Utility-Scale Evaluation of Hybrid G3-PLC/RF AMI in Pakistan

The Advanced Metering Infrastructure (AMI) communication over low tension (LT) distribution network has to overcome a number of technical challenges such as impulsive noise, attenuation, impedance mismatch, and topology dependent signal degradation. In the past few years, Narrowband Power Line Communication (NB-PLC) has become popular for AMI applications, which is based on existing power lines, and also supports the native power line networking provided by the Internet Protocol (IP) version 6 (IPv6). But in the real world it has been discovered that PLC-only deployments can suffer from reduced packet delivery, increased retransmission rates, and unknown routing when using the grid. Regulations on the amount of transmit power allowed, spectrum congestion and coverage uncertainty, especially in dense urban areas, can significantly impact Sub-GHz Radio Frequency (RF) communication based on IEEE 802.15.4. To address these limitations, a hybrid PLC–RF communication architecture has been designed integrating both mediums into the same protocol and enabling the adaptation of the communication medium based on the link quality estimation in real time. This paper discusses the first documented utility scale field deployment and evaluation of a hybrid G3-PLC and RF AMI communication system in Pakistan that is deployed on a pilot basis within the Islamabad Electric Supply Company (IESCO) AMI project. In a number of regions, field measurement results show significant improvements, with an average improvement from 86.4% to 97.2% in Meter Read Success Rate (MRSR), an average increase from 83.5% to 95.8% in Packet Delivery Ratio (PDR), a 34% (from 320ms to 210ms) reduction in end-to-end latency, and a reduction in retransmissions from 3.2 to 0.9 per read, mostly on feeders with high and highly dynamic PLC loss. The proposed hybrid solution enables near complete data collection in a certain number of meter clusters which are facing challenges in PLC and allows for full compliance with regulatory requirements of the Pakistan Telecommunication Authority (PTA) and Frequency Allocation Board (FAB).