Your utility may want to evaluate all of their technology options before completely shifting away from narrowband wireless networks. There have been significant changes in the last few years that can provide you with a more reliable, higher speed solution, while maintaining the benefits of a licensed radio network.
Refreshing the radio may cost you 1/10th of what a complete system overhaul to a new unlicensed network, additionally and site conversions can be completed in just a few hours per site at a much lower risk to the utility.
Electric, water, gas and wastewater utilities have a long history of using Federal Communications Commission (FCC) licensed radio frequencies for interconnecting remote facilities to provide telemetry data and control of the utility infrastructure. One of the uses of these licenses has been for Supervisory Control and Data Acquisition (SCADA) networks where remote facilities are monitored by the utility control network.
In recent years utilities have been migrating many of these licensed wireless systems over to commercial cellular data networks or to unlicensed radio spectrum. Often the reasoning supporting these decisions are for higher data rates, security or Ethernet capability. While adopting a new technology, many utilities have been abandoning their legacy licensed radio systems.
While there are some facilities where multi-megabit connectivity is needed for video or Voice over IP (VoIP) most of the SCADA traffic continues to require only a few tens of kilobits/second of network speed.
Your network may need to become a hybrid of several technologies; deploying high bandwidth microwave or fiber links critical facilities. In most utilities, the majority of sites do not need megabits/second of speed, the same amount of data will be required for monitoring and control. From past experiences in deploying several thousand sites for many different utilities at least 90% of the sites did not need multi-megabit capacity.
Advantages to remaining with the same type of network:
- The radio path performance is known
- The antenna structures, feedline and antennas are already in place and may be reusable
- Power requirements and physical space limitations are similar
- A gradual migration on a site by site basis from serial based to Ethernet protocols is possible
Some of the advantages of a licensed network:
- The utility has legal recourse in the event of harmful interference
- Exclusive licensing within a service area so the channel is not shared
- Higher transmitter power limits than what is permitted for unlicensed systems
- Greater distances are possible between sites when using similar radio spectrum
Over the past few years, several wireless equipment manufacturers have designed solutions that can provide higher data speeds across the traditional, narrow bandwidth radio. Once the FCC issued a ruling that permitted the use of advanced radio modulation techniques on narrowband channels, the potential data rate went from approximately 9600 bits/second up to 60,000 bits/second. Presently you can provide sufficient bandwidth for SCADA systems to support Ethernet, multi-protocol support, encryption and adaptive data rates to weaker sites or where the link is degraded.
Utility companies that have currently deployed licensed narrowband wireless networks should re-evaluate the technology landscape and determine if a refresh is an appropriate fit for their applications. Licensed spectrum is not a renewable resource and once a license is surrendered, expired or abandoned, it can be very difficult to secure a new license with the same performance characteristics.
There are processes that a utility can go through to evaluate the usefulness of their existing system and determine if a technology refresh will allow the existing licensed spectrum to continue to meet future demand. Some of the steps may include:
- Current state assessment of the communications network
- Identifying the future requirements for throughput, latency, reliability and data security
- Defining how the pushing of internet protocol (IP) to the edge of the network will integrate
- Analyzing existing performance
- Projecting how a technology refresh will perform
- Identifying remedial actions that can correct immediate performance or reliability issues
- Identify the business objectives and how the wireless network serves the needs of the utility
- Establish capabilities requirements
- Evaluate technology solutions based upon quantifiable metrics
- Selection of appropriate vendors, integrators and project management teams
- Pilot testing, full scale deployment and issues management
- Continual process improvement, training and integration in to traditional monitoring and support organizations
Oftentimes wireless technology refreshes fail to meet the objectives of the business due to poorly defined expectations, a lack of understanding in how to measure success or a failure to build up the systems and personnel to support a network after the deployment is complete. Each utility has unique requirements and expectations that need to be identified and clearly communicated throughout the organization.