Abstract:
The present disclosure relates to an asset tracking system for tracking assets configured to be rack mounted in at least one of a plurality of shelf (“U”) locations of an equipment rack. The system may have a plurality of radio frequency identification (RFID) tags each secured to a separate asset and encoded with information concerning the asset to which it is secured. A plurality of antennas may each be secured adjacent to specific shelf locations. This uniquely associates each antenna with at least one specific shelf location. A subsystem selectively obtains information from the antennas, one by one, to determine when assets are positioned in specific ones of the shelf locations. The RFID tags may also supply information on an identity of each asset present in each shelf location.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority from U.S. Provisional Application Ser. No. 61/677,122 filed on Jul. 30, 2012. The entire disclosure of the above-referenced application is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to asset tracking systems and methods, and more particularly to an asset tracking system and method for use with equipment racks which incorporates a switchable antenna that can be selectively activated to sense an RF sensing device, carried on an asset, which has been moved into a shelf position of the rack in close proximity to the antenna. 
       BACKGROUND 
       [0003]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0004]    Many attempts have been made at developing asset tracking systems to help data center personnel track and monitor the locations of various computer and network related components in a data center. Asset tracking has become extremely important as the size and complexity of modern day data centers has increased. Present day data centers may often include hundreds or even thousands of data center components including servers, network switches, integrated keyboard/display systems, etc. 
         [0005]    Many of these modern day data center components are designed to fit in industry standard equipment racks. In large data centers there may be hundreds or even thousands of such racks within one or more distinct rooms that make up the data center. Keeping an inventory of assets in the data center can thus become quite challenging. If manual records are kept, then the burden is on data center personnel to manually note in which specific rack specific equipment rack items are installed. When equipment is moved from one rack to a different rack, the data center worker must manually note this change. Obviously, this method presents significant opportunity for error in recording the locations of data center devices and maintaining up to date equipment location records. 
         [0006]    Various automated systems have also been developed which make use of RFID (Radio Frequency Identification) tags that are placed on assets (i.e., components) before the assets are placed in a rack. These systems have met with varying degrees of success. Some have required an RFID at each “U” location (i.e., each equipment slot) of a rack as well as a separate RFID tag on each piece of equipment. The RFID tag on the equipment covers up the RFID tag at a given U location when a piece of equipment is inserted into that specific U location. An antenna determines when the signal being sensed changes. As can be appreciated, this type of system thus requires the use of two RFID tags for each U location where a piece of equipment is installed. In a data center employing hundreds or thousands of rack mounted equipment items, with possibly hundreds or even thousands of racks, this type of sensing system can be prohibitively costly. 
       SUMMARY 
       [0007]    In one aspect the present disclosure relates to an asset tracking system for tracking assets configured to be rack mounted in at least one of a plurality of shelf (“U”) locations of an equipment rack. The system may comprise a plurality of radio frequency identification (RFID) tags. Each RFID tag may be secured to a separate rack mountable asset and may be encoded with identification information concerning the rack mountable asset to which it is secured. The information may uniquely associate each rack mountable asset with its associated RFID tag. A plurality of antennas may each be secured to the equipment rack adjacent a specific shelf location of the equipment rack. In this manner each antenna is uniquely associated with at least one specific shelf location of the equipment rack. A subsystem may be configured to selectively read information from the antennas, one by one, to determine when rack mountable assets are positioned in specific ones of the shelf locations of the equipment rack. The RFID tags may also supply information on an identity of each rack mountable asset present in each shelf location. 
         [0008]    In another aspect the present disclosure relates to an asset tracking system for tracking assets configured to be rack mounted in at least one of a plurality of shelf (“U”) locations of an equipment rack. The system may comprise a plurality of radio frequency identification (RFID) tags. Each one of the RFID tags may be secured to a separate rack mountable component and may be encoded with identification information concerning the rack mountable asset to which it is secured. The information uniquely associates each rack mountable asset with its RFID tag. A plurality of antennas may be secured to the equipment rack adjacent a specific shelf location of the equipment rack. In this manner each antenna is uniquely associated with at least one specific shelf location of the equipment rack. A plurality of switches may each be uniquely associated with one of the antennas. A radio frequency identification (RFID) tag reader may be included for reading information obtained from the RFID tags via the antennas. A processing system may be used for controlling operation of the switches and using information obtained from the RFID tag reader to determine which shelf locations of the equipment rack have assets installed therein, as well as an identity of each asset installed in each shelf location of the equipment rack. 
