Wireless communication device with tamper resistant configuration settings

Devices (302, 702, 800) with embedded control programs are provided are provided with RF-ID devices (114, 504) or other non-contact read data carriers (604) that provide configuration data, on which the execution of the embedded control programs is contingent. Preferred embodiments include wireless communication devices (302, 702, 800) provided with RF-ID devices (114, 504) or set of magnets (604) that encodes data embedded in front fascia. Embodiments of the invention increase the security of configuration data, and allow for functionality to enhanced by replacing the front fascia.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to embedded software controlled devices. More particularly, the present invention relates to safeguarding the configuration data of programmable radios.

2. Description of Related Art

Currently in the interest of exploiting economies of scale in manufacturing, two way radios that are made for different end use markets and which may use slightly different frequencies, and have different functionality, share a common hardware design, and only differ in so far as configuration settings that are defined in data read by embedded software. In a given locale, one or more user groups (e.g., a police department) may be allocated a portion of spectrum for conducting communication, and be outfitted with two way radios configured to operate securely at frequencies within the allocated spectrum. For many user groups, such as a police department, there is a desire to maintain conversations conducted through two way radios confidential. Unfortunately, the fact that operating frequencies, and other configuration settings, are defined in software, makes it possible for individuals to reprogram such two way radios to change their operating frequency and other configuration settings in order to use those radios to listen to, or send messages using spectrum that the individual is not authorized to use. All that may be required to do so is record information on a Programmable Read Only Memory (PROM) Chip or, on an Electrically Erasable Read Only Memory (EEPROM) Chip. To make large changes in operating frequency some changes to the RF to IF modulator/demodulator hardware may be required.

In a different area of wireless communication, namely cellular telephony, a variety of additional functionality beyond simple voice communication has been introduced. Examples of additional functionality added to cellular communication devices, includes, text messaging, World Wide Web (WWW) surfing, and data exchange. Certain more advanced cellular telephones, are able to communicate using multiple communication protocols. The market for cellular communication devices is stratified according to the level of functionality beyond basic voice telephony and includes devices having a wide range of functionality. It would be desirable to provide a way for users to upgrade the capability of their phones, without having to purchase an entirely new replacement phone.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The terms a or an, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language). The term coupled, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.

FIG. 1is a partial x-ray perspective view of a first front fascia102of a first wireless communication device302(FIG. 3) according to the preferred embodiment of the invention andFIG. 2is a cross sectional view of the first front fascia102. The front fascia102preferably comprises an injection molded shell and a plurality of openings including a plurality of speak grill openings104, a display window106, a menu navigation button opening108, a plurality of key holes110, and a set of microphone grill openings112. Screw hole bosses202are used for mounting the first front fascia102. The first front fascia102also includes a first information bearing Radio Frequency Identification (RF-ID) device114. The first RF-ID device114is embedded within the first front fascia102. The first front fascia102with embedded first RF-ID device114is preferably manufactured by insert molding. The functioning of the first RF-ID device114is described further hereinbelow.

FIG. 3is a perspective view of the first wireless communication device302without the front fascia102shown inFIG. 1. The first wireless communication device302is preferably a cellular telephone, and/or a two way radio. The first wireless communication device302comprises a plurality of components supported in a rear housing part304. The front fascia102mates with the rear housing part304. The wireless device302includes a main antenna306, a speaker308a display310, a menu navigation button312, a plurality of keys314, and a microphone316. Additional screw hole bosses318that line up with the screw hole bosses202in the front fascia102are provided inside the rear housing part304for accommodating screws used to attach the front fascia102, to the rear housing part304. According to an alternative embodiment of the invention the front fascia102includes integrally mold mounting tabs, and snap fits to the rear housing part302. According to an alternative embodiment of the invention the first RF-ID device114is included in a cosmetic fascia that fits over a primary front fascia. An air interface in the form of a first inductive coil320is also included in the first wireless communication device302. The first inductive coil320serves as an antenna for exchanging data with the first RF-ID device114. According to an alternative embodiment (not shown) one or more, and preferably a pair, of capacitive electrodes are included in the first wireless communication device302instead of the inductive coil320. As described below in more detail with reference toFIG. 9the inductive coil320is coupled to circuits used to send and receive information. Internal electrical circuitry of the first wireless communication device, according to the preferred embodiment of the invention is described below in more detail with reference to the block diagram shown inFIG. 9.

