## 2 Related Works  
To obtain an answer to the research question, related works have been sought on the types of jamming, techniques for detecting jamming and WSN performance metrics, as well as node densities and cooperative and collaborative schemes. Jamming is one of the most effective denial of service (DoS) attacks; the attacker prevents legitimate data from reaching its target and causes packets to collide, so legitimate packets cannot be delivered through channels [4]. A classification of the existing types of jamming is presented in Table 1.  
While _elementary proactive jamming_ sends jamming interfering signals in a network whether the data communication is there or not, _reactive jamming_ senses the network in active state and ongoing communication and then it initializes the sending of jam signals. Reactive jammers use more energy than active jammers as they are always monitoring the network, going to an active state every time there is a transmission on the channel. On the other hand, advanced _smart hybrid jamming_[11] can be proactive, reactive or hybrid. This attack hinders the communication bandwidth in an important part of the network, adding energy in certain strategic places; however, it could be _function-specific_[11], having a programmed function that attacks a single channel or multiple channels simultaneously, maximizing the jamming throughput irrespective of the energy usage. It can change to another channel according to their specific functionality. The most common attacks in the industrial environment are elemental elements, which in IWSNs are sometimes confused with the noise generated by the machines in the production process. The first elementary type of jammer is the _constant_[4; 12; 13; 14], which is achieved by sending bits continuously to the network without an established protocol to saturate the transmission channel, and so that the legitimate nodes cannot engage in communication correctly, Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol is not validated as random bits are constantly sent. Nodes receive corrupted packets and the processor works more, which leads to greater battery consumption. The second is _deceptive_ jammer [4; 14; 15], which is simulated by sending packets continuously, but they are legitimate packets and no longer random, causing legitimate nodes to always be listening, and with a lot of traffic, they cannot change from receive state to send state. Since they have the appearance of a legitimate transmission, their impersonation is more difficult to distinguish. The third is _random_ jammer [4; 12; 13; 14], which, being also active, tries to block communication and can be simulated if interference periods alternate with sleep \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Types of Jammers** & \multicolumn{2}{c}{**Saving of**} & **Proactive (P) or** \\  & & & **Energy** & **Reactive (R)** \\ \hline \multirow{4}{*}{Elementary} & \multirow{4}{*}{Proactive} & Constant & & P \\  & & Deceptive & & P \\  & & Random & & P \\ \cline{2-5}  & & Data/Ack (acknowledge) & & R \\  & & Request to send (RTS)/ & & R \\  & & Clear to send (CTS) & & R \\ \hline \multirow{4}{*}{Advanced} & \multirow{4}{*}{Smart Hybrid} & Control Channel & & P and R \\  & & Implicit & & P and R \\ \cline{1-1}  & & Flow & & P and R \\ \cline{1-1} \cline{2-5}  & & Follow On & & P \\ \cline{1-1} \cline{2-5}  & & Channel Hopping & & R \\ \cline{1-1}  & & Pulsed Noise & & P \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Types of jamming attacks. state periods. When it emits interference, it does so randomly, behaving like a constant jammer or as a deceptive jammer, while when it switches to the sleep state it acts as a reactive jammer and stops consuming energy considerably, decreasing data processing and increasing battery life. Finally, _reactive_ jammer [4; 12; 13; 14] is the most difficult to detect.