Abstract:
An RFID portal is enhanced to provide communication capability to RFID communication enabled devices. Such devices include cameras, PDAs, voice communicator, keyboards, displays, indicators, storage devices, etc. Devices are made RFID communication enabled by providing them with an RFID interface and an RFID tag “front end”. Such an enhanced device communicates with an enhanced portal via an RFID reader/interrogator associated with the portal. The portal may have connection to other communication channels, such as an Ethernet tie to a network, a landline phone connection, a cellular interface, an 802.11 connection, a Bluetooth channel, etc. Such connections allow an RFID communication enabled device to communicate beyond the enhanced portal to the outside world.

Description:
BACKGROUND 
       [0001]    The invention relates in general to the arrangement and use of radio frequency identification (RFID) tags and systems. In particular, the invention relates to the use of an RFID portal as a communication access point for receiving data from and sending data to devices equipped with an RFID tag “front end”. Such devices are referred to herein as “RFID Comm Enhanced” devices. 
         [0002]    Radio frequency identification (RFID) tags are electronic devices that are typically attached to items whose presence is to be detected and/or monitored. For example, they are quite useful in inventory control and tracking. RFID tags are classified based on standards defined by national and international standards bodies (e.g., EPC Global and ISO). Standard tag classes include Class 0, Class 1, and Class 1 Generation 2 (referred to herein as “Gen 2”). The presence of an RFID tag, and therefore the presence of the item to which the tag is affixed, may be checked and monitored wirelessly by an “RFID reader”, also known as a “reader-interrogator”, “interrogator”, or simply “reader.” Readers typically have one or more antennas for transmitting radio frequency signals to RFID tags and receiving responses from them. An RFID tag within range of a reader-transmitted signal responds with a signal including a unique identifier associated with only that particular RFID tag. Thus, an item to which an RFID tag is attached is uniquely identified by its tag responding to an RFID interrogator signal. 
         [0003]    With the maturation of RFID technology, efficient communication between tags and readers has become a key enabler in supply chain management, especially in manufacturing, shipping, and retail industries, as well as in building security installations, healthcare facilities, libraries, airports, warehouses etc. Many processes, as well as the status of many items, may be readily monitored via RFID tags. 
         [0004]    However, traditionally, an RFID tags only communicates information indicative of its unique identifier. It is not useful for communicating any other information even though a communication channel is established between an RFID tag and an interrogator. An RFID portal, typically including an RFID interrogator, traditionally function only to send interrogation signals looking for the presence of RFID tags, read response signals (backscatter) from RFID tags bearing RFID tag identifying information, and keep track of the various RFID tag “reads” that occur so that received information can be used by software to provide some inventory control function. Such portals are not capable of further communication functions. 
       SUMMARY 
       [0005]    This section is for the purpose of summarizing some aspects of the inventions described more fully in other sections of this patent document. It briefly introduces some preferred embodiments. Simplifications or omissions may be made to avoid obscuring the purpose of the section. Such simplifications or omissions are not intended to limit the scope of the claimed inventions. 
         [0006]    The inventions relate generally to providing additional functionality and capability to an otherwise conventional RFID portal. In a conventional RFID system, a portal includes an RFID reader/interrogator. It regularly transmits an interrogation signal to any RFID tags that may be within range of the portal. An RFID tag within range responds with a backscatter signal including identification data indicating the identity of the tag responding. 
         [0007]    The invention described herein provides enhanced communication functionality for RFID portals and for various devices. An ordinary device, such as, for example, a PDA, phone, digital camera, keyboard, touchpad, etc. can be enhanced to create an RFID enhanced device by providing it with an RFID interface and an RFID transponder acting as a “front end” for communication with an enhanced RFID portal. A typical RFID portal is enhanced by providing it with augmented software/firmware and additional communication capabilities. 
         [0008]    An RFID enhanced device, in addition to transmitting its usual unique ID information to a portal, is able to transfer of other types of digital data. For example, an RFID enhanced digital camera can transmit its digital image files to an enhanced portal using an RFID communication channel established between its RFID transponder and an interrogator associated with the enhanced portal. 
