Thursday, May 22, 2014


This posting is to bring more information and to speak against active RFID's (Radio Frequency Identification) within school systems. It's inspiration comes from the plans of my old school district to implement a RFID system.

Types of RFID
    RFID's operate in one of two ways,  passive and active. Passive tags don't do anything for the most part, and are considered mostly inert. However when they receive power from a reader, they reply by emitting a burst of the data in radio waves. This is the method used for tagging pets and is used in credit cards. The reader is moved into vicinity of the tag, and the tag responds with the power generated.  Passives can also have a small battery attached, but still require a reader nearby before they transmit. When current is created by the reader, the tag "wakes up" and uses battery power to transmit the data. 
     The range of all RFID's depend on the size of the tag (that defines how big the antenna can be), how much power is sent into the antenna, what the tag is surrounded or attached to, and the frequency the tag uses. Usually passives have a range of a couple meters, at the time I'm writing this, some are being produced capable of a 15 meter read range. Using a battery with a passive tag increases it's range.

    Active tags have to have a battery. Usually they pulse their data at a given interval. Example, every 45 seconds the tag sends out a signal identifying itself by it's unique number. Active means just that, it is always active and transmitting when it has current, basically as long as the battery/ies have a charge. These also have a much more powerful transmission, and can work up to 500 meters away (over a quarter mile). Transmission range on these can be adjusted by making the tag with a smaller antenna, or by changing the current to the antenna, less power less range. Both of these are considerations made when the tag is produced as physically changing theme after production is more trouble than it's worth. These still require a reader to interpret them, but the signal is constant or pulsed, depending on design. 

Benefits of RFID's in Schools
    In a properly set up system, these can be used to identify a person's location to within a certain area. Obviously, this makes finding people much easier, instead of searching a whole complex you only have an area within the complex to search. It also lets you know who is still in the complex. During a fire or other emergency this can be very useful. A school district that implemented this for a trial basis, used it to determine which camera recordings to view when a special education student didn't arrive at home after school. The only other two instances the district mentions were locating a student for parents to pick up when the child was sick, and locating students in the building after the school had been evacuated for a gas leak. However the students had left their badges behind during the evacuation. 
    Other benefits are more for the school. Assisting in attendance records, which contributes to how much funding the school gets. Of course locating a student for whatever reason is the primary advantage, and the school is responsible for them while at school.

Cons of RFID's in Schools
    They can be used to identify a person's location. Specifics mentioned are from a districts one year trial run which used active RFID's. These ID's pinged data every 45 seconds, operated at 433 MHz, and I could find no specification for the range disclosed by the district.
    In that one year, the pilot school reported 3 cases where this was a benefit. THREE. With a student population of about 3000, 8 students (6 badges were involved in the gas leak) received a claimed benefit. 0.27% of the student body received a potential benefit from the RFID's, according to the school's publicly released information. As only two of these had an actual benefit, that percentage is actually 0.07%. To the students and the parents benefiting, these situations may have been invaluable, especially in the case of the student not arriving at home on the bus, but let's look at the situations without the RFID's. 
    The ill student, was located in the band hall. If the ailment had been something serious, the student would have been in the nurse's office when the parent's arrived. The nurse's office located the student for them. A copy of the student's schedule would have given the same result. In the case of the special education student, it sounds like the school dropped the ball. Students are only allowed to be picked up by authorized persons, and the only benefit the RFID presented was to reduce the cameras recordings that had to be checked. The cameras provided the vital information, not the ID. The ID only limited the search criteria. In the gas leak evacuation, post evacuation roll call would have shown the students as unaccounted for had they remained in the school. However this case shows how, in a school wide emergency the RFID's do have some footing.

