EBU - Technical Review

In his Foreword to this book, Joseph Mitola [1] writes: "Walter has done it again". Indeed, following his first book on software-defined radio (SDR), published in 2002 [2], Walter Tuttlebee collated his second book on the same topic less than a year later. Both books are published in the Wiley Series on software radio. This series aims to present an up-to-date and in-depth picture of the technologies, potential implementations and applications of software radio.

For a reader of this book review, it may be useful to explain why SDR may be of any interest at all. The traditional SDR concept introduces flexible terminal reconfigurations – by replacing hardware terminals by ones that are configurable and programmable in software. This concept may include reconfiguration of the terminal antenna, its RF parts and the baseband processing. Recently, the SDR concept has been extended to include the reconfiguration of applications and services as well as networks.

However, as with many other novel technologies, the development of SDR commercial applications is still slow. It is not the complexity of the technology used that is the main problem – it is the cost efficiency.

As a result, SDR is still in the domain of R&D. In early 2000, the EU launched the first call for proposals for its IST (Information Society Technologies) R&D programme. This is now coming to an end, but it seems that reconfigurability will play an important role also in the 6^th Framework programme of EU-funded R&D, because many new projects have been proposed. This effort will be focused on the standardization of the relevant network and service aspects, as well as the regulatory implications.

As with telecommunications systems, SDR may potentially provide adaptable future-proof solutions for the broadcast industry as well. As in telecommunications, the broadcast terminals would benefit significantly from having elements of reconfigurability, intelligence and software programmable hardware. For example, reconfigurable middleware and protocol-adaptable mechanisms would overcome the problems which may arise due to different proprietary API standards in digital television (MHP, MediaHighway, OpenTV, etc.). In digital radio and television, SDR may help the smooth introduction of new audio and video coding algorithms, as they become popular in the marketplace.

However, it should be pointed out that, in promoting SDR, the commercial aspects should not be neglected. As broadcasting is a mass market activity, often with hundreds of millions of receivers in use, the cost of terminals plays a crucial role in determining how successful any new technologies may be.

With this in mind, this book is designed to serve as a training resource for both engineers and marketers. SDR may become a major functional enabler of business processes and will enable new business models.

The book contains four parts. Part 1 provides an introductory base, giving both context and definitions. Part 2 addresses the requirements and design of SDR front-end RF components. Part 3 is perhaps interesting for broadcasters, as it explores baseband processing technologies. It reviews the traditional technologies used in microprocessors, DSPs (Digital Signal Processors) and FPGAs (Field Programmable Gate Arrays) and the "parameterization" approach. Finally, Part 4 considers the role of software in SDR, from several angles. This latter part introduces commercial products which are just beginning to emerge on the market. It also considers the matters associated with the dynamic download of software to a mobile terminal, addressing aspects such as download technologies and on-the-fly equipment upgrades. The final chapter of Part 4 introduces the concepts of WDL (Waveform Description Language), which is a design technique and toolset to allow the specification and rapid deployment of new interface waveforms in the field, without incurring major costs and incompatibilities. This concept has been validated empirically already within the defence arena and offers promise for commercial applications.

Walter Tuttlebee should be congratulated for this compendium and we look forward to further developments in the area of SDR, particularly its applications in broadcasting.

[1] Joseph Mitola wrote a first book on the subject of software radio, back in 1991. He indeed coined the term Software Defined Radio (SDR).

[2] Software Defined Radio: Origins, Drivers and International Perspectives, edited by Walter Tuttlebee, Wiley Europe 2002.

Access to internet services has over the years become a day-by-day commodity. However, such access normally assumes a physical connection over PSTN, ADSL or cable. This book focuses on a very interesting subject : how to bring internet services to wireless and mobile users. It should be said immediately that the book is not an easy afternoon reading. It is intended for a range of different technical audiences, starting from senior-level university undergraduates to postgraduate students, research engineers, system developers and professional engineers.

