Two Groups Face Off on Number Predictions

Each year it is the North American Numbering Plan Administration's (NANPA) responsibility to estimate when the supply of numbering plan area codes (NPAs) will run out. In 1998, NANPA selected Lockheed Martin to conduct its numbering study and provide expert advice on the problem. Later, the study was reviewed -- and disputed -- by the CTIA-initiated NANPA Exhaust Review Team.

"The review team used our models (the NPA demand model and the central office code-demand model) with some alternative assumptions to come up with some potentially different exhaust dates," said Tom McGarry, NANPA chief technical industry liaison. "It all comes down to a difference of opinion with regard to a simple concept -- the NANPA team believes that the demand for NPAs and central office (CO) codes will continue to increase; the review team believes it will slow."

Lockheed Martin estimated exhaust based on a combination of data compiled from 1995-1998, the first three months of 1999 and the experience of NPA and CO code planners to support the prediction that demand will continue to increase for at least another two years.

"Our demand model estimates that the demand for CO codes will peak at about 2001; the review team believes that the demand has already peaked," McGarry said.

The review team also disagreed with Lockheed Martin's exhaust date using the pooling model. The review team was concerned that NANPA's model assumed the implementation of pooling in all NPAs at the same time and that the assumptions didn't address technical feasibility and availability. The review team did agree with Lockheed Martin on one point -- that the effect of pooling could extend the life of the North American Numbering Plan (NANP) into the mid-21st century.

"The definition of 'exhausting a NANP' is running out of area codes," McGarry said. "Once you have no more area codes, you have to start adding more digits." At the end of 1998, there were 247 of the 680 available area codes in use internationally and domestically with 23 in use or reserved as service codes. That leaves 410 area codes remaining.

"When all of the area codes exhaust, not all of the central office codes are exhausted," McGarry said.

There are 792 CO codes per area code. When the CO code is exhausted, an area code is split or overlaid. When all the CO codes exhaust, there are a lot of spare telephone numbers left in the area code.