When Phase II wireless E911 location services started in October 2001, how many callers were actually benefited from the location data? Considering the national statistics being reported, not many. Here I detail how the huge number of calls to a typical comm center is quickly reduced when you look at how many calls are 911, how many are wireless, are emergencies, and when the caller has no idea where they are. The total: about 1% of all callers to a typical comm center will benefit from Phase II features.

Of course, this graph doesn't take into account one important fact -- the value of saving even one caller's life can't be calculated. It also doesn't take into account the guiding philosophy of public safety communications that you always do the best you can, given the personnel and technology you have available. Nevertheless, given the statistics that are floating around (almost all are based on estimates), curiosity drove me to calculate how many persons might be directly impacted by Phase II services.

To draw the graph, I've obviously had to make some assumptions. Coherent statistics are not easy to find--they're often stated different ways (% of all calls, % of 911 calls, etc.), and stats must be hand-counted, which means estimates are more common and less accurate. We're hoping NENA's full Report Card to The Nation provides a better handle on all this.

Even so, there is a way to make some sense out of the numbers. We'll start with a theoretical 1,000 incoming telephone calls....

First, we eliminated 7-digit, administrative and other non-emergency types of calls, leaving just the 911 calls. We used a 30% figure, although some large cities report receiving a very large percentage of 911. If we had used a larger figure, it would have affected the results only by a factor of 2-3, which would have resulted in a final figure not much different than we tallied. Remaining calls: 300 calls.

Second, we considered only wireless calls. However, there is little uniformity in reporting these types of calls. Some agencies report wireless calls as a percentage of all the types of calls they handle (non-emergency , etc.), while other state them as a percentage of 911 calls only. We've used data from various sources (below) to arrive at the percentage of calls (or 911 calls) that originate from wireless phones. At one end a U.S. Representative said "60%," while an agency representative stated "13%." We split the difference and used a generous 35% figure. Again, even if you figure wireless calls are twice that figure (70%), it would result in a final 1% total. Remaining calls: 105.

Third, we subtract hoax, accidental or otherwise non-emergency wireless 911 calls. We had to use our experience that very few of the wireless 911 calls an agency receives are actual "emergencies," that is, a threat to life (fire or EMS), or a crime in-progress or just prior. Many agencies are reporting 98%+ accidental or hoax rates on wireless 911 calls, so our 5% figure is again somewhat conservative.Remaining calls: 5.25.

Next, we removed duplicate calls where the caller is reporting something that someone else already reported. We took out a conservative 20% of the calls, although one could surmise that overall, 50% might be more accurate. Remaining calls: 4.2

Lastly, we take out those calls where the caller already knows their location. We found one statistic claiming that 25% of wireless callers did not know their location when dialing 911. We've tracked down a similar figure that callers didn't know "what city or county there were in." Again, it's hard to quantify the figures exactly--estimates are common. Remaining calls: 1.05.

So, out of 1,000 total calls to a typical comm center, the calculations show that only one caller would be assisted by Phase II features. Pretty dramatic...

Gary Allen

updated 12/2/03

Here are several data sources that we could locate for the percentage of calls arriving from wireless phones. Also check our Facts and Figures page.