FIG. 4is a cross sectional view of the first RF-ID114device. The first RF-ID device comprises an air interface in the form of a second inductive coil402wound in a magnetic core404that includes an annular recess406for accommodating the second inductive coil402. The second inductive coil402is used as an antenna for exchanging data with the first wireless communication device302. The magnetic core404is accommodated at an open end of a can408lead wires410of the second inductive coil402extend through holes in the magnetic core404and connect to a first RF-ID Application Specific Integrated Circuit (ASIC)412, that is located in the can408behind the magnetic core404. The first RF-ID ASIC412is surrounded by a tamper resisting epoxy potting compound414. The first RF-ID ASIC412preferably includes communication circuits coupled to the second inductive coil402, a memory for storing information that is used to operate the first wireless device302, as well as logic circuitry for reading out the memory and driving the communication circuits to transmit contents of the memory. The logic circuitry of the first RF-ID ASIC412preferably comprises a programmable microprocessor. Alternatively, the logic circuitry of the RF-ID ASIC412includes state logic.

FIG. 5is a partial x-ray perspective view of a second front fascia502of a second wireless communication device (not shown) according to an alternative embodiment of the invention. The second front fascia502comprises a second RF-ID device504that differs from the first RF-ID device114. Rather than including the second inductive coil402, the second RF-ID device504preferably includes an air interface in the form of a center loaded dipole antenna506. The dipole antenna506is coupled to a second RF-ID ASIC508that includes a load for the dipole antenna506. In order to transmit data from the RF-ID ASIC, which preferably has no internal power source, the load on the dipole antenna506is modulated to encode information. The second RF-ID device504is embedded within the second front fascia502. The second RF-ID device has the advantage that it can receive signals from a main antenna of the second wireless communication wireless device, thereby obviating the necessity for the first inductive coil320used in the first wireless communication device302. Alternatively, a dedicated antenna is provided for exchanging signals with the loaded dipole antenna506.

FIG. 6is a partial x-ray perspective view of a third front fascia602of a third wireless communication device702(FIG. 7) according to another alternative embodiment of the invention. A set of magnets604is embedded within the third front fascia602. The magnetic poles of each of the set of magnets604is selected to encode information that is used to control the operation of the third wireless communication device702. For example by having either a north or south pole of each magnet face a predetermined direction (e.g., inward with respect to the third wireless communication device702) a binary digit can be encoded.

FIG. 7is a perspective view of the third wireless communication device702without the front fascia602shown inFIG. 6. The third wireless communication device702includes a set of magnetic field sensors, mounted together in a magnetic field sensor module704. The magnetic field sensor module704is used to read the arrangement of the set of magnets604, and make information encoded in the set of magnets available to a microprocessor (not shown inFIG. 7) that is coupled to the magnetic field sensor module704. The magnetic field sensor module704preferably comprises one or more Hall effect sensors. The magnetic field sensor is a form of non contact reader for reading data encoded in the set of magnets604.

Although as described above with reference toFIGS. 1,2,5,6a device or devices that stores configuration data is preferably located in a front fascia102,502,602, alternatively a device or devices for storing configuration data are included in other detachable components of a wireless communication device such as a volume knob, a function key, frequency knob, or an escutcheon.

FIG. 8is a block diagram of an RF-ID device800according to the preferred embodiment of the invention. The internal architecture of the first RF-ID device114, and the second RF-ID device504preferably corresponds to what is shown inFIG. 8. Referring toFIG. 8, the RF-ID device800comprises an air interface802which in the case of the first RF-ID device114takes the form of the second inductive coil402, and in the case of the second RF-ID device504takes the form of dipole antenna506. The air interface is coupled to a demodulator804. The demodulator is used to process signals received from a wireless device from which the RF-ID device receives signals.

