Truly open broadband network

The FCC's auction for 700-MHz bandwidth, scheduled for later this year, is gearing up to be an epic sale that could have a major impact on the world of wireless technology, especially with FCC Chair Kevin Martin now calling for an "open broadband network," one that will open the door to a lot of innovative wireless services.

You buy a cell phone, load any software you want on it, then choose your carrier. This vision of expanded consumer choices in the wireless world might be a little closer today than it has ever been, especially with reports that the chair of the Federal Communications Commission (FCC) is circulating an "open platform" proposal for the upcoming auction of the 700-MHz band.

FCC Chair Kevin Martin told USA Today on Monday that "whoever wins this spectrum" will have to provide a "truly open broadband network -- one that will open the door to a lot of innovative services to the consumer."

He said an open network would mean a consumer could "use any wireless device and download any mobile broadband application, with no restrictions," except for illegal or malicious software. USA Today and other news outlets are reporting that Martin has sent or is about to send a draft proposal to his fellow commissioners.

Martin noted that, in some other countries, consumers usually take their unlocked devices with them when they change carriers, as opposed to in the U.S., where cell phones typically are locked for use only on a given carrier's network.

Writing on Forum Oxford, Ajit Jaokar called this as the 'carterphone principle'

And the news gets better...

Writing Tuesday on its public policy blog, Google Telecom and Media Counsel Richard Whitt applauded the reports of Martin's proposal. Whitt, hired by Google a few months ago, formerly headed up MCI's regulatory department.

Google, which said it has not decided whether it will participate in the auction, sent a letter to the FCC on Monday, according to Whitt, urging that winning bidders be required to adopt several types of "open platforms."

A key part of open platforms, Google contends, is that consumers would be able to use any combination of devices, software applications, content, or services. In addition, the company maintains, resellers should be able "to acquire wireless services from a 700-MHz licensee on a wholesale basis," and ISPs should be able to interconnect "at a technically feasible point" to a 700-MHz licensee's wireless network.

However, Current Analysis analyst Bill Ho identified potential issues with these ideas, notingthat interconnection and the use of any device could require some uniform or encompassing technological standards, rather than the competing standards that now exist.

The auction for bandwidth, scheduled for later this year, is gearing up to be epic. The sale will include spectrum in the 700-MHz band that has been used for analog television since the beginning of that medium, as U.S. TV is going completely digital by mid-2009.

The 700-MHz spectrum is particularly valuable because it penetrates walls and various obstacles more effectively than other frequencies, and the FCC is now developing the rules for the auction.

A 108-MHz block of bandwidth will become available after the analog TV stations complete their transition. Of that 108 MHz, 60 MHz will be auctioned in January 2008, public safety officials will receive 24 MHz, and 24 MHz already has been sold.

Estimates indicate that the auction could yield $20 to $30 billion for the government.

Motorola sales decline, but still clueless

Motorola looks in danger of losing its position as the world's second-largest mobile phone maker after reporting a collapse in sales during the second quarter of the year. With the Korean manufacturer Samsung gaining ground on the American technology company, pressure is building on Motorola to develop a new hit phone to replicate the success of its wildly popular Razr handset. The company's decision to pull out of the race to sell low-end handsets in emerging markets has boosted its average selling price but hit its volumes.

Motorola sold up to 35 million handsets in the second quarter of the year, 21 per cent lower than the 45 million it sold in the previous three months and 31 per cent lower than a year ago. After missing its sales and profit targets over the period, the company said it no longer expects to make a profit from its mobile phones sales this year.

This makes me wonder, why is Motorola in such a situation? Some years back when it brought RAZR, its sales were up and they started getting recognition they have been looking for. 'But' poor interface design and very poor GUI has been always there to haunt them. Also, they do not seem to care too much of UE stability and Phones freezing and crashing have been common problems.

Combined with all of the above, there are too many political problems and their habit of looking for short term gains (laying off people so that the share prices dont go down too much) rather than long term aims is hurting their innovation.

