Fault-tolerant ZigBee-based Automatic Meter Reading Infrastructure

Abstract: Due to low cost, low-power, and scalability, ZigBee is considered an efficient wireless AMR infrastructure. However, these characteristics of ZigBee can make the devices more vulnerable to unexpected error environments. In this paper, a fault-tolerant wireless AMR network (FWAMR) is proposed, which is designed to improve the robustness of the conventional ZigBee-based AMR sys-tems by coping well with dynamic error environments. The experimental results demonstrate that the FWAMR is considerably fault-tolerant compared with the conventional ZigBee-based AMR network. Keywords: AMR, AMI, Fault Tolerance, ZigBee 1. Introduction Automatic meter reading (AMR) enables utility companies to communicate remotely with residential utility meters using communications. Traditionally, field technicians ac-cessed utility meters on the customer premises to record usage information manually. With today’s smart meters, utility companies (electricity, gas, water, etc.) can now avoid this costly manual work, and set up two-way data communications between the utility’s data center and the meters. More detailed customer information can serve to offer enhanced services such as time-of-use pricing, man-agement of demand, and load profiles. Remote meter reading systems have been developed in parallel with various network technologies for many years. The communication technology used for AMR systems can be largely categorized into wired and wireless. For a wired AMR network, a Telephone network [3, 11] or PLC [6-7, 9] has been used. In particular, PLC is an efficient way for power metering since an inherent means of communication already exists within the infrastructure. So metering data can be transmitted over the power line itself via power line communications. However, for the installation cost, and safety, gas meters or water meters cannot be electrically connected together by a power line. So, recently, the use of wireless technology is more common. Wireless AMR networks include Cellular networks [4, 10] WLAN [4, 8], Zigbee (or IEEE802.15.4) [1-2], and other short range wireless systems [12-13]. Oska et al. [9] proposes a hybrid system: WLAN communication consisting of PLC-ethernet bridges. Recently, AMR systems associated with wireless sensor networks are introduced in [5, 14]. In particular, due to several advantages of easy inexpensive installation and development cost, flexibility, scalability, and so on, the popularity of ZigBee-based AMR systems is explosively arising. However, the ZigBee devices are extremely limited in resources including processing, memory, and power. In addition, ZigBee is an autonomous network. Therefore, the network is not always in user-intervention, but operates self-regulated. Sometimes these characteristics of ZigBee can make the devices more vulnerable to unexpected error environments. In this paper, a fault-tolerant wireless AMR network (FWAMR) is proposed, which is designed to improve the robustness of the conventional ZigBee-based AMR systems by coping well with dynamic error environments. The remainder of this paper is organized as follows: Sec-tion 2 examines some weaknesses of ZigBee-based AMR networks. The proposed FWAMR scheme is introduced in Section 3. Performance is evaluated in Section 4 through experiments based on real system implementation. Finally, this paper concludes with Section 5.