Abstract:
An enhanced emergency call system allows for the emergency dispatcher to capture and control the call. When the dispatcher captures the call, the caller would be precluded from terminating the call without authorization from the dispatcher. A set of standard codes may be used to indicate the type of emergency in the event the caller is unable, or desires not to speak. The dispatcher may also use messaging services to communicate with the caller. The caller may respond using the messaging services, or the dispatcher may prompt the caller for a response.

Description:
TECHNICAL FIELD  
         [0001]    This invention relates to emergency calls, and more particularly to providing enhanced control and standardized messaging during emergency calls.  
         BACKGROUND  
         [0002]    Cellular radiotelephones have become increasingly popular for many different reasons, including their potential availability in case of emergency. However, conventional cellular phones may not adequately meet emergency communication service needs because they are designed to achieve goals other than providing emergency communication services.  
           [0003]    Emergency communication services differ from normal communication services. Emergency communication services are seldom needed, but when they are needed it is desirable that they be highly reliable and dependable. Emergency situations often are accompanied by extreme stress or panic on the part of callers, and very little mental or physical effort on the part of a caller is desirable in obtaining emergency communication services.  
           [0004]    A recent development in mobile cellular systems is the ability to transfer short messages between an application residing on a mobile station and another application residing on a mobile network element, such as a message center for example. This service is sometimes referred to as a SMS (short message service). These messages might include mobile originated point-to-point messages, mobile terminated point-to-point, and broadcast for example.  
         SUMMARY  
         [0005]    An enhanced emergency call system allows for the emergency dispatcher to capture and control the call. When the dispatcher captures the call, the caller would be precluded from terminating the call without authorization from the dispatcher. A set of standard codes may be used to indicate the type of emergency in the event the caller is unable, or desires not to speak. The dispatcher may also use messaging services to communicate with the caller. The caller may respond using the messaging services, or the dispatcher may prompt the caller for a response. 
       
    
    
     DESCRIPTION OF DRAWINGS  
       [0006]    These and other features and advantages of the invention will become more apparent upon reading the following detailed description and upon reference to the accompanying drawings.  
         [0007]    [0007]FIG. 1 illustrates components of a wireless communication system appropriate for use with an embodiment of the invention.  
         [0008]    [0008]FIG. 2 is a block diagram showing features of a mobile station according to one embodiment of the invention.  
         [0009]    [0009]FIG. 3 is a flowchart showing the process used by the communication system to control the emergency call according to one embodiment of the invention.  
         [0010]    [0010]FIG. 4 is a chart showing an example of emergency codes according to one embodiment of the invention. 
     
