Wireless
By: Top • Research Paper • 616 Words • April 1, 2010 • 802 Views
Wireless
Types of Wireless Antenna
Wireless antenna fall into five general categories:
• Omni
• Parabolic or Dish
• Yagi
• Patch
• Sector
Omnidirectional Antenna
An omnidirectional antenna works equally well in picking up signals from every direction. Omni's make excellent general purpose and mobile antenna's. The longer an omnidirectional antenna is, the better performance it will have.
Specifications:
Electrical
Frequency range 30 - 100 MHz
VSWR 1:2.5 (in band), 1:3 (at band Extreme)
Power Handling 250 W
Impedance 50 Ohm
Gain +1 dBi (avg.)
Azimuth Omnidirectional
Polarization Vertical
Mechanical and Environmental
Length 2.8 meter
Top Diameter 2.7 meter
Weight 12 Kg (net)
Packing Canvas type bag
Mounting Adapter to 1.5-2" pole
Color Olive Green
Wind Resistance 130 Km/h
Temperature, Operating -40°C to +55°C
Temperature, Storage -40°C to +75°C
Connector N-type (female)
Humidity Certified to 95% per MIL-STD-810D
Saline Fog Certified to 96 hours per MIL-STD-810D
Operational
Erection Time 20 minutes (by 2 trained people on ground level)
Recommended Height 4 meters minimum above ground (bottom)
Parabolic or Dish Antenna
A parabolic antenna will give you the greatest range for your signal. The trade-off is that they are more difficult to aim. A parabolic antenna is the obvious choice for a point-to-point fixed wireless installation.
MMDS Specifications
Fixed/Mobile Fixed
Circuit/Packet n/a
Max Bandwidth 10Mb
Range 70 miles
Frequency 2.5Ghz-2.686Ghz
Host Network None
Definer IEEE (Institute of Electrical and Electronic Engineers)
URL http://grouper.ieee.org/groups/802/16/
MMDS and DOCSIS+
LMDS and MMDS have adapted the DOCSIS (Data Over Cable Service Interface Specification) from the cable modem world. The version of DOCSIS modified for wireless broadband is known as DOCSIS+.
Data-transport security is accomplished under MMDS by encrypting traffic flows between the broadband wireless modem and the WMTS (Wireless Modem Termination System) located in the base station of the providers network using Triple DES.
DOCSIS+ reduces theft-of-service vulnerabilities under MMDS by requiring that the WMTS enforce encryption, and by employing an authenticated client/server key-management protocol in which the WMTS controls distribution of keying material to broadband wireless modems.
LMDS and MMDS wireless modems utilize the DOCSIS+ key-management protocol to obtain authorization and traffic encryption material from a WMTS, and to support periodic reauthorization and key refresh. The key-management protocol uses X.509 digital certificates, RSA public key encryption, and Triple DES encryption to secure key exchanges between the wireless modem and the WMTS.
MMDS