Forums

Home Forums

    • Forum
    • Topics
    • Posts
    • Freshness
    • About GPS signals
      L5 frequency information Broadcast on the L5 frequency (1176.45 MHz, 10.23 MHz × 115), which is an aeronautical navigation band. The frequency was chosen so that the aviation community can manage interference to L5 more effectively than L2.
    • 0
    • 0
    • No Topics

    • About Rolling Codes and Encryption
      unlock-car-door-1-1Modern keyless entry system broadcast on a frequency between 300 and 400 MHz (megahertz). But if your keyfob sent out just a single signal, then every fob would open every car of that make and model. To ensure that no one can use his or her fob to open your car door, it's necessary produce a signal that is unique to every car. This is where rolling codes, also known as hopping codes, come in. Whenever you press the button to unlock your car, the exact frequency transmitted by the fob is changed, and the receiver inside the car only grabs onto that particular signal. In other words, the code "rolls" or "hops" each time you use it. A controller chip inside the car receives the signal and is responsible for changing the code each time the lock or unlock button is pushed. Before this rolling code system was developed, thieves were able to use electronic devices called "code grabbers" to lock onto your keyfob's unique signal. With rolling codes, the signal is unique every time, rendering a code grabber device useless. In addition, the code is stored inside the car, not within the keyfob. A thief would need to break into the car to access the code, which defeats the purpose of getting it in the first place. The numbers generated when the code hops is random. However, in theory, an astute hacker dead-set on stealing your car could find a way to anticipate the next code in the sequence. For this reason, the codes are encrypted as well, making each electronic keyfob have billions of possible codes. However, no security system is totally foolproof. In 2007, a group of researchers discovered vulnerability in the algorithm used by nearly every car manufacturer to encrypt their security codes. With this vulnerability, they found they were able to unlock any car made by that automaker with the keyfob from just one of them  
    • 1
    • 2
    • 1 year, 5 months ago

       Jeff-T

    • About UHF and VHF
      About UHF and VHF Understanding Wireless Technology Frequency Band Designations The following table lists various frequency bands and their common designation. Frequency Band Designation Frequency Range Min Max ELF - Extremely Low Frequency 30 Hz 300 Hz VF - Voice Frequencies 300 Hz 3000 Hz VLF – Very Low Frequency 3 KHz 30 KHz LF - Low Frequency 30 KHz 300 KHz MF – Medium Frequency 300 KHz 3000 KHz HF - High Frequency 3 MHz 30 MHz VHF - Very High Frequency 30 MHz 300 MHz UHF - Ultra High Frequency 300 MHz 3000 MHz SHF - Super High Frequency 3 GHz 30 GHz EHF – Extremely High Frequency 30 GHz 300 GHz
    • 7
    • 9
    • 2 years, 1 month ago

       Jeff-T

    • Robotics application
      Robotics is a multidisplinary field of technology that recently receives extensive attention from robotics community. The focus on the robotics industry has contributed positively in economic growth and the improvement of the strategic needs. Robotics application :Robots in Industry,Intelligent Systems,Robots in Medicine,Robots in Recreations and Sports,Robots in Space,Underwater Robots,Robots in Military and Security http://ctstechnologys.com/category/security-robot
    • 1
    • 1
    • 2 years, 4 months ago

       Jeff-T

    • UAV Jammer
      Definition of UAV [gallery columns="1" ids="2849"] An unmanned aerial vehicle (UAV), commonly known as a drone and also referred to as an unpiloted aerial vehicle and a remotely piloted aircraft (RPA) by the International Civil Aviation Organization (ICAO), is an aircraft without a human pilot aboard. ICAO classify unmanned aircraft into two types under Circular 328 AN/190.
    • 0
    • 0
    • No Topics