In order to fulfil the objectives several key aspects have been identified which will be addressed by different activities. One of these key aspects is the Economic and Technical Viability of the proposed 4GBB access scheme and its Requirements. Among the relevant features to be studied is Power feeding, as the provision of power to the nodes is expected to come from the end-user side via the existing telephony wiring, and since there is no standard in this respect new requirements need to be defined. Power consumption is also a significant issue, not only from the environmental point of view but also from a practical perspective, as battery powered emergency operation is an important requirement.
The use of the existing telephony wiring forms one of the main challenges, as this wiring was designed for the transport of voice-band frequencies (300 – 3400 Hz). 4GBB rates require to extend this frequency range up to 300 MHz and very little is known about the performance beyond 30 MHz, so to build up the missing knowledge Cable and Noise Measurements will be performed and Models will be created. Performance will be studied in reference scenarios, and methods for Qualifying and Monitoring the Loop will be developed.
The requirements and models defined will allow the Development of Transmission Techniques for the Physical Layer (PHY) that will enable the efficient operation in the proposed extended frequency range overcoming problems like signal attenuation, crosstalk, noise and impairments. The main lines of work include Spectrally Efficient Modulation Techniques, Multiuser strategies and Precoding Schemes and Dynamic Spectrum Management and Scheduling.