# Design of a Technique for Accelerating the WSN Convergence Process
## 1 Introduction  
The present time brings demand for the use of Internet of Things (IoT) devices, which results in an increasing load on the transmission networks and devices ensuring transmission in the wireless sensor network (WSN) [1]. A higher load on the network makes it more susceptible to outages, which affects the proper functioning of critical services, ensuring, for example:  
* Security (sensors can collect sensitive data, and it is critical to ensure the authentication and authorization of devices in the network, secure data transfers, and protect against attacks) [2, 3, 4];
* Management of the energy level of individual sensors, since WSNs have a limited energy capacity, i.e., monitoring the state of the batteries to ensure constant power supply to the network [5, 6];
* Efficient routing and data transfer are crucial, given limited energy resources and limited bandwidth. Effective routing algorithms minimize energy consumption, maximize the use of available resources, and ensure reliable data transmission [7, 8];
* Fault detection [9, 10] and self-repair [11] (a combination of mechanisms such as monitoring, diagnostics, and sensor redundancy ensure that networks are fault-tolerant, highly available, and able to automatically adapt to changing conditions [12]). Fast network recovery mechanisms are designed to minimize the time required to re-establish a connection. They focus on outage detection and providing an alternate path for data that would otherwise be lost during convergence [13, 14]. This work is focused on WSN technology [15], which is used in IoT. Convergence in such a network is important, as it is also used by applications where the reliability of data transmission is critical and battery life is problematic. In WSNs, the key element of network convergence is routing protocols. The choice of a specific protocol depends on variousfactors, such as application requirements, network size, etc. The most commonly used routing protocols in WSNs are Low-Energy Adaptive Clustering Hierarchy (LEACH) [16], Dynamic Source Routing (DSR) [16; 17; 18], Sensor Protocols for Information via Negotiation (SPIN) [19], Threshold-Sensitive Energy Efficient sensor Network protocol (TEEN) [20; 21], and Ad hoc On-Demand Distance Vector (AODV) and, precisely because of its wide usability and good simulation support, AODV was chosen as the basis for the design and implementation of a new module that will speed up WSN recovery after an outage. The presented article deals with the acceleration of the WSN convergence of the AODV protocol. The exceptionality of this solution lies in fast network recovery (FRR), which will enable connection continuity in the event of a line or node failure. The AODV protocol allows us to effectively deal with dynamic topological changes in the network. Implementing a new additional module based on RFC 5880 (BFD) is an important element that can speed up error detection, even in complex network environments. The proposed solution can speed up recovery in a wireless sensor network, which is a specific type of network that requires effective solutions for fast recovery. The proposed solution focuses on this area. The goal of this solution is to create mechanisms that will not only speed up the detection and recovery of the network but also ensure the reliability of the network. This is important in a variety of applications, from commercial networks to critical infrastructures. So, excellence lies in the combination of these factors, which focus on fast, reliable, and efficient network recovery in different contexts. As part of our long-term research, we use the OMNeT++ simulator to verify new techniques in the field of FRR, which contains a complete and especially functional library for using the AODV protocol. Although the AODV protocol is quite old, its use is proven by current scientific works [22; 23; 24; 25; 26]. However, the principle of this acceleration can also be applied to other WSN protocols.