|
Contact US
Creating a Corporation
May
SITE MAP
Class Training For Pc Repair
A Plus Guide
A plus Os
LAPTOPS
X86 Tech
January
February
March
Osi
auto parts
Winserver8
windows7
Virtualization
Cloud Computing
Security
Cash fast
B & I SNOWDEN-Find a
Wealth of Products and Services
| |
Wireless Standards
IEEE 802.11b, and HomeRF are all fairly slow when it comes to data transfer
speeds. As with everything in life, there are trade-offs: When it comes to
adding more speed and maintaining the same range, we need more power. Power is a
major concern in the design of network devices, considering that most of the
wireless applications are produced for devices that are intended to be powered
by batteries. Power is essentially proportional to throughput at a given range,
so achieving 50 Mbps takes approximately 5 times the power of 10 Mbps. The
result is that 54-Mbps, 5-GHz designs must be more power-efficient to achieve
similar range or power usage as 11-Mbps, 2.4-GHz designs. In wireless LANs,
maximum power is usually consumed while sending data.
| Standard |
IEEE 802.11a, WLAN |
| Frequency wavelength |
5GHz |
| Data bandwidth |
54Mbps, 48Mbps, 36Mbps, 24Mbps, 12Mbps, 6Mbps |
| Security measures |
WEP, OFDM |
| Optimum operating range |
150 ft. indoors, 300 ft. outdoors |
| Best suited for a specific purpose or device type |
Roaming laptops in home or business; computers when wiring
is inconvenient |
| Devices or manufacturers currently using the standard |
None for consumers at this time; chipsets made by Atheros
and Radiata |
IEEE 802.11a
IEEE 802.11a hasn't actually appeared on the market for consumers yet. In many
ways it is similar to 802.11b, both being a wireless variation of the Ethernet
standard. They both share WEP, although it is being expanded upon for the newer
802.11a. They also share similar software layers. The primary difference lies in
the physical layer of the standard, which changes to a different wavelength and
higher data bandwidth speeds. Once again, international partitioning of
frequency bandwidth causes problems for worldwide interoperability; less
bandwidth is permitted for use in Japan, and this standard has to meet more
requirements to be passed by ETSI, the European standards board.
|
OFDM
W-OFDM tries to solve the problem that Bluetooth and 802.11b networks
have when operating in the same frequency range. It enables the
implementation of low power multipoint RF networks that minimize
interference with adjacent networks. This reduced interference enables
independent channels to operate within the same band allowing multipoint
networks and point-to-point backbone systems to be overlaid in the same
frequency band.
Wideband Orthogonal Frequency Division Multiplexing (W-OFDM) is a
transmission scheme that enables data to be encoded on multiple
high-speed radio frequencies concurrently. This allows for greater
security, increased amounts of data being sent, and is claimed to be the
industry's most efficient use of bandwidth.
A series of articles could be devoted to OFDM technologies alone, but
for now, know that it's a way of arranging the signal to reduce
interference and to keep the speed of transmission high. Combined with
Direct Spread Spectrum, and WEP, this signal is fairly complex to try
and spy on. Again, security is not a passive practice, and users should
supplement wireless communications with as much encryption as deemed
necessary.
New Tech
|
need other links go to
SITE MAP
home
B & I SNOWDEN-Find a Wealth of Products and Services
|