Taking a step towards tackling the 5th Mobile Communications challenges head-on, the European research community at large are targeting a potential new air-interface based on filter bank technology, referred to as Filter Bank Modulation Carrier (FBMC). Research into FBMC has shown much better interference behaviour than its predecessor, based on Orthogonal Frequency Division Multiplexing (OFDM) modulation thus providing the possibility to employ smaller guard bands. In addition, flexible spectrum harvesting and aggregation can be carried out by nulling carriers where harmful interference occurs making FBMC well suited for unplanned deployments.

Unfortunately to date, dynamic access schemes that could exploit the degrees of freedom offered by FBMC have not been addressed sufficiently. Future networking architectures will be multi-tier, support heterogeneous services and dynamic in nature; where the end-user is expected to be connected to the best available network. This paradigm will exert stringent design requirements on the access scheme to provide a truly flexible allocation medium (in time, frequency and space) that can adapt to the varying traffic requirements across cells and systems. In i-Five we study just that, we propose an adaptive frame size and duplex approach, that exploits the benefits of FMBC-PHY in interference limited scenarios and in very dynamic allocation contexts.

The next generation of deployed systems can be expected to build on the LTE-A/3GPP approach and support sharing mechanisms in 'white' spectrum, whereas most of the available(unlicensed/lightly-licensed) spectrum below 6GHz will be increasingly 'dirty' (or 'grey'). i-Five will investigate the implications of sharing non-clean spectrum in capacity and coverage expansion scenarios.

To close these gaps, i-Five proposes to design and develop an advanced MAC that will be able to exploit the characteristics of the existing FBMC PHY for both dynamic and interference limited mobile network (such as heterogeneous and small cell networking {HetSNet} environments) and spectrum sharing scenarios. The MAC approach will be validated on a system level experimental platform to contribute to a deeper understanding of the existing FBMC approaches in terms of their impact on the newly devised interference mitigation techniques in practical environments, and their gain over legacy OFDM based solutions. Such innovations, supported through research together with experimental proof of concepts planned in i-Five, will encourage development of new products/services beyond what is already available today or likely to be available in the next 5 years. Moreover, the mobile standardization group (3GPP) are developing the concept of the 5G New Radio (5GNR), based on developing a unified access stratum to support heterogeneous services, deployments, and spectrum. This project is not only aligned with the 3GPP roadmap, but well placed to provide candidate solutions during the project lifetime.