  Small wireless cells have the potential to overcome bottlenecks in wireless
access through the sharing of spectrum resources. A novel access backhaul
network architecture based on a Smart Gateway (Sm-GW) between the small cell
base stations, e.g., LTE eNBs, and the conventional backhaul gateways, e.g.,
LTE Servicing/Packet Gateways (S/P-GWs) has been introduced to address the
bottleneck. The Sm-GW flexibly schedules uplink transmissions for the eNBs.
Based on software defined networking (SDN) a management mechanism that allows
multiple operator to flexibly inter-operate via multiple Sm-GWs with a
multitude of small cells has been proposed. This dissertation also
comprehensively survey the studies that examine the SDN paradigm in optical
networks. Along with the PHY functional split improvements, the performance of
Distributed Converged Cable Access Platform (DCCAP) in the cable architectures
especially for the Remote-PHY and Remote-MACPHY nodes has been evaluated. In
the PHY functional split, in addition to the re-use of infrastructure with a
common FFT module for multiple technologies, a novel cross functional split
interaction to cache the repetitive QAM symbols across time at the remote node
to reduce the transmission rate requirement of the fronthaul link has been
proposed.
