Wireless for Utilities

IP network destined to connect smart appliances to home or office

• By Cosimo Malesci
• Dec 01, 2012

Utilities and governments around the world are investing billions of dollars into upgrading the existing analog electric, gas and water grids into two-way communication networks capable of optimizing distribution and reducing costs for consumers. The long-term objective is a sustainable and affordable fruition of energy, gas and water.

The key component of all smart grid initiatives is a pervasive IPnetwork to connect smart appliances and meters in homes and offices with electricity producers. Thanks to this network, the usage patterns of each resource can be optimized based on its availability on the grid.

A smart grid network can usually be broken down into three parts: the home area network (HAN), the meter area network and the metro/wide area network (M/WAN). HAN is the network in the home usually created between all the smart appliances using Zigbee or similar technologies. HAN connects all the appliances to a smart meter. The meter area network connects a certain amount of meters to a substation, thus gathering information from multiple houses. Most of the time, it covers a few city blocks. Finally, the M/WAN is the network that connects substations, as well as distributed generators, synchrophasors and transformers to the grid.

M/WAN connects multiple meter area networks together, and the meter area network connects multiple HANs together.

The advantage of using wireless technology for creating a smart grid how easily and quickly it can be installed. Given the brutal costs of running fiber, wireless is, for most cities, the only viable solution to upgrade their grid. In the realm of the wireless world, mesh networks have established themselves as the leader in the smart grid space, for they offer a lot of flexibility in the deployment, as well as an additional level of reliability. Zigbee, a type of mesh network, has now become the leader of HAN while 900 MHz and 5.8 GHz mesh networks own the meter area network and M/WAN covers longer distances and provides more throughput.

From a frequency standpoint, the meter area network is usually at 900 MHz because line of sight is often impossible to achieve. In the M/WAN, mesh networks usually operate on the 5 GHz band—the best tradeoff between data rate and cost.

5 GHz mesh has become the leading technology for meter and M/WAN due to its flexibility and the lack of a single point of failure. With meters spread across a city, it is impossible to be able to stick to a specific network topology such as point-to-point or pointto- multipoint.

In addition, networks tend to grow and change in topology over time, making it even harder to stick to a certain type of network over the life of the system. Mesh networks do solve the problem, providing unlimited flexibility in the deployment. It is also worth noting that using a mesh network on the 900 MHz and 5 GHz range offers the best compromise in terms of performance and price and is totally capable of addressing the connectivity need of many utilities out there.

Today’s mesh networks have improved substantially in terms of reliability and ease of use, making them an even better solution for these types of applications. First of all, the most advanced radios come with an integrated antenna, making them much easier to install and to service. This also makes them much smaller or more powerful because there is no need for external antenna cables, surge suppressors or grounding wires. In addition, many mesh radios used for backhauling are switching to directional antennas—the best way to guarantee throughput and cover long distances up to 15 miles, or even more. They also make the network less sensitive to interferences, leading to a reliable solution. This aspect is particularly important for utilities because the distances are long and the data throughput might be substantial given the large number of devices on the network.

The applications for wireless in a utility are numerous, but when it comes to smart grids they are mainly automatic meter reading (AMR), substation automation and distribution automation. Without getting too much into the details, the goal of the network is to provide live information on the performances of the grid without having to send people around reading meters. This applies to power utilities as well as water utilities.

In fact, both of them have a need to gather data from their devices live at any point in time so they can act on it and become more efficient. The overall result is a more cost-effective solution for the customers and a reduced amount of wasted energy.

Wireless has also helped many utilities to deploy video surveillance cameras in remote areas where there is no fiber available. Given the amount of throughput now available on license-free wireless networks, many utilities are deploying video surveillance cameras to monitor their assets and protect their properties. Thanks to new developments in radio technology such as MIMO and in video compression, we are now able to easily send high-definition video from multiple cameras across one single wireless link. In addition, using wireless allows many utilities to change the location of their cameras more easily during the life of the system, guaranteeing they will always be monitoring what matters the most to them. This clearly opens up a whole new world of opportunities for many utilities that, until a few years back, were still struggling with analog communication.

Wireless also is deployed in a utility to provide broadband connectivity to different buildings and create an enterprise network between their properties. Although this is probably the least innovative of the applications, it still solves a major connectivity problem that affects many utilities trying to provide better tracking of their assets.

This article originally appeared in the December 2012 issue of Security Today.