In currently deployed wireless networks, the lack of dynamic control across wireless resources leads to suboptimized and unbalanced spectrum loads, especially in below 6GHz bands, which in turn creates a (perceived) capacity bottleneck in end users. This issue can be addressed through the adoption of the eDSA (extended Dynamic Spectrum Access) paradigm, which consists of enhanced resource management techniques with three degrees of freedom: densification, rationalized traffic allocation over heterogeneous wireless technologies, and better load balancing across the available spectrum. The objective of this paper, triggered by the ongoing work in the SPEED-5G research project, is twofold: i) present a survey of the most promising enhanced techniques for 5G networks at MAC and RRM level, and ii) propose inter-RAT mechanisms to cope with the above mentioned issues, mainly focusing on access aspects of the next-generation networks in below and above 6GHz bands.