Help is on the way - Enhanced 911

Services for VoIP, Cellular and MLTS Phone Systems

Robert Morris
December 6, 2011


The ability to access 911 emergency services, regardless of the technology used to place the call, is an essential component of public safety in the United States. Identifying the caller’s accurate location is also critical, especially in cases of a fire, break-in, kidnapping and other events where the caller cannot verbally communicate their location. Since 1968, 911 services have been available for landline phone systems, but with the advent of cellular, multiline telephone systems (MLTS) and voice-over-internet protocol (VOIP), enhanced 911 (E911) obligations became necessary. And so, the Federal Communications Commission (FCC) now requires providers of “interconnected” Voice-over-Internet Protocol (IVOIP) telephone services and cellular telephone services to meet these obligations. Furthermore, about 16 states have enacted E911 legislation requiring organizations purchasing a new Multiline Telephone System or Private Branch Exchange (PBX) to implement E911.

Needless to say, a failure in the prompt performance of 911 and E911 systems, and subsequent delays of emergency services, can result in increased property loss, exacerbation of an injury and/or potential loss of life. In addition, from an insurance perspective, it can result in liability losses in the form of property, workers compensation or general liability claims.

Standard 911 Services

Traditional landline phone services associate a particular phone number with a fixed address, which is generally the home or business address of the caller. When you call 911 from a traditional phone, the call is sent to a Public Safety Answering Point (PSAP) serving a specific geographic area. By identifying your phone number, the PSAP locates your fixed
address and requests emergency response to that location.

Enhanced 911 Services

Enhanced 911 works the same way as the standard 911 services, except the E911 system attempts to automatically identify the location of the 911 caller even when the call is placed from a location other than the fixed address of the telephone service subscriber. The location may be the physical address from where the 911 call originated or other geographic reference information such as longitude/latitude map coordinates.

Determining the actual location of a caller making a 911 call from a VoIP, Cellular or MLTS telephone system is much more difficult since the call generally does not originate from the physical address registered with the telephone service. Due to the portability of wireless phones and VoIP service, 911 calls can be placed from virtually anywhere and the telephone extension used to place the call through a MLTS may not even be in the same building as the billing address registered with the phone service. The challenge with these three technologies is to provide an accurate location of the 911 caller, no matter where the call originates.

VoIP Systems

The FCC defines “interconnected VoIP” as VoIP over broadband that interconnects with the public switch telephone network. It allows a person to make and receive calls to and from traditional phone numbers using an Internet connection—generally high-speed broadband, DSL, cable or wi-fi.

VoIP Challenges

Since VoIP service may work differently from traditional phone service, consumers that use a VoIP service should understand how VoIP 911 service differs from the traditional 911service. Two of the more critical differences are:

  • VoIP services do not work during a power outage, or when the internet connection fails or becomes overloaded.
  • VoIP customers need to provide information on their actual location or otherinformation to their VoIP providers for their VoIP E911 service to function properly. Most importantly, this information must be updated whenever the location of the VoIP phone changes

VoIP FCC Requirements

To reduce these differences and any possible risks to public safety using VoIP E911 service, the FCC has imposed the following requirements for those offering VoIP services:

  • All providers must automatically provide 911 services to all their customers as a standard, mandatory feature without customers having to specifically request 911 service. Providers may not allow customers to “opt out” of 911 service.
  • Before a provider can activate a new customer’s service, the provider must obtain fromthe customer the physical location where the service will be first used. This will allow emergency services personnel to locate any customer dialing 911. The provider must have an easy way for their customers to update the physical location they registered with the provider, if a change occurs. This is very important since the customer’s registered physical location is the address that will be provided to the 911 call center.
  • Providers must transmit all 911 calls, along with a callback number and the caller’s registered physical location, to the appropriate emergency services call center or local emergency authority.
  • Providers must take the appropriate action to ensure that their customers have a clear understanding of any limitations of their 911 service.
  • Provider must obtain affirmative acknowledgement from all existing customers that they are aware of and understand the limitations of their 911 service.

