The use of wireless Networking devices has seen a tremendous increase in the recent past. The number of mobile handsets has already exceeded that of fixed telephone lines, and forecasts predict that by 2010 there will be 1.7 billion mobile services subscribers worldwide. Future networks will have to accommodate those users efficiently and enable ubiquitous computing at an affordable price.

Expectations on 4G systems will only be met if demanding technical requirements are fulfilled. The traditional circuit-switched data flows designed for speech transmission are supplanted by packet-based networks, which are better suited for rich multimedia traffic. Voice will be yet another service included in a wider offer of bandwidth-demanding services.

End users will ask for stringent quality-of-service (QoS) guarantees. As they travel either by car, train or plane, users will expect contracted services to be provided seamlessly from one system to the next, independent of the underlying technology. Ubiquitous computing will be enabled by the cooperation and interworking of different systems integrated in a common packet-based environment. This is precisely the vision of ITU-R on systems beyond 3G as illustrated in Figure 1.

EU project WINNER

The vision of WINNER for 4G is of a single radio system concept with adaptation capabilities to all the envisaged environments, ranging from short-range to wide-area. Several modes of a common technology will be leveraged to provide efficient operation in each considered scenario.

WINNER is seeking a concept that uses the best component technologies based on the most recent and promising research results in Networking theory. On its way to a future system realization, WINNER will provide considerable enhancements to the current systems in terms of peak data rate, latency, mobility, spectrum efficiency, coverage and supported environments.

The approach is to optimally combine advanced radio technologies on the basis of indentified scenarios for the WINNER system concept. Different radio network topologies and deployment concepts are considered so as to provide ubiquitous radio coverage. System efficiency is improved through cooperation mechanisms at the radio-level, and flexible sprectrum sharing methods.

The Sensor Network group at IBM's Zurich Research Laboratory is contributing to the WINNER air interface definition for the short-range scenarios. We focus on the PHY and MAC layers, and investigate how their are impacted by the introduction of advanced techniques such as relaying and multiple-antennas. For further information on the WINNER consortium, please consult their Web site.