# A Smart Collaborative Routing Protocol for Reliable Data Diffusion in IoT Scenarios
## 2 Related Work
### Routing Protocols Based on Geographic Location  
For the routing protocols based on geographic locations, the routing path is selected by referring to the nodes' location information instead of the routing tables, which shortens the transmission range of nodes and extends the network life-cycle. [PERSON] and [PERSON] [15] raised a Location-aware and Fault tolerant Clustering Protocol for Mobile WSN (LFCP-MWSN) to optimize energy consumption and reduce the end-to-end transmission delay. A fault tolerant mechanism was combined with the routing protocols to identify failures of data links and sensor nodes. However, the proposed protocol was not particularly better than other protocols in terms of end-to-end delay. The simulation results of them were almost identical. Moreover, the Cluster Head (CH) were considered ideally that they would not move out of the cluster in the current round. [PERSON] and [PERSON] [16] focused on the efficient management of sensing energy and computational capabilities of network. A novel energy-efficient algorithm ZEEP (Zone based on Energy Efficient routing Protocol) was proposed to improve the packet delivery ratio and enlarge the network life-cycle. The proposed protocol can be applied to both stationary and mobile nodes, without super abundant computation and mechanisms. However, the issues of network security, which could subject to malicious attacks, was not considered by the authors. In [17], [PERSON] et al. presented a gateway-based and energy-efficient routing protocol, i.e., M-GEAR for optimizing the energy consumption and network life-cycle. First, the sensor nodes were divided into four logical regions on the basis of their locations. The Base Station (BS) was installed out of the sensing area, while the gateway nodes were installed at the center of the sensing area. Finally, the communication mode of nodes was selected based on whether the distance of two equal regions was beyond the threshold distance. The proposed protocol was a multi-hop routing protocol, which improved three performance metrics (i.e., network life-cycle, residual energy and throughput). A new geographic routing protocol was presented in [18] by levering the energy-sensing technology. The authors focused on the Quality of Service (QoS) to analyze the n-hop neighborhood information, which satisfied the demand of network in real-time video surveillance. The final results showed that the proposed protocol was able to make a better decision than the greedy forwarding. However, more parameters should be taken into account in the simulation. Inspired by GAF (Geographic Adaptive Fidelity), [PERSON] and [PERSON] [19] modified the selection criteria of the active node sequence in the discovery phase of an optimized GAF. The selection of the active nodes was based on higher residual energy and less distance from BS. After the network was divided into multiple grids, the chosen active node of each grad can sense data. The simulation results demonstrated that the proposed protocol improved energy efficiency and extended the network life-cycle. In [20], a modified geographical energy aware routing was presented in WSN. The gateway node and the approaches for CH selection were integrated together to optimize energy consumption efficiency and enlarge the network life-cycle. The CH selection was based on the probability and residual energy of nodes. The network was divided into four parts, where the two regions made use of direct communication and the rest of regions adopted the clustering hierarchy. Finally, the sensor nodes in WSN were better distributed. [PERSON] et al. [21] presented an Energy-Balanced Greedy forwarding Routing (EBGR) protocol based on the geographical routing protocols to balance the energy consumption of routing paths. The routing path was established by combing the residual energy levels of nodes with the remaining hop counts, instead of considering the Euclidean distance, which optimized the energy efficiency and improved the network life-cycle.