  Fog computing plays a crucial role in satisfying the requirements of
delay-sensitive applications such as connected vehicles, smart grids, and
actuator networks by moving data processing close to end users. Passive optical
networks (PONs) are widely used in access networks to reduce the power
consumption while providing high bandwidth to end users under flexible designs.
Typically, distributed fog computing units in access networks have limited
processing and storage capacities that can be under or over utilized depending
on instantaneous demands. To extend the available capacity in access network,
this paper proposes a fog computing architecture based on SDN-enabled PONs to
achieve full connectivity among distributed fog computing servers. The power
consumption results show that this architecture can achieve up to about 80%
power savings in comparison to legacy fog computing based on spine and leaf
data centers with the same number of servers.
