Patent Application
20060022802
This invention relates to the field of radio frequency identification (RFID) and, more particularly, to various RFID-based systems and methods for wireless communication devices and wireless network infrastructures.
Communication via wireless media is becoming increasingly popular, and its usage is in numerous and varied business environments also continues to increasing. A major reason for its increased popularity and usage is that computers and other communication devices are no longer encumbered by wired network connections, which can substantially inhibit, if not totally prevent, device mobility. Instead, devices with wireless communication capabilities users of such devices may freely move about and access one or more communication networks.
It logically follows that, to implement complete wireless capability, a device should include a stand-alone power source so that it is not continuously connected to a fixed, external power source via a wired connection. Thus, many wireless communication devices are powered, or are capable of being powered, by a rechargeable power source, such as one or more rechargeable batteries. Typically, the rechargeable power source is charged by connecting it to a fixed, external power source. Once the rechargeable power is sufficiently charged, the device may be disconnected from the external power source, and used to implement full wireless communication with, for example, a wireless local area network (WLAN).
Many wireless devices include power management systems and/or methods conserve the power stored in the rechargeable power source when the wireless device is disconnected from the external power source. For example, many wireless devices are configured to go into a “low-power” or “sleep” mode after a period of non-use. In the sleep mode many of the device internal circuits are not drawing power from the mobile device power source. In many instances, the wireless device is further configured to periodically “wake up,” or exit the sleep mode, and to poll or query the WLAN to determine whether the WLAN wants to communicate with the wireless device. These periodic “waking up” and polling operations can significantly deplete the rechargeable power source. This in turn can reduce the amount of time that the wireless device can continue complete wireless operations, can increase the recharge frequency of the rechargeable power source, and can reduce the overall lifetime of the rechargeable power source.
Hence, there is a need for a system and method of power management of wireless communication devices that improvise on one or more of the above-noted drawbacks. Namely, a system and method that increases the amount of time that a wireless device can continue complete wireless operations, and/or decreases the recharge frequency of wireless device rechargeable power sources, and/or increases the overall lifetime of wireless device rechargeable power sources. The present invention addresses one or more of these drawbacks.
The present invention provides RFID-based systems and methods for wireless communication devices and wireless network infrastructures that, among other things, improve on presently known power management methods, provide selective software routine launching capabilities by the wireless communication devices, and provide enhanced device and network security features.
In one embodiment, and by way of example only, a wireless device includes an RFID tag and a wake-up circuit. The RFID tag is configured to receive an RFID interrogation signal and, upon receipt thereof, to supply one or more transition signals. The wake-up circuit is coupled to receive the transition signals and is configured, upon receipt thereof, to transition the wireless device from a first operational state to a second operational state.
In another exemplary embodiment, a wireless communication system includes an RFID tag and a wireless communication device. The RFID tag is configured to receive an RFID interrogation signal and, upon receipt thereof, to supply at least a transition signal. The wireless communication device is configured to operate in a plurality of operational states, is coupled to receive the transition signal, and is configured, upon receipt thereof, to transition from at least a first operational state to a second operational state.
In yet another exemplary embodiment, a system for controlling the operational state of a wireless device includes an RFID transceiver and an RFID tag. The RFID transceiver is configured to at least transmit an RFID interrogation signal. The RFID tag is configured to receive the RFID interrogation signal and, in response thereto, to at least transmit a transition signal that, upon receipt thereof by the wireless device, transitions the wireless device from a first operational state to a second operational state.
In still a further exemplary embodiment, a method of managing the operation of a wireless communication device having an RFID tag in operable communication therewith includes the steps of transmitting an RFID interrogation signal to the RFID tag and, upon receipt of the RFID interrogation signal, transitioning the wireless communication device from a first operational state to a second operation state.
Other independent features and advantages of the preferred system and method will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary, or the following detailed description.
A functional block diagram of an exemplary system 100 according to one embodiment of the present invention is shown in
Referring once again to
In a particular preferred embodiment, each access point 102 in the WLAN 200 is configured to serve multiple mobile units 104 in a defined area and, as such, is able to handle all WLAN communications in that defined area. However, an access point 102 can become busy if, for example, one of the mobile units 104 in the defined area requests a large amount of information. Thus, in areas where the coverage area of one access point 102 is, or may be, insufficient, multiple access points 102 are included. When multiple access points 102 are included in a defined area, the access points 102 include protocols that allow the different access points 102 to hand off mobile units 104 between one another, as necessary, as the mobile unit 104 moves about the defined area.