The air interface802is also coupled to a load modulator806that is used to modulate a load on the air interface802. The load modulator806preferably comprises a field effect transistor (FET) configured as a variable resistor. In the case of the second inductive coil402, the variable resistor is preferably connected in parallel with the inductive coil402. In the case of the dipole antenna506, such the variable resistor is preferably coupled between the two arms of the dipole antenna506. The RF-ID device800is able to transmit information back to a wireless device with which the RF-ID device800is communicating by modulating the load on the air interface802. A device with which the RF-ID device808is communicating receives information by that is encoded in detectable changes in load.

A microcontroller808is coupled to the demodulator804, and to the load modulator806. The microcontroller808reads data from the demodulator including messages received by the RF-ID device800, and drives the load modulator806in order to send data. The microcontroller808is coupled to a program memory810that stores a program that is used to control the operation of the RF-ID device800. The program memory810is a non volatile memory. The microcontroller808is also coupled to a second nonvolatile memory812. The second nonvolatile memory812is used to store configuration data that is used by the operating program of an external device such as the above mentioned first302, second and third702wireless communication devices to control the operation of the external device. Although the two memories810,812are presented as separate in order to highlight there different purposes, in practice the two memories810,812can be implemented as two address blocks within a single physical memory.

The air interface802is also coupled to a power rectifier and filter814that serves to extract power, for powering circuits of the RF-ID device from RF signals received through the air interface802. The power rectifier and filter814, for example, comprises a full wave bridge rectifier followed by a filter capacitor. The power rectifier and filter814is coupled to and supplies power to the demodulator804, the load modulator806, the microcontroller808, and the memories810,812. The demodulator804, the load modulator806, the power rectifier and filter814, the microcontroller808, the program memory810, and the non volatile data memory812are preferably implemented as a single ASIC816, which in the case of the first RF-ID device114is embodied in the first RF-ID ASIC412, and in the case of the second RF-ID device504is embodied in the second RF-ID ASIC414. The RF-ID device800is a non-contact read out information bearing device.

In operation, in response to signals received from an external device, configuration data for the external device is read out of the non volatile memory812and sent to the external device via the load modulator806. Optionally sending of the configuration data, is conditioned on successful authentication of the external device using cryptographic methods. Preferably, the configuration data sent is encrypted. The configuration data is alternatively encrypted as stored in the non volatile memory812, or encrypted prior to sending.

FIG. 9is a block diagram of the first wireless communication device302shown inFIG. 3in accordance with a preferred embodiment of the invention. As shown inFIG. 9, the wireless communication device302comprises a transceiver module902, a processor904(e.g., a digital signal processor), an analog to digital converter (A/D)906, a key input decoder908, a digital to analog converter (D/A)912, a display driver914, a program memory916, a modulator918, a demodulator920, and a volatile memory922coupled together through a digital signal bus924.

The transceiver module902is coupled to the antenna306. Carrier signals that are modulated with data, e.g., audio data, pass between the antenna306, and the transceiver902.

The microphone316is coupled to the A/D906. Audio, including spoken words, is input through the microphone316and converted to digital format by the A/D906.

The keys314are coupled to the key input decoder908. The key input decoder908serves to identify depressed keys, and provide information identifying each depressed key to the processor904.

The D/A912is coupled to the speaker308. The D/A912converts decoded digital audio to analog signals and drives the speaker308. The display driver914is coupled to the display310.

The modulator918, and the demodulator920are coupled to a carrier frequency generator926, and to the air interface in the form of the first inductive coil320. The air interface320in combination with the demodulator920is a type of non-contact reader for reading information from the RF-ID device800(114). In operation, preferably upon powering up the first wireless communication device302, signals are sent through the modulator918to the RF-ID device800(414) and optionally after carrying out an authentication handshake procedure, and optionally negotiating and encrypted communication link, configuration data for the first wireless communication device302is received through the demodulator920from the RF-ID device800(414). Thereafter the configuration data is preferably decrypted and stored in the volatile memory922. In the latter case upon powering down the first wireless communication device, the configuration data will be erased and thus will not be accessible to persons seeking to pirate the configuration data. An encryption key used to decrypt the configuration data is preferably stored in the program memory916. Alternatively, a user is prompted to enter the decryption key through the keys314. The volatile memory922, program memory916and the processor are preferably integrated in a single chip making it difficult to read the configuration data in decrypted form.

