Inscape Data AirEther BR3000 Series, Руководство пользователя

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SB3000 & BR3000 Series User
’
s Manual
`
Rev. 1.1 (July, 2012) 91
When considering wireless communication for data and video security applications, there
are two wireless technology options, proprietary or standardized. The install base for
proprietary wireless technology is small and costly relative to standardized wireless
technology based on Wi-FI (802.11). In 1999, 802.11b boosted speed to 11 Mbps using
DSSS. The 1 and 2 Mbps DSSS modes were retained so that devices could throttle down to
lower speeds when signals became weak. Using the orthogonal FDM (OFDM) transmission
method, two higher-speed standards followed 802.11b that provided up to 54 Mbps:
802.11a transmits in the 5 GHz frequency range and is not backward compatible with 11b,
but, 11g transmits in the same 2.4 GHz range and is compatible with 11b. If 11b and 11g
devices are communicating, it is done at the slower 11b speed. Wi-Fi is well proven and
readily available since late 1998. It is also one of the most successful industry standards in
history. Wi-Fi is experiencing rapid advancement with newer extensions released to
enhance wireless performance.
WiMax is another wireless standard rapidly gaining ground and holds lots of promise for the licensed
bands. However, the industry anticipates cost effective WiMax equipment to emerge within a few years.
Inscape Data’s long range wireless equipment based on WiFi is available today and brings a host of
benefits to the security market. Table I provides a rough overview of license free band characteristics
and use of each band if available in your deployment region.
License Free
Frequency
Equipment
Cost Allowable Tx
Power Channel
Bandwidth Data Rate Non-Line-
of-Site
Support Purpose
315/433
MHz Good Good Poor Poor Excellent Voice
900 MHz Good Good Poor Poor Very Good Voice/Data
2.4 GHz Excellent Good Very Good Very Good Good Voice/Data/Video
5.x GHz Very Good Good Very Good Very Good Good Voice/Data/Video
24 GHz Poor Very Good Very Good Very Good Poor Data/Video
60 GHz Poor Excellent Excellent Excellent Poor Data/Video
FSO/Laser Very Poor Excellent Excellent Excellent Very Poor Data/Video
Table I. License Free Frequency Review (FSO, Free Space Optics)