         [0009]    In an embodiment, an enhanced portal has portal firmware installed therein that processes data (from an RFID enhanced device) in addition to the normal identification data that would be received from an RFID tag. 
         [0010]    An ordinary device can be transformed into an RFID enhanced device by fitting it with an active or passive RFID transponder and an appropriate interface. Systems using active or passive RFID transponders as their front end, transfer data to an enhanced portal. An enhanced portal, like an ordinary portal, is typically connected to some backend infrastructure via a Ethernet or 802.11 connection. Enhanced portals may have added peripheral devices associated with them. For example, an enhanced portal may have an associated display, keyboard, mass storage device, speaker, etc. It may also be fitted with additional communication capability such as, for example, a Bluetooth transceiver, an infrared transceiver, etc. RFID enhanced devices are able to gain access to any enhanced portal resource simply by being within range of the enhanced portal. Enhanced portal resources may include, but are not limited to: Ethernet connection, 802.11 communication facility, memory, data input devices, speakers, microphones, keyboard, camera, indicators and displays. Similarly, resources of an RFID enhanced device can be accessed by the enhanced portal. 
         [0011]    Devices intended to communicate with the portal can be hung on hooks near the portal antenna to charge (using the charge pump of the RFID transponder or other energy harvesting techniques) their internal batteries from the relatively large field strength near the antenna of the enhanced portal. 
         [0012]    In an embodiment one RFID enhanced device is a portable communicator. Like a conventional cell or mobile phone, it has a microphone and speaker. However, a modulator produces a stream of digital data corresponding to a voice signal. That digital data is communicated via its RFID transponder thereby allowing a voice over IP (VOIP) telephone call to be made. A user can make a VOIP call using the nearest RFID portal to access various networks via the portals communication connections (802.11, Ethernet, etc.). 
         [0013]    A portable keypad can be used to program and control an enhanced portal. 
         [0014]    A portable camera can automatically “dump” its digital image objects as it passes through an enhanced portal. 
         [0015]    A portable device can collect a history log from a portal that does not have a communication connection to some infrastructure so that the history log can be carried to remote location. 
         [0016]    A portal alternative can be provided by associating an RFID interrogator with an access point such that RFID enhanced devices can gain network access without a full portal. 
         [0017]    The invention can be implemented in numerous ways, including methods, systems, devices, and computer readable medium. Several embodiments of the invention are described below, but they are not the only ways to practice the invention described herein. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES 
         [0018]    The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. 
           [0019]    In the drawings, like reference numbers indicate identical or functionally similar elements. 
           [0020]    Additionally, references numbers which are the same, but vary by virtue of an appended letter of the alphabet (for example,  412 ,  412 R,  412 P,  412 S) or an appended letter and number (for example,  412 ,  412 S 1 ,  412 S 2 ) indicate elements which may be substantially the same or similar, but represent variations or modifications of the basic element. In some cases, the reference number without the appended letter or without the appended letter and number (for example,  412 ) may indicate a generic form of the element, while reference numbers with an appended letter or an appended letter and number (for example,  412 S,  412 S 1 ,  412 S 2 ,  412 P) may indicate a more particular or modified form of the element. 
           [0021]    Additionally, the leftmost digit(s) of a reference number identifies the drawing in which the reference number first appears. For example, an element labeled  412  typically indicates that the element first appeared in  FIG. 4 . 
           [0022]      FIG. 1  shows an environment where RFID readers (interrogators) communicate with an exemplary population of RFID tags. 
           [0023]      FIG. 2  is a block diagram of receiver and transmitter portions of an RFID reader. 
           [0024]      FIG. 3  is a block diagram of an exemplary radio frequency identification (RFID) tag. 
           [0025]      FIG. 4A  is a schematic diagram of a typical RFID portal. 
           [0026]      FIG. 4B  is a schematic diagram of an enhanced RFID portal according to the invention. 
