  Cellular communications are evolving to facilitate the current and expected
increasing needs of Quality of Service (QoS), high data rates and diversity of
offered services. Towards this direction, Radio Access Network (RAN)
virtualization aims at providing solutions of mapping virtual network elements
onto radio resources of the existing physical network. This paper proposes the
Resources nEgotiation for NEtwork Virtualization (RENEV) algorithm, suitable
for application in Heterogeneous Networks (HetNets) in Long Term
Evolution-Advanced (LTE-A) environments, consisting of a macro evolved NodeB
(eNB) overlaid with small cells. By exploiting Radio Resource Management (RRM)
principles, RENEV achieves slicing and on demand delivery of resources.
Leveraging the multi-tenancy approach, radio resources are transferred in terms
of physical radio Resource Blocks (RBs) among multiple heterogeneous base
stations, interconnected via the X2 interface. The main target is to deal with
traffic variations in geographical dimension. All signaling design
considerations under the current Third Generation Partnership Project (3GPP)
LTE-A architecture are also investigated. Analytical studies and simulation
experiments are conducted to evaluate RENEV in terms of network's throughput as
well as its additional signaling overhead. Moreover we show that RENEV can be
applied independently on top of already proposed schemes for RAN virtualization
to improve their performance. The results indicate that significant merits are
achieved both from network's and users' perspective as well as that it is a
scalable solution for different number of small cells.