The program memory916is used to store programs that control the first wireless communication device302. The programs stored in the program memory916are executed by the processor904. The configuration data is used by the programs that control the wireless device302. The configuration data can be used to control a variety of aspects of the operation of the wireless device. Examples of aspects of operation data that can be controlled by the configuration data include, frequency of operation, and enabling and disabling enhanced functionality such as, but not limited to, secure voice communication, web browsing, text messaging, and/or email. The configuration data preferably comprises binary encoded values, e.g., binary encoded frequencies, and binary flags e.g., flags that determine the outcome of decision statements in programs that control the operation of the first wireless communication device302. The configuration data can for example includes what is termed in the art of wireless communication devices a ‘code plug’ for the wireless device302.

According to an alternative embodiment of the invention when the front fascia102is mounted for the first time, configuration data is transferred from the first RF-ID device114to the wireless communication device302in response to keyed user input, and thereafter the configuration data is stored in a non volatile memory.

FIG. 10is a flow chart of a method of operating the first RF-ID device114, in conjunction with the first wireless communication device302according to the preferred embodiment of the invention. In step1002the first wireless communication device302is powered up. In optional block1004, cryptographic procedures are used to authenticate the first wireless communication device302to the RF-ID device114, and to authenticate the RF-ID device114to the first wireless communication device302. Block1006is a decision block the outcome of which depends on whether the authentication performed in step1006was successful. If not then the process terminates. If on the other hand authentication was successful the process continues with block1008in which an encrypted communication link is set up between the first wireless communication device302, and the first RF-ID device114. Known authentication and encryption methods can be used in performing the blocks1004,1008. In block1010the configuration data is wirelessly transmitted from first RF-ID device114the first wireless communication device320. In block1011the configuration data is stored in the volatile memory922of the first wireless communication device320. In block1014the first wireless communication device320is operated in response to user input and in accordance with the configuration data. In block1016the first wireless communication device320is powered down. When the first wireless communication device320is powered down the configuration data is lost from the volatile memory922and thus not available for unauthorized reading from the first wireless communication device320.

Storing configuration data for a wireless communication device in an RF-ID device makes the data more secure, and makes it more difficult for configuration data to be altered in order to make a wireless communication device perform functions that it was not intended to perform when it was initially sold. Storing configuration data in an RF-ID device, or otherwise (e.g., by magnets) encoded, in a detachable part (e.g., front fascia102,502, or602) also allows phones to be upgraded in terms of functionality by replacing the detachable part.

FIG. 11is a front view of a fourth wireless communication device1102according to yet another embodiment of the invention. The fourth wireless communication device1102differs from the first wireless communication device302, in that the fourth wireless communication device1102includes a removable control knob1104, that includes a third RF-ID device1106, as opposed to the removable front fascia102including first RF-ID device114of the first wireless communication device302. The removable control knob1104with third RF-ID device1106is preferably manufactured by insert molding. The removable knob1104fits onto a shaft1108of the fourth wireless communication device1102. The shaft1108is preferably part of a rotary switch or a rotary continuously variable impedance adjustment device such as a potentiometer used to control volume. The knob1104including the third RF-ID device1106can be easily removed, carried and put on a wireless communication device in order to enable such wireless communication device to operate in accordance with configuration date stored in the third RF-ID device.

FIG. 12is a cross sectional side view of a fifth wireless communication device1200according to a further embodiment of the invention. The fifth wireless communication device1200includes an internal circuit board1202that supports and electrically interconnects a number of components including an elastomeric keypad1204. A fourth RF-ID device1206is molded within the elastomeric keypad1204. The circuit board1202also supports a third solenoid1208that is used to exchange data with the fourth RF-ID device1206, and other circuit components1210that embody the electrical circuits described above with reference toFIG. 9. A battery1212is also provided.