           [0027]      FIG. 5  is a schematic diagram showing an enhanced portal  400  with various peripheral devices attached thereto and communication link to infrastructure  430 . 
           [0028]      FIG. 6  is a schematic diagram illustrating a general principle of the invention. 
           [0029]      FIG. 7  is a schematic diagram of an embodiment of the invention featuring an enhanced camera  534 , that has been fitted with an RFID transponder  524 . 
           [0030]      FIG. 8  is a schematic diagram of an embodiment of the invention featuring a portable keypad  802  as an enhance device. 
           [0031]      FIG. 9  is a schematic diagram of a system including an enhanced portal  400  and an enhanced storage device  902 . 
           [0032]      FIG. 10  is a schematic diagram of an embodiment of the invention. It includes enhanced device  1002  which may include, but is not limited to an enhanced PDA  1004 , an enhanced keyboard  1006  and an enhanced camera  1008 . 
           [0033]      FIG. 11  is a schematic diagram of an RFID transponder  524 . 
           [0034]      FIG. 12  is a schematic diagram of an interface suitable for adapting an ordinary device to communicate with RFID transponder  524  shown in  FIG. 11 . 
           [0035]      FIG. 13  is a flow chart of software or firmware for operating the enhanced portal. 
       
    
    
     DETAILED DESCRIPTION 
       [0036]    In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention, including structures, systems, and methods, may be practiced without these specific details. The description and representation herein are the common means used by those experienced or skilled in the art to most effectively convey the substance of their work to others skilled in the art. In other instances, well-known methods, procedures, components, and circuitry have not been described in detail to avoid unnecessarily obscuring aspects of the invention. 
         [0037]    References in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. 
         [0038]    RFID Tag Basics 
         [0039]    Before describing embodiments of the invention in detail, it is helpful to describe the arrangement and implementation of an RFID tag system.  FIG. 1  illustrates an environment  100  where RFID tag readers  104  (readers  104   a  and  104   b  shown in  FIG. 1 ) communicate with an exemplary population  120  of RFID tags  102 . As shown in  FIG. 1 , the population  120  of tags includes seven tags  102   a - 102   g . A population  120  may include any number of tags  102 . 
         [0040]    Environment  100  includes any number of one or more readers  104 . For example, environment  100  includes a first reader  104   a  and a second reader  104   b . Readers  104   a  and/or  104   b  may be requested by an external application to address the population of tags  120 . Alternatively, reader  104   a  and/or reader  104   b  may have internal logic that initiates communication, or may have a trigger mechanism that an operator of a reader  104  uses to initiate communication. Readers  104   a  and  104   b  may also communicate with each other in a reader network (see  FIG. 2 ). 
         [0041]    As shown in  FIG. 1 , reader  104   a  “reads” tags  120  by transmitting an interrogation signal  110   a  to the population of tags  120 . Interrogation signals may have signal carrier frequencies or may comprise a plurality of signals transmitted in a frequency hopping arrangement. Readers  104   a  and  104   b  typically operate in one or more of the frequency bands allotted for this type of RF communication. For example, the Federal Communication Commission (FCC) defined frequency bands of 902-928 MHz and 2400-2483.5 MHz for certain RFID applications. 
         [0042]    Tag population  120  may include tags  102  of various types, such as, for example, various classes of tags as enumerated above. Thus, in response to interrogation signals, the various tags  102  may transmit one or more response signals  112  to an interrogating reader  104 . Some of the tags, for example, may respond by alternatively reflecting and absorbing portions of signal  104  according to a time-based pattern or frequency. This technique for alternatively absorbing and reflecting signal  104  is referred to herein as backscatter modulation. Typically, such backscatter modulation may include one or more alpha-numeric characters that uniquely identify a particular tag. Readers  104   a  and  104   b  receive and obtain data from response signals  112 , such as an identification number of the responding tag  102 . In the embodiments described herein, a reader may be capable of communicating with tags  102  according to various suitable communication protocols, including Class 0, Class 1, EPC Gen 2, other binary traversal protocols and slotted aloha protocols, and any other protocols mentioned elsewhere herein, and future communication protocols. Additionally, tag population  120  may include one or more tags having the packed object format described herein and/or one or more tags not using the packed object format (e.g., standard ISO tags). 
