Bluetooth - CompTIA A+ 220-1101 – 4.21

Video Description

Let’s have a look at Bluetooth. Download PowerPoint: https://itfreetraining.com/handouts/ap11/4d30.pptx Bluetooth The name Bluetooth was originally intended as a temporary placeholder until a better name could be devised by the marketing department. It was derived from the Danish king Harald Bluetooth, who united Denmark and Norway during the 10th century. Harald Bluetooth had a blueish, blackish tooth and this is where he got the name from. They tried to find another name, but other names proved to be unusable for various different reasons. The Bluetooth name started getting used, so they gave up trying to find a new name. They say Harald Bluetooth united Denmark and Norway, but who would have thought his legacy would be uniting smartphones and headphones centuries later! Personal Area Networks (PAN) Bluetooth is considered a Personal Area Network or PAN. These are small wireless networks with a limited range. They are essentially devices that are worn by a person or are in close proximity. PAN networks are designed to have low power consumption. Bluetooth devices are designed to run for a long time. To do this, they use a few tricks to reduce power usage when transmitting and receiving data. They are designed to be secure, thereby preventing eavesdropping and your devices being hijacked. In the case of Bluetooth, it is designed to be resilient. This means it is resistant to interference and congestion on the network. Lastly, they are designed to be mobile. If you are running, traveling in a car or on a plane, the device should remain connected. How Bluetooth Works Bluetooth uses a master slave communication system. Master slave terminology was often used in the old days to describe the relationship between devices. It is when one device controls the other just like a conductor would control an orchestra. The terminology does not get used that much nowadays as other terminology is now more commonly used. Bluetooth was initially created in 1998 when this terminology was commonly used, but nowadays there is a shift toward a different terminology. In the case of Bluetooth, it could also be described as controller and device. So, for this video I will use these terms. When looking at technical documentation, keep in mind the terminology used will most likely be master and slave. In order to use Bluetooth and keep it secure, a pairing system is used, where the device pairs itself with the controller. This pairing establishes a secure connection which allows the device to communicate but also prevents eavesdropping on the communication. Bluetooth was also designed to operate in secure environments with a lot of other devices. Let’s have a look at how it achieves this. Frequency Hopping Bluetooth uses frequency hopping to increase security and reduce interference in crowded environments. It is very unlikely you will get a question on this in the exam, but it will help you understand why we get the results we do when using Bluetooth. Let’s consider that we have three different Bluetooth devices. The keyboard and earplugs are paired to a laptop and phone respectively. The speaker is connected to a different device which is not displayed in this scenario. The Bluetooth signal traveling between the two devices will change frequency. This is what you call frequency hopping. Frequency hopping reduces interference by rapidly switching the communication signal among many frequency channels, minimizing the chance of long-term interference with other signals. It also enhances security by making it difficult for unauthorized entities to intercept or disrupt the signal, as they cannot predict the changing frequencies. The controlling device decides the frequency and timing for communication with the paired device. Essentially, it instructs the paired device when to transmit by specifying that it will be listening at this time, and you should also be listening during these times as I may send you data. This allows the paired device to work better in environments with a lot of interference as the controlling device can select channels with less interference and can dynamically change channels if needed. Description too long for YouTube. Please see the following link for the rest of the description. https://itfreetraining.com/ap11/4d30 References “The Official CompTIA A+ Core Study Guide (Exam 220-1101)” page 154 “Mike Myers All in One A+ Certification Exam Guide 220-1101 & 220-1102” pages 846 to 847 “Picture: Bluetooth logo” https://simple.wikipedia.org/wiki/Bluetooth#/media/File:Bluetooth-Logo.svg Credits Trainer: Austin Mason http://ITFreeTraining.com Voice Talent: HP Lewis http://hplewis.com Quality Assurance: Brett Batson http://www.pbb-proofreading.uk