A 3-dimensional group management MAC scheme for mobile IoT devices in wireless sensor networks

We are truly entering the era of Internet of Things (IoT) in which all things are connected and can be used in a variety of ways regardless of time and place. Various types of sensor devices using advanced technology will gather data around us and deliver the information wherever we want. In this paper, we propose an energy efficient MAC scheme for IoT ecosystem environments that include mobile IoT sensor devices. The mobile sensor devices in a target IoT ecosystem gather and collect any required data while moving and transmitting the collected data to a sink node. Energy consumption of the sensor devices depends on the distance from the sink node and also affects overall lifetime of the IoT ecosystems. The proposed 3-D group management MAC (3-D GM MAC) scheme groups sensor devices based on the distance (hop) from the sink node and transmits the collected data only to the next higher group level. That is, the data is transmitted only in the direction to the sink node. In addition, the energy efficiency of the entire IoT ecosystem can be improved by transmitting data based on pre-configured buffer threshold values that are set differently for each group and consequently minimizing the energy consumption of sensor devices near the sink node. When any sensor device cannot transmit data to the next higher group level due to movement, it is newly assigned an appropriate group number and transmits data using a new route. We have shown that the proposed 3-D GM MAC scheme shows excellent behavior in the aspect of energy efficiency for the target IoT ecosystem by simulation. Therefore, the proposed scheme might be adaptable for mobile sensor devices used in various kinds of computing and networking environments such as IoT, big data, cloud computing, and fog computing.