(Updated 3:50 p.m. with response from AT&T) AT&T officials are not offering much information about why their cell phone service is offline throughout large portions of Connecticut, particularly those that were hit hardest by Tropical Storm Irene.

Other networks appear to be functioning a lot better, at least based on an unscientific survey of cell phone users, but CL&P’s ongoing problems are having a domino effect on the telecommunications network.

Gov. Dannell P. Malloy said Monday that close to 300 AT&T towers were not functioning. What appears to be happening is that while some of AT&T’s Connecticut cell towers are largely intact, they are simply not getting electricity. Inexplicably, other networks are functioning with equipment on many of the same towers.

“We are currently seeing some impact to our network in parts of Connecticut due to commercial power outages and damage affecting cell sites and facilities,” AT&T spokeswoman Meaghan Wims said in the hours following Irene’s departure. “As soon as our technicians are safely able to, they will be activating generators to help bring these facilities back up and complete necessary repairs to restore service to our customers.”

But by Tuesday morning AT&T service still was not restored in the impacted areas, with many customers in the shoreline region unable to make or receive calls. Other customers were also unable to make calls in regions where electricity has been restored or was never lost. Beyond her prepared statement, Wims would not comment on whether preparations were made ahead of the storm or as to why backup generators have not been brought in to power the towers. AT&T has long struggled with network capacity issues throughout most of the country.

The towers lasted through most of the storm, likely running on limited battery power, but went down shortly afterward.  Typical backup batteries only provide enough power for a few hours before the a generator is needed.  Generators can run for a day or two without being refueled. 

Sources say AT&T has brought in 1,000 generators to help correct the problem, but is only able to estimate how many of its customers are without telephone, Uverse, and Voice Over Internet Protocol which are run from the large boxes on utility poles. An estimated 12,500 customers are without telephone or Uverse. It’s unclear how many cellphone customers are impacted.

In small shoreline communities averse to unsightly cell towers, carriers often share the same space. AT&T’s largest competitor in Connecticut, Verizon Wireless, was functioning in the affected areas and throughout most of the state using many of the same towers.

“Overall the Verizon Wireless network in Connecticut is performing very well given the circumstances. Our ability to anticipate and prepare was very important. For example, many cells that have lost commercial power have backup generators helping us continue to deliver wireless service to our customers,” said Verizon Wireless spokesperson Michael Murphy.

Verizon likely was helped by their technology as well. Verizon’s infrastructure is based on Code Division Multiple Access (CDMA) technology, while AT&T relies on the older Global System for Mobile Communications (GSM) standard. CDMA allows for more calls to be transmitted on the same bandwidth and also has superior range — meaning Verizon likely has less towers to support post-storm than their competitors.  Verizon also claims to have installed more backup generators in New England.

“More than 90 percent of Verizon Wireless’ cell sites throughout New England have both backup batteries and permanent generators designed to maintain our wireless network during the loss of commercial power. We were also able to stage additional mobile generators to address cell sites that lack a permanent generator due to landlord or permitting restrictions,” said Murphy.

The importance of keeping towers operating after natural disasters is underscored by a 2010 report from The Centers for Disease Control and Prevention that says nearly 25 percent of U.S. households have dropped traditional landlines for cellular phones. The CDC reports that approximately 17 percent of Connecticut residents have made the switch, but the report does not account for many others who have dropped a traditional landline to one supplied by their cable company.

Following Hurricane Katrina, efforts were made by the Federal Communications Commission to require that all cellular service towers have a backup power supply. The measure was strongly opposed by all of the cell phone carriers as being too onerous to implement. Many carriers already have battery backups installed that can withstand a few hours without power, but not prolonged outages.

Other factors can impact cellular communications as well.  Voice and data are carried back from a cell tower to the carrier’s core network.  If that is over a copper or fiber connection, as most are, flooding and storm damage can cause additional difficulties.

CTTechJunkie received the following from AT&T spokesperson Chuck Coursey:

“In preparation of the storm, AT&T deployed extra generators throughout the east coast to provide power to our networks in the event of loss of commercial power to our facilities, network or equipment.

A large portion of that deployment was in Connecticut, with a staging area in Wallingford.  Additional generators are also being deployed from other markets to Connecticut as needs in those other markets has subsided.  In addition to our Connecticut-based employees, AT&T teams from throughout the country have been deployed to assist in Connecticut restoration efforts.

Maintaining and restoring power to those networks is our primary focus and we are aggressively assessing and implementing the best available options to restore service to our customers as quickly and safely as possible.

AT&T commends the Governor and his administration for working seamlessly with the municipalities, federal and state government, and private entities to ensure that residents of Connecticut have services restored as expeditiously as possible.”