Airlogic ABM-400 Bedienungsanleitung PDF herunterladen (Seite 37)

- 37 -

ZigBee

2.4 GHz

915 MHz

868 MHz

~ 50 m

~250 kbps @

2.4 GHz

~40kbps @

915 MHz

~20kbps @

868 MHz

- Extremely low power consumption for

life

- Low cost (device, installation,

maintenance)

- High density of nodes per network

- Interfaces with RFID devices

RFID

UHF: 859-

960 MHz

HF: 13.56

MHz

Also: 125

KHz, 430

MHz, and

2.45 GHz

HF (~3 m)

UHF

(~20m)

~ 100 kbps

- RFID chips are extremely difficult to

counterfeit

- Different levels of security can be

applied to data on the tag

- Direct line of sight is not required

between tag and reader.

- Tag reading occurs automatically.

- RFID technology can be used in

conjunction with bar-code systems and

WiFi networks.

Wi-Fi Wireless Technology

Wi-Fi uses both single carrier direct-sequence spread spectrum radio technology (part of the

larger family of spread spectrum systems) and multi-carrier OFDM (Orthogonal Frequency

Division Multiplexing) radio technology. Unlicensed spread spectrum was first authorized by the

Federal Communications Commission in 1985 and these FCC regulations were later copied with

some changes in many other countries enabling use of this technology in all major countries.

These regulations then enabled the development of Wi-Fi, its onetime competitor HomeRF, and

Bluetooth.

The precursor to Wi-Fi was invented in 1991 by NCR Corporation/AT&T (later Lucent & Agere

Systems) in Nieuwegein, the Netherlands. It was initially intended for cashier systems; the first

wireless products were brought on the market under the name WaveLAN with speeds of 1 Mbit/s

to 2 Mbit/s. Vic Hayes, who was the primary inventor of Wi-Fi and has been named the 'father of

Wi-Fi,' was involved in designing standards such as IEEE 802.11b, 802.11a and 802.11g.

1 2 ... 32 33 34 35 36 37 38 39 40 41 42 ... 147 148

Kommentare zu diesen Handbüchern

Keine Kommentare

Airlogic ABM-400 Bedienungsanleitung Seite 37

Kommentare zu diesen Handbüchern