Saying that AT&T and Verizon have failed to consistently provide quality phone service, the California Public Utilities Commission (CPUC) has demanded that the companies pay for a study of their network infrastructure.

The decision, issued August 31, came after objections from both phone companies. CPUC's staff is now required to initiate the investigation and "report on progress towards its completion within six months." Within three months, CPUC staff have to provide a status report on collecting funding for the study from AT&T and Verizon. Though the companies must pay for the study, it will be conducted by an independent consultant under contract with the commission.

The study is years in the making. CPUC staff recommended an investigation after widespread outages caused by winter storms in December 2010 and January 2011, and penalties for companies that fail to meet standards. In February 2013, the CPUC found that a "study of carrier network infrastructure, facilities, policies, and practices" was necessary to gauge the condition of carrier infrastructure and facilities and ensure that the needs of customers and public safety are being met.

The decision last month finally sets a timeline for the study to begin. AT&T and Verizon have "consistently failed to meet existing service quality metrics," the CPUC order said. Back in 2011, CPUC found that AT&T and Verizon weren't meeting the standard for the amount of time it takes to restore service after outages, even though smaller phone companies were consistently meeting that standard. There has been no significant improvement in the carriers' performance in the years since, CPUC said.

AT&T had claimed that the commission's out-of-service metric is "inherently flawed" and that the commission should "eliminat[e] service quality metrics" because of the "competitive market" and declining use of traditional landline phones.

Verizon, which is seeking state approval to sell its California wireline network to Frontier Communications, argued that a different metric measuring the number of customer trouble reports "shows that both AT&T and Verizon’s networks are healthy and reliable."

But CPUC said it would not "defer to the regulated entities on the standards that those entities should meet... all existing service measures and standards remain in place at this time, and cannot be simply disregarded at the regulated entity’s request."