**9. Future work**

After describing the previous contributions in the literature and outlining the differences with the presented approach in Section 2, the problem was defined and formulated in Sections 3 and 4, then the novel proposed method to address the formulated problem was presented in Section 5, and its efficiency was demonstrated in Section 6. Hence, the role of this section is to introduce some interesting future research directions.

In addition to a more thorough and detailed investigation of the topics described in Sections 7 and 8, future work would consist of implementing the proposed methods in a sensor network testbed and of matching the simulation results with actual energy measurements. Another interesting research direction is to consider SNs with variable power sources, and to distinguish between battery powered SNs and SNs having access to renewable energy sources (e.g. solar powered) or mains powered. The problem can be reformulated by imposing a constraint that the latter SNs should be cluster heads since they can transmit large amounts of aggregated data on the LR without suffering from energy shortage.
