  The ever-continuing explosive growth of on-demand content distribution has
imposed great pressure on mobile/wireless network infrastructures. To ease
congestion in the network and to increase perceived user experience, caching of
popular content closer to the end-users can play a significant role and as such
this issue has received significant attention over the last few years.
Additionally, energy efficiency is treated as a fundamental requirement in the
design of next-generation mobile networks. However, there has been little
attention to the overlapping area between energy efficiency and network caching
especially when considering multipath routing. To this end, this paper proposes
an energy-efficient caching with multipath routing support. The proposed scheme
provides a joint anchoring of popular content into a set of potential caching
nodes with optimized multipath support whilst ensuring a balance between
transmission and caching energy cost. The proposed model also considers
different content delivery modes, such as multicast and unicast. Two separated
Integer-Linear Programming (ILP) models are formulated for each delivery mode.
To tackle the curse of dimensionality we then provide a greedy simulated
annealing algorithm, which not only reduces the time complexity but also
provides a competitive performance. A wide set of numerical investigations
reveal that the proposed scheme reduces the energy consumption up to 80%
compared with other widely used caching approaches under the premise of network
resource limitation. Sensitivity analysis to different parameters is also
meticulously discussed in this paper.
