Method and apparatus for alerting a communication unit in a communication system

A method for a calling communication unit in a communication system to alert a called communication unit of an attempt to communicate, the method comprising the steps of:

• transmitting to a communication infrastructure a dispatch communication request that includes a dispatch identification of the called communication unit;
• receiving an indication of which services are available to a user of the calling communication unit related to the dispatch communication request;
• and
• when the indication indicates that alert service is available to the user of the calling communication unit, transmitting an alert request message to the communication infrastructure, the alert request message requesting that the called communication unit be alerted of an attempt by the calling communication unit to communicate with the called communication unit.

A method for a communication infrastructure in a communication system to alert a called communication unit of an attempt by a calling communication unit to communicate with the called communication unit, the method comprising the steps of:

• receiving from the calling communication unit a dispatch communication request that includes a dispatch identification of the called communication unit;
• transmitting to the calling communication unit, in response the dispatch communication request, a telephone number associated with the called communication unit;
• receiving from the calling communication unit an alert message and the telephone number associated with the called communication unit, the alert message including a dispatch identification of the calling communication unit and a user message;
• and
• transmitting the alert message to the called communication unit based on the telephone number associated with the called communication unit.

A method for a calling communication unit in a communication system to alert a called communication unit of an attempt to communicate, the method comprising the steps of:

• transmitting to a communication infrastructure a dispatch communication request that includes a dispatch identification of the called communication unit;
• receiving from the communication infrastructure a telephone number associated with the called communication unit in response to the dispatch communication request;
• and
• transmitting an alert message and the telephone number associated with the called communication unit to the communication infrastructure, the alert message including a dispatch identification of the calling communication unit and a user message.

A communication unit comprising:

• a transmitter that transmits a dispatch communication request to a communication infrastructure, the dispatch communication request including a dispatch identification of a called communication unit;
• a receiver that receives, responsive to transmission of the dispatch communication request, a telephone number associated with the called communication unit;
• and
• a processor, coupled to the receiver and the transmitter, that instructs the transmitter to transmit an alert message to the called communication unit via the communication infrastructure, wherein the alert message includes the telephone number associated with the called communication unit, a dispatch identification of the communication unit, and a user message.

A communication infrastructure comprising:

• a base site that receives a dispatch communication request from a calling communication unit, the dispatch communication request including a dispatch identification of a called communication unit;
• a dispatch controller, coupled to the base site, that obtains the dispatch communication request from the base site, and when the dispatch communication request cannot be fulfilled, provides a telephone number associated with the called communication unit to the calling communication unit via the base site;
• and
• a short message processor, coupled to the base site, that receives an alert message and the telephone number associated with the called communication unit from the base site when the dispatch communication request cannot be fulfilled, the alert message including a dispatch identification of the calling communication unit and a user message, and that conveys the alert message to the called communication unit based on the telephone number associated with the called communication unit.

A communication infrastructure comprising:

• a base site that receives an alert request and a dispatch identification of a called communication unit from a calling communication unit;
• a dispatch controller, coupled to the base site, that obtains the dispatch identification and the alert request from the base site, determines a telephone number associated with the called communication unit, and generates an alert message that includes a dispatch identification of the calling communication unit;
• and
• a short message processor, coupled to the dispatch controller, that receives the alert message and the telephone number associated with the called communication unit from the dispatch controller and conveys the alert message to the called communication unit based on the telephone number associated with the called communication unit.