## 4 Numerical Simulation and Result Analysis
### Numerical Simulation Scenario Design  
In the process of network simulation experiment, the mobility model is one of the necessary simulation parameters. It is used to describe the movement mode of the mobile node, including movement characteristics such as position, speed, direction, and accelerated speed of the mobile node. In the awareness combat network, due to the movement of the nodes, their positions are constantly changing, and the distance between the nodes is also dynamically changed, thus causing a dynamic change in the network topology [18]. The performance indicators of the network protocol, such as transmission delay, network throughput, and routing effectiveness, are closely related to the locations of various nodes in the network and are affected by the node mobility model [19]. Different mobility models have different effects on network performance [20]. In order to achieve the best network design performance, network protocols must be studied under the corresponding mobility model. Therefore, the mobility model is a basic problem of mobility research and is also the key modeling technology in the process of protocol research [21].  
At the micro level, the research of the mobility model mainly includes the node location, node speed, and its correlation with other nodes. These factors determine the connection establishment and disconnection of links between nodes, which directly affect the topology of the network and consequently affect the performance of the protocol. In a sensor network, most of the nodes are in a stationary state, and the nodes can be placed in a specified location as required. In a civil Ad-hoc network, most of the nodes are independent of each other, and the movement of the nodes is strongly random. In most studies, a random way-point mobility model is used. In a tactical Ad-hoc network, nodes cooperate with each other, move in a group, and adopt a reference point group mobility model. However, in an awareness combat network, the mobile mode of the node is particularly complex; it has the characteristic of a variety of mobility modes and there is not only one mobility model [22].  
The mobility model of a node in the actual battlefield environment is very complex. Command actions among aircrafts, armored vehicles, and infantry corps, and the movement between these groups, generally have their own reference point paths. In hierarchical mobility models, for example, helicopters and infantry regiments, the characteristics of the nodes in these two groups are completely different. No matter which mobility model is selected, it can only describe the characteristics of the selected models, and cannot represent the mobility characteristics of other mobility nodes. It is obviously inappropriate to only use the conventional reference point group mobility model. The mobility model of the battlefield environment can be comprehensively designed using a variety of existing mobility models, i.e., the Integrated Mobility Model (IMM).  
The integrated mobility model is based on the RPGM model and sets different groups in the moving scenario to simulate different group characteristics. In order to simulate a single operational unit, one or more groups of on-the-spot models can be set up, and a corresponding number of nodes and coverage can be set up according to the operational unit's combat purpose. In the simulation of cooperative operations, the troops are relatively concentrated and they move in the same area;in this situation, groups of overlapping models are more appropriate. Dynamic groups are used when simulating group splitting and merging. Random way-point mobility models or random direction mobility models are used when simulating a single node that does not belong to any group. Static nodes are used when simulating a relatively stationary command center.