The present second-generation (GSM) cellular networks are already able to provide some sort of wireless data services and internet capabilities to mobile users. Nevertheless full internet services will only be provided by third-generation (3G) UMTS systems. The intermediate step, GPRS, is a packet-mode service designed on top of GSM and is capable of providing data services (including Internet) at higher bit-rates than GSM to mobile users.

The book goes beyond IMT-2000 and describes future 4G mobile interacting networks using full IP network implementation.

The second part of the book is the central one; it describes some fundamental topics in wireless IP, such as Quality of Service (QoS) in a mobile environment, traffic modelling and traffic management for wireless IP and the related transport and internet protocols for wireless IP.

Part 3 covers some advanced topics in wireless IP and discusses the perspectives on wireless IP. The book ends up with a description of satellite IP services.

Reading this book is highly recommended to those who are involved in developing IP applications for broadcast networks such as DAB and DVB. This book could help development engineers assess the advantages and disadvantages of using IP tunnelling in digital broadcast networks. IP seems to be a must, if broadcasters plan to broadcast video and audio streams and files towards "convergent" terminals such as PDAs, mobile phones, etc. IP could represent an important step in the direction of network convergence.

The book provides an extensive bibliography for further reading. As there are many other books covering IP in telecommunications, it should be stressed that this book gives an excellent overview and systematic description of the important topics within wireless and mobile IP. It is highly recommended.

Takeshi Natsuno, the author of this book, has been directly responsible for all the strategy matters of i-mode ^[1]. He joined NTT DoCoMo ^[2] in 1997 with the task of launching i-mode services in Japan. He is known as the founder of i-mode and was selected in 2001, by Business Week, as one of the 25 most influential e-business leaders worldwide.

As opposed to most books reviewed in EBU Technical Review, this book is not an engineering book – it is about marketing and business strategy. It describes how it may be possible to harness a technology to make it a commercial success in particular business environments. In Natsuno's words: "This book tells the reader how to conquer the incredibly rich new world of mobile multimedia opening out before us".

The book is totally oblivious of technicalities such as bit-rates, QoS, browsers, packet-switched networks and media servers; rather, it primarily focuses on content and services, and on how people can reach them easily, without needing to consult a 100-page user manual.

There is not the slightest doubt that i-mode is commercially successful in Japan and is on its way to conquer the world. Since its launch in February 1999, it has become a mass market service, with more than 37 million paying subscribers in Japan, France and Germany, and soon also in Italy, Spain and other countries. The number of registered voluntary i-mode web sites by October 2000 were 28’000 (as reported by Digital Street which offers an i-mode search engine). More than 3000 companies work in the i-mode world. I-mode is organized as a commercial company which sells to customers via m-commerce, creates i-mode-specific information products and services and advertises products and services. The large majority of i-mode subscribers use e-mail and browse web pages every day. Around 70 or more different DoCoMo handsets (counting colour variations) are available in Japan – see an example given in Fig. 1.

So which services are available on i-mode? The most popular application is sending e-mail, but users may get the weather forecasts, look at sports result, load ringing melodies into their handsets, play games, do online banking, online stock trading, purchase air tickets and train tickets, download cartoons and images, look for restaurants and look for new friends. Increasingly, corporations also use i-mode for company internal work, such as supply chain management.

Technically, i-mode is an overlay over NTT-DoCoMo’s ordinary mobile voice system. While the voice system is "circuit-switched" (i.e. you need to dial-up), the i-mode is "packet-switched". This means that i-mode is, in principle, "always on". For standard handset models for 2G i-mode services, the maximum speed for i-mode download is 9.6 kbit/sec. In practice, this is sufficient for simple i-mode data. The packet size is 128 B. An i-mode page needs to be smaller than 5 KB. I-mode is also available on Japanese 3G mobile networks (FOMA) where it provides bitrates in the order of 200 kbit/s.

Currently, i-mode uses gif images and animated gif images, but no videos. However, on FOMA, DoCoMo's i-motion service provides video clips. Most handsets have colour screens with 65’000 colour resolution and can display colour images.

