The ZigBee protocol enables communication using multiple network topologies, including star, tree and mesh . It is particularly challenging to ensure reliability of the communication channel for smart meter designs, especially with the use of wireless-based backhaul channels and ZigBee is particularly suited to this application with its mesh network topology. In case a meter is out of range of a central tower or otherwise obstructed by buildings or other objects, ZigBee-based meters enable communication between meters and relaying of information back to the data collection point . Furthermore, since ZigBee devices utilize the unlicensed 2.4GHz spectrum, they have a very low cost of deployment and allow seamless integration and networking of many ZigBee devices. Although they have many benefits, ZigBee devices are designed primarily for short-range communication and low device power requirements , requiring a separate wireless protocol for long-range transmission. ZigBee is a key technology enabling the OpenHAN networking standard discussed later in this paper.
OpenADR (Automated Demand Response)
Because electricity is charged at a constant price in the current power system, regardless of time of use, consumers therefore have little incentive to put forth effort to change their usage patterns. Introducing smart grids will allow for dynamic billing based on market pricing at the time, and thus give more incentive to customers to plan their energy usage . With the proposed automated demand response, individual smart meters will have the capability of monitoring system wide conditions, determining when the system is stressed and appropriately allocate power to different appliances. Automated demand response will aim for reducing high loading during peak times, in an attempt to remove excess stress from the power system .
Open Automated Demand Response is a standard currently under development , which aims to ensure interoperability between various smart meter infrastructure devices. It will provide a way for users program appliances to operate according to current electricity prices, for example to do laundry when power is cheapest.
OpenHAN (Home Area Network)
Open Home Area Network is a proposed standard to interface with the smart meter in residences with appliances in the home. OpenHAN can allow for utility control of the appliance, customer coordination and timing of appliance activation, and operational states of appliances based on set-points such as price. Upon completion and implementation of this standard, residents will be capable of having appliances automatically run during times when electricity is cheapest, and utilities will be able to cease operation of appliances during peak loading times. OpenHAN is the fundamental idea behind automated demand response, where there exists a link between the smart meter of the customer and the customer’s appliance .
Worldwide Interoperability for Microwave Access (WiMAX)
WiMAX is an industrial wireless interoperability standard related to the existing technology known as the Global System for Mobile Communications (GSM) . It is typically used for land-based wireless Internet service providers, particularly those serving rural communities; however, it is finding applications within power systems as a backhaul for smart meter telemetry data .
Broadband over Power Lines
Several different startup companies have explored the use of Broadband over Power Lines (BPL) as an Internet service delivery or as a backhaul for telemetry from smart meters . While it is no longer a serious contender for delivering Internet access to remote communities, the technology still has its niche applications, particularly within the realm of power systems. Some smart meter vendors continue to sell smart metering equipment that transmits telemetry over power lines  rather than using its own radio frequency, which requires the purchase of costly spectrum.
Furthermore, using BPL couplers traditionally used for sending and receiving data across power lines can be used to listen for types of noise characteristic of certain types of equipment failures; for example, a cracked insulator beginning to fail will induce a specific signature pattern that can be detected using BPL couplers .
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One of my partners wrote the majority of this article for a report submitted to ECE4439: Conventional, Renewable and Nuclear Energy, taught by Professor Amirnaser Yazdani at the University of Western Ontario. It is included here for completeness with the rest of the articles. I edited the article and wrote the sections entitled: Worldwide Interoperability for Microwave Access (WiMAX) and Broadband over Power Lines.