The mobile unit 104 may be any one of numerous devices configured to wirelessly communicate with one or more access points 102 including, for example, a wireless personal computer (PC), a cellular telephone, a beeper, a wireless RFID reader, or a wireless bar code reader. In a particular preferred embodiment, the mobile unit 104 is implemented as a wireless device that is readily transportable from one location to another, either by hand or other device. However, it will be appreciated that the mobile unit 104 could also be implemented as a fixed, non-moveable device configured to wirelessly communicate with one or more of the access points 102. As shown in
With reference now to
The WLAN base-band chip 304 is coupled between the DSP 302 and the WLAN transceiver 306. The WLAN base-band chip 304, which may be any one of numerous known on-chip circuits configured to perform the hereafter described function, converts received WLAN signals 114 to digital data signals, and digital data signals to appropriate WLAN signals 114. More particularly, the WLAN base-band chip 304 is preferably configured to receive WLAN signals 114 from the WLAN transceiver 306, and to convert these WLAN signals 114 to digital data signals that the DSP 302, as described above, can appropriately manipulate. The WLAN base-band chip 304 is also preferably configured to convert digital data signals generated by the DSP 302 to an appropriate WLAN signal 114 that the WLAN transceiver 306 can then transmit, for example, onto the WLAN 200.
The WLAN transceiver 306 is coupled to one or more WLAN antennas 314, and is configured to receive WLAN signals 114 from, and transmit WLAN signals 114 to, other wireless devices, such as other access points 102, the mobile unit 104, or the server computer 106. The WLAN transceiver 306, as mentioned above, is also configured to supply and receive WLAN signals 114 to and from, respectively, the WLAN base-band chip 304. It will be appreciated that the WLAN transceiver 306 may be any one of numerous types of circuits configured to implement wireless communications. In a particular preferred embodiment, the WLAN transceiver 306 is compliant with wireless communication protocol standards such as, for example, the IEEE 802.XX standards, though it will be appreciated that other wireless communication protocols could be used.
The PoE controller 308, which may be any one of numerous circuits configured to implement IEEE standard 802.3af, receives power and data packets via a wired network connection, and supplies power to the various circuits of the access point 102. It will be appreciated that the use of the PoE controller 308 is merely exemplary of one particular embodiment, and that the access point 102 may be powered via any one of numerous known devices and methods including, for example, one or more batteries, or a wired connection to a power source.
The RFID transceiver 310, which is also colloquially referred to as an “RFID reader,” is coupled to an antenna switch 312, and to the DSP 302 via so-called “Glue Logic” 316. The RFID transceiver 310 is configured to transmit RFID signals 116 to, and to receive RFID signals 116 from, one or more RFID tags (or RFID transponders). More specifically, the RFID transceiver transmits RFID interrogation signals 116 to one or more RFID tags (not shown in
As was noted above, the RFID transceiver 310 is coupled to the DSP 302 via the Glue Logic 316. As is generally known, Glue Logic 316 is any device configured to interface two or more devices and/or two or more communication protocols. In the depicted embodiment, the Glue Logic 316 interfaces the RFID transceiver 310 and the DSP 302 to allow intercommunication between the WLAN and RFID portions of the access point 102. It will be appreciated that the Glue Logic 316 may be implemented in hardware, software, firmware, or combination thereof.
Turning now to
The processor 404 may be any one of numerous known general-purpose microprocessors or an application specific processor that operates in response to program instructions. The processor 404 is in operable communication with one or more memory storage devices 418 (only one shown for convenience), which in the depicted embodiment includes both RAM (random access memory) 420 and ROM (read only memory) 422. It will be appreciated that the memory storage devices 418 could be physically implemented apart from the processor 404, as shown in the depicted embodiment, or the memory storage devices 418 could be partially or fully implemented on the processor 404.
No matter the particular physical implementation of the memory storage devices 418, it will be appreciated that some or all of the program instructions that control the processor 404 are stored in either, or both, the RAM 420 and the ROM 422. For example, operating system software may be stored in the ROM 422, whereas various operating mode software routines and various operational parameters may be fully, or partially, stored in the RAM 420. It will be appreciated that this is merely exemplary of one scheme for storing operating system software and software routines, and that various other storage schemes may be implemented. Indeed, as will be discussed in more detail further below, various software routines may be fully, or partially, stored in memory associated with the RFID tag 410.
