Access control method utilizing a key battery

#This invention relates in general to a two-way portable communications device and more particularly to controlling access to local device functionality in a user-agnostic manner by means of a key battery.

#Two-way portable communications devices such as two-way radios and the like have many applications for both business and pleasure. It is often desirable that certain features or capabilities of the device be restricted from general use. In one instance, certain features or capabilities may only be appropriate for users with special training. In other instances, certain features may be legally or administratively authorized only for a specific group of users. In such cases, the typical user has no access or use of the special features of the device.

#It is undesirable to control access to special features of each device by configuring each differently. One such implementation would be to program some devices with “basic” firmware and program enhanced devices with “extended” firmware. This approach provides maximum security but no flexibility. Each device has a static configuration and may not be changeable in the field. If it is changeable, this would effectively be an upgrade and would likely require a personal computer (PC), software, and customized cables. As can be easily recognized, this process is both time-consuming and inconvenient. A reverse process may be required to restore a device to the “basic” level of functionality. One additional solution is to program configuration information in each device that selects whether the extended functions are available. In this approach, the extended level firmware is present in all devices, but is selectively blocked based on pre-programmed configuration data. This approach is less secure in that an unauthorized person can potentially change the configuration data. Activating or de-activating functionality is still time-consuming and inconvenient, because a PC, software and customized cables are all required to re-program the configuration data.

#FIG. 1 is a block diagram illustrating a communication device consisting of a radio transceiver and a radio battery pack in accordance with the preferred embodiment of the present invention.

#FIG. 2 is a block diagram of selected radio transceiver components and radio battery including a memory component in accordance with the preferred embodiment of the invention.

#FIG. 3 is a flowchart diagram showing a method for enabling functionality to a set of locked device functions in a portable communications device in accordance with the preferred method of the present invention.

#While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the following description in conjunction with the drawing figures, in which like reference numerals are carried forward.

#Portable communications devices today often utilize battery packs that contain one or more primary or secondary cells, a memory device, and sensors, such as for battery temperature. The memory device is typically a non-volatile device, such as a PROM or serial EEPROM. To minimize the number of electrical connections to the battery, serial devices are commonly utilized. The memory devices typically contain parameters about the battery, such as chemistry type, charging rates, etc. This information, which is generally programmed when the battery is manufactured, is used by the battery charger to properly and safely charge the battery. This information can also contain thresholds to be used by the radio to provide a multi-segment battery gauge, or “battery life remaining” indicator.

#Referring now to FIG. 1, a portable communication device, or radio, consists of radio transceiver 110 which is powered by radio battery 120 which is typically included in a housing that is physically attached to the radio. A number of connections may exist between transceiver 110 and battery 120, including ground connection 140 and battery voltage supply 130. In addition, data connection 150 provides read capability for the radio to access stored information in radio battery 120. Data connection 150 is sufficient for “one wire” serial memory devices, but those skilled in the art will recognize that some serial devices require multiple lines for clock, control signals, etc.