Browse Prior Art Database

LOCATION-BASED 911 CALL ATTEMPT ADMISSION CONTROL

IP.com Disclosure Number: IPCOM000004664D
Original Publication Date: 2001-Mar-23
Included in the Prior Art Database: 2001-Mar-23
Document File: 3 page(s) / 15K

Publishing Venue

Motorola

Related People

John M. Harris: AUTHOR

Abstract

This paper presents an algorithm sketch for significantly reducing the capacity impact of multiple emergency cell phone calls to report of a single event to 911 and cellular phone systems.

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LOCATION-BASED 911 CALL ATTEMPT ADMISSION CONTROL

by John M. Harris

ABSTRACT

This paper presents an algorithm sketch for significantly reducing the capacity impact of multiple emergency cell phone calls to report of a single event to 911 and cellular phone systems.

The structure of this paper is as follows.

First, the definition of the problem is addressed. Second, the algorithm itself is presented. Next a performance analysis of the benefits of using this algorithm are presented. Conclusions and future work follow in the last section.

PROBLEM STATEMENT

When a highly visible emergency such as a car fire occurs, often dozens of calls reporting it can be placed, overwhelming the capacity of the 911 system, and/or that of the cellular system.

Also, when dispatchers fail to identify repeat calls quickly, multiple police can be unnecessarily sent to the same event because each call can generate a separate police dispatch request.

Many reports from emergency dispatchers and emergency personnel corroborate this problem's existence and prevalence. However, this author is not aware of any field statistics on its frequency.

ALGORITHM PROPOSED

This paper proposes a simple algorithm that can help to reduce the impact of repetitive calls. The algorithm is basically:

If the 911 system (or cellar system) is experiencing a heavy load, then give lower priority to emergency calls which originate from location where emergency calls have been recently attempted.

This algorithm could take the form depicted in Figures 1 and 2. This algorithm causes calls from the same location (which are likely to be repetitive) to be queued or blocked when the 911 (or cellular) system becomes completely overwhelmed.

This algorithm is most appropriate in a cellular system where each caller's location accompanies its call attempt. This is because more accurate location estimates make it easier to identify redundant calls.

THE NOVEL ASPECTS OF THIS ALGORITHM INCLUDE:

911 call attempt blocking based on the location of the attempt and the location and time of other 911 calls.

When the 911 system is overloaded, block 911 call attempts based on the location of the attempt and location and time of other recent 911 calls.

When the cellular system is overloaded, block 911 call attempts based on the location of the attempt and the location and time of other recent 911 calls.

BENEFIT OF ALGORITHM PROPOSED

The benefit of this algorithm is intuitive. Quantitative statements about its benefits are more difficult because of a lack of source statistics on the frequency or multiple reports per incident. First, we outline an intuitive argument for why this algorithm is beneficial. This is followed by a quantitative analysis, which results from a specific set of assumptions about the 911 call model.

INTUITION BEHIND BENEFITS

One way of capturing this algorithm's benefit is to observe that the incremental value in having one more emergency call reporting an event which has already reported is smaller than the value of receivi...