a42d8c4cea2976e4895c34db92b20aa8.ppt
- Количество слайдов: 8
Cellular, Bluetooth/Wi-Fi, RFID http: //www. mobile-review. com/phonemodels/sonyericsson/image/t 610 -1. jpg http: //www. macos. utah. edu/documentation/hardware/bluetooth/main. Column. Paragraphs/010/image/bluetooth_logitech_mx. png http: //img. alibaba. com/photo/11311936/A 6 sset_Tag. jpg http: //www. cnet. com. au/shared/images/products/wi-fi_200 x 150. jpg
Frequency Range u Cellular phone systems – 824 -894 MHz. (older system- no long in use) – 1850 -1990 MHz. (Most common –PCS band 0 u Bluetooth and Wi-Fi – 2400 -2497 MHz. Unlicensed Band - ULB) u RFID – 850 -980 MHz (Other frequencies also used)
Cellular Phone System u u u Cell phones operate in “cells” which is a small geographic area Calls are switched from cell to cell as needed. Each cell varies in size based on demand A cell can be looked at as a geographic coverage area with a base station (tower) which transmits signals to, and receive signals from, the mobile phones in its cell. Calls are routed to a central switching station and then forwarded to complete your call via other cell towers, land lines, microwave links, fiber optic lines, satellite links, etc.
Bluetooth u u u The name Bluetooth comes from a Danish king that united various kingdoms. Erickson initially used the term Bluetooth allows devices such as cellular phones, computer input and output devices, digital cameras, earpiece devices, and video game consoles to communicate with one another wirelessly. Bluetooth has a typical range of 1 -10 meters and operates at low power (1 -10 milliwatts) http: //kuwin. ku. ac. th/images/bluetooth-picture. jpg
Wi-Fi u u u Wireless-Fidelity or Wi-Fi ranges to about 100 meters. Wi-Fi can operate at 2. 4 GHz and 5. 0 GHZ – The most common is a 2. 4 GHz u u u Wi-Fi specifications are set by the IEEE Wi-Fi is primarily used to provide internet access from your computer without a hard wire connection. “Hotspots” refer to an area with Wi-Fi access – Hotels, airport lobbies, restaurants, coffee shops are common places to find W-Fi available u Wi-Fi can reach data transferable rates of – 54 Mbps (802. 11 a and 802. 11 g) – 11 Mbps (802. 11 b) u Wi. MAX (new) range to 2 miles – cover a city with internet access
RFID u u u Radio-frequency identification (RFID) automatically identifies Relies on storing and retrieving data using devices called transponders. Radio-frequency identification is passive, active, or semi-passive. Passive RFID tags use the incoming signal for power to respond An RFID system consists of antenna, a transceiver, and a transponder. http: //www. racoindustries. com/images/socket-rfid-6 e-device 3. jpg http: //www. rexam. com/files/reports/2005 cpr/images/pictures/pho_media_rfidchip 2_lg. jpg
http: //upload. wikimedia. org/wikipedia/commons/9/99/RFID_hand_1. jpg RFID tag before http: //upload. wikimedia. org/wikipedia/commons/c/c 5/RFID_hand_2. jpg RFID tag after An RFID tag implanted under the skin
a42d8c4cea2976e4895c34db92b20aa8.ppt