• The Mid-America Regional Council (Kan.) reported in a 8/29/2001 press release that 53% of their calls at 43 PSAPs are wireless.
• In April 2001 Clebourne County (Ala.) reported 50% of their calls are from wireless phones.
• The Brevard County (Fla.) Sheriff reports 30% of their calls are wireless.
• U.S. Rep. Fred Upton (R-Mich.) told a reporter in Feb. 2001 that "Sixty percent of 911 calls nationally are made using cellular phones."
• Paul Rogers, vice-chairman of Michigan's Emergency Telephone Service Committee, said in the same story that 50% of all "emergency" calls originate from wireless phones. NENA estimates that one-third of all 911 calls made during 2000 were from wireless phones.
• In Sept. 2000 King County (Wash.) reported that 30% of their 911 calls originated from wireless phones.
• In July 2001 Tarrant County (Tex.) reported that 40% to 60% of all their calls came from a wireless phone.
• Beth Ferrell of the Nebraska Association of County Officials told the state legislature in March 2001 that over 50% of Custer County's calls are from wireless phones.
• In May 2001 Thera Bradshaw, head of the Emergency Communications Department for the City and County of San Francisco, said her center receives 30% of its 3,500 daily calls from wireless phones.
• In Jan. 2001 Robert Full, Allegheny County (Penn.) emergency services chief told a reporter that slight more than 50% of calls to the county's northwest dispatch center are from wireless phones.
• In May 2001 Delaware County (Ohio) reported that 16% of all calls were from wireless phones.
• In Oct. 2001 John Melcher (Tex.) told a Senate sub-committee that 27% of 911 calls in the U.S. are made from wireless phones, and that percentage is higher in heavily populated areas. At the same hearing, FCC Wireless Telecommunications Bureau Chief Thomas Sugrue said that 30-50% of all 911 calls were made from wireless phones.
• In an Oct. 22, 2001 Associated Press article, Jack O'Conner of New Hampshire's Bureau of Emergency Services told the reporter he didn't know how many of New Hampshire's approximately 1,500 daily, state-wide emergency calls came from wireless phones.
• In an Oct. 2001 press release, NENA past president Norm Forshee said that St. Clair County (Ill.) received 56,000 calls to 911 for the first nine months of the year, and that 44% of them were from wireless phones.
• In a Jan. 2002 story from the Raleigh News & Observer newspaper, officials of Johnston County (NC) stated that 41% of their calls during 2001 came from wireless phones, up from 28% during 2000.
• At Chicago's 911 Center, about 35% of the calls coming in are from cellular phones. [WLS-TV, Feb. 2002]
• Cortez Trotter, executive director of Chicago's Office of Emergency Communications, told a townhall meeting in May 2002 that 30% of his comm center's 5 million annual 911 calls are "misdials."
• In a May 2002 news article, New Scotland Yard reports it receives 8,500 emergency calls a day on 999, and that their "silent solutions" call-screening system intercepts about 2,000 calls a day--either accidental or prank callers who don't press 5-5 on their phone.
• In June 2002 Elaine Sexton, 911 program administrator for the Georgia's Emergency Management Agency, said 35% to 45% of the state’s 911 calls originate from wireless phones.
• In a July 17, 2002 The New York Times article, Norm Forhsee of the St. Clair County (Ill.) comm center said "about half" of the 911 calls they receive are wireless.
• In a July 2002 Philadelphia Inquirer story, Charles Brennan, deputy commissioner of emergency services for science and technology for the city said wireless 911 calls accounted for about 30% of the 3.3 million emergency calls logged in 2001.
• In that same July 2002 Inquirer story, it reported that during 2001 wireless callers made 40 percent of the nine million emergency calls handled in New Jersey.
• In July 2002 the Mid-America Regional Council reported that, "more than half of all 9-1-1 calls in the Kansas City metro area come from wireless devices." In another quote, they said that 53% of their 911 calls are from wireless devices.
• In August 2002 the Minnesota Wireless Foundation said that 40% of the 911 calls fielded by the State Patrol are accidental calls.
• In an August 2002 St. Paul Pioneer-Press newspaper story, Minnesota State Patrol officials said that 40% of the wireless 911 calls to the agency during 2001 were accidental.
• In Sept. 2002 Tom McCormack, 911 coordinator for St. Louis County (Mo.), told a local newspaper that 70% of his county’s 911 calls come from wireless phones.
• In a Sept. 2002 Washington Post article, the reporter said, "In the Washington area, nearly 50 percent of all 911 calls are made from cell phones."
• In an Oct. 2002 Dallas Morning News article, Plano (Tex.) officials said about 35% of their 911 calls are from wireless phones.
• In a Nov. 2002 Associated Press story, the CHP estimated that 60% of the 1.8 million calls handled by its Los Angeles comm center were either accidental or non-emergencies. The same story stated that "nearly half" of Californias 7.8 million wireless 911 calls made during 2001 were either accidental or non-emergencies, but didn't say where that statistic came from.
• In a Dec. 2002 newspaper article, Ken Schneider, managing deputy director of Chicago's Emergency Communications Center, said, "About 36 percent of the 13,000 to 15,000 daily phone calls to Chicago's 911 center are from wireless phones." But he did not estimate how many of those are accidental or unintentional.
• In May 2003 the Mid-America Regional Council (Kan.-Mo.) said that 53% of its 2 million annual 911 calls come from wireless phones.
• In Dec. 2003 a news article stated that 53% of New Hampshire's 911 calls are made from wireless phones.

Here is the one source of data we could find on the number of callers that don't know their location:

• A Nov. 1998 article by consultant Clement Driscoll in GPS World said that an estimated 25% of wireless 911 callers "cannot accurately describe their location." That figure has been referenced several times in other literature we found. We have not located the original source of this claim, however.