A mass call event or mass calling event (also MCE in

telephony Telephony ( ) is the field of technology involving the development, application, and deployment of telecommunications services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is ...

usage) is a situation in which an extraordinarily high number of

telephone call A telephone call, phone call, voice call, or simply a call, is the effective use of a connection over a telephone network between the calling party and the called party. Telephone calls are the form of human communication that was first enabl ...

s are attempted into or out of an area, causing tremendous network congestion, and resulting in service that is significantly degraded or potentially unavailable. The term is typically used with mobile telephony systems, in which there are simply not enough radio channels available in a given cell or cells. This causes blocked calls or dropped calls. However, it can also apply to landline phones, in which not enough trunking telephone circuits are available into and out of any given

telephone exchange A telephone exchange, telephone switch, or central office is a central component of a telecommunications system in the public switched telephone network (PSTN) or in large enterprises. It facilitates the establishment of communication circuits ...

or equivalent switching office at any level of the

public switched telephone network The public switched telephone network (PSTN) is the aggregate of the world's telephone networks that are operated by national, regional, or local telephony operators. It provides infrastructure and services for public telephony. The PSTN consists o ...

(PSTN). An MCE is typically caused by a sudden

disaster A disaster is an event that causes serious harm to people, buildings, economies, or the environment, and the affected community cannot handle it alone. '' Natural disasters'' like avalanches, floods, earthquakes, and wildfires are caused by na ...

of some sort, such as an

earthquake An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...

explosion An explosion is a rapid expansion in volume of a given amount of matter associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Explosions may also be generated ...

. One of the earliest examples was the Iroquois Theatre Fire in Chicago in 1903. The 1963 Kennedy assassination represented a mass call event for

Washington, DC Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and Federal district of the United States, federal district of the United States. The city is on the Potomac River, across from ...

. One of the most notable examples of a MCE was the 9/11 attacks. A more recent example was the 2013 Boston Marathon bombing, in which mobile network service was so degraded by people checking on the safety of friends and family (or reporting their own status to others) that

journalist A journalist is a person who gathers information in the form of text, audio or pictures, processes it into a newsworthy form and disseminates it to the public. This is called journalism. Roles Journalists can work in broadcast, print, advertis ...

s and the public both assumed that the networks had been shut down to prevent further remote

detonation Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with ...

s, although this was not the case with any mobile phone company. Access-class barring is one solution in such a situation, allowing

public safety Public security or public safety is the prevention of and protection from events that could endanger the safety and security of the public from significant danger, injury, or property damage. It is often conducted by a state government to ensu ...

(PS) personnel such as emergency responders to have priority on the network, as well as general emergency calls to public-safety answering points (PSAPs). This typically only affects voice calls, therefore

text messaging Text messaging, or texting, is the act of composing and sending electronic messages, typically consisting of alphabetic and numeric characters, between two or more users of mobile phones, tablet computers, smartwatches, desktops/laptops, or ...

is a very effective way of communication during an MCE, as it only needs a brief connection to the network to be sent or received, and uses almost nothing in terms of network resources like bandwidth. Mass call events can also be caused by planned events. In 1982, Eddie Murphy's Larry the Lobster shtick on

Saturday Night Live ''Saturday Night Live'' (''SNL'') is an American Late night television in the United States, late-night live television, live sketch comedy variety show created by Lorne Michaels and developed by Michaels and Dick Ebersol that airs on NBC. The ...

resulted in record call volume, as Murphy held a live

lobster Lobsters are Malacostraca, malacostracans Decapoda, decapod crustaceans of the family (biology), family Nephropidae or its Synonym (taxonomy), synonym Homaridae. They have long bodies with muscular tails and live in crevices or burrows on th ...

and declared that the show's audience would determine whether he lived or died via telephone calls. The gathering in Washington, D.C. for the 2009 U.S. Presidential Inauguration of

Barack Obama Barack Hussein Obama II (born August 4, 1961) is an American politician who was the 44th president of the United States from 2009 to 2017. A member of the Democratic Party, he was the first African American president in American history. O ...

also created a MCE. In this case, network overload was avoided by deploying multiple cell-on-wheels (CoW) units with their own wireless backhauls. This was a particularly major situation for cell carriers because many attendees wanted to be live on the phone (via voice call or video chat) with others who could not attend the ceremony, further increasing network usage.

References

Telephony Mobile telecommunications {{Telecomm-stub