Meanwhile, Nokia, the Finnish group that transformed itself from a forestry company and a producer of rubber boots into the world's largest handset maker, is thought to have taken substantial market share from its US rival over the past three months, with Sony Ericsson and Samsung also expected to gain ground. Amid the hype around Apple's entry into the mobile phone market with its top-end iPhone, Nokia has been forging ahead with a number of high-end handsets and a strong position in emerging markets.

The joint venture between Sweden's LM Ericsson and Japan's Sony Corp. said net profit rose 54% to 220 million euros ($303 million) from 143 million euros in the same period last year.

Sony Ericsson seems to have done well with its Walkman-branded music and camera phones, where Motorola had a bad time with the ROKR, famously produced in association with Apple. Motorola has also been the leading proponent of Linux-based phones, but there's no indication whether this helped or hindered either sales or profits.

Femto-Mania catching on

Recently there is a lot of activity that is going on, on the Femtocell front.

It is an excellent concept as it would now be possible to have small (see figure on left) base stations in your house that will give you a reliable coverage even in your basement.


The most high profile announcement was by Nokia-Siemens Networks who plan to launch the technology commercially by Q3 2008.

According to Wireless Week, DSL box developer Thomson have partnered Nokia-Siemens to develop 3G devices for in-home wireless broadband access.

“Our novel Femto Home Access solution meets what the market really needs. It is a strong combination of telecommunications end-to-end expertise, femto cell know-how and consumer mass market understanding,” says Ari Lehtoranta, Head of Radio Access, Nokia Siemens Networks. “We are driving a network solution with standard and open interfaces to enable open innovation and variety of supply for the Femto customer premises equipment.”

The Nokia Siemens Networks 3G Femto Home Access solution introduces a new network element, Femto Gateway. Femto Gateway does not require changes in the operators’ existing core network, as it connects to the core network over a standard interface. Furthermore, by extending this standards-based approach towards the Femto Customer Premises Equipment (CPE) at homes, the Femto Gateway will allow customer equipment from multiple vendors to be connected to it. The Femto Gateway will support any Femto CPE certified by Nokia Siemens Networks to conform with the interface. Nokia Siemens Networks will co-operate with Femto CPE vendors to ensure interoperability of their equipment to the Nokia Siemens Networks interface.

Femto CPE’s use IP broadband backhaul and are easy to install at home in the same way as xDSL/WiFi modems. The Femto cell functionality can be packaged to the operator-specific home gateway devices together with other functionalities, like WiFi, Ethernet routing or storage.

On the operator side, O2 has previously expressed interest in the technology, while Orange and Vodafone are assessing the potential of femtocells. The Japanese operator Softbank has also talked about launching the technology commercially.

It's not known which operators will be the first to undertake trials, said Nick Johnson, chief technology officer of IP Access, one of several companies that makes femtocells, the small 3G base stations that enable the improvement.

Mobile phone company Vodafone Group PLC has issued a request-for-proposal to femtocell vendors, said Stuart Carlaw, research director for ABI Research. "When you get to an RFP, it's pretty serious stuff," he said.

Sprint Nextel Corp. and Softbank Corp. in Japan are also out in front, with Softbank demonstrating femtocells earlier this week in Tokyo.

IP Access demonstrated its Oyster 3G home access femtocell deep in a London wine cellar on Friday (6th July), transmitting a video conference call between two mobile phones.

The technology will compete with other carriers' Wi-Fi coverage, which enables UMA (Unlicensed Mobile Access), a way to make call over a Wi-Fi hotspot that's plugged into a home DSL (Digital Subscriber Line) connection and have them billed to a mobile phone account. UMA is used in offerings such as BT Group PLC's Fusion service.

Femtocells hold an advantage in that they can be used by 3G mobiles, while only a few models support UMA and Wi-Fi, Carlaw said.