Cellular Phone Systems

Since cell phones are mobile and a 911 call can be made from just about anywhere, locating a mobile caller is far more complicated. To improve the speed and accuracy of locating a 911 call from a cell phone, the FCC has rolled out E911 requirements for wireless phone providers in two phases.

Cellular FCC Requirements & Challenges

Phase 1- The FCC’s rule requires the wireless carrier to provide the PSAP with the phone number of the wireless 911 caller and the location of the cell site or base station transmitting the call. This allows the PSAP operator to call back if there is a disconnection.

Phase 2 – This phase has the following two requirements.

  • 95% of a network operator’s in-service phones must be E911 compliant by December 31, 2005; and
  • Wireless network operators must provide the latitude and longitude of callers within 300 meters (985 ft.) and in less than 6 minutes when requested by a PSAP. This FCC accuracy rate for any participating PSAP service area should be met by September 11, 2012.

Cell phones can be located geographically either through the cell phone’s built-in GPS receiver or through a network based solution. GPS is the most common and accurate of these two tracking solutions. A GPS based system uses at least three of the overhead GPS satellites and trilateration to determine its location. A network based system uses the
cellular provider’s radio tower network, relative signal distance to three of the closest towers to the phone, and trilateration to determine its location.

Multiline Telephone Systems (MLTS)

The challenge of E911 for an MLTS is to provide the accurate location of the caller placing a 911 emergency call. When 911 calls are made, only the central telephone number and billing address may be transmitted to emergency workers. However, information on the caller’s telephone extension or physical location (building, floor level, office/suite number,etc.) may not be transmitted unless the system is configured to do so. Responders may go to an incorrect address wasting valuable time. An organization that uses MLTS is currently responsible for collecting and reporting the accurate location of all the telephone extensions for a MLTS so the automatic location information (ALI) database can be updated. Having complete and accurate information will allow the public safety agencies to respond properly when an emergency call originates within a MLTS system. Unfortunately, many organizations have not been able to commit the time, money and resources to acquire and report this much needed information.

There are technology solutions available today for a MLTS that can help ensure emergency help gets to the right people. These are some of the features that should be in place with a MLTS E911 solution.

  • The solution should continuously monitor phone traffic for 911 calls. When a 911 call is detected, it will instantly send accurate location information to the PSAP and any designated on-site responders within the organization.
  • The E911 solution should include a call-back extension feature that will give the dispatcher the information needed to determine whether the 911 hang up is a mistake, a prank or something actually requiring an emergency response.

As the three telephone systems described in this paper steadily replace landline phones as the consumers’ primary form of telephonic communications, it is necessary for emergency services to provide the same level of response when needs arise. Although fulfilling E911 requirements may increase costs to the service providers and users of these systems, the benefits of reducing or preventing property loss and personal injury by allowing responders to pinpoint the exact location of an emergency situation should far outweigh these expenses.

To learn more about how OneBeacon Technology Insurance can help you manage online and other technology risks, please contact Lloyd Takata, Vice President of OneBeacon Technology Insurance at or 706.474.9003.

This article is provided for general informational purposes only and does not constitute and is not intended to take the place of legal or risk management advice. Readers should consult their own counsel or other representatives for any such advice. Any and all external websites or sources referred to herein are for informational purposes only and are not affiliated with or endorsed by OneBeacon Insurance Group. OneBeacon Insurance Group hereby disclaims any and all liability arising out of the information contained herein.


  • 9-1-1 Magazine – “E911: Raising Awareness for a Critical Component of
    Emergency Communications” (March 3, 2011)
  • FCC Guide – “Voice Over Internet Protocol (VoIP)”
  • FCC Guide – “VoIP and 911 Service”
  • FCC Guide – “Wireless 911 Services”
  • How Stuff Works – “Enhanced 911”
  • RedSky – “Assessing E911 Liability Risk”
  • – “I Ping the Body Electric”
  • TechNewsWorld – “VoIP Providers Tackle E911 Issues”
  • Webopedia – “What is E911”
  • Wikipedia – “Enhanced 9-1-1”