II. Background

The 310 area code serves Local Access and Transport Area (LATA) 730⁴ located in Los Angeles County. The 310 area code was created in late 1991 to relieve numbers exhaustion in the 213 area code. The 310 area code was subsequently split in January 1997, forming a separate 562 area code, again to replenish number supplies. On February 18, 1998, industry representatives submitted to the Commission yet another proposed relief plan for the 310 area code, again claiming impending numbers exhaustion.

On May 7, 1998, the Commission issued D.98-05-021, approving a 310 area code relief plan, calling for the implementation of the first area code overlay ever used within California. In conformance with federal rules, the overlay plan also required the implementation of mandatory 1+10-digit dialing within the 310 area code and the newly created 424 area code.

On June 9, 1999, shortly after implementation of mandatory 1+10-digit dialing, Assemblyman Wally Knox, with other parties, petitioned to modify D.98-05-021, seeking to halt the opening of the overlay scheduled to occur on July 17, 1999, and to end mandatory 1+10-digit dialing. In D.99-06-091, issued on June 24, 1999, the Commission temporarily suspended mandatory 1+10-digit dialing in order to provide time to address the full merits of the Petition. In D.99-09-067, the Commission granted the Knox Petition, suspending the 310 area code overlay plan, eliminating mandatory 1+10-digit dialing, and instituting a program of number pooling and related conservation measures to extend the 310 area code life.

The traditional system for assigning numbers was a legacy from an era in which one incumbent carrier provided all customers with local service in a given area code. Under the traditional system, a carrier wishing to serve only a few customers in an area is allocated telephone numbers in blocks of 10,000 for each rate center in that area. That system worked reasonably well as long as only one incumbent local exchange carrier required numbering resources. With the opening of the local exchange market to competition, together with the growth in the market for wireless and advanced technological telecommunications services, the traditional number assignment system could no longer keep up with the growing demand for numbers. The traditional system did not lend itself to efficient distribution of numbers in a competitive market where numbers are assigned to multiple carriers to serve customers in each rate center.

Moreover, industry claims of impending number exhaustion were based merely upon carriers' forecasts of numbering resource requirements. No independent analysis had been provided concerning the reliability of such forecasts or carriers' actual utilization of numbering resources. Accordingly, in D.99-09-067, the Commission ordered the staff to undertake a study of 310 area code number utilization to ascertain how efficiently carriers were actually using numbering resources already assigned to them. The Commission stated that a full accounting of 310 area code numbers actually in use would be required before setting any further date for the opening of a new area code.

We also adopted various number reporting and conservation measures in D.99-09-067 to utilize numbering resources more efficiently in view of the delegated authority granted by the Federal Communications Commission (FCC) in a September 15, 1999 Order.⁵ Since the adoption of D.99-09-067, the Commission has made significant progress toward promoting more efficient utilization of existing numbering resources through thousand-block number pooling and related conservation measures.

Number pooling allows telephone companies to receive numbers in smaller blocks than the traditional 10,000 numbers, enabling multiple providers to share a 10,000-number block and therefore use this limited resource much more efficiently. Wireless carriers implemented the technology to enable their participation in number pooling beginning in November 2002. Previously, only wireline carriers could participate in number pooling, and those carriers received telephone numbers solely through the number pool. Wireless carriers received numbers in 10,000-number blocks through a Commission-administered monthly rationing system, or "lottery," and through emergency requests to the Commission. Currently, both wireline and wireless carriers in California receive numbers through the state's number pools. Only paging companies, which are still exempt from local number portability requirements, now receive numbers through the monthly lottery system.

On March 16, 2000, the Commission's Telecommunications Division (TD) issued its "Report on the 310 Area Code" (Report) presenting findings on how efficiently numbering resources remaining in the 310 area code were actually being utilized by carriers, in compliance with the directive of D.99-09-067. Parties were permitted to file responses to the Report. As reported by TD, there were approximately three million unused numbers as of November 1999. Of the three million unused numbers reported as of November 1999, only 466,000 were identified in the Staff Report as belonging to wireless carriers. At the date of the Report, wireless carriers were not able to participate in the current 310 area code number pool; they had to rely on the semi-monthly 310 area code lottery of central office prefix codes to meet their numbering needs. Since that time, wireless carriers (except for paging companies) have become subject to FCC number pooling requirements.

As an additional measure to extend the life of the 310 area code, the Commission filed a petition with the FCC on September 5, 2002,⁶ seeking a waiver from the FCC "contamination" or number use, threshold requirement. Specifically, the Commission requested the FCC to grant California the authority to increase the existing 10% "contamination" rate. Under FCC rules, carriers must donate to each area code's common number pool all thousand-blocks of telephone numbers that contain less than 10% "contaminated," or used, numbers. An increased level of allowable contamination or usage rates for poolable thousand-number blocks (from current 10% to 25%) would increase the number of thousand-blocks that are available to all carriers through each area code's number pool, thereby extending the life of the 310 area code.

The FCC acted upon this Petition by its Order adopted August 5, 2003 and released August 11, 2003. While the FCC declined to grant a statewide waiver of the 10% contamination rate, it did find good cause to justify raising the contamination level in the 310 and 909 area codes, on an interim basis, while the Commission implemented area code relief in those areas. The FCC concluded that the additional thousand-blocks that will be made available by increasing the level of contamination from 10% to 25% would extend the life of the 310 area code by one additional month.

In order to augment the stock of number blocks available in the number pool, we implemented the revised requirements for donations to the 310 area code pool effective August 21, 2003, increasing the allowable number block" contamination" threshold from 10% to 25%. Since August 2003, carriers have returned 413 additional blocks for use in the 310 number pool.

In addition to more efficiently managing number distribution, California also requires companies to more efficiently manage the numbers they already have. The number conservation measures that we have adopted, including requirements in D.99-11-027 for carriers to return unused codes, fill rate and sequential numbering rules in D.00-03-054, and thousand block number pooling for LNP-capable carriers, help ensure that the unused numbers in the 310 area code are allocated as efficiently as possible.

Carriers must return any 10,000- and 1,000 number blocks held for more than six months without being used. Carriers must show they will be out of telephone numbers within six months before a request for additional numbers can be granted. Carriers must also show they have used at least 75% of the numbers they hold before requesting additional numbers (known as the "fill rate requirement"). Companies must assign numbers in thousand-block sequence (called "sequential numbering"), moving to the next thousand-block only after using 100% of their numbers.