Carriers will likely end up subsidizing the cost of a femtocell, which is probably now around US$120 to $130, or bundling it as part of a service package, Carlaw said. "A consumer is not going to pay," the analyst added.

Ubiquisys, a leading femtocell vendor, expects trials to begin in Europe this year. Martin McNair, a general partner at Advent Venture Partners, which has backed Ubiquisys, said that the technology would provide customers with better reception than a digital cordless phone, and will benefit mobile phone companies by stimulating more usage indoors, where most mobile phone calls are made. He said that mobile phone companies are likely to subsidise the mini base stations - which will be about the size of a small router and plug into a broadband connection - to benefit from higher mobile usage and increased customer loyalty.

PicoChip expects to triple revenues this year, and triple them again next year to about $15m a quarter, the level the firm has identified as suitable for an IPO, according to CEO Guillaume d'Eyssautier. "We expect to get to $15m a quarter in between 18 to 24 months," d'Eyssautier told EW. Driving a large part of the anticipated revenue growth is the adoption of femtocells by the wireless carriers.

Recently FemtoForum has been formed. Holding their first plenary Monday (July 2) in London ahead of the first Home Access Point and In-Building Conference that opens Tuesday (July 3) , the group has revealed the names only of seven of the founding members of the Forum. "We have about 40 members and sixty companies will be represented at the plenary, but some prefer for now to keep their powder dry as regards membership", Simon Saunders, an independent consultant who will chair the Forum told EE Times Europe .

Those going public now include femtocell technology pioneers such as picoChip, ip.access, Ubiquisys, Airvana, Netgear, RadioFrame, and Tatara.

ABI predicts around 52,000 femtocell units will ship this year, with around 1 million in 2008 when deployments become more widespread. However, femtocells are not likely to replace Wi-Fi, as some carriers already have huge investments in that technology.

(3G) Civil War in US?

Interesting article from Telecom Magazine

In US Sprint Nextel and Verizon Wireless fly the flag for CDMA2000, while AT&T and T-Mobile USA spearhead the W-CDMA charge.

So far, CDMA2000 clearly has taken the high ground. Verizon laid claim to about 60.7 million CDMA2000 customers by the end of March 2007, while Sprint Nextel said it had captured 53.6 million. The W-CDMA operators, by comparison, could muster just 2.5 million customers between them.

The CDMA Development Group (CDG), which lobbies for CDMA2000, attributes this gulf to a technology lead. CDMA2000 operators, it notes, have deployed enhancements like EV-DO Revision A, which can deliver speeds of up to 3 Mbps for VoIP and multimedia applications. W-CDMA, in stark contrast, is still unavailable in many parts of the U.S. Even where it has been deployed, it typically is capable of a far less impressive 384 kbps.

W-CDMA, however, is definitely on the march. AT&T and T-Mobile USA are planning rollouts using HSDPA, a W-CDMA enhancement that offers speeds of up to 3.6 Mbps. More importantly, while W-CDMA’s customer base of 2.5 million appears low when judged alongside CDMA2000, it has grown from just 350,000 late last year.

“AT&T uses a higher frequency [than its CDMA2000 competitors], which is a disadvantage,” explains Allen Nogee, a principal analyst with In-Stat.
Generally, U.S. operators have deployed CDMA2000 using spectrum in the 800 MHz or 1900 MHz bands, while AT&T is rolling out W-CDMA using 2100 MHz spectrum. The lower frequencies have better propagation characteristics, allowing CDMA2000 operators to serve a wider area using fewer base stations.

“AT&T is also in a transitional phase,” Nogee adds. “Although it can advertise its new HSDPA network, that network has not been rolled out everywhere yet.”

Meanwhile, T-Mobile USA, the fourth largest operator in the U.S., plans to launch a W-CDMA service using the 2110 MHz to 2155 MHz spectrum it purchased in last year’s auction for advanced wireless services. Although it did not respond to requests for an interview, T-Mobile USA previously issued a statement on its 3G intentions in which it says the company will transition to a next-generation technology, which may include W-CDMA/UMTS with HSDPA, in the next two-to-three year timeframe.

