  In this paper, we investigate the performance of incremental redundancy
combining as a new cooperative relaying protocol for large M2M networks with
opportunistic relaying. The nodes in the large M2M network are modeled by a
Poisson Point Process, experience Rayleigh fading and utilize slotted ALOHA as
the MAC protocol. The progress rate density (PRD) of the M2M network is used to
quantify the performance of proposed relaying protocol and compare it to
conventional multihop relaying with no cooperation. It is shown that
incremental redundancy combining in a large M2M network provides substantial
throughput improvements over conventional relaying with no cooperation at all
practical values of the network parameters.
