Advanced Metering Infrastructre

Explanation

There are two main elements of a Smart Metering System, Smart meter and the advanced metering infrastructure (AMI). The AMI is then split into HAN (Home Area Network) and WAN (Wide Area Network).

The main purpose of a smart metering system is to instigate energy and CO2 reductions. Here vast amounts of data are collected via half hourly readings, to allow for the evaluation of electricity consumption habits of consumers, so that energy reductions can be made. In order to accommodate the volume read out of large quantities of meters every half hour, a dedicated communication network is needed.

There are many facets to energy reduction which range from flexible tariff change to credit meters that can be remotely converted to prepayment meters and home energy monitors that allow consumers to monitor their usage.

One of the more critical elements of the system is the communication method and there are many proposed methods each with advantages and disadvantages. Of note is Zigbee which is a meshed system ideal for WAN but unable to communicate with the now common blue tooth devices hence not ideal for HAN.

For example a separate home energy display is required instead of displaying the energy on a Bluetooth enabled PDA/mobile phone, which would be more convenient. Bluetooth on the other hand is ideal for HAN, communicating with appliances, but cannot be meshed and therefore is not ideal for WAN. Of note is the relatively new BLE (Bluetooth Low Energy) which could do both.

Power Line Carrier (PLC).

PLC is a well established method for propagating signals through the power cables. However, it has a problem where the transformer often prevents propagating the signal beyond a voltage level and therefore PLC often includes multiple technologies in order to create large networks.

General packet radio service (GPRS)

This system has the advantage that a meter can operate in isolation but like mobile phones payment are based on the volume of data traffic.

Zigbee

ZigBee is a low-power, wireless mesh networking standard aimed at industrial applications and is ideal for WAN, but has the disadvantage that it cannot communicate with Bluetooth devices for easy home user access on Smartphone’s, Apple Ipads, laptops & PCs. Therefore meters using Zigbee will require additional costs of a dedicated home monitor.

Bluetooth

Bluetooth is a proprietary open wireless technology standard for exchanging data over short distances using Star Networks. It does not need a dedicated home monitor but does not have the meshing range of Zigbee and is not suitable for WAN.

Bluetooth Low Energy (BLE)

BLE is a low power Bluetooth that has all the makings of an ideal solution for Smart Metering. Currently, it is still in development, so there are questions whether it will use mesh networking, but it is clearly targeted at industrial applications competing with Zigbee. The key to the success of BLE is its backward compatibility of the existing Bluetooth architecture based on the Star Based network. This will allow industrial equipment integrations into everyday mobile devices, eliminating costs of having dedicated control and monitoring systems. Of course security aspects will be a top concern and will have to be overcome.

Wi-Fi

Wi-Fi is a common system ideal for mains powered systems. It's high power consumption is a disadvantage in battery operated systems. Most metering systems also include a hand held unit (HHU), which would be battery operated.

Low Powered Wi-Fi

There are some tractions forming in Low Powered Wi-Fi, it is too early to consider this as a main player for industrial application, though there are a number of companies working in this direction.

Technology integration

The borders for each individual technology are being drawn. The dominant technology needs to have complete cross platform integration. Just as Microsoft dominated the Desktop PC. Zigbee will have to get into the Home and portables market or eventually become a niche product. Zigbee Smart Meters could become a dead end technology if they do not, as BLE & Wi-Fi are moving into these industrial sectors & applications.