And finally we cannot have a discussion without looking at the future (4G?):

Although W-CDMA is still in its early days in the United States, operators already are thinking about the next generation of mobile technology.
While a 4G standard is not yet defined, marketing departments are applying the label to some technologies already in development.

For W-CDMA operators such as AT&T and T-Mobile USA, the technology typically viewed as 4G is called long-term evolution, or LTE. It represents the destination on their journey through upgrades to HSPA, but will use a different air interface called OFDMA and require more work. Theoretically LTE will deliver downlink speeds of 100 Mbps and uplink speeds of 50 Mbps.

CDMA2000 operators also have 4G in their sights in the shape of EV-DO Revision C. Like LTE, Revision C promises vast improvements over the current crop of wireless standards. Allen Nogee, a principal analyst with In-Stat, thinks both LTE and Revision C could see commercial deployment by 2010.

In the meantime, Sprint Nextel has been vocal about another 4G technology. Last year, it earmarked US$2.5 bn for investment in a nationwide deployment of WiMAX, using 2.5 GHz spectrum it already owned. WiMAX proponents have made some bullish claims about its capability (promising up to 70 Mbps on the downlink), but the technology has not evolved from other standards—unlike LTE and Revision C—and will lack any scale economies when it is launched next year.

Chris Pearson, president of 3G Americas (a lobby group for W-CDMA), is unconvinced by the WiMAX business case. “It’s a wild card. In our view, most subscribers will be using W-CDMA and EV-DO for years to come.”

3GPP Release 8 = 3GPP IMS + ETSI TISPAN

Interesting development that happened last month at the 3GPP plenary meeting in Busan, Korea earlier this month, an agreement was reached on how to proceed with Common IMS to meet the needs of fixed, mobile, broadband and wireless users.

In cooperation with the European Telecommunications Standards Institute, the 3rd Generation Partnership Project (3GPP) has re-chartered a services group tasked with common ETSI-3GPP development of IP Multimedia Subsystem (IMS) Version 8.

Both standards bodies hailed the early June agreement, reached during a meeting in Busan, Korea, as an effective way to keep 3GPP IMS and ETSI Telecoms & Internet converged Services & Protocols for Advanced Networks (TISPAN) work.

Both IMS and TISPAN comprise next-generation network standards efforts designed to forge a higher signaling and control plane infrastructure layer to support delivery of content and applications to subscribers across any fixed or mobile network or device.

“ETSI TISPAN has taken the first steps in migrating fixed IMS requirements to 3GPP in a co-operation that will prevent fragmentation of IMS standards,” Dr. Walter Weigel, ETSI Director-General, said. “A Common IMS, developed in one place, is a big step forward and will bring enormous economies of scale and reductions in capital and operational costs.”

Common IMS developments will form part of 3GPP Release 8, which is expected to be functionally frozen by end 2007.

“Over the next few months we must stabilize the Release 8 requirements and absorb the incoming Common IMS work,” Stephen Hayes, Ericsson Inc., 3GPP TSG-SA Chair Stephen Hayes of Ericsson Inc., said. “3GPP has a history of successfully meeting challenges and I have no doubt we will meet these challenges as well.”

AIPN Scenarios

AIPN or All-IP Network is being introduced part of 3GPP Release 7. TS 22.978 shows some scenarios where AIPN will play a big part

USE CASE 1 (see left in the daigram): Bob has his own Personal Area Network (PAN). While at home, this network is composed with the Home Area Network using WLAN, which in turn connects externally with a local hotspot service, which in turn connects to a cellular network. Bob's PAN, Bob’s Home-WLAN, the local hotspot service and the AIPN cellular access system are under different administrative domains. Still, if Bob moves outside coverage of his Home-WLAN, his PAN will communicate with the outside world via the local hotspot service. If he moves outside coverage from the hotspot service, his PAN will communicate with the outside world via the AIPN cellular access system.