         [0009]    In yet another aspect the present disclosure relates to a method for tracking rack mountable assets configured to be mounted in an equipment rack, and where the equipment rack has a plurality of shelf locations for receiving the rack mountable assets. The method may comprise securing radio frequency identification (RFID) tags to separate rack mountable assets. The method may also involve encoding the RFID tags with identification information concerning the rack mountable asset to which it is secured. This serves to uniquely associate each rack mountable asset with its RFID tag. The method may further involve securing a plurality of antennas adjacent specific shelf locations of the equipment rack such that each antenna is uniquely associated with at least one specific shelf location of the equipment rack. The antennas may be used, one by one, to obtain information from the RFID tags, one by one, to determine when rack mountable assets are positioned in specific ones of the shelf locations of the equipment rack. Information may also be obtained on an identity of each rack mountable asset present in each shelf location of the equipment rack. 
     
    
     
       DRAWINGS 
         [0010]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0011]      FIG. 1  is a high level block diagram of one embodiment of a system in accordance with the present disclosure in which a switchable antenna system is used to sense the presence of an RFID tag at each U location of an equipment rack; and 
           [0012]      FIG. 2  is a flowchart illustrating various operations that may be performed by the system shown in  FIG. 1 . 
       
    
    
       [0013]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0014]    Example embodiments will now be described more fully with reference to the accompanying drawings. 
         [0015]    Referring to  FIG. 1  there is shown a system  10  in accordance with one embodiment of the present disclosure. The system is well suited to sensing the presence and/or absence of equipment at each U location within an equipment rack  12 . In this example the equipment rack has eight U locations labeled U 0 -U 7 . Locations U 0 , U 2 , U 3  and U 5  have assets positioned therein. The assets may be servers, network switches, an integrated keyboard/display system, etc. It is also possible that one asset may take up two or more U locations in the rack  12 , although for this example the assets are all shown as each taking up a single U location. 
         [0016]    Each asset further includes an RFID tag  14  positioned thereon. The RFID tags are each positioned on a common side of the asset, in this example along the left side of each asset and preferably near either a forward edge of the asset or a rear edge of the asset. Preferably, the RFID tags  14  are generally vertically aligned with one another when the assets are fully inserted into the U locations of the rack  12 . Each RFID tag  14  may be programmed in advance with various information about the asset to which it will be attached. Various information such as make, model number, type of device, serial number, power requirements, warranty information, etc., may be encoded onto each RFID tag  14 . 
         [0017]    The system  10  further makes use of a plurality of switchable antenna systems  16   0 - 16   7 , which are positioned on the rack  12  to correspond to U locations  0 - 7 . By that it is meant that they are aligned with their respective U location such that when, for example, an asset is inserted into the U 0  location, the switchable antenna system  16   0  will be in close proximity to the RFID tag on the asset and will be able to wirelessly sense or “read” the data encoded onto the RFID tag  14 . It will be appreciated that wherever the RFID tags  14  are located on their respective assets, the wireless reception range will be quite limited, preferably on the order of about one meter, and more preferably less than one meter. More preferably still, the RFID tags will be selected and/or configured such that a transmission range of each is on the order of only an inch or two, which eliminates the possibility of one antenna picking up wireless signals from two different RFID tags. It will also be appreciated that, preferably, there will be one antenna system for each U location of a rack. Thus, if a rack with 10 U locations is being used, then there would be ten antenna systems  16  employed. It is possible, however, that if one knows in advance that a rack will be using one or more components that each take up 2 U locations in the rack  12 , that a correspondingly lesser number of antenna systems could be employed. But a separate antenna system  16  should be used for each component that will be placed in the rack  12 . 
