July 2019, Vol. 246, No. 7
2019 P&GJ Metering & Measurement
Choosing Correct AMI System for Gas Utilities
By Dan Bennett, Sensus
The natural gas industry continues to build upon a customer-first approach and is always looking for new and better ways to operate. There’s no doubt, advanced metering infrastructure (AMI) systems have emerged as attractive solutions for local distribution companies (LDC) seeking to improve both customer and employee operations.
Progressing well beyond consumption needs, AMI capabilities have paved the way for a new smart gas infrastructure that leverages communications platforms, smart meters, new sensor technology and analytics software to monitor the health and status of the entire distribution network.
Yet not all AMI systems were created equal. In this article, I’ll define the available options when it comes to selecting an AMI system, then offer a real-world example with a gas service provider.
Network Confusion
Multiple options exist for wireless communication networks within the AMI framework. On one end of the spectrum is mesh, a system in which radios communicate to each other with messages hopping from meter-to-meter. Each point on the network can receive, store and transmit signals to other network points within close proximity.
This network architecture blankets an area with coverage and uses unlicensed spectrum, operating on public radio frequencies, which run the risk of interferences because they are available for anyone or anything to use. Other common devices range from baby monitors to routers to smart doorbells.
Alternatively, a point-to-multipoint communications system is ideal for using FCC primary-use licensed spectrum. Combining this network with smart meters enables better connectivity and smart infrastructure for the utility. With this architecture, a collector, or base station, directly communicates to many endpoints within a large coverage area.
Before installing a point-to-multipoint system, a propagation study is used to determine optimum base station deployments to ensure maximum performance. This network design is ideal for many different topographies and excels in both urban and rural areas.
By operating on licensed RF spectrum, point-to-multipoint systems can transmit much farther than mesh systems, with twice the transmitting power of a system operating in public frequency band. With this network design, the increased range enables each endpoint to communicate directly with a base station without having to hop from endpoint to endpoint to send the data back to headquarters.
This allows point-to-multipoint endpoints to stay in low-power modes most of the day as they only need to communicate occasionally and can conserve the rest of the time.
Additionally, point-to-multipoint systems can listen and send messages at the same time, making them true two-way networks. And, because licensed RF spectrum networks are private, each utility is assigned an RF bandwidth range that only they can use. These licensed RF channels are protected by federal regulations and interference can be mitigated quickly and efficiently.
Real-World Application
The city of Long Beach, which sits just 22 miles south of downtown Los Angeles, is routinely rated as one of the most walkable cities in the country. It’s a city where people are always on the move to check out a local gallery in the East Village Arts District or make their way across campus at the local California State University campus.
“Long Beach has a high-density population and pedestrian friendly streets that can make it feel like a small town,” said Long Beach Energy Resources Business Operations Analyst Renee Williams.
Years ago, meter readers were among the walkers, going house to house to collect usage readings. More recently, new technologies and a growing population have changed the face of gas service delivery to residents and businesses in its eight neighborhood districts.
“We enjoy having a tight-knit community, but it’s important for us to respect our city’s size and growth when it gets down to serving customers.”
Time for Change
The journey to technological advancement began with the adoption of a mesh network that allowed communication between the city and more than 156,000 meters via publicly available spectrum. The system opened the doors for remote meter monitoring and management but failed to meet growing security requirements.
“In the midst of high-density growth and development, data privacy is our chief priority,” said Williams. “We felt that transitioning to a system with a privately licensed network would help to protect customer data while also improving metering accuracy.”
Long Beach decided to upgrade its gas utility infrastructure and wanted a solution that would offer benefits beyond security. The city transitioned to an AM) point-to-multipoint solution from Sensus, a Xylem brand, that would address current needs, boost efficiency and establish tools for future growth.
In 2014, the city began deploying its Sensus AMI solution with R-275 and 415 gas meters and the SmartPoint GM transceiver. Running on the two-way FlexNet communication network, the system enables reliable end-to-end communications and data integrity over a radio spectrum that is protected from interference. The network solution has proven dependable and accurate for the city from the start.
“In the five years since we installed the system, we’ve had outstanding read rate success across our meters,” said Williams. “Consistently accurate data is a huge asset, particularly when you combine that with the extra privacy it ensures for our customers.”
With its sizable university population, Long Beach service technicians used to make frequent trips to address the ever changing student population. The new system has helped the city address this time consuming process with on-demand capabilities.
“We’ve eliminated about 80 truck rolls per-day using the AMI solution,” said Williams. “We now have a soft-off policy that allows staff to monitor meters remotely as residents transition between properties, saving us two trips to manually shut down and re-start the meter.”
Since its successful rollout was completed in 2017, Long Beach decided to move forward with the transition of water meters across 90,000 endpoints to the same system it uses for gas. The city is able to make this move with no extra additional infrastructure or service costs.
“We’ve seen how the solution benefits our gas services, so it made perfect sense for us to extend the system,” said Williams. “Being able to unite water and gas meters this seamlessly really underscores the value the system brings in helping us maximize our investment.”
Looking ahead, the city is conducting a pilot with an upcoming residential gas meter to continuously improve customer service. The utility team will continue to explore new solutions that keep the city on an innovative trajectory.
Conclusion
As a network architecture solution, a point-to-multipoint system can support today’s applications, while adding new functionalities, data rates and capacity on the same system. Moreover, by supporting every generation of product and solution on one network, existing assets can be used while new technologies are being implemented. P&GJ
Author: Dan Bennett is the director of global gas marketing at Sensus, a Xylem brand. He has six years of service with the smart technology company. He earned bachelors of science degrees in electrical engineering and computer engineering from North Carolina State University in Raleigh.
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