The display 406 is used to display various images and data, in either or both a graphical and a textual format, to thereby supply visual feedback of mobile unit operations. It will be appreciated that the display 406 may be any one of numerous known displays suitable for rendering image and/or text data in a viewable format. Non-limiting examples of such displays include various cathode ray tube (CRT) displays, and various flat panel displays such as, for example, various types of LCD (liquid crystal display) and TFT (thin film transistor) displays.
The user interface 408 may be any one, or combination, of various known user interface devices including, but not limited to, a touch sensitive display, a cursor control device, such as a mouse, a trackball, or joystick, and/or a keyboard, one or more buttons, switches, or knobs. No matter the particular implementation, the user interface 408 is configured, among other things, to allow a user to input data to the processor 408.
The RFID tag 410 may be separately coupled to, and interfaced with, the mobile unit 104, or provided as an integral part of the mobile unit 104. In either case, the RFID tag 410 is configured to receive RFID interrogation signals 116 from the RFID transceiver 310 in one or more of the access points 102 and, in response to the RFID interrogation signals 116, to selectively supply one or more RFID response signals 116 and one or more transition signals. As is generally known, the RFID response signals 116 include, among other things, identification data stored in the RFID tag 410. As will be described more fully further below, the identification data is used, among other things, to identify, and to determine the location of, the mobile unit 104.
The transition signals supplied by the RFID tag 410, as will also be described in more detail further below, cause the mobile unit 104 to transition from one operational state to one or more other operational states. For example, in one embodiment, the transition signals include one or more command or interrupt signals that cause the mobile unit 104 to transition from a “sleep mode,” or other low-power idle state, to an “awake mode,” or other a full power-on state. In another embodiment, the transition signals include one or more command or interrupt signals that cause the mobile unit 104 to implement one or more software routines. In yet another embodiment, the transition signals include one or more command or interrupt signals that cause the mobile unit 104 to transition from a “sleep mode,” or other low-power idle state, to a full power-on state, and to implement one or more software routines. Thus, as shown in
The wake-up circuit 412, in one embodiment, is configured to periodically poll the RFID tag 410 to determine whether the RFID tag 410 is transmitting one or more of the above-mentioned transition signals. If the RFID tag 410 is transmitting a transition signal, the wake-up circuit 412 applies power (e.g., from a non-illustrated battery) to the remaining circuits in the mobile unit 104. If the RFID tag 410 is not transmitting a transition signal during the periodic poll, the wake-up circuit 412 leaves the mobile unit 104 in the “sleep mode,” or other low-power idle state. To conserve power, the wake-up circuit 412 is preferably configured to operate at low current even while polling the RFID tag 410. The wake-up circuit 412, as will be appreciated, may be implemented using any one of numerous known wake-up circuit configurations. Moreover, although shown as being implemented as a separate circuit, it will be appreciated that the processor 404 could alternatively implement the wake-up circuit functionality.
The power source 414 is electrically coupled to, and powers, each of the above-described circuits in the mobile unit. For clarity of illustration, the electrical interconnections of the power source 414 are not shown. The power source 414 may be any one of numerous types of power sources, but in a preferred embodiment, the power source 414 is a rechargeable power source such as, for example, one or more rechargeable batteries. In an exemplary embodiment, the power source 414 is charged by connecting the mobile unit 104, or just the power source, to an external power source (not illustrated) for a period of time. Thereafter, once the power source 414 is charged, it can be disconnected from the external power source, and used to supply power for the mobile unit 104.
Referring once again to the RFID tag 410, it will be appreciated that it may be any one of numerous known types of RFID tags, the overall function and structure of which is generally known. Thus, although a description of an exemplary embodiment of the RFID tag 410 is not needed to provide either an enabling or fully descriptive disclosure, such a description will nonetheless be provided. Before doing so, however, a brief overview of RFID tag operational types will be provided. As is generally known, an RFID tag may be implemented as an active tag, a semi-active tag, or a passive tag. An active RFID tag typically includes an on-board power source, such as an internal battery, to transmit data, and typically includes the ability to read and write greater amounts of stored data than either passive or semi-passive tags. A passive RFID tag includes no on-board power source, transmits data by reflecting and absorbing energy from the RFID signals transmitted from an RFID reader (e.g., an RFID transceiver 310), and uses energy absorbed from the RFID signals for data storage, retrieval, and manipulation. A semi-passive tag is somewhat of a hybrid of the active and passive tags. In particular, a semi-passive tag includes an on-board power source, such as an internal battery, to power, for example, volatile memory or an on-board sensor but, similar to a passive tag, transmits data by reflecting and absorbing energy from the RFID reader. In addition, some RFID tags are implemented as multi-mode tags that, among other things, can operate as either a passive tag or a semi-passive tag.
