Gartner Blog Network

How much emergency power does your home phone have?

by Jay Heiser  |  November 2, 2012  |  2 Comments

Our home telephone is totally dependent upon the electrical power grid, and a lead acid battery of unknown age is all that stands between us and total loss of external connectivity.

Fiber to the home, which we’ve now had in 2 different houses, represents an opportunity for high speed, flexibility, and economics, providing a single source for television, telephone, and Internet.  Unlike analog phones and broadcast TV, ‘advanced residential communications’ in ‘Smart Neighborhoods’ offering ‘Blazing Speed’ that will ‘exceed your expectations’ are totally dependent upon a powered-up interface box. Unlike an old-fashioned copper phone line, or a TV antenna, you can’t receive fiber optic transmission without a powered device that splits out the three services and interfaces them to the in-home wiring. If the power goes out, the fiber no longer blazes—it flares out.

In order to maintain telephone service, high-tech homes have a backup battery hidden in the customer premise equipment.  Nobody claims they last over 8 hours, they are not routinely maintained, and common wisdom is that they often do not last that long. 

It isn’t just the home fiber interface that requires power. The (currently unapproved) franchise agreement between our provider and the county requires 2 hour of backup for all distribution amplifiers and fiber optic nodes, 24 hours for all head end tower and HVAC, and at least one dispatchable portable generator to do something somewhere.  I don’t know how reassuring that is to people who have already experienced 2 multiday power outages this year.

Clearly, there are reliability advantages to the plain old telephone system (POTS), which only requires emergency power at the central office.  Given a choice, telecommuters with 2 lines sometimes do decide to make one of them analog—but increasingly, you don’t get that choice. Once a neighborhood switches over to fiber, the providers become extraordinarily reluctant to support copper.  Our new neighborhood has no POTS, and the single telecom provider has exclusive cabling rights for the remainder of my lifetime—and well beyond.

Obviously, there are many advantages to wireless, which becomes the channel of choice when the home or office phone is powered out.  Unfortunately, it tends to fail when it is most needed.  After hurricane Katrina, the FCC attempted to force providers to include 8 hours of backup for all cells (which would barely last past the excitement of the storm).  This 2007 blog post, correctly discussing the unlikelihood of that happening, states “Well, we are likely headed for the big one here soon and it stands to reason we’ll want to have some cell phone service in the aftermath. As we saw last month during a 5.6 earthquake, you don’t have to have cell towers go down to lose service. There was enough congestion in that first hour to bring conversations to a halt. But in a much bigger scenario, having additional power could keep information flowing in the hours after a disaster, helping speed aid and relief to the right places.” New York and New Jersey have just had their big ones, and information is still not flowing in the aftermath of that disaster.

Reporters based in New York city, and Gartner staff living in the areas hardest hit by Sandy have reported total failures of cell phone in their neighborhoods, with some providers apparently doing worse than others.  The FCC reported yesterday that “the number of cell site outages overall has declined from approximately 25 percent to 19 percent” (the perceptive observer might ask, percentage of what population of sites).

In addition to significant traffic increases during a natural disaster, there are at least 3 reasons for cell phone failure, with the first one being particularly acute for cell systems:

  1. Power: Batteries get drained pretty quickly.  While a growing number of cells do have generators, the generators need fuel replenishment, which in the post-Sandy world is becoming a logistical problem for several reasons.  At the same time that the power grid is coming back online, a growing number of cell sites are running out of backup power.
  2. Physical damage: wind damage to antenna, or water damage to electronics can impact service, and it takes time after a disaster to deploy existing repair crews across a transportation-challenged region.
  3. Network failures: The backhaul networks between towers and the switching offices are subject to physical damage, especially from flood water, and they require electrical power (see 1 above).

There’s a lot to be said for the continuity advantages of POTS and analog phones, but other than rural areas, its likely to be phased out in favor of home digital connectivity and cell phones.  If you want to do some contingency planning, you might want to scout your neighborhood for pay phones.

Specific details on the post-Sandy status of each wireless provider can be found in yesterday’s NYT blogs.

Category: bcpdr  risk-management  

Tags: cell-phones  hurricane-sandy  power-failure  redundancy  sandy  

Jay Heiser
Research VP
6 years at Gartner
24 years IT industry

Jay Heiser is a research vice president specializing in the areas of IT risk management and compliance, security policy and organization, forensics, and investigation. Current research areas include cloud and SaaS computing risk and control, technologies and processes for the secure sharing of data… Read Full Bio

Thoughts on How much emergency power does your home phone have?

  1. Neil MacDonald says:

    I am in Connecticut and lost both cell service and POTS.

    The cell service was restored the next day. POTS 2 days after that. Power 5 days later.

    Neil MacDonald

Comments are closed

Comments or opinions expressed on this blog are those of the individual contributors only, and do not necessarily represent the views of Gartner, Inc. or its management. Readers may copy and redistribute blog postings on other blogs, or otherwise for private, non-commercial or journalistic purposes, with attribution to Gartner. This content may not be used for any other purposes in any other formats or media. The content on this blog is provided on an "as-is" basis. Gartner shall not be liable for any damages whatsoever arising out of the content or use of this blog.