Increasing use of cell phones and voice-over-Internet technology instead of traditional phone lines reduces E-911 revenue under current surcharges, the E-911 director said.

In years to come, the shift to new technologies could pose a threat to funds for E-911 centers around the state, said Geoffrey Greetham, director of the consolidated center for Vicksburg and Warren County.

Greetham made his comments in his report Wednesday to the county’s E-911 Commission after returning from a statewide conference of E-911 center directors.

Dispatch centers were created starting about 15 years ago using then-new Caller ID technology from BellSouth. The advantage was dispatch centers instantly knew the location of a caller and could draw on stored data such as special health needs of residents or, in case of a business, the names of keyholders and such.

State legislation allowed local votes on charging each phone customer a monthly surcharge is $1 for each home line and $2 for each business land line. Warren County voters OK’d the added toll in 1989.

As cell phones started gaining popularity, the state also allowed $1 per month fees for them, but the E-911 center receives a smaller proportion of the surcharge for each cell-phone line, though, since about 30 cents of every dollar collected is earmarked for return to the companies for equipment upgrades, Greetham said.

This year the center here is expected to receive about $498,000 of its $893,500 budget, or about 56 percent, from such phone surcharges. Most of the remainder of the center’s operating budget comes from a $371,000 subsidy, $241,500 from city tax collections and $129,500 from county residents who live outside the city limits.

“A big concern was declining revenues,” Greetham said of the talk he heard at the conference.

The decline in recent years in the use of land lines has slowed or stopped and the number of such lines in use is expected to remain relatively stable over the next two to three years, Greetham said later.

Congress has provided for no surcharges for voice-over-Internet service, Greetham said.

In addressing matters the E-911 commission voted to recommend: