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IEEE 802.15.4 Beaconing Strategy and the Coexistence Problem in ISM Band

Over a home area network, between smart appliances and the smart meter, and over an 802.15.4g smart utility network, from a smart meter toward the utility center, IEEE 802.15.4 assists with advanced metering infrastructure components in a smart grid. Adopting the synchronous beacon-enabled mode of the IEEE 802.15.4 standard provides a slotted framework for low-power, real-time collection, and distribution of power information. However, the shared nature of the industrial, scientific, and medical (ISM) band introduces the beacon corruption issue, and confronts the 802.15.4-based network with service interruptions and large delays. This paper, experimentally and analytically, studies how interference from collocated networks affects the beaconing functionally and, consequently, network performance. Investigations indicate that beaconing contributes in low-power and low-delay communications over an 802.15.4 network only when its proper operation is guaranteed over a coexistent environment like ISM band; otherwise, the application delay is significantly compromised. In this regard, a standard-conforming enhancement, called the beacon corruption recovery scheme (BCRS), is proposed to mitigate effects of coexistence on beaconing performance by migration of the network to a cleaner channel. Simulation results show that by applying the BCRS, an 802.15.4 network experiences a less fragmented accesses to the medium and better fulfills real-time bidirectional flow of monitoring information.