         [0043]      FIG. 2  shows a block diagram of an example RFID reader  104 . Reader  104  includes one or more antennas  202 , a receiver and transmitter portion  220  (also referred to as transceiver  220 ), a baseband processor  212 , and a network interface  216 . These components of reader  104  may include software, hardware, and/or firmware, or any combination thereof, for performing their functions. 
         [0044]    Baseband processor  212  and network interface  216  are optionally present in reader  104 . Baseband processor  212  may be present in reader  104 , or may be located remote from reader  104 . For example, in an embodiment, network interface  216  may be present in reader  104 , to communicate between transceiver portion  220  and a remote server that includes baseband processor  212 . When baseband processor  212  is present in reader  104 , network interface  216  may be optionally present to communicate between baseband processor  212  and a remote server. In another embodiment, network interface  216  is not present in reader  104 . 
         [0045]    In an embodiment, reader  104  includes network interface  216  to interface reader  104  with a communications network  218 . As shown in  FIG. 2 , baseband processor  212  and network interface  216  communicate with each other via a communication link  222 . Network interface  216  is used to provide an interrogation request  210  to transceiver portion  220  (optionally through baseband processor  212 ), which may be received from a remote server coupled to communications network  218 . Baseband processor  212  optionally processes the data of interrogation request  210  prior to being sent to transceiver portion  220 . Transceiver  220  transmits the interrogation request via antenna  202 . 
         [0046]    Reader  104  has at least one antenna  202  for communicating with tags  102  and/or other readers  104 . Antenna(s)  202  may be any type of reader antenna known to persons skilled in the relevant art(s), including for example and without limitation, a vertical, dipole, loop, Yagi-Uda, slot, and patch antenna type. 
         [0047]    Transceiver  220  receives a tag response via antenna  202 . Transceiver  220  outputs a decoded data signal  214  generated from the tag response. Network interface  216  is used to transmit decoded data signal  214  received from transceiver portion  220  (optionally through baseband processor  212 ) to a remote server coupled to communications network  218 . Baseband processor  212  optionally processes the data of decoded data signal  214  prior to being sent over communications network  218 . 
         [0048]    In embodiments, network interface  216  enables a wired and/or wireless connection with communications network  218 . For example, network interface  216  may enable a wireless local area network (WLAN) link (including a IEEE 802.11 WLAN standard link), a BLUETOOTH link, and/or other types of wireless communication links. Communications network  218  may be a local area network (LAN), a wide area network (WAN) (e.g., the Internet), and/or a personal area network (PAN). 
         [0049]    In embodiments, a variety of mechanisms may be used to initiate an interrogation request by reader  104 . For example, an interrogation request may be initiated by a remote computer system/server that communicates with reader  104  over communications network  218 . Alternatively, reader  104  may include a finger-trigger mechanism, a keyboard, a graphical user interface (GUI), and/or a voice activated mechanism with which a user of reader  104  may interact to initiate an interrogation by reader  104 . 
         [0050]    In the example of  FIG. 2 , transceiver portion  220  includes a RF front-end  204 , a demodulator/decoder  206 , and a modulator/encoder  208 . These components of transceiver  220  may include software, hardware, and/or firmware, or any combination thereof, for performing their functions. Example description of these components is provided as follows. 
         [0051]    Modulator/encoder  208  receives interrogation request  210 , and is coupled to an input of RF front-end  204 . Modulator/encoder  208  encodes interrogation request  210  into a signal format, such as, for example, one of pulse-interval encoding (PIE), FM0, or Miller encoding formats, modulates the encoded signal, and outputs the modulated encoded interrogation signal to RF front-end  204 . 
