# Multilayered Network Model for Mobile Network Infrastructure Disruption
## 4 Routing in MNM
### Routing in WSN Layer  
The routing of urgent data begins in the WSN layer. The sensors of the WSN layer periodically measure data and routes them into cloud services on the Internet if the AP is available on the network. In Section 3.2. we provide technology recommendations for WSN layer. The best way to make WSN data propagation to the Internet is the implementation of the routing protocols based on IPv6 protocols. The most suitable technology for MNM is IEEE 802.15.4 ZigBee with 6 LoWPAN or RPL protocol. In the MNM, we assume that sensors in the WSN layer will be fixed without mobility and also will be able to communicate in a multihop manner. The authors in [30] provide a protocols survey based on 6 LoWPAN technology. Protocols are classified based on multihop support, Network or Host-based mobility or presence of local entity among other specifications. The classification of routing protocols with multihop support can be seen in Figure 7.  
The same authors also point out that proactive protocols are most suitable for WSN with 6 LoWPAN, since, it helps to reduce the handover delay by reducing the configuration time and also to avoid the disconnection of nodes, which reduces the data loss rate. Therefore, it is useful to use protocols in the Proactive branch chart. Another important division is based on mobility. The authors described Micro and Macro mobility, where the \"Micro mobility\" refers to the node mobility within the same sensor network domain and \"Macro mobility\"refers to the node mobility between different sensor networks. Since sensors in MNM are fixed, the maximum allowed mobility of sensor node is Micro mobility. Since WSN layer in MNM uses the gateway system, the best suitable routing protocols based on presented assumptions are Based-Cluster [31] and RPL-Weight [32]. In the case of the Based-Cluster protocol, the main advantage is network architecture based on a clustering tree topology, which leads from the lowest layers of sensors to one leading sensor (Cluster Head), which in the case of MNM can be considered to be a WSN gateway sensor. RPL-Weight is a  
Figure 6: The example of communication between MANET nodes, MANET gateways and UAVs. hierarchical protocol based on Directed Acyclic Graph (DAG), which defines a network topology and uses Destination Oriented DAG (DODAG) algorithm for routing. It supports sink node mobility, which reduces power consumption and to increase the network lifetime. This is also very useful for MNM, where the sink node can act as a gateway to the MANET Layer or AP. The clustering tree topology of Based-Cluster protocol and sink node mobility of the RPL-Weight protocol are shown in Figure 8.  
However, both Based-Cluster and RPL-Weight protocols are not designed to support urgent data transmission through WSN gateway sensors to the MANET layer. Therefore, it is important to implement an exception mechanism for those or other deployed protocols. The algorithm responsible for the routing of urgent data in WSN layer of MNM is proposed in flowchart depicted in Figure 9.  
Figure 8: The example of Based-Cluster and RPL-Weight routing mechanisms. Figure 7: WSN protocols based on 6 LoWPAN with multi-hop support [30]. This algorithm needs to be implemented as an exception to the main routing algorithm. In the beginning, if AP is available in the network, all measured data are processed as usual by the main routing algorithm. If AP is not available, measured data needs to be evaluated based on Threshold. This threshold is set based on type or nature of measured data that evaluates them as urgent. Since the sink routing model is considered, it is possible to assume, those nodes near the sink node connected to MANET layer will be asked to forward packets more frequently as nodes that are far. This could affect the network's performance. Figure 9: The WSN Layer routing flowchart. the energy consumption of those nodes and also cause traffic congestion.