Background Prior Art Two-way radios have become popular communication tools where phones or other communication methods are not cost effective or simply not efficient.

These 2-way radios generally allow users to communicate with one another without experiencing interruptions caused by other users. such as the case with citizen band radios.

Early two-way radio systems relied on the voice of one of the users to call or gain the attention of a fellow user. As improvements were made to these systems, a call feature was added. The call feature would notify the user of an incoming communication by producing an audible tone.

In many instances. an audible tone is ineffective in getting the attention of the intended receiver. Since two-way radios are often used in environments such as construction sites where there is a great deal of noise. users often miss calls and important messages.

In other instances, the receiver may not want the audible tone to alert others of incoming messages. When the receiver is in a quiet area such as a library, church, movie, or other area where audible disturbances are unwelcome, the receiver would have to turn off the two-way radio or risk causing a disturbance.

Because audible annunciation methods in two-way radio communication systems are often undesirable. a need has developed for a method of alerting a two- way radio user of an incoming call which does not produce an audible tone.

Summarv of the Invention It is an object of the invention to provide a method of announcing a communication in a handheld two-way radio. The method of announcing comprises the steps of transmitting a communication within fixed frequency range from a first handheld radio ; receiving the communication with a second handheld radio ; and, announcing the communication by producing a vibrational movement in the housing of the second handheld radio.

Other features and advantages of the invention will be apparent from the following specification.

Detailed Description While this invention is susceptible of embodiments in many different forms, there will herein be described in detail, a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspects of the invention to the embodiment illustrated.

The present invention relates to a two-way radio communication system.

The two-radio system comprises a plurality of handheld radios. The handheld radios are protected by a plastic housing. Most preferably, the housing measures 4 inches high. 2-1/2 inches wide, and 1-3/8 inches deep and includes a retractable antenna. Each handheld radio is equipped with a receiver and a transmitter. The receivers and transmitters operate over a fixed frequency range, preferably from 462.5 MHz to 463.0 MHz or any range or combination of ranges therein. This ultra high frequency range provides outstanding penetration and frequency modulation provides clear reception. Alternatively. the receivers and transmitters may operate over a fixed frequency range from 446.00625 MHz to 446.09375 MHz, specifically including the operating frequencies of 446.00625 MHz.

446.01875 MHz. 446.03125 MHz, 446.04375 MHz, 446.05625 MHz. 446.06875

MHz. 446.081'5 MHz, and 446.09375 MHz. in accordance with the Private Mobile Radio (PMR) standards widely used in European countries. Signals are transmitted directly between or among other radios on the system, rather than via an intermediate carrier. such as is done by cellular telephones.

The radios are capable of delivering about 500 mW of radiated power.

This provides maximum distance at full radiated power to deliver maximum range capabilities. Each radio has 14 user selectable channels for privacy. In the preferred embodiment, the radios include 38 additional private tone codes that provide 532 different channel combinations to insure a clear channel can be found.

These 38 subcodes can be electronically scanned to locate active communications.

The radios also include memory locations for storing the most frequently used channel/subcode combinations. Furthermore, each radio has a private call which is a special voice scrambling circuitry to further insure that communications remain private.

The radios further include a confirmation tone. The confirmation tone is an electronic, mechanical, or electro-mechanical sound that indicates the completion of one transmission and alerts another user to the fact that he/she may begin a transmission.

The radios generally operate on DC power. Accordingly. any source of DC power can be used. Preferably, four AAA alkaline batteries are used.

Rechargeable nickel cadmium batteries may also be utilized as well as a cigarette lighter adaptor power cord connecting the radio to a vehicle battery.

A call feature to alert a user of an incoming message is also included in the radios. This call feature includes a push button which'rings or notifies a user or users of an incoming communication. The notification means is normally an audible. electronic, mechanical, or electro-mechanical tone. However, in the present invention. a virtually silent notification means is present. This virtually

silent notification means is a vibrational system which causes the radio housing to pulse. This vibrating or pulsing alerts the user that he/she has an incoming message. This relatively inaudible notification system allows the user to receive notifications in environments where an audible tone is undesirable, such as churches or meetings where disturbances are frowned upon or loud construction sites where audible tones cannot be heard.

Additional features that can be incorporated into the radios include, but are not limited to, charge ports for recharging the batteries, wrist straps for easy carrying, auto squelch for noise control, monitor control. liquid crystal displays. removable belt clips, speaker and microphone jacks, battery saver circuitry, and low battery indicators.

It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.