         [0052]    RF front-end  204  may include one or more antenna matching elements, amplifiers, filters, an echo-cancellation unit, a down-converter, and/or an up-converter. RF front-end  204  receives a modulated encoded interrogation signal from modulator/encoder  208 , up-converts (if necessary) the interrogation signal, and transmits the interrogation signal to antenna  202  to be radiated. Furthermore, RF front-end  204  receives a tag response signal through antenna  202  and down-converts (if necessary) the response signal to one within a frequency range amenable to further signal processing. 
         [0053]    Demodulator/decoder  206  is coupled to an output of RF front-end  204 , receiving a modulated tag response signal from RF front-end  204 . In an EPC Gen 2 protocol environment, for example, the received modulated tag response signal may have been modulated according to amplitude shift keying (ASK) or phase shift keying (PSK) modulation techniques. Demodulator/decoder  206  demodulates the tag response signal. For example, the tag response signal may include backscattered data formatted according to FM0 or Miller encoding formats in an EPC Gen 2 embodiment. Demodulator/decoder  206  outputs decoded data signal  214 . 
         [0054]    The configuration of transceiver  220  shown in  FIG. 2  is provided for purposes of illustration, and is not intended to be limiting. Transceiver  220  may be configured in numerous ways to modulate, transmit, receive, and demodulate RFID communication signals, as would be known to persons skilled in the relevant art(s). 
         [0055]    The invention described herein is applicable to any type of RFID tag, with suitable additional features, as described in further detail below in conjunction with  FIG. 4  and beyond.  FIG. 3  is a schematic block diagram of an example radio frequency identification (RFID) tag  102  as already known to those practiced in the art. Tag  102  includes a substrate  302 , an antenna  304 , and an integrated circuit (IC)  306 . Antenna  304  is formed on a surface of substrate  302 . Antenna  304  may include any number of one, two, or more separate antennas of any suitable antenna type, including for example dipole, loop, slot, and patch. IC  306  includes one or more integrated circuit chips/dies, and can include other electronic circuitry. IC  306  is attached to substrate  302 , and is coupled to antenna  304 . IC  306  may be attached to substrate  302  in a recessed and/or non-recessed location. 
         [0056]    IC  306  controls operation of tag  102 , and transmits signals to, and receives signals from RFID readers using antenna  304 . In the example of  FIG. 3 , IC  306  includes a memory  308 , a control logic  310 , a charge pump  312 , a demodulator  314 , and a modulator  316 . Inputs of charge pump  312 , and demodulator  314 , and an output of modulator  316  are coupled to antenna  304  by antenna signal  328 . 
         [0057]    Demodulator  314  demodulates a radio frequency communication signal (e.g., interrogation signal  110 ) on antenna signal  328  received from a reader by antenna  304 . Control logic  310  receives demodulated data of the radio frequency communication signal from demodulator  314  on an input signal  322 . Control logic  310  controls the operation of RFID tag  102 , based on internal logic, the information received from demodulator  314 , and the contents of memory  308 . For example, control logic  310  accesses memory  308  via a bus  320  to determine whether tag  102  is to transmit a logical “1” or a logical “0” (of identification number  318 ) in response to a reader interrogation. Control logic  310  outputs data to be transmitted to a reader (e.g., response signal  112 ) onto an output signal  324 . Control logic  310  may include software, firmware, and/or hardware, or any combination thereof. For example, control logic  310  may include digital circuitry, such as logic gates, and may be configured as a state machine in an embodiment. 
         [0058]    Modulator  316  is coupled to antenna  304  by antenna signal  328 , and receives output signal  324  from control logic  310 . Modulator  316  modulates data of output signal  324  (e.g., one or more bits of identification number  318 ) onto a radio frequency signal (e.g., a carrier signal transmitted by reader  104 ) received via antenna  304 . The modulated radio frequency signal is response signal  112  (see  FIG. 1 ), which is received by reader  104 . In one example embodiment, modulator  316  includes a switch, such as a single pole, single throw (SPST) switch. The switch is configured in such a manner as to change the return loss of antenna  304 . The return loss may be changed in any of a variety of ways. For example, the RF voltage at antenna  304  when the switch is in an “on” state may be set lower than the RF voltage at antenna  304  when the switch is in an “off” state by a predetermined percentage (e.g., 30 percent). This may be accomplished by any of a variety of methods known to persons skilled in the relevant art(s). 