I-mode uses cHTML (compact HTML, sometimes also called iHTML), which is in part a subset of ordinary HTML. However, in addition to HTML tags, there are some special i-mode-only tags (for example a tag to set up a link which, when pressed, dials a telephone number – or another i-mode-only tag which informs search machines that a particular web page is an i-mode page). In addition, there are also special DoCoMo characters which are symbols for joy, kisses, love, sadness, hot spring baths, a telephone, Shinkansen train, encircled numbers etc. There are quite a large number of these special non-standardized characters, and DoCoMo adds new image characters from time to time.

The book shows that these are multiple. First of all, i-mode conceptually fits well into the Japanese way of life. Japanese people do not use PCs for internet access as much as in some other countries, so mobile phones are sort of a natural choice as a means for accessing the Internet. Mobile phone penetration is high in Japan (60 million mobile subscribers) and, in addition, Japanese people love gadgets.

Secondly, i-mode adopted a very convenient business-to-consumer relationship. I-mode handsets are relatively low priced for consumers at the point of purchase. Users are attracted by the service costs; as i-mode is"always on", charges go according to the amount of information accessed, not the usage time. Therefore, the overall costs can be relatively low. In addition, there is an efficient micro-billing system attached to the mobile phone bill. Micro-billing systems makes it easy for subscribers to pay for value-added services at premium sites, and attractive for site owners to sell information to users.

Thirdly, it is comparatively easy to develop specific i-mode websites. The system uses cHTML, which makes it easy not only for developers but also for ordinary consumers to develop content. This has resulted in the explosive growth of content and rapid development of many attractive applications. An AOL-type menu list of partner sites gives users access to selected content and services on these partner sites, which is included in the micro-billing system.

And last but not least, i-mode is a technically sound system. Its development was driven by the market requirements. Compared to the European GSM/WAP system, which cannot be called a resounding commercial success due to its numerous technical and business problems, i-mode is technically less complex, less technically advanced but more efficient. In particular, when a user selects an i-mode item on the handset menu, data is usually immediately downloaded. There is no dialling delay when setting up a connection. However, there is a delay for data to reach the user, but this delay is similar to the delay in PC-based internet connections after clicking on a link. Also, it seems that i-mode’s cHTML, which is a subset of HTML, is relatively easier to learn for website developers than WAP's markup language "WML". Another main difference is that, at present, an i-mode user is charged for the amount of information downloaded (plus various premium service charges, if used), while WAP services were introduced with “circuit-switched” GSM, where the user is charged by the connection time. This may change now, however, as WAP will be used with “packet-switched” and faster GPRS technologies.

In summary, i-mode has been successfully introduced as the core of everyday life in Japan. It will shortly be rolled out as part of the third-generation mobile services, using the IMT-2000 standard, developing e-commerce, including e-Money. 3G i-mode will enable users to view short clips of full-motion video, coded in MPEG-4. Finally, there are plans to expand i-mode internationally and make it truly worldwide.

So if any readers would like to make a commercial success of i-mode, this book comes highly recommended. But readers should look elsewhere in order to gain an understanding of the technicalities of i-mode.

^[1] It may be important to understand where the name “i-mode” or “imode” comes from. Most people assume that the "i" in "i-mode" stands for information, internet, etc. However, in Japanese “i” may mean many other things, as there are literally hundreds of words pronounced "i". One of them is "love". This latter meaning has actually been used extensively in some of DoCoMo's campaigns.

^[2] NTT-DoCoMo is a subsidiary of Japan's incumbent telephone operator NTT. The majority of NTT-DoCoMo's shares is owned by NTT, and the majority of NTT's shares is owned by the Japanese government.

Review 1:	Software Defined Radio: Enabling Technologies Walter Tuttlebee (Editor)	Wiley Europe
Review 2:	The Wireless Mobile Internet: Architectures, Protocols and Services Abbas Jamilipour	Wiley Europe
Review 3:	I-mode Strategy Takeshi Natsuno	Wiley Europe