## 2 Establishment of a BDIIM for Node Wake-Up Control
### Modeling of the Biomimetic Infectious-Immune Process
#### 2.2.2 Previous Distributed Infectious Disease Model  
Our previous DIDM is designed based on the infection mechanism. In this section, we briefly describe the DIDM. Before the description, some concepts must be listed first. * A pathogen refers to a microorganism that may make humans or animals sick. Such a pathogen may be transmitted to other individuals within a certain distance. An immune cell refers to the cells produced by humans or animals that have the ability to kill the pathogen and keep the organism healthy. Figure 1: The problem formulation of sensor wake-up and architecture of a sensor node. * Infectivity refers to the ability that one individual has to potentially infect other individuals. * Individuals who are infected by the infectious disease carry a certain amount of the pathogen. On the contrary, immunity refers to the capability of individuals to resist the pathogen, thereby keeping the organism healthy. * An infection source is an individual who has infectivity, while susceptible people are the individuals who do not have immunity and have the chance to be infected if in contact with infection sources. Infected individuals are infection sources for cross-infection. * A superspreader is an individual who carries an unusually large number of pathogens and has sustained infectivity to susceptible individuals within the infection distance. A superspreader is the infection source for direct infection. * A direct infection (DI) refers to the event where one individual with immune deficiency to a DI contacts the superspreader and becomes infected. * A cross-infection (CI) refers to the event where one individual with immune deficiency to a CI contacts other infected individuals and becomes infected. * Individuals have immunity to DI when they contact the superspreader and do not become infected. Individuals have immunity to CI when they contact other infected individuals and do not become infected. The corresponding DIDM only considers the infection mechanism during epidemic spread. The infection mechanism is mainly formulated based on six infection rules (Rules 1-6). These rules are briefly listed as follows:  
1. (bound of pathogen quantity) The quantity of pathogen carried by each individual is limited. This means the pathogen quantity in each individual has lower and upper limits. 2. (monotonous characteristic of CI occurrence probability) When an individual has immune deficiency to CI, the more pathogen this individual carries, the worse the health situation of this individual is. 3. (occurrence probability to direct infection) Regardless of whether an individual with immune deficiency to DI is located within or without the epidemic's DI zone, there always exists the probability that this individual will become infected by the pathogen or some other cause. 4. (cross-infection intensity) When an individual carries a greater pathogen amount or there is a shorter distance to their neighbor with immune deficiency to CI, the CI intensity of this individual is larger. 5. (cross-infection infectivity) An individual must be directly infected before they can infect their neighbors with immune deficiency to CI. 6. (cross-infection tendency) With CI infectivity increasing or decreasing consistently in some regions, movement of the superspreader away from or closer to these regions will occur gradually. This leads to infectious enhancement or reduction. Based on the six infection rules, the detailed infection progressing of every individual is represented. However, the DIDM is established mainly based on the infectious mechanism. As for the immune mechanism, it only introduces a prior identical immunity repairing ratio, which hardly represents the natural processes and dynamic behavior in the whole biological immune system. These important, but ignored processes and variation-tendency behavior in the previous work mainly contain immune deficiency, occurrence probabilities, immune cell production, pathogen accumulation, and immune memory mentioned above in the section on the immune mechanism.