  Network Slicing (NS) is expected to be a key functionality of the upcoming 5G
systems. Coupled with Software Defined Networking (SDN) and Network Function
Virtualization (NFV),NS will enable a flexible deployment of Network Functions
belonging to multiple Service Function Chains (SFC) over a shared
infrastructure. To address the complexities that arise from this new
environment, we formulate a MILP optimization model that enables a cost-optimal
deployment of network slices, allowing a Mobile Network Operator to efficiently
allocate the underlying layer resources according to the users' requirements.
For each network slice, the proposed solution guarantees the required delay and
the bandwidth, while efficiently handling the usage of underlying nodes, which
leads to reduced cost. The obtained results show the efficiency of the proposed
solution in terms of cost and execution time for small-scale networks, while it
shows an interesting behavior in the large-scale topologies.
