate their success. The report provides unique guidance to mobile operators (as well as MVNOs and third party service providers) on the best opportunities to increase their non-voice service revenues.

1. Vodafone’s Casa FASTWEB DSL service (Italy)

2. O2’s SMS service (UK)

3. 3’s 3G mobile TV and video streaming service (UK)

4. T-Mobile’s BlackBerry email and instant messaging service (USA)

5. Sprint Nextel’s CDMA2000 EV-DO Revision A mobile broadband service (USA)

6. 3’s DVB-H mobile TV broadcasting service (Italy)

7. KDDI au’s EZ Chaku-uta Full music downloading service (Japan)

8. SK Telecom’s Cyworld Mobile community portal service (South Korea)

9. NTT DoCoMo’s DCMX mobile credit service (Japan)

10. Vodafone’s MiniCall ‘voice SMS’ service (Egypt)

Mobile TV services are a key element of the 3G service mix that has enabled 3 UK to claim non-voice ARPU of more than USD25 per month, which is currently the highest in the world”, says Dr Mark Heath, co-author of the report.

“In Italy, mobile TV subscribers of 3’s DVB-H service generate 60% higher ARPU than its other mobile customers. While some mobile TV services, such as Virgin Mobile’s DAB-IP service in the UK, are making slow progress, 3 shows that it is possible to make a short-term success of mobile TV.”

Mobile TV and MBMS will co exist

Someone brought my attention towards a Digitimes article where some people from Israel-based mobile chip designer Siano Mobile Silicon are talking about Mobile TV and MBMS. Some of the interesting points below.

Q: And what about multicast?

A: (Jashek) Again, multicast will end up placing a strain on the system bandwidth. The current MBMS (Multimedia Broadcast Multicast Service) capacity is limited to 2Mb/sec, while a broadcast system will provide bandwidth of 16-32Mb/sec, which is the bandwidth needed to support about 20 channels. Upgrading any existing cellular network so that it supports MBMS at 15-20Mbps (while not hurting the voice capabilities of the network) requires an investment that is by far larger than building a good mobile TV broadcast system.

We believe video-over-cellular services such as MBMS will continue to exist, but will gradually focus on “on demand” services, while actual mobile TV services will use a broadcast platform.
(Raab) Content will be broadcast to users, but users will be involved in the content, such as in programs that involve voting. And the way to create profits from this is to get more people involved in the service and bundling services to increase the amount of data that is going through the network, but in such a way that it does not strain the system.

Q: But who will build the broadcast infrastructure? Do you expect broadcasters and cellcos to be competitors or partners?

A: (Jashek) Most operators are facing the question of whether they should invest themselves or whether they should partner with a broadcaster to develop the infrastructure. In Italy, Telecom Italia Mobile (TIM) has deployed a mobile TV service where it is the service provider, even though Mediaset (a broadcaster) built the primary broadcast infrastructure. On the other hand, 3-Italia have made their own investment into a DVB-H network, and they enjoy a very good attach rate.

In the US, Qualcomm's subsidiary MediaFLO has solved this dilemma for the operators by building the network itself. The only thing Verizon or Cingular had to do was sign a contract with Qualcomm and offer the service.

Thus, different models exist. The relationship between broadcasters and cellcos will be one of the key issues affecting the success of mobile TV in the future. Most broadcasters already have the spectrum, as well as the content. They are currently using that for analog terrestrial TV, but in the future it will be used for digital mobile TV. However, cellcos already have a network that supports interactive programming. They also have an infrastructure in place for service and billing.

The question is how well can cellcos and broadcasters get along. What TIM has done, is take revenues from its mobile TV service and split it evenly with the broadcaster. In the future, we expect to see a similar type of model where broadcasters focus on broadcast services and operators focus on interacting with the customer.

Q: You mentioned that current analog TV spectrum will be allocated to mobile TV in the future. Can you add more color to that statement and explain how that will affect the development of the mobile TV market?

A: (Jashek) I should note that the development of mobile TV will go hand in hand with the migration of terrestrial analog TV to digital TV. For example, if you look at the DVB standard (DVB-T for terrestrial TV and DVB-H for mobile TV), which will be the DTV standard deployed in the most markets worldwide, currently about 30 countries have DVB-T networks, while another 30 will join in one to three years. Once the DVB-T networks are in place, you will see huge growth in DVB-H support because it does not take much investment to add DVB-H support to a DVB-T network.

Getting back to your specific question, a lot of countries have allocated spectrum to mobile TV on a temporary basis. Once governments start turning off their analog services in 2010, that spectrum will be allocated to mobile TV on a more permanent basis, and you will see a big jump in the size of the market.

We expect to see 120-130 million mobile TV users worldwide by 2010, with DVB-H being the number one platform. By 2012-2013 when more markets switch off their analog services, we expect to see 300-400 million people enjoying broadcast mobile TV.

Q: As you mentioned, DVB-H will be deployed in the most markets, however the global mobile TV market remains fragmented. Can you comment on the implications of how such a fragmented global market might affect the development of mobile TV?

A: (Raab) Obviously, with the huge expected size of the mobile TV market, a lot of different organizations would like to have a piece of the pie. Hence, a number of broadcast mobile TV technologies have been developed. Eventually, economy of scales will not allow more than about four technologies to survive in large volumes. It looks like the partitioning will be geographical.
(Jashek) DVB-H has its stronghold in Europe, where it was originally pushed by local players such as Nokia and Philips, and where DVB-T, the "mother" of DVB-H, has strong momentum. We have no doubt that DVB-H will dominate mobile TV in Europe, and DVB-T will also be supported on some hand-held devices. DVB-H is also expected to be the dominant standard in Southeast Asia – Taiwan, Singapore, Vietnam, Malaysia – and the Pacific Rim. In countries with vast rural areas, such as Russia or Canada, we expect that, around 2010-2011, DVB-H will be unified with DVB-SH (the satellite version of DVB-H). This will optimize the coverage with respect to the infrastructure investment required.

MediaFLO seems to be the winner in North America, although we would not be surprised if DVB-H will also be deployed there.

In Japan, as well as Brazil and a couple other South American countries, ISDB-T will dominate. And South Korea will continue with its T-DMB for some time, although being the only nation to have large-scale deployment of this standard will make it difficult for Korea to maintain it for many years. In China, the homegrown standard known as CMMB (S-TIMI) will be the main platform for mobile TV.

(Raab) Another thing to remember is that not only are the standards fragmented but so is spectrum support.

With the big picture being so unclear, device makers are looking for help to develop a solution that fits as many markets as possible. That’s why three years ago Siano came up with the concept of a multi-standard and multi-band mobile TV chip solution.

Our chips currently support the DVB-H/T, DAB and T-DMB standards, as well as covering the VHF, UHF, L1 (1450-1490MHz) and L2 (1660-1680MHz) spectrums. In addition, we will very soon have ISDB-T supported, while CMMB and MediaFLO are also on our roadmap. We are members of the CMMB working group, and the FLO Forum.

Q: Several mobile TV trials have been hampered by a lack of handset support, why is that?

A: (Raab) Handset makers need to digest and endorse a new technology – new types of antennas, receiver chips, software, etc. This is not easy. Some of the first few DVB-H phones were bulky, use antennae that were too long (making them unacceptable for most users), and have a reception sensitivity that was not that great.

The above diagram is from a Vodafone presentation ( Mobile TV from pure Broadcast to Interactivity, 19th Oct 2006 ). It shows how Mobile TV technologies will coexist with MBMS and the traditional unicast services