Utility communications: matching technology to needs
Business, utility and industrial radio users like to control their own communications networks. While the traditional SMRs grapple with expanding services and new technology, the large, industrial end-users often have creative applications for their private networks.
Industrial users rarely make the headlines in two-way news. Most of them have a high comfort level with this industry and know the equipment and technology well. They have been using two-way radio for years and find it an excellent private communications system. Often their service areas cross city, county and even state boundaries, and they may have hundreds of thousands of users. Industrial users are also an economic force to reckon with for both manufacturers and resellers.
This article takes a look at what one of the nation’s largest utilities, a statewide provider of electrical power, is doing with two-way radio and peripheral technologies.
Peeling back the covers Voice and SCADA (supervisory control and data acquisition) figure prominently in this utility’s communications applications. Utilities, in general, need automatic monitoring of sites such as power plants, pipelines and distribution centers. SCADA uses radio frequencies for such monitoring.
This utility uses conventional and trunked two-way radio for communications and specialty applications. (See Table 1 on page 44.) Its network is typical, providing wide-area coverage for mobile-to-mobile and mobile-to-base communications. Most of the utility’s voice communications are open channel, with privacy sacrificed for wide-scale operability.
Because the utility serves a large area, its radio system has more than 70 repeaters and 2,000 to 3,000 mobiles. VHF frequencies are used because their propagation characteristics fit diverse topography. VHF also has superior range, helping to keep the number of necessary repeater sites to a minimum.
Diversity-Not just for reception The utility uses a mix of mobile radio types. Some users need voice only, some need data, some require security and still others need multiple-frequency agility. Power of mobile units also varies greatly. In some regions, 25W mobiles work fine; in other areas, 100W mobiles are needed. When the utility went to bid last time, it discovered that no manufacturer offered radios with all of the desired features to replace its aging GE Delta units.
During the last round of upgrades, the utility wrote RFB specifications and invited all manufacturers to bid. The mobile specification included functions such as large channel capacity, alphanumeric display and a wide operating frequency range (5MHz to 6MHz) because the repeaters are “wideband.” Most large manufacturers came back with mobiles matching part of the spec, but none could meet all of the requirements. The two major bid winners were Motorola, with the Spectra line for high-power installations, and Kenwood Communications, with its TK line for the low-powered mobiles. Shortly after the bid was awarded, Motorola discontinued its Spectra line, and the order was replaced with Kenwood radios. Today, almost all mobility units used by the utility are Kenwood.
Next, the utility looked at repeaters’ upgrades. Most of the original repeaters were GE Mastr II series with a broadband (5MHz) front end. Fortunately, these repeaters were capable of being upgraded to the Mastr II-E status by replacing the current component shelf with an aftermarket shelf and by installing a wiring harness from IDE. The decision to upgrade was approved, at a cost of about $2,000 per repeater. This gave extended life to an existing system, whereas total replacement would surely have been more costly.
Future communications Most large private land mobile radio (PLMR) users, such as utilities, industrial companies and other businesses, make changes in phases, and this utility is no exception. Its “drawing board” pictures a lot for its next generation of communications.
A must requirement for future equipment is security. This utility doesn’t have any security on its radio channels, not even tone signaling. This is about to change.
Utility field workers sometimes collect money from customers. With unsecured communications, anyone with a radio can listen in when amounts, credit card or account numbers are communicated to the office, possibly compromising both the customer and the employee. The current procedure to work around this is to use in-house codes over unsecured communications channels (much like the police “10-codes”) to relay instructions. At a minimum, this keeps radio listeners from knowing what is going on and can be relatively effective as long as the situation isn’t too complex.
Typically, such security-sensitive situations involve non-payment or late payment of utility bills, resulting in a shutoff being imminent or just completed. In these circumstances, customers often want to pay the shortage immediately. For any number of circumstances, it may not be practical for the customer to do so, especially in rural locations. So, it becomes an issue of getting the money and restoring service as soon possible.
When service is terminated, the utility dispatches an employee to the customer’s location. Once the money changes hands, the service technician restores service and reports back to the base. Sometimes the employee may be carrying several hundred dollars, after completing several such jobs.
Obviously, secured transmissions (or mobile data) are necessary. The utility is also sensitive to other situations (leaks or fires) that need to be kept confidential.
This forward-thinking utility is also grappling with the eventual implementation of narrowbanding in the bands traditionally used by utilities. This will have an effect on the current infrastructures, especially the repeaters.
This utility foresees VHF and UHF trunking as a possible technology to boost the capacity of some of its conventional channels in more populous areas in the near future.
In the more distant future, the utility foresees using a yet-to-be-defined “digital stream” to carry its diverse communications including voice, data and control. Whether this digital stream will be part of the utility’s own system, part of a common carrier or a satellite system, is unclear to the utility’s managers.
Mobile data The utility has been testing how effectively mobile data equipment and software can be used for control instead of communications. If it works well, the company may integrate mobile data with automatic meter connects and disconnects. With mobile data, service connects and disconnects could be handled differently than before.
As the service technician starts the day, data would already be downloaded to the service vehicle’s data terminal. The service technician would have all of the information necessary: the amount, the customer ID and the service required. Once the job is done, information would be sent back to the base, updating the records-all without a single transmission over voice channels. The service technician would collect the money and then, using mobile data technology, reconnect the service electronically. Furthermore, such jobs could be done on a real-time basis, throughout the day as well, without compromising either the utility or the customer. In the future, the service technician may even electronically transfer the customer’s funds.
Although mobile data has many applications, for this utility, customer service would be the first step. As software and hardware continue to mature, mobile data could eventually be used to control any number of power functions, such as grid manipulations, load balancing, switching pumps and bringing motors on line. Other future mobile data functions include automated maintenance scheduling, crew assignments, substation monitoring and control, and real-time data collection.
For now, some of this is done with SCADA, but SCADA is not as dynamic as mobile data, nor does it have the ability to cross platforms as easily. SCADA systems are mostly self-contained, using dedicated hardware and frequencies, so moving the function to another frequency band and technology requires replacing sensor transmitters and antennas. In many cases, mobile data can be added to existing networks. This utility envisions mobile data, in part, as either an adjunct or a potential solution to SCADA’s limitations.
Welcome to the 21st century There are issues other than computer date interpolation that must be addressed in the next century. For this utility, visions include systems that can handle both voice and data simultaneously (referred to SVD), integrated AM/FM digital radios and bringing power line carrier (PLC) control over to a digital platform. But perhaps the most forward-thinking comment from this utility involves, in the not too distant future, the convergence of voice, data, SCADA, PLC and control in a small, hand-held PC (HPC) format. The system will be platform-independent and won’t matter which type of communication the user initiates. The system’s artificial intelligence will take care of details.