    Cost is the next consideration. Software to handle the network side, 70 readers installed (in this school), networking the readers on their own network (CAT6 cabling was used in this case), each RFID, building a student database to match the ID's to particular students. "Approximately $261,000" is reported as the cost for setting up this system in 2 schools. This district boasts over 100 schools, full implementation would cost around 26 million dollars. 
   Literally this system creates an environment where less attention is paid to the overall population. There's a word for this, lazy. The district reports that the system helped in attendance by showing students who were on campus, but not accounted for in manual attendance. This sounds like there are issues that need to be addressed with staff and policy, before implementing a project of this scale. 
    Privacy is a large concern, and it seems the greatest question asked was if these could be used to tell how long a student was in the bathroom. The district emphatically declared "NO!" This may be true for their system, but RFID's themselves could be used to determine a more precise location. If readers are installed so that the ID pings hit enough readers, you can actually triangulate the readers position more precisely. All that takes is math, and a computer is tracking everything. Math is easy for a computer. Triangulation is how your GPS system works, and how earthquake epicenters are determined. All it would take is an upgrade at a later date, and the system was already approved.

Readers in the Wrong Hands
     I admit, this section does contain some fear mongering, but this is reality and has to be considered. Once things become wireless, it becomes much easier to discover things with a little ingenuity. 
    The district repeatedly said the system could not be used outside of school, for this to be true a passive system would have to be employed. The only information I found about this said the battery life of the readers is 2 years, with a ping every 45 seconds. Never was it stated that the RFID's were passive with a battery system, and never was it said they were inoperable outside of school. This causes a real problem. Each device is ALWAYS active. 
    The fear mongering commences. Shooter in the school with a reader. Students hiding in the cabinets, closets, utility room, anywhere not immediately visible? Found ya. Granted a single reader wouldn't be able to give an exact location, but a reader capable of displaying the signal strength of the received signals would allow someone to play a hot and cold game to get closer to someone they may have overlooked. However, I have always and continue to maintain that if a shooter gets into a school, the system has already failed. 

    For the stalker, always active RFID's are a godsend. 433 MHz gives possibility of the largest range, the quarter mile I quoted earlier. Physical barriers can reduce this range, even if the device is designed to transmit that far. Usually stalking requires visual confirmation, and that gives an edge to the person being stalked if they pay attention to their surroundings. With a reader, visual confirmation isn't necessary, and process of elimination can single out a particular student. I'm not saying it is extremely easy, but a serious stalker would put forth the effort to do this. 
    The ID's do transmit some identifying information about the system it is used on, manufacturer, and a unique code for each student that matches no other records. So if a student is in public with the RFID, a stalker who has done their research now has limiting factors to help them hone in on their target. Plus once this person has been associated with this ID, no matter that the ID tells the stalker nothing of value, it's a tracking device. Once the stalker knows the ID#, regardless of if they know the student personally or not, it's just time and a game of  hot and cold to determine the student's routes, hangouts, and even home.

Practical RFID Usage
    RFID's can provide the school with the benefits it seeks without running these insane risks. Passive ID's would accomplish this. Just like the ones in credit cards, some have a very short transmission range. The catch is anything a short range RFID can do for keeping track of students can be done with a bar code or magnetic stripe ID system. The benefit of RF is not requiring a swipe, which can slow movement and create a larger hassle than it solves. This was probably rejected in the mentioned pilot because more readers would be required. One in each doorway, which would probably increase implementation costs. However, passive ID's cost less than active ones, so the cost of the most replaced unit is reduced
    Placing a reader with a 1-2 meter range next to a classroom doorway would track that a student enters or exits class. Readers on all exterior exits would show when a student enters and exits campus. Tracking would be limited to checkpoints which are logged, instead of a real time tracking which the discussed system was built on. In conjunction with cameras this system would be more than adequate. Even if this system does not work seamlessly at that range, students would just have to pass their ID over the reader by hand.
    Making the ID's of the system passive, increases the safety of the users. Stalkers would have to get very close to the ID to track the student, so methods of tracking due to the ID outside of the school would be nearly eliminated. They definitely couldn't tell which house a student lives in without going into the house, or using methods that RFID would in no way affect, such as visual. 
    In all the instances the school cited as benefits of RFID's, a passive system would have done exactly the same. The ill student last passed the reader at the band hall door, the missing student exited this door, the 6 badges that didn't evacuate were last in this classroom. 

    Technology is a wonderful thing, and it makes many more things possible and easier. However, implementing systems without knowledge of the technology or consideration of all possible implications is never responsible behavior.

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