    
     DETAILED DESCRIPTION  
       [0011]    [0011]FIG. 1 illustrates components of a wireless communication system  100 . A mobile switching center  102  communicates with a base station  104 . The base station  104  broadcasts data to and receives data from mobile stations  106  within a cell  108 . The cell  108  is a geographic region, roughly hexagonal, having a radius of up to 35 kilometers or possibly more. The base station  104  may also communicate with an Internet Service Provider (ISP)  110 . The ISP  110  provides an interface between the wireless communication system  100  and the world wide web, or Internet. In some embodiments, the mobile station  106  communicates with the ISP  110  through the base station  104 . However, it can be appreciated that the mobile station  106  may directly communicate with the ISP  110 .  
         [0012]    One technique used by the mobile station  106  to interface with the wireless communication system is the Wireless Application Protocol (WAP). WAP sends multiple WEB pages, for example, in a single transmission as a “deck” of “cards,” each card corresponding to a page of structured content and navigation specifications. The use of WAP along with SMS provides one technique for communication of short messages to the mobile station  106 .  
         [0013]    The mobile station  106  is capable of receiving data from and transmitting data to a base station  104 . Additional cells adjacent to the cell  108  permit mobile stations  106  to cross cell boundaries without interrupting communications. This is because base stations  104  in adjacent cells assume the task of transmitting and receiving data for the mobile stations  106 . The mobile switching center  102  coordinates all communication to and from mobile stations  106  in a multi-cell region, thus the mobile switching center  102  may communicate with many base stations  104 .  
         [0014]    The mobile stations  106  may move about freely within the cell  108  while communicating either voice or data. The mobile stations  106  not in active communication with other telephone system users may, nevertheless, scan base station  104  transmissions in the cell  108  to detect any telephone calls or paging messages directed to the mobile station  106 .  
         [0015]    One example of such a mobile station  106  is a cellular telephone used by a pedestrian who, expecting a telephone call, powers on the cellular telephone while walking in the cell  108 . The cellular telephone synchronizes communication with the base station  104 . The cellular telephone then registers with the mobile switching center  102  to make itself known as an active user within the wireless network.  
         [0016]    The mobile station  106  scans data frames broadcast by the base station  104  to detect any telephone calls or paging messages directed to the cellular telephone. In this call detection mode, the mobile station  106  receives, stores and examines paging message data, and determines whether the data contains an identifier matching an identifier of the mobile station  106 . If a match is detected, the mobile station  106  establishes a call with the mobile switching center  102  via the base station  104 . If no match is detected, the mobile station  106  enters an idle state for a predetermined period of time, then exits the idle state to receive another transmission of paging message data.  
         [0017]    [0017]FIG. 2 shows a block diagram of the mobile station  106  and the processing that occurs in that mobile station  106 . A processor  205  is driven by programs stored in a memory  210 . Any information received by the mobile station  106  may be stored in the memory  210  or a buffer  215 . The buffer  215  may store information obtained from the Internet service provider  110 .  
         [0018]    [0018]FIG. 3 is a flowchart showing the process  300  the communication system  100  uses to distribute emergency messages. The process  300  begins in a START block  305 . Proceeding to block  310 , the communication system  100  receives an emergency call from the network. An emergency call may be initiated by a user on a mobile station  106  dialing 911 or any other designated emergency number. The network recognizes the emergency number and identifies the call as an emergency call.  
         [0019]    Proceeding to block  315 , the emergency dispatcher in the communication system  100  may capture the emergency call. By capturing the call, the communication system  100  may prevent the mobile station  106  from disconnecting the call. This allows the dispatcher to determine when it may be safe to end the call. The dispatcher may also activate any messaging features on captured calls.  
         [0020]    Proceeding to block  320 , the process  300  determines if communication via the messaging system is desired. Messaging may be activated by either the dispatcher, the user, or by the communication system  100 . The communication system may use any for of messaging, such as SMS or DTMF messages. If messaging is not desired, the call may continue using normal voice communications and the process  300  proceeds along the NO branch to block  330 . If messaging is desired, the process  300  proceeds along the YES branch to block  325 . In block  325 , communications and/or control commands are transmitted via messaging.  
         [0021]    The dispatcher may conduct a variety of communications or controls via messaging. For example, the dispatcher may transmit a message causing the mobile station  106  to alert the user, such as by ringing or vibrating. The message may even indicate whether the mobile station  106  rings at a low, medium, or high volume level. This feature may be advantageous if the dispatcher desires to inform the user that the dispatcher has returned to the call. Further, the dispatcher may ring the mobile station  106  to assist rescue workers in locating the user. This may be helpful in situations where the user is unable to respond to any requests.  
         [0022]    The dispatcher may also use the messaging system to communicate with the mobile station  106 . For example, the dispatcher may user DTMF messages to query the user if the user is unable to talk. The dispatcher may send questions (such as yes/no or multiple choice) that can be answered by pressing buttons on the keypad. Thus, the dispatcher may be able to obtain information such as “Is there a burglar in the house now?” without requiring the caller to speak and reveal a hiding place. The dispatcher may also use SMS messages to achieve a similar result. The dispatcher may send an SMS message requesting the nature of the emergency, and whether it is safe for the user to make noise. The SMS messages may use graphical characters where available to overcome reading or language barriers.  
         [0023]    The dispatcher may also use the messaging system to query the user to pinpoint the location of the user for rescue purposed. If location information is available, the dispatcher may begin with that information. Determination of the position of a mobile station  106  may be accomplished in a variety of manners known in the art, such as global positioning, triangulation, etc. and will not be discussed herein. For example, the position information obtained from the mobile station  106  may indicate the user is in a house. The dispatcher may then use the messaging system to determine the precise location in the house. Such information may then be used by fire, police, or other rescue personnel to aid the caller.  
         [0024]    The caller may also append a code to the original call to indicate the nature of the emergency. FIG. 4 illustrates an exemplary table of codes that may be appended to the emergency call. For example, a two digit code may be used, thus providing a large range of emergencies that may be identified. However, the two digit code may be small enough for children to memorize. Thus, if a caller was placing the emergency call due to a fire, the caller may dial “911-01.” This dispatcher would then immediately know the emergency call concerns a fire.  
         [0025]    Proceeding to block  330 , the process  300  determines if the call is complete. As stated above, when the dispatcher captures the call, the mobile station  106  may be prevented from disconnecting the call. Thus, the mobile station  106  may only request the call be disconnected, and the call will remain connected until the dispatcher determines it is appropriate to terminate. If the call is not complete, the process  300  proceeds along the NO branch back to block  320  to continue communicating. If the call is complete, the process  300  proceeds along the YES branch to block  335 . In block  335 , the dispatcher releases the call to allow the mobile station  106  to terminate the connection. The process  300  then terminates in an END block  340 .  
         [0026]    Numerous variations and modifications of the invention will become readily apparent to those skilled in the art. For example, although the invention is described with reference to a mobile communication system, it can be appreciated that the present invention may also be used with a land based communication system. Accordingly, the invention may be embodied in other specific forms without departing from its spirit or essential characteristics.