6.9.4 Practice Questions Infrared, Bluetooth, And NFC

Move the printer closer to the computer. Block any direct and reflected sunlight from the pathway between the PC and the printer. Explanation Infrared light is light that is near visible in the electromagnetic spectrum. Therefore very bright lights and in particular sunlight may cause interference with infrared interfaces. The best way to manage this interference is to minimize the distance between the connected devices and minimize interfering sunlight.

Bluetooth Explanation Bluetooth would be the best choice because it has a high transfer rate and because it automatically detects other Bluetooth devices in the area and creates an encrypted PAN between them. 802.11g is a wireless networking standard for communicating between computers, not for connecting wireless devices to a computer. PS/2, IEEE 1394 (FireWire), and USB are all wired connections standards.

100 M Explanation Bluetooth version 2.0 class 1 devices have a maximum range of about 100 meters. Earlier versions had a maximum range of only about 10 meters.

2.4 GHz radio wireless. Ad hoc connecitons. Explanation Bluetooth is a wireless networking standard that uses 2.4 GHz radio waves. These are the same type of radio waves used with 802.11 wireless networking, so radio transmission can go through walls (not limited to line-of-sight connections). Bluetooth uses ad hoc connections between devices. Infrared uses red spectrum light waves and is limited to line-of-sight transmissions.

24 Mbps Explanation Bluetooth v3 and v4 devices have a maximum transmission speed of up to 24 Mbps. Bluetooth v1.2 devices have a maximum transmission speed of up to 1 Mbps. Bluetooth v2 devices have a maximum transmission speed of up to 3 Mbps. The wireless standard 802.11b transmits data at a rate of up to 11 Mbps.

Bluetooth Explanation A Bluetooth connection would be the best choice because it automatically detects Bluetooth-enabled devices and creates a wireless PAN between them. It can be used for both voice and data signals, and it also provides 128-bit encryption to protect sensitive information in transit. Infrared is a line-of-sight medium so it may be difficult to maintain connectivity, it also doesn't provide encryption. Cellular WAN provides very little security for information in transit and requires a cellular connection for each device. Wireless Ethernet is used for transferring data, not connecting devices.

Wireless Ethernet Explanation You could use an 801.11 wireless Ethernet connection for the printer. 802.11 wireless Ethernet has a greater range than infrared, and will go through walls. The other interfaces are wired interfaces. IEEE 1394 is Firewire. IEEE 1284 is parallel.

NFC Explanation Near Field Communication, or NFC, uses the 13.56 MHz frequency and has a very short range- in order for devices to communicate, they have to be within two inches of each other. NFC chips are being used for such applications as passports and credit cards to contain all the information about the passport holder or the credit card account. NFC chips use encryption algorithms to secure the connection but are constantly emitting a signal and use a much slower transmission speed than other wireless technologies.

Bluetooth

Infrared

Bluetooth

Radio frequency wireless transmissions can reach up to 356 meters, depending upon the 802.11 standard used and interference present in the environment. Infrared wireless transmission work best for devices within 1 meter, but can operate up to 30 meters in areas without ambient light interference. The maximum Bluetooth transmission distance depends on the device class: - Class 3 devices transmit up to 1 meter. - Class 2 devices transmit up to 10 meters. - Class 1 devices transmit up to 100 meters.