TANDBERG D12809 manual Overview Of Wireless Standards, 1.1 802.11 Wireless Ethernet, BlueTooth

TANDBERG TANDBERG and Wireless LANs

1. Overview Of Wireless Standards

1.1 802.11 Wireless Ethernet

Ethernet was pioneered by Xerox in the 1970’s and was in fact a registered trademark of Xerox Corporation. After further development, the technology was improved and became known as Ethernet II. Xerox, with the help from Digital and Intel began establishing and publishing the standards. Realizing the international community would not recognize the standard, IEEE was charged with formalizing the standard along with other LAN technologies. The 802 committee was assembled to investigate Ethernet, Token Ring, Fiber Optic, and other LAN technology.

1.1.1 802.11a

The 802.11a specification applies to wireless ATM systems and is primarily used in access hubs. This specification operates at 5GHz and 6GHz. By using a modulation scheme of orthogonal frequency division multiplexing (OFDM), 802.11a can achieve speeds up to 54Mbps. However, speeds of 6Mbps, 12Mbps and 24Mbps are more common.

1.1.2 802.11b

The 802.11b specification, also known as Wi-Fi, uses complementary code keying (CCK) phase-shift keying (PSK) instead of the traditional phase-shift keying (PSK) used in 802.11. The use of CCK allows for higher data speeds and less interference to multipath-propaga tion interference. 802.11b operates at 2.4GHz and allows for speeds up to 11Mbps.

1.1.3 802.11g

The 802.11g specification allows for speeds up to 54Mbps over short distances. The 802.11g standard also operates at 2.4GHz and is compatible with 802.11b.

1.2 BlueTooth

BlueTooth is another wireless standard named for the 10th Century Viking king Harald Blåtand of Denmark. The Bluetooth wireless specification defines a low-power, low-cost technology that provides a standardized platform for eliminating cables between mobile devices and facilitating connections between products. Bluetooth operates at the unlicensed 2.4GHz frequency. The standard uses a spread spectrum, frequency hopping, full-duplex signal at up to 1600 hops/sec. The signal hops among 79 frequencies at 1 MHz intervals to give a high degree of interference immunity.