         [0059]    Charge pump  312  (or other type of power generation module) is coupled to antenna  304  by antenna signal  328 . Charge pump  312  receives a radio frequency communication signal (e.g., a carrier signal transmitted by reader  104 ) from antenna  304 , and generates a direct current (DC) voltage level that is output on tag power signal  326 . Tag power signal  326  powers circuits of IC die  306 , including control logic  320 . 
         [0060]    Charge pump  312  rectifies a portion of the power of the radio frequency communication signal of antenna signal  328  to create a voltage power. Charge pump  312  increases the voltage level of the rectified power to a level sufficient to power circuits of IC die  306 . Charge pump  312  may also include a regulator to stabilize the voltage of tag power signal  326 . Charge pump  312  may be configured in any suitable way known to persons skilled in the relevant art(s). For description of an example charge pump applicable to tag  102 , refer to U.S. Pat. No. 6,734,797, titled “Identification tag Utilizing Charge Pumps for Voltage Supply Generation and Data Recovery,” which is incorporated by reference herein in its entirety. Alternative circuits for generating power in a tag, as would be known to persons skilled in the relevant art(s), may be present. Further description of charge pump  312  is provided below. 
         [0061]    It will be recognized by persons skilled in the relevant art(s) that tag  102  may include any number of modulators, demodulators, charge pumps, and antennas. Tag  102  may additionally include further elements, including an impedance matching network and/or other circuitry. Furthermore, although tag  102  is shown in  FIG. 3  as a passive tag, tag  102  may alternatively be an active tag (e.g., powered by a battery, not shown). 
         [0062]    Memory  308  is typically a non-volatile memory, but can alternatively be a volatile memory, such as a DRAM. Memory  308  stores data, including an identification number  318 . In a Gen-2 tag, tag memory  308  may be logically separated into four memory banks. 
         [0063]    Typical Portal Configuration and Use 
         [0064]      FIG. 4A  is a schematic diagram of an RFID portal  400 . Typically, a portal has at least one RFID “reader/interrogator”, such as interrogator  426  and one or more antennas such as antenna  490  housed within a housing, such as housing  420 . A typical portal installation may include two housings (although many installations have only a single portal structure and some have more than two portal structures), such as housing  420  and housing  422 , positioned in a manner to mark the boundaries of a pathway through which items affixed with RFID tags travel. For example, a pallet  424  of RFID tagged items, carried by a fork lift  428 , may be transported through a portal in a warehouse so that an interrogator  426  associated with the portal can register that particular tags, such as “TAG 1” . . . “TAG N”, have come into “view” and thereby keep track of all tagged goods passing from one point in the warehouse to another. Portal  400  may be connected to infrastructure  430  via an Ethernet connection  432 . 
         [0065]    Enhanced Communication for Portal 
         [0066]    The portal shown in  FIG. 4B  is “enhanced” in that it has communication capabilities that can be utilized in various ways as will be further explained below. Infrastructure  430  may connect to the “outside world” through an 802.11 connection  434  or by, for example a direct connection  436  to the internet  486 . It may also be connected to a conventional telephone land line  438  or have a cellular interface  440 . Such connections to the outside world make possible various enhanced communication capabilities of portal  400 . Portal  400  has a processor  470 , operated by firmware  472  that is designed to in a manner to handle the communication of various data communicated between an enhanced portal and an RFID enhanced device. 
         [0067]    RFID Communication Enabled Device 
         [0068]      FIG. 5  is a schematic diagram explaining a basic concept of the invention. An enhanced portal  500  communicates with infrastructure  430  via an Ethernet connection  432 . Portal  400  has various peripheral devices attached to it with are operated by a processor (not shown) under the control of firmware (not shown). An interrogator  426  performs dual roles: 1) receiving RFID tag responses to interrogation signals, and 2) communicating with RFID enhanced devices  504 , via an RFID communication channel  506 . 
