The Grays Harbor Public Utility District in Aberdeen, Wash., has deployed Exalt Communications' microwave backhaul systems to carry critical SCADA and automated meter reading (AMR) traffic from its substations to its main data center.

The district provides electrical service to customers in northwestern Washington, and its network also carries two-way radio and 911 voice traffic for Grays Harbor county agencies and Ethernet traffic for Internet service providers.

GHPUD uses a combination of fiber and microwave to link its 22 substations with its main data center. While microwave systems have been in use at GHPUD for a decade or more, the District's technical staff was having reliability problems with legacy microwave systems at eight of the substations. The GHPUD team selected Exalt microwave systems not only for their high reliability but also because the Exalt systems can carry both native TDM and IP traffic.

As configured for GHPUD, the Exalt systems carry 100 megabits per second (Mbps) of Ethernet traffic and up to 11 T1 lines. While the amount of IP traffic on the network is relatively small at this point, the Exalt systems offer plenty of scalability for new applications and traffic over time.