In a particular preferred embodiment, the mobile unit RFID tag 410 is implemented as a passive tag, a semi-passive tag, or a multi-mode tag configured to implement either of these paradigms. It will nonetheless be appreciated that the RFID tag 410 could also be implemented as an active tag, in which case the RFID tag 410 preferably receives its operational power from the mobile unit power source 414. A simplified functional block diagram of an exemplary preferred embodiment of the RFID tag 410 is depicted in
The RFID tag antenna 502, which may be any one of numerous known RFID antennas, is coupled to the RF interface 504, which may similarly be implemented using any one of numerous known RFID tag interface circuit configurations. The RFID tag antenna 502 and RF interface 504 are configured to receive RFID interrogation signalsl 16 from, and to emit RFID response signals 116 to, the RFID transceiver 310 in one or more of the access points 102. It will be appreciated that the RF interface 504 may include, for example, one or more storage capacitors to store energy received by the RFID antenna 502, if the RFID tag 410 is not powered by an internal storage battery (e.g., is a passive tag), or is powered by both an internal storage capacitor and a battery (e.g., a semi-passive tag).
The tag processor 506 may be any one of numerous known general-purpose microprocessors or an application specific processor that operates in response to program instructions. In the depicted embodiment, the tag processor 506, among other things, controls the overall operation of the RF interface 504, supplies the transition signals to the wake-up circuit 412 and/or the mobile unit processor 404 via one or more of the above-mentioned communication links 424, 426, and controls data read and write operations from and to, respectively, the tag memory 508. Moreover, if the RFID tag 410 is implemented as a multi-mode type of tag, the tag processor 506 may additionally run a tag emulation selection routine that switches the type of tag paradigm that the RFID tag 410 will emulate (e.g., active, semi-passive, or passive).
The tag memory 508 is in operable communication with the tag processor 506 and stores various types of data. The stored data, as was just alluded to above, may be selectively retrieved by, or supplied from, the tag processor 506. The stored data may include, for example, one or more interrupt flags, complete sets of program instructions, and tag and/or mobile unit identification data. As will be described more fully further below, the interrupt flags and/or program instructions are selectively supplied from the tag memory 508 to the mobile unit processor 404, which in turn causes the mobile unit 104 to initiate one or more software routines. The identification data, as will also be described more fully below, is sent as part of the RFID response signal 116 to the particular access point 102 from whence the corresponding RFID interrogation signal 116 was received. Although depicted as being physically implemented as part of the RFID tag 410, it will be appreciated that the tag memory 508 could be implemented as shared memory. That is, the tag memory 508 could, for example, be in operable communication with the mobile unit processor 404 or other interface circuitry in the mobile unit 104. In such an embodiment, which is shown in phantom in
The tag memory 508 is preferably non-volatile memory; however, it will be appreciated that it could be any one of numerous types of memory or memory subsystems including, for example, a collection or combination of read-write volatile memory, read only non-volatile, read/write non-volatile. It will additionally be appreciated that the tag memory 508 may be physically implemented in any one of numerous known configurations including, for example, flash memory, EEPROM, ferro-electric random access memory (FRAM), magneto-resistive RAM/ROM, magnetic RAM/ROM, one or more magnetic storage devices, or one or more optical storage devices.
The system and devices described above function together to provide RFID-based methods of, among other things, power management, selective application launching on power-up, location-based application launching, and secure device operation and control, for various types of wireless mobile units 104. These RFID-based methods, it will be appreciated, may be implemented alone or in various combinations with one another. Particular embodiments of each of these overall methods are individually depicted in flowchart form in
Turning now to
When the specified RFID tag 410 receives the RFID interrogation signal 116, it is put into a responsive mode, and transmits an appropriate RFID response signal 116 back to the access point 102 (604). In a preferred embodiment, in which the RFID tag 410 is a passive or semi-passive tag, the RFID response signal 116 is transmitted by modulating a back scattered signal. The RFID response signal 116, as described above, includes data, stored in the RFID tag memory 520, which identifies either, or both, the RFID tag 410 or the associated mobile unit 104. Thus, the access point 102 will be able to determine that the RFID interrogation signal 116 it sent was indeed received by the proper RFID tag 410.
