Introduction
Broadband telecommunication means are of vital importance to run our modern society, which is becoming ever more dependent on information, at any time, anywhere. These means form the arteries and the veins for economic activities ranging from research to manufacturing, for transport, health care, banking, logistics, leisure activities, etc. They need to span the globe, but also have to reach out to the individual users. Broadband communication technologies are needed providing transparently ample communication capacity, both wireless and wired, at affordable costs for the end users, yielding a traffic-jam free communication world.
Aim and Mission
All network levels need to co-operate tightly in order to achieve flawless end- to- end communication. Our vision is a seamless ultra-broadband communication network, the “boundless communication ether”, where connections between the hierarchical network layers are made fully transparent and end-to-end all-optical communication is established, with a possible exception for the last link to the user devices, which in the majority of cases will be by wireless radio signals (potentially also wireless optical signals). It encompasses all-optical traffic routing and interworking with wireless high-capacity last drop links to the end users, such that the user experiences a virtually congestion-free instantaneous access to any service demands he may have. The vision opens the route to the ultimate in flexibility and capacity of telecommunications, and augmented by means of seamless wireless (optical) connections to the user also to the ultimate in user mobility; thus the “anywhere-anytime-anything-anyhow” provisioning of broadband telecommunication services can be achieved. The common goal in this SRA theme is to provide the technological basis for such a wide-ranging self-organising (cognitive) network, which possesses the transparency to provide a wide variety of communication signals and the intelligence to locate by itself the resources with the adequate capabilities requested by the user. To provide the infrastructural means in order to reach this common goal, three research tracks are foreseen:
Wideband communication techniques
Techniques will be explored, which enable to exploit a wide frequency range in the radio spectrum, e.g. 0.5-10.6 GHz, or several GHz around an e.g. 60 GHz carrier. In particular, these techniques encompass wideband frontend stages for radio transceivers which should be low in power consumption for saving battery life. Such wideband signals also require carefully designed antennas, matching the signals’ propagation characteristics. The system robustness can be further enhanced by antenna diversity schemes, multi-input multi-output signal processing algorithmes, and wideband scanning schemes. Also adaptive coding and signal modulation schemes will improve the wideband system performance characteristics.
Self-organised adaptive spectrum utilization techniques
As the heavy usage of radio spectrum necessitates a scrutinous and efficient deployment of spectrum resources, techniques need to be explored, which optimize the usage of the available radio spectrum by meeting the capacity and Quality of Service demands of the user while at the same time minimizing the interference with radio channels serving other users. Such radio spectrum optimization techniques should be based on theoretical spectral efficiency benchmarks for spectrum re-use, and affiliated transmit power control schemes for ad-hoc spectrum re-use. They will deploy smart analog frontends for these functionalities, and antennas as well as digital baseband hardware and software for optimizing the radio channel characteristics. The overall system needs an efficient and operationally stable frequency allocation policy, allowing users to connect via fair shared access protocols, and giving them adequate Quality of Service and security.
Flexibly routed format-transparent signal transport
In order to interconnect smoothly and without congestion the users in their geographically spread wireless cells, techniques will be explored which provide the means for interconnecting these cells in a way which is transparent to the various signal formats used, thus extending the coverage of cognitive networking. These techniques will encompass wireless optics techniques providing line-of-sight high-capacity connections, as well as optical techniques for transporting (ultra-)wideband techniques via optical fibre. The interconnecting optical fibre backbone network will have optical adhoc reconfiguration functions, which can be set to deliver capacity and QoS on-demand at any location. At the edges, such a network needs wideband power-efficient converters translating radio signals into optical ones and vice-versa, while within the network optical multiplexing and routing functions are needed for transporting and delivering the radio signals to their appropriate destinations. These optical functions encompass wavelength-specific routing, wideband optical amplification, and fast optical signal processing for optical crossconnecting and add/drop/continue functions.
