Specification Customized SUN with Enhanced MAC Functions for the Wireless Grid Application to the Future IoT Services

The paper proposes effective system customizations in order to realize the future diversified Internet of Things (IoT) applications by employing the concept of wireless grid that is defined as a grid like topology made up by several radio devices. This paper proposes a realization of the wireless grid by suitably exploiting the existing wireless Smart Utility Networks (SUN) that is standardized by IEEE 802.15.4g/4e task groups and is certified by Wi-SUN alliance. In this paper, Medium Access Control (MAC) layer functions that is mainly defined by IEEE 802.15.4e standard and IEEE 802.15.10 recommended practice are effectively modified according to the assumed IoT services and satisfy two major requirements of harmonized mesh activities by massive radio devices, and flexible service supporting activities with low-energy operation capability. In order to realize the harmonized mesh activities by massive radio device cooperation, SUN radio devices that exploit Layer 2 Routing (L2R) control scheme in IEEE 802.15.10 are employed to realize the autonomous mesh management function, the data concatenation function and the multiple service supporting function. On the other hand, in order to realize the flexible service supporting activities with low-energy operation capability, SUN devices implementing the low-energy superframe structure defined in IEEE 802.15.4e are employed and enable low-latency and multiple MAC parameters support in a Personal Area Network (PAN). Those performances for both required activities are evaluated through the experiments by employing the developed SUN devices. Consequently, this paper confirms that the customization of the multiple service supporting functions effectively improve frame exchange performances for both upstream and downstream data forwarding, and the modified low-energy superframe structure in a SUN can realize preferable frame latency management as well as expected communication channel allocations.