USE CASE 2: The user is driving a car. While being under good radio coverage, he starts an IMS session with several media. The car goes through a tunnel where there is no radio coverage, and comes out of the tunnel into good radio coverage a minute later. Connections using disruption resilient transport protocols are automatically re-established and these protocols restore the communication to the point they were before the interruption.

USE CASE 3: Alice has a mobile device and Bob has a fixed one. Both devices have equal audio but different video capabilities in terms of screen size, number of colors and video codecs supported. Alice establishes a multimedia connection with audio and video components to Bob. The terminal capabilities are discovered and it is realized that Bob's terminal has better video capabilities than Alice. The terminal informs the network that it is unable to support new the new video codec and the AIPN then introduces a video transcoder in the path of the video media to adapt the video signal (stream, codec, format, etc) to the video capabilities and bit rates available on each side of the transcoder.

Enhanced Services should be possible with AIPN:

• Support for advanced application services
• Support for group communication services, e.g. voice group call, instant group messaging, and multicast delivery. In some cases, a group may include a large number of participants.
• Support for integrated services, e.g. a service including a mixture of services among SMS/MMS/Instant Message, or a service including voice call/video call/voice mail.
• Provision of seamless services (e.g. transparent to access systems, adaptable to terminal capabilities, etc) Users should be able to move transparently and seamlessly between access systems and to move communication sessions between terminals.
• Support ubiquitous services (e.g. associations with huge number of sensors, RF tags, etc.) ... see right side of diagram above.
• Improve disruption-prone situations when network connectivity is intermittent.

Disruption-free network connectivity may not be cost effective, or even feasible, in all cases (e.g. cell planning for full radio coverage for all services, disruption-free inter-access system handovers, disruption-free IP connectivity in all network links). An AIPN should consider solutions for making services as resilient to temporary lack of connectivity as possible.

Introduction to All-IP Network (AIPN)

The All-IP Network (AIPN) is an evolution of the 3GPP system to meet the increasing demands of the mobile telecommunications market. Primarily focused upon enhancements of packet switched technology, AIPN provides a continued evolution and optimisation of the system concept in order to provide a competitive edge in terms of both performance and cost. Moreover, it is important that developments of the 3GPP system are compliant with Internet protocols. The AIPN is not limited to consideration of only the transport protocol used within the 3GPP system but adheres to the general concept of a network based upon IP and associated technologies, able to accommodate a variety of different access systems. Although, it is possible to use a variety of different access systems to connect to the AIPN, the AIPN provides an advanced, integrated service set independent as far as possible from the access system used.

The high level objectives of introduction of the AIPN are to realise:

• universal seamless access
• improved user experience
• reduction of cost (for AIPN operators)
• flexibility of deployment.

There are also a number of motivations and drivers for the introduction of the AIPN which include but are not limited to:

• diversification of mobile services
• need to satisfy user experience of early adopters
• anticipation of PS traffic to surpass CS
• desire to encompass a variety of access systems
• need for increased system efficiency and cost reduction (OPEX and CAPEX) and
• advances of next generation radio access systems and broadband wireless IP-based networks.

The key aspects of the AIPN can be summarised as follows:

• Support for a variety of different access systems
• Common capabilities provided independent to the type of service provided with convergence to IP technology considered from the perspective of the system as a whole
• High performance mobility management that provides end-user, terminal and session mobility
• Ability to adapt and move sessions from one terminal to another
• Ability to select the appropriate access system based on a range of criteria
• Provision of advanced application services as well as seamless and ubiquitous services
• Ability to efficiently handle and optimally route a variety of different types of IP traffic including user-to-user, user-to-group and ubiquitous service traffic models
• High level of security and support for user privacy e.g. location privacy, identity privacy
• Methods for ensuring QoS within and across AIPNs
• Appropriate identification of terminals, subscriptions and users
• Federation of identities across different service providers

Further Reading:
3GPP TS 22.258: Service Requirements for the All-IP Network (AIPN);
Stage 1

3GPP TR 22.978: All-IP Network (AIPN) feasibility study

Wireless and Mobile All-IP Core Networks and Services

Next Generation Mobile Systems: 3G & Beyond

C-Mobile: 3GPP MBMS for systems beyond 3G

Came across the C-Mobile website, searching for some information and the site caught my eye.