         [0069]    Enhanced portal  500  has various resources in the form of peripheral devices including a speaker transducer  508 , a Bluetooth communication device  510 , a keyboard  512 , a mass storage device  514  and a display  516 . As will be further described, enhanced device  504  can access and make use of the various resources of portal  500  including its peripheral devices and its various communication capabilities, all through communication channel  506 . Enhanced device  504  is created by fitting an ordinary device  520  with an RFID transponder  524  and an appropriate interface  522 . Device  520  can be any of a variety of devices that might benefit from communication with portal  500  or which might enhance portal  500  by making its own resources available to it. 
         [0070]    Interface  522  and RFID transponder  524  can be considered to be “add on” modules that can be fitted to ordinary devices  520  such as, for example, a PDA  530 , a keyboard  532  or a camera  534 . Ordinary device  520  can be other devices as well. A schematic diagram of interface  522  is shown in  FIG. 10 . A schematic diagram of RFID transponder  524  is shown in  FIG. 11 . 
         [0071]    Enhanced communication capabilities can be provided for an RFID tag in at least two ways. A first way to provide enhanced communication functions is to map existing tag memory space to new communication functions. Using this approach there is little software overhead associated with managing these communication functions. Existing protocols used for RFID tags can be extended, but few extension are necessary. A second way to provide enhanced communication functions is to implement a new protocol that is specifically designed for enhanced devices. Using this approach, tag memory is not critical to the implementation. 
         [0072]      FIG. 6  is a schematic diagram illustrating a general principle of the invention. An RFID enhanced device  504  includes an RFID transponder  524  that is able to communicate with any of a plurality of enhanced portals such as  602 ,  604 , and  606 . Such communication occurs over various RFID communication channels  608 ,  610  and  612 , respectively associated with portals  606 ,  604 , and  602 . 
         [0073]      FIG. 7  is a schematic diagram of an embodiment of the invention featuring an enhanced camera  534 , that has been fitted with an RFID transponder  524 . In the presence of an enhanced portal  400 , camera  534  is able to “dump” its images via a communication channel  702  to enhanced portal  400  utilizing the reader/interrogator  426  (not shown in  FIG. 7 ) incorporated into the enhanced portal. 
         [0074]      FIG. 8  is a schematic diagram of an embodiment of the invention featuring a portable keypad  802  as an enhance device. Keypad  802  has been fitted with an RFID transponder  524 . The portable keypad is then able to access enhanced portal  400  via an RFID communication channel  806  using portable keypad  802  in the presence of portal  400 , an operator can change programming of portal  400  and perform other tasks with respect to portal  400 , including manipulating data related to various tags such as tag 1 . . . N read by portal  400 . 
         [0075]      FIG. 9  is a schematic diagram of a system including an enhanced portal  400  and an enhanced storage device  902 . A conventional storage device  904 , such as a hard drive with associated driving circuitry is fitted with an RFID transponder  906 . Using a communication channel  910 , established between portal  400  and RFID transponder  906 , portal  400  is able to access data and write data to storage device  904  using communication channel  910 . 
         [0076]      FIG. 10  is a schematic diagram of an embodiment of the invention. It includes enhanced device  1002  which may include, but is not limited to an enhanced PDA  1004 , an enhanced keyboard  1006  and an enhanced camera  1008 . In general, the device that is enhanced is referred to by reference numeral  1010 . Device  1010  is associated with an interface  1012  and an RFID transponder  1014 . RFID transponder  1014  may communicate via an RFID communication channel  1020  to an RFID interrogator  1022 , having an antenna  1024 . RFID interrogator may be part of an enhanced portal such as portal  400  shown in  FIG. 9  and in other figures. RFID interrogator  1022  is associated with a further communication channel such as, for example, an 802.11 connection  1030 , symbolized by antenna  1032  and arrow  1034 . Using this scheme, any enhanced device, such as PDA  1004 , keyboard  1006  and camera  1008  can communicate to the internet via RFID communication channel  1020 , RFID interrogator  1022  and 802.11 connection  1034 . 
