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To untangle Karen from her mess of wires the team discusses everything related to wireless communication! Learn the difference between ELF, SLF, ULF, VLF, LF, MF, HF UHF, and THF frequency bands and different technologies for electronics communication such as WIFI, xBee, Bluetooth, RFID, NFC, and mobile networks.
Ben goes over commonly used radio frequency bands. ELF, extremely low frequency (3-30Hz range), is generally used for long range communication like submarine use and maritime use. SLF, super low frequency (30-300Hz range), is still mostly maritime use. VLF, Very Low Frequency (3kHz-30kHz range), is still used for mostly radio navigation and maritime military use. LF, Low Frequency (30kHz-300kHz range), is still used for a lot of radio navigation but it’s also used for amateur radio and universal clock signals. MF, Medium Frequency (300kHz-3MHz range), is used for AM radio. HF, High Frequency (3MHz-30MHz range), is used for short wave radio, CB radio, RFID radar, and more amateur radio. VHF, Very High Frequency (30MHz -300MHz range), is used for FM broadcasts and TV broadcasts. UHF, 300MHz-3000 MHz, is used for TV, cell phones, and other consumer devices. SHF, Super High Frequency (3GHz-30GHz range), is used for WIFI and cellular technology as well as microwave transmitters. EHF, Extremely High Frequency (30GHz-300GHz range) is used for radio astronomy and the millimeter wave scanner used for airport security. THF, Tremendously High Frequency (300GHz-3000GHz range), is used for crazy experimental stuff like particle physics, medical imaging, atomic blasters, and things of that elk.
The 2.4 GHz /5 GHz wireless range is usually expressed when referring to the 802.11 (a, b, g, and n) wireless standards. 2.4 GHz is a popular range for products with their own proprietary protocols.
2.4 GHz is the most common protocol with the XBee signal. XBee signals are a little slower than Bluetooth but they have a longer range. XBee signals are a good choice if you have to do point to point data transfers.
Bluetooth runs in the 2.4 GHz range as well. The difference between Bluetooth and Wifi is the range is shorter and the bandwidth is much less. Bluetooth is best for connecting peripherals to a nearby host device. Bluetooth allows you to pair enabled devices to multiple systems where as WiFi is more of an ad hoc network. Ben and Felix examine various Bluetooth enabled devices. The advantage of Bluetooth is that it is a ubiquitous standard and has low power consumption. However, it has a shorter range of transfer and lacks support for large data transfers making it ideal for audio but not video.
RFID, radio frequency identification, technology uses two parts, a tag and a reader. The tag has a number and the reader interprets that. There are two different types of tags, Active Tags and Passive Tags. An Active Tag has a power source in it so it can emit the signal and a passive tag takes the signal, use the wireless transmitted from the reader to power itself to spit back the signal. Some have a small amount of RAM so they can send back more than just a number or a larger number. RFID technology allows an administrator to grant or restrict access remotely. Unlike using physical keys, you can restrict access to a facility without having to change the locks on the building.
NFC, Near-Field Communication, is like RFID, but smaller distances and actively controlled by a phone instead of just a static tag. Apple Pay is an example of this. The shorter range makes it more secure because people cannot intercept the signals. RFID uses a passive tag with a number on it that can be read whereas NFC can be two way communication and the tags are active so it can change the information and number its sending. An NFC cell phone can work as the reader or the tag and go both ways.
Finally, they discuss cellular protocols. 1G, 2G or Edge Network, 3G, and 4G LTE are discussed. Multi-band GSM phones can work anywhere, including other countries. Multiple bands increase the chance a carrier is compatible.