Including the fourth RF-ID device1206in the keypad1204facilitates differentiating otherwise identical devices, substituting different keypads1204that have different text, and icons on keys of the keypad1204, and changing in a complementary way configuration data that controls the function of the keys, and optionally other configuration data such as the content of menus displayed on a display1214. The function of individual function keys included in the keypad1204is preferably determined by configuration data stored in the RF-ID device1206, and indicated by text or icons printed on each function key. Thus by changing the keypad1204wireless communication devices can be differentiated to suit different user groups, e.g., teenagers interested in gaming vs. professionals more interested in organizing contact information, or Spanish speakers vs. English speakers.

According to an alternative embodiment of the invention, a detachable part of a wireless communication device includes an RF-ID device that includes a read/write memory, and the wireless communication device itself is programmed to transmit configuration data that includes user data to the RF-ID device, and also to receive the configuration data from the RF-ID device, and the RF-ID device is programmed to store the user preferences received from the wireless communication device for future use, and thereafter transmit the user data to the wireless communication device. Such an embodiment allows the detachable device that stores the user's data to be moved from one wireless communication device to another. The user data can for example comprise volume settings, default channels, screen layout, display contrast, font size, date and time format, soft button definitions and/or personal phone book listings. This embodiment is particularly useful in situations where the user can be assigned one of many wireless communication devices from a pool of devices available to the user's organization, or in the case that a user rents or is loaned a wireless communication device. In such instances, simply by attaching the detachable device including the RF-ID device, including previously stored user data a wireless communication device that is new to the user can be readily configured according to the user's data by transferring that data in the form of configuration data from the RF-ID device to the wireless communication device.

FIG. 13is a flow chart of a method of operating a read/write capable RF-ID in conjunction with two separate reconfigurable apparatuses (e.g., two way radios, cellular telephones). In step1302a detachable part (e.g., front fascia102,502,602, knob1104, keypad1206) that includes a read/write capable RF-ID device is attached to a first reconfigurable apparatus. Attaching the detachable part serves to insure that the RF-ID device included in the detachable part is positioned such that good signal strength can be achieved in exchanging data signals between the reconfigurable apparatus and the RF-ID device using without the need for high power signals. In step1304, user input of data (e.g. frequencies to use, volume settings, phone book entries) is read in. To perform step1304, the first reconfigurable apparatus is programmed to accept user input, e.g., through keys314. The first reconfigurable apparatus is preferably programmed to present one or more menus, e.g., on the display310, that guide the user in entering input.

In step1306wireless communication is established between the RF-ID device and the first reconfigurable apparatus, and in step1308the user data previously entered by the user and accepted in step1304, is transmitted from the first reconfigurable apparatus to the RF-ID device. In step1310the user data is stored in a nonvolatile memory in the RF-ID device. The first reconfigurable apparatus is preferably programmed to transfer any changes to configuration data made by a user to the RF-ID device in the detachable part.

In step1312the detachable part including the read/write capable RF-ID device is attached to a second reconfigurable apparatus, and in step1314wireless communication is established between the second reconfigurable apparatus and the read/write capable RF-ID device. In step1316user data that was stored in the RF-ID device in step1310is transmitted from the RF-ID device, and received by the second reconfigurable apparatus. In step1318the second reconfigurable apparatus is operated with the user data received from the RF-ID device. For example, the second reconfigurable apparatus will be configured according to volume and frequency settings received from the RF-ID device, and phone book entries stored on the RF-ID device will be available on the second reconfigurable apparatus.

Although the invention as described above with reference to several specific embodiments is particularly applicable to wireless communication devices, such as cellular telephones, and two way radios, it should be noted that the invention can be applied to other types of electronic devices, such as for example video game consoles, set top boxes, digital cameras etc.

While the preferred and other embodiments of the invention have been illustrated and described, it will be clear that the invention is not so limited. Numerous modifications, changes, variations, substitutions, and equivalents will occur to those of ordinary skill in the art without departing from the spirit and scope of the present invention as defined by the following claims.