ireless technology continues to grow in terms of both market success and technological innovation in spite of the recent woes in the telecommunications industry. Global cellular demand has been disappointing in recent years, and mobile-data-usage forecasts have not materialised. The promise of Third Generation Wireless Systems, known as 3G, has also remained unfulfilled, hurting the industry which has sunk billions of dollars into global research and development, as well as the purchase of operating licences and spectrums.

Terrorism, war, and severe acute respiratory syndrome (SARS) get much of the blame for the generally poor performance of the world's economy. As a result, the last few years have seen a consolidation within the industry, with companies right-sizing or merging. Some have been forced to exit the business altogether. However, localised areas of high growth, especially in the Asia-Pacific region, have provided subsistence to the survivors, and analysts believe the industry is on the threshold of a new growth cycle driven by technological innovation.

In their search for new sources of revenue within the wireless industry, companies have come up with perhaps unexpected services. A good example is the recent rapidly expanding wireless local area network (WLAN), or Wi-Fi, hotspot rollout. Often seen as a competitor to traditional cellular mobile services, small start-ups have shown the way while telecommunications service providers around the world still try to decide whether to incorporate this technology and business into their offerings.

Problems of security, seamless roaming, and capacity remain but are now being seriously tackled by the standards bodies, IEEE 802.11a/b/g/f. Another advance to watch is the unconventional approach of the rapidly emerging ultra-wideband (UWB) technology, the development of which is again led by start-ups. The United States Federal Communications Commission allocated a spectrum for UWB in February 2002 after much lobbying, and industry giants such as Intel, Motorola, Matsushita, and NEC have since moved in with significant R&D investment. A standards battle has begun within the IEEE 802.15 Wireless Personal Area Network Working Groups (802.15.3a for high- and 802.15.4a for low-data rates), which have in principle adopted UWB as the base technology.

Singapore is known for its excellent telecommunications infrastructure and its pervasive use of information technology. The island-wide deployment of wireless infrastructure also positions it among the world's leaders. The July 2003 mobile-subscriber-penetration rate was 80.6%, owing largely to the Singapore government's belief in, and hence emphasis on, the creation of an outstanding business-support infrastructure as a route to high-tech economic growth.

The Infocomm Development Authority (IDA), the Economic Development Board (EDB) and, most recently, the Media Development Authority (MDA) are all government statutory boards armed with programmes to support a Singapore wireless industry. In addition, the Agency for Science, Technology and Research (A*STAR) and its predecessor, the National Science and Technology Board (NSTB), established the Centre for Wireless Communications (CWC) in 1992 to spearhead wireless R&D. The sector grew rapidly when in April 2003 CWC became a part of the Institute for Infocomm Research (I²R). The National University of Singapore and the Nanyang Technological University have been very active in the field, while the four polytechnics have produced many innovations.

This special focus has been broadly organised into four main sections. The first opens with some observations on wireless research activities in Singapore by a panel of thought leaders from industry and academia who visit Singapore regularly as advisors. This is followed by an article from IDA, which is both regulator and promoter of telecommunications in Singapore, giving an overview of the national wireless technology roadmap.

The next section, on UWB technology, highlights a significant research achievement by an I²R team in demonstrating an experimental UWB system that runs in the laboratory at a data rate of 500Mbps over several metres. Next is a bold IDA plan to promote UWB deployment that covers taking technology to market, including R&D, field trials, regulation, application, and training. Another group within I²R displays its latest work on antenna design in general and a UWB aerial in particular.

The third section covers a number of important developments in WLAN, the current flavour of the month in wireless circles. Field trials of public-access hotspots produce interesting results on the performance of the newer IEEE 802.11a system in a real hotspot environment and compare it with the current industry workhorse, IEEE 802.11b. An update and statistics of wireless deployment and hotspots follow, providing an indication of the new service's commercial potential. Next comes a deeper insight into the underlying MIMO and OFDM technologies which enable incredibly high data rates over a limited bandwidth, with a description of how speed in the order of 150Mbps could be achievable in future systems. Applications have great importance in driving wireless implementation, and researchers offer some available solutions based on WLAN technology. A new concept for increasing the coverage of WLAN cells using low-cost radio-over-optical-fibre systems is presented, implying the possibility of reducing the overall cost of deploying WLAN in both private and public hotspot environments. The segment is rounded off with innovation in the design of RFIC low-noise amplifiers for WLAN transceivers.

The last section contains a collection of articles that deal with a broad range of topics in the field. I²R work on smart antennas promises increases in capacity and signal quality. Identifying wireless applications as an important market, Oki recently set up Oki Techno Centre in Singapore to conduct R&D projects. I²R's AMASE project focuses on developing a mobile middleware that enables seamless roaming across heterogeneous networks. Security is a key concern in all-wireless systems; some local work gets highlighted. Next, in a departure from the wireless communications focus, radio-frequency identification is applied in a modern library scenario. Finally, we get a glimpse of the exciting future widespread adoption of software radio architecture could make possible.

To round off the wireless focus, the Spotlight and Viewpoint sections give the insights of two outstanding researchers. The spotlight falls on Randy Katz, a renowned expert responsible for setting up the White House portal, who shares his thoughts on R&D in the fiercely competitive wireless arena. Complementing this in Viewpoint, industry veteran Louis-Francois Pau of Ericsson addresses the business challenges of the mobile market.