The present invention relates generally to communication systems and, in particular, to a communication system that employs a method and apparatus for allowing a user of a display-based terminal to communicate with communication units in the communication system.
Dispatch communication systems are known to include a wireless infrastructure and a plurality of communication units, such as two-way radios. Some dispatch systems, such as those used for public safety, also include a dispatch console and a so-called xe2x80x9ccomputer aided dispatch (CAD) systemxe2x80x9d that includes a display-based terminal to control communications between the communication units. The CAD terminal typically displays categorized tables of information to the terminal user (typically referred to as a xe2x80x9cdispatcherxe2x80x9d or xe2x80x9cdispatch operatorxe2x80x9d). For example, the CAD terminal may display queues of currently pending incidents and/or a list of communication units that are currently available. In addition, some CAD terminals include an integrated mapping program that enables the CAD terminal to display locations of communication units on a map that represents a geographic area supported by the dispatch system. The locations of the communication units are typically provided to the CAD system on a periodic basis by an automatic vehicle location (AVL) system that is coupled to the CAD system via a dedicated communication link.
In addition to receiving communication unit location information, the CAD system may also receive incident information from a 911 system that is coupled to the CAD system. In such a case, the map displays the origination point of a 911 telephone call to the dispatcher as an icon on the map. By viewing communication unit location, communication unit status, and incident location on the map, the dispatcher can quickly determine which communication unit users (e.g., policemen, firemen, paramedics, and so forth) would be in the best situation to respond to the incident. As an incident is attended to by users of the communication units, the status of the communication units associated with such users is updated either manually by the dispatcher or automatically by the CAD system responsive to messaging from the wireless infrastructure. In the latter case, the wireless infrastructure receives status updates over a wireless communication channel from the communication units that are participating in the handling of the incident. Changes in communication unit status are typically indicated to the dispatcher by some type of visual change, such as a color change or icon update, to the participating unit""s representation on the map.
A map display, with icons representing the incidents and the communication units with their current status, gives a dispatcher a powerful tool for quickly evaluating an emergency situation. By using standard graphical user interface (GUI) cursor interaction (e.g., point and click or drag and drop), the dispatcher can manipulate the screen icons to assign units to incidents. In some systems, the action of assigning communication units to incidents on the map automatically sends data to the assigned communication units (e.g., if the units are equipped with mobile data terminals) to enable the communication unit users to immediately obtain critical information related to the incident, such as the incident location and other details.
In many situations, the assignment of a communication unit to an incident is followed by a voice conversation between the dispatcher and the user of the communication unit. Such a voice conversation enables the dispatcher and the communication unit user to discuss additional details about the incident which may not have been automatically relayed via data messaging. Voice communication during the handling of an incident is critical because it provides the communication unit users with real-time updates of the situation and the parties involved as the incident progresses.
Although the aforementioned voice communication between the dispatcher and the assigned communication unit users is critical, such voice communication cannot be initiated from the map environment with prior art CAD systems or terminals. Rather, in existing systems, the dispatcher must access a separate dispatch console program (which may be displayed on the CAD terminal in a different environment from the map) to control the voice communication with the communication unit users, thereby losing the benefit of viewing the overall picture of the incident as provided by the map.
One conventional dispatch system is currently being developed for a municipal transit authority, but as yet has not been implemented, in an attempt to integrate voice control into the CAD terminal map display. In this proposed system, which will include a first map displaying a subway system and a second, separate map displaying train locations, the dispatcher will be able to select a section of the subway from the first map and automatically initiate a voice call to all trains in the selected area of the subway only. As noted above, the first map display does not, however, include the locations of the trains. Therefore, the dispatcher cannot select particular trains individually or as a group to communicate with. Moreover, the proposed system does not facilitate trunked communications and does not take into account various communication parameters, such as private line, digital private line, encryption, and others. Therefore, although this proposed system may allow initiation of voice calls to a geographic area depicted on the first map, the system does not insure that any communication will actually occur because the dispatcher will not know from the first map display whether or not trains are in the selected area of the subway and the dispatcher cannot select the trains themselves, either individually or in a group, to communicate with from either map display. Consequently, although the proposed dispatch system does suggest a type of map-based voice dispatch, it has many practical shortcomings.
Therefore, a need exists for a method and apparatus that allows a user of a display-based terminal, such as a CAD terminal, having an integrated mapping program to communicate directly with communication units from a single map environment.