It’s 2:30 a.m.; Do you know where your paging system is?
Even large paging operators cannot baby-sit a system 24 hours a day. Remote monitoring detects and announces problems before they become catastrophes.
It’s 2:30 a.m. when the phone next to Alan Gilmour’s bed starts to ring. Gilmour is the vice president/operations manager of Sprint Paging, a large paging system operator in Victoria, British Columbia, Canada. Gilmour does not like being awakened from sleep by a jangling phone any more than the rest of us, but this is one call he is grateful to receive. When he picks up the receiver, the voice on the other end of the line is familiar-very familiar. In fact, it is his own voice, a recording being played back by a remote paging monitor. The prerecorded message informs him that a major part of Sprint’s system has just gone down, and it gives him the location. Gilmour holds down the star key for a couple of seconds to cancel the alarm. Then he hangs up and dials BC Tel, his local telephone company.
At 2:30 in the morning, 20,000 other BC Tel customers who have lost their phone service do not know it yet. Even BC Tel does not know. Gilmour is about to enlighten them.
Ditch the switch Gilmour describes what happened on that long, sleepless night: “BC Tel had just replaced one of their major switches. It was a switch they weren’t familiar with, and they didn’t realize they had programming problems until we called in. Once they started looking at our problem, they found other problems. The situation spiraled downhill from there.
“At five in the morning, while I was waiting for the phone company to call me back, I decided to call into my Internet provider and found that his system also wasn’t working.” Gilmour was able to pass on the unhappy news to his Internet service provider, who otherwise would still have been in the dark.
First come, first served Most importantly, the fact that Gilmour was the first to call into BC Tel meant that Spring Paging was the first subscriber to get fixed.
“We were up and running three hours later,” Gilmour said. “By six in the morning, when our customers started to use their pagers, they had no idea there had ever been a problem.” Sprint’s customers were the lucky exception; 10,000 BC Tel customers still did not have their phone and paging service fully restored until three days later.
An ingenious modification Gilmour had specially modified a model 1512 Zetron Sentridial monitor so that it could monitor paging transmissions and provide dial-out voice alarms in the event of a system failure. “We took a model 1512 and added some external timer circuits and a pager,” Gilmour said. “We wrote a dial-in loop and then an alarm sequence once that loop was broken for any length of time.”
The modified monitor worked like a charm. Gilmour described his innovation to Zetron engineers while visiting the company’s booth at a Canadian Wireless show in Vancouver. As a result, Zetron developed and refined Gilmour’s idea into the new model 1515 Veripage monitor. The system is set up with a vibrating pager, of any make, connected to a verifying monitor located inside the coverage area. The verifying monitor dials a paging terminal at user-defined intervals to activate the pager to which it is connected. The monitor detects when the pager receives the signal and resets its interval timer until the next page. If the page is not received within a reasonable amount of time, the verifying monitor automatically dials as many as 10 preprogrammed telephone numbers to deliver voice, numeric or alphanumeric messages to maintenance employees.
Number one on the List The modified monitor at Sprint Paging is set up in a similar fashion. When an alarm occurs, it follows a preprogrammed dialing list, calling technicians’ homes and cellphone numbers until the alarm is acknowledged. Not surprisingly, Gilmour’s name is number one on that list.
Gilmour explained why he created the automated alarm system in the first place: “We’ve got a very well-designed system at Sprint Paging, but we’ve got no operators or answering service-everything is strictly direct-dial into the paging terminal. After hours, our telephones are call-forwarded to our pager, so if we had a major system outage it would be very difficult for us to find out about it. It’s not like we have an operator on duty 24 hours a day who can start phoning us. Basically, the model 1512 gives us peace of mind. It has been in place for two years now. We’ve had a couple other incidents, but this was one of the first real major outages since the system was installed.”
Sprint Paging A division of Sprint Radio Systems, Sprint Paging is the largest independent paging provider in that area of British Columbia, with several thousand customers in a coverage area spread across Victoria, Vancouver Island and greater Vancouver. Sprint’s paging system relies on an automated, high-end paging terminal with links to repeaters in each of its service areas. To provide complete coverage, Gilmour has a total of three modified monitors in operation, as shown in Figure 1 on page 22.
“We’ve got one of these units in each different sector of our paging system, because Victoria could be fine, but if one of our links goes down it could take out half a dozen sites somewhere else,” Gilmour said.
The monitor for Sprint’s Victoria service area is located at Gilmour’s home. “I’ve got the unit located off-site, so it does a full check-out of the system,” he explains. “It phones in the trunk lines and tests right from end to end. If it was located at our terminal unit, we could use it for some external reset or switchover function.”
Better than insurance? Gilmour may have lost a few hours sleep during that night, but his company did not lose any revenue. Thanks to his ingenious modification of an existing autodialer, Sprint Paging’s customers did not have to wait three days before they could use their pagers again. Having an electronic watchdog to sound the alarm will make any paging system manager sleep a little easier.