         [0018]    Each of the switchable antenna systems  16   0 - 16   7  may incorporate an antenna element  16   a  and a switch  16   b.  The antenna element  16   a  may take any variety of forms, for example a trace antenna on a printed circuit board (PCB). The switch  16   b  may also take a variety of forms but in one preferred form may be an RF FET switch. When the switch  16   b  is open, the antenna element  16   a  is disabled, meaning it is not able to pass any sensed data from an adjacent RFID tag  14  on to an RFID reader subsystem  18  of the system  10 . When the switch  16   b  is closed, then the antenna element  16   a  is active and will be providing any wirelessly sensed information from an adjacent RFID tag to other components of the system  10 . An RFID reader subsystem  18  is able to decode the signals received from each of the antenna systems  16  and to pass the decoded signals on to a processing system  20 . Together the RFID reader subsystem  18  and the processing system  20  form a subsystem for obtaining and using the information collected via the antenna systems  16  from the RFID tags  14 . 
         [0019]    Referring further to  FIG. 1 , the system  10  may include a controller  22  responsive to the processing system  20 , or as part of the processing system  20 , for controlling activation of each of the antenna systems  16   0 - 16   7  via an associated control line  21 . More specifically, the controller  22  may be a microcontroller that selectively opens or closes the switches  16   b  of each antenna system  16   0 - 16   7  via its associated control line  21 , one at a time, so each antenna system  16   0 - 16   7  may wirelessly sense and obtain any information from an adjacently positioned RFID tag  14  on an asset. The controller  22  may turn on the antenna systems  16   0 - 16   7  sequentially while incorporating a suitable delay between the turn on of adjacent antenna systems, or the antenna systems may be activated in any desired order. It is not imperative that the sensing of each U location be accomplished at very short time intervals. Since the system  10  is using newly obtained information and comparing it to previously obtained information for a given U (i.e., shelf location) to detect whether a change in equipment configuration has occurred in the rack  12  (i.e., either the insertion of a new component into a U location or the removal of a component at a given U location), and since these actions will not be happening several times per second, it would be sufficient if each antenna system  16   0 - 16   7  is turned on possibly only 1 or more times per hour throughout the day. However, virtually any desired frequency of checking the U locations could be employed. 
         [0020]    Optionally, a display  24  may also be used by which the processing system  20  can use a suitable software program to display information on the assets present in each and every equipment rack in the data center. The information could be displayed in a list format, or possibly in a graphical format, or even a combination of the two. 
         [0021]    Turning now to  FIG. 2 , a flowchart  100  illustrating one example of a sequence of operation will be described for the system  10  shown in  FIG. 1 . Initially at operation  102  the controller  22  is used to initiate a polling cycle by turning on the antenna system  16   0  at rack location U 0 . At operation  104  the RFID reader  18  is then used to read the information obtained by the antenna element  16   a.  At operation  106  a check is then made to see if all the U locations of the rack  12  have been checked during the current polling cycle. If the answer to this check is no, then the U location is incremented by 1, as indicated at operation  108 , and operations  104  and  106  are repeated. 
         [0022]    If the check at operation  106  indicates that all the U locations of the rack  12  have been checked during a single polling cycle, then a check is made at operation  110  to determine if there are more racks  12  to check. If the answer at operation  110  is “no”, then the routine may end, or may be altered to immediately start over checking the first numbered rack. If the check at operation  110  indicates that there are additional racks to check, then at operation  112  the rack number of the next rack to check is incremented by 1, and then operations  102 - 108  are repeated. It will be appreciated that a suitable software system may be running on the processing system  20  which has information coded into it that indicates the total number of racks in the data center that need to be checked. 
         [0023]    The methodology shown in  FIG. 2  could also allow the system  10  to go to any specific rack in the data center and make a check of the components within every U location of the chosen rack. Still another feature that could be easily implemented would be a component lookup feature where the user types in a component identifier (serial number, model number, etc.), and the system  10  indicates (either graphically or via a list) the location (or locations) of any and all such components present in the data center. Those skilled in the art will appreciate that various other enhancements could be made to accommodate specific data center needs. 
         [0024]    A significant advantage of the system  10  is that only a single RFID tag needs to be used for the U location sensing to be accomplished. This may result in a significant cost savings over asset identification/tracking systems that require the use of two RFID tags for each U location of a rack. Also, no manual action is required by a data center person to collect or track asset information. The system  10  will automatically sense when a component is inserted into a rack, as well as when a component is removed from a rack, and will record this information for data center personnel to use. By “automatically sense” it is meant that the insertion of an asset in the rack or removal of an asset from the rack will be detected by the system  10  during its polling of the antenna elements  16  and its comparisons of newly obtained information with previously obtained information for each U location of the equipment rack. 
         [0025]    The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.