Impairments-aware time slot allocation model for energy-constrained multi-hop clustered IoT nodes considering TDMA and DSSS MAC protocols

The possibility of Internet of Things (IoT) is that a large number of live items (e.g., apparatuses) in the network are available, detected, and interconnected. In any case, the performance of IoT networks may be limited due to several impairments, most importantly, the energy-constrained IoT nodes. In fact, this limitation opens the door to many researchers where using network clustering has proven to be efficient energy saving mechanism. To the best of our knowledge, there are no prior research, in the field of multi-hop clustered IoT networks, which addressed the energy-constrained IoT nodes problem along with the delay in receiving data messages from devices, located far away from the remote users (or control center), in timely basis. Practically, it is significantly challenging to contemplate and clarify this issue. Consequently, in this paper, we make major amendments on the prior work, Improved Energy and Distance Based CH Selection with Balanced Objective Function (IEDB-CHS-BOF), and particularly propose a multi-hop routing (MR) protocol in which the IoT network is divided into a number of virtual sections with lengths held below the cross-over communication distance, thereby ensuring minimal energy depletion. Over those virtual sections, efficient forwarder and cluster head selection algorithms are further proposed. Interestingly, we propose a novel delay-, power-, and interference-aware time slot allocation model in which Time Division Multiple Access (TDMA) and Direct Sequence Spread Spectrum (DSSS) MAC protocols are operated. Furthermore, it is a good representation of the above-mentioned proposals. As a result, our protocols are referred to as MR-IEDB-CHS-TDMA and MR-IEDB-CHS-DSSS, respectively. To this end, numerous simulations have been conducted for evaluating the performance of the proposed protocols in the perspective of IoT network lifetime. In addition, sufficient comparisons have been conducted with the existing state-of-the-art protocols. In overall, the MR-IEDB-CHS-TDMA protocol keeps the IoT network functioning the longest.