In addition to transmitting the RFID response signal 116, the RFID tag 410 also generates one or more transition signals in response to the RFID interrogation signal 116 (606). In the depicted embodiment, the transition signals cause the mobile unit 104 to transition from the “sleep mode” to the “awake mode” (608). As was noted above, the wake-up circuit 412 in the mobile unit 104 may be physically implemented in any one of numerous ways. Thus, as was also previously noted, the wake-up transition signals may be generated in any one of various forms such as, for example, one or more commands or interrupt signals. No matter the particular manner in which the wake-up circuit 412 is physically implemented, or the particular form in which the wake-up transition signal is generated, once the mobile unit 104 is fully-powered up, it can then begin communicating with the WLAN 200.
Thereafter, when the WLAN 200 no longer wants to communicate with the mobile unit 104, one of the access points 102 transmits an additional RFID interrogation signal 116 to the mobile unit RFID tag 410 (610). Upon receipt of the RFID interrogation signal 116, the RFID tag 410 is again put into a responsive mode, and once again transmits an appropriate RFID response signal 116 (612) and generates one or more transition signals (614). In this instance, however, the transition signals cause the mobile unit 104 to transition from the “awake mode” back to the “sleep mode” (616). Thus, energy is not unnecessarily depleted from mobile unit power source 414, thereby conserving power and reducing the frequency of re-charge cycles. Although not depicted in
In addition to implementing a power management process, such as the process 600 described above, the system 100 can implement a process in which the mobile unit 104, upon transitioning to the “awake mode,” will also selectively launch one or more software routines. An embodiment of such a process 700 is shown in
Turning now to
Although the above-described process 700 is depicted and described as also implementing the previously-described power management process 600, it will be appreciated that the process 700 can also be implemented apart from the power management process 600. Indeed, in such an embodiment, any time the mobile unit 104 is in the “awake mode,” the mobile unit 104 may be configured to receive one or more additional transition signals from the RFID tag 410 that cause the mobile unit 104 to launch one or more specific software routines.
The above-described processes 600 and 700 may be further enhanced to additionally, or instead, include location-based application launching capabilities. In particular, the system 100 can implement a process 800, an exemplary embodiment of which is shown in
As shown in
Once the access point 102 determines the location of the mobile unit 104 (802), it then transmits a location-based launch signal that causes the mobile unit 104 to launch one or more specific software routines (804). The access point 102 may transmit the location-based launch signal in any one of numerous ways. For example, the location-based launch signal may be transmitted as either, or both, a WLAN signal 114 or an RFID signal 116. If the location-based launch signal is a WLAN signal 114, then the signal 114 is received directly by the mobile unit 104, which appropriately processes the signal 114 and determines the particular routine(s) to launch. Conversely, if the location-based launch signal is an RFID signal 116, then the signal 116 is received by the RFID tag 410, which appropriately processes the signal 116 and determines the particular routine to launch. This determination is then communicated to the mobile unit 104. If the location-based launch signal is a combination of a WLAN 114 and an RFID signal 116, then the access point 102 may transmit data, such as a particular flag, command, or interrupt routine, to the RFID tag 410 for storage in a particular location in the RFID tag memory 508, and a command to the mobile unit 104 that instructs the mobile unit 104 to access and retrieve the data transmitted and stored in the particular location in the RFID tag memory 508. The mobile unit 104 will then launch a specific software routine based on the retrieved data. In a particular preferred embodiment, the location-based launch signal is an RFID signal 116 that either includes, or sets, a particular flag in the RFID tag memory 508. The mobile unit 104 then launches a particular software routine based on that particular flag.
It will be appreciated that the location-based application launching process 800 described above provides not only a convenient method by which a mobile unit 104 can be powered up and/or configured upon being positioned at or near a particular location, but the process 800 can also be used for security purposes. For example, the system 100, 200 can be configured to prevent the mobile unit 104 from transitioning from the “sleep mode” to the “awake mode,” based on the location of the mobile unit 104. Alternatively, the system 100, 200 can be configured to prevent the mobile unit 104 from launching one or more specific software routines, or from communicating with the WLAN 200, based on the location of the mobile unit 104. Such a capability (or capabilities) prevents a mobile unit 104 from communicating with the WLAN 200 if it is located outside a particular area, and/or not positioned at a particular location.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims and the legal equivalents thereof.