The strategic objective of C-MOBILE is to foster the evolution of the mobile broadcast business by providing enhancements to the 3GPP MBMS for systems beyond 3G.

Having worked with MBMS for some time and having completed atleast 4 trainings, the topic definitely holds my interest.

C-MOBILE will help to understand how best to organise and schedule MBMS content from the BM-SC through the core network, radio access, to the end users. Since this is multimedia content, interactions with the 3GPP IP Multimedia Subsystem are expected and C-MOBILE will explicitly investigate how best MBMS can make use of capabilities provided by the IMS.

The current concept of group communication is narrow within Release 6 MBMS specification.
C-MOBILE will research, investigate and define ways to use multicast technology to support personalized services and in particular the concept of multicast content community where users also contribute to the multicast service.

Key market and business requirements for multicast-broadcast services will be identified to aid defining research directions, leading also to new business models involving the various players.

To that end it is critical to understand the needs of multicast-broadcast users, network operators, and content providers.

The project intends to make important contributions to the standardisation bodies and to prove experimentally or via system level simulations innovative concepts.

There are no high profile names with C-mobile yet but there is Qualcomm and 3 UK in the participants list.

Some documents of interest are available here.

Push-to-share over MBMS

During one of my MBMS trainings last month in Anritsu, i set everyone a task of defining a service based on MBMS. One of the services mentioned was Push to Talk (PTT) over MBMS.

Theoretically it should be possible to use MBMS for PTT. The voice in the UL is sent via a normal CS RAB. On the Downlink the data is Broadcast using MBMS. Since we would like the data to be sent to a particular set of users, it would be Multicasted rather than Broadcasted. Also this would mean that only the users in a particular Service Area will be able to receive this.

From operators point of view, Service Area should be big enough so that the user is seamlessly able to move a wide geographical area. At the same time it should not be too big because localised services (and adverts) can generate more revenue.

A bit of Googling and i came across some patents that are trying to do the same. Following is an extract from a patent Fresh Patents:

[0009] Use of a PoC application server together with a multimedia
broadcast/multicast service (MBMS) server for providing multicast transfer of
data in the downlink direction has been suggested. In the uplink direction PoC
typically uses Real Time Protocol (RTP) traffic unicast. In the uplink PoC
clients send speech data to the PoC application server, which then directs the
speech data packets either to the MBMS for the downlink leg to those
participants who receive the speech via multicast service or directly to those
recipients who prefer to receive via unicast directly from the PoC server. Use
of multicast in downlink direction improves the spectral efficiency in the case
of group communications with great number of participants. In addition, without
multicast it may not be possible to support large group sizes, if the
participants are located geographically in the close proximity.

Another was a patent on free patents:

0032] Herein, the MBMS service refers to a service for transmitting the same
multimedia data to a plurality of recipients through a wireless network. In this
case, the recipients share one radio channel, thereby saving radio transmission
resources. For example, the MBMS service includes a stock information service,
sport broadcast service, Push-to-Talk (PTT) service, and the like.

In fact C-Mobile is working on something similar. One of their documents highlight the limitations of the current MBMS architecture and suggests how we can improve the architecture in future for B3G Architecture.

My personal feeling is that till the Architecture is eveolved enough, PTT may not be very practical over MBMS but we should be able to use Push-to-share over MBMS. Some interesting short video clip or Breaking News Clip or maybe personal Valentine messages, etc can be shared using MBMS. It now needs to be seen if some operator picks on this idea and how soon.

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.