         [0077]    Thus, using the principles of the invention, it is possible for enhanced devices to communicate with an enhanced portal. It is also possible for devices to make use of peripheral devices attached to the enhanced portal and for the enhanced portal to make use of or access peripheral devices that are enhanced by the addition of an interface and RFID interrogator. 
         [0078]    RFID Transponder 
         [0079]      FIG. 11  is a schematic diagram of an RFID transponder  524 . Transponder  524  receives signals from and transmits signals to an interrogator (not shown) via an antenna  1102 . Some energy from received signals may be harvested by an optional charge pump  1104  which can provide power to the various circuits of transponder  524 . A transponder  524  may have an optional active power source  1106 . In some arrangements, a transponder  524  may have both a charge pump  1104  and an active power source  1106  such as a rechargeable battery. Information contained in signals received from the interrogator at antenna  1102  are demodulated by a demodulator  1108 . Information to be sent to the interrogator via a backscatter or other transmission is modulated onto the transmitted signal using a modulator  1110 . Control logic  1112 , which may reside in firmware, controls the functions of modulator  1110  and demodulator  1108 . 
         [0080]    Interface 
         [0081]      FIG. 12  is a schematic diagram of a transponder  524  including components of interface  522  suitable for adapting an ordinary device to communicate with the transponder. Components common to  FIGS. 11 and 12  will not be described. Control logic  1112 , in addition to controlling modulator  1110  and demodulator  1108 , also control indicators, displays, sounders, etc.  1202  and switches, sensors, microphones, etc.  1204  as needed to interact with a device  520  (see  FIG. 5 ) so that it can communicate via transponder  524  and be controlled as necessary by signals received via transponder  524 . For example, in the case of a camera  534 , as shown in  FIG. 5 ), control logic  1112  upon receipt of a “download” signal from demodulator  1108 , would communicate the appropriate command to camera  534  to read its electronic image files from its memory and send them via switches, sensors, microphones, etc.  1204  to control logic  1112  so that information corresponding to the image files can be modulated by modulator  1110  onto a backscatter signal responding to an interrogator. 
         [0082]    Enhanced Portal Software/Firmware 
         [0083]      FIG. 13  is a flow chart explaining the operation of an enhanced portal. The interrogator (such as interrogator  426  shown in  FIG. 4A ) includes a microprocessor and/or control logic that may be in the form of software or firmware for controlling the operations of an enhanced portal. At  1302  operations of the interrogator are initialized. Most of the time the interrogator will performing its normal functions, i.e. regularly sending interrogation signals and listening for responses from any RFID tags that may be nearby. A backscatter signal from a nearby RFID tag will typically including information identifying the particular tag responding by including the tag&#39;s unique identifying number coded into the backscatter transmission. Such normal interrogating operations are carried out at  1304 . Periodically, control passes to  1306  during which the interrogator tries to identify any enhanced communication devices within its range. When the interrogator identifies an enhanced device within its range at  1306 , control passes to  1308 . At  1308  communication is established according to predetermined protocols between the interrogator and the enhanced device. After communication has occurred between the enhanced device and the interrogator, control passes back to  1304  and the interrogator resumes its normal task of sending periodic interrogation signals to any RFID tags that may be within its range. Security support is provided to protect communication including voice and data via an interrogator associated with an access portal. Such support can be provided in the same manner as it is for other forms of communication, e.g. encrypting, rights management, etc. 
         [0084]    Conclusion 
         [0085]    The above examples of a system and method for customizable, mechanically programmable RFID tags are exemplary only. Persons skilled in the relevant arts will recognize that a variety of alternatives may exist in terms of materials, relations of structural and operational elements, and methods of employing or applying the same. Such variations fall within the scope and spirit of the invention which is not limited by the particular examples described above. 
         [0086]    While various embodiments of the invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.