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ANYKEY9254 is outdoor wireless bridge with high performance and
data rate, up to 54M data rate can be applied on Internet network, data,
multi-media, image and newly IP network application.
The series of high rate wireless bridge has been promoted after
Forward take experience of producing outdoor microwave equipment
for many years, adopt the U.S. import device and test on the
spot in Beijing, Wuhan for half year as well as improve
constantly, Forward does not consider that while the device
demonstration in laboratory operate successfully, this kind of
device may assure in good order in other places in China due to
complicated Chinese geological environment. Forward also ever
ran into painful lesson that the same kind of product operates
in good order in north but with continuously faults in the
south, it is fortunate that Forward passed through with user
support. The unique waterproof constant temperature design make
Forward device suit weather in almost areas in China. Especially
automatic power control( APC) automatic power control technology can assure device with
strong anti-interference capability to realize stable long
distance transmission. The adoption of OFDM modulation
technology boosts device anti-multipath interference and
diffraction capability
Transmission rate
Standard:6,9,12,18,24,36,48,54 Mbps with dynamic conversion
band :2.4 ~ 2.4835 GHz
Modulation mode :OFDM 16 QAM,64 QAM ,DQPSK,DBPSK
Encryption/security :40 bit(also named 64 bit),128 bit WEP wired
equivalent encryption.
LAN interface :10/100M Ether net interface
Radio frequency interface: N type (UNF1/24)
Operating temperature:0°C to A30460°C
operating humudity:5% to 95%,non-condensing
Electromagnetism compatibility
FCC Part 15 Sub Class B,CE
Power supplying mode
AC:110~260V DC:12V~64V
POE remote power supply
The full name of OFDM is
Orthogonal Frequency Division Multiplexing. This technology is
the base of HPA (HomePlug Power line Alliance) industry
regulation; it adopts discontinuous multi-tone technology to
combine large quantity of signals into single signal to realize
signal transmission. On account of the technology with feature
transmitting signal under spurious-wave interference, therefore
it is available to transmit media easily to be interfered by
outside or with low anti-interference capability.
In fact, OFDM is not new technology developed nowadays; its
application has nearly 40 years history which mainly used for
military wireless high frequency communication system. But OFDM
system structure is so complicated that limit its further
development. Until 70’s, discrete fourier transform was put
forward to simplify system structure and OFDM technology became
practical. In 80’s applying OFDM technology on high rate MODEM
was under research. Since 90’s, OFDM technology extended to
broadband data transmission on wireless frequency modulation
channel. At present OFDM technology has been extensively applied
to broadcast audio and video field and civilian communication
system, mainly are: Asymmetric Digital Subscriber Line (ADSL),
Digital Audio Broadcast (DAB),Digital Video Broadcast, High
Definition TV (HDTV),Wireless Local Network (WLAN) conform to
ETSI standard.
OFDM is high speed transmission technology under wireless
environment. Frequency response curve of wireless channel are
mostly unevenly, while the main idea of OFDM technology lies in
dividing given channel into many quadrature sub-channels in
frequency field, modulating using sub-carrier wave on each
sub-channel and every sub-carrier wave operate parallel
transmission. Thus although the overall channel is unevenly with
frequency selectivity, but relatively each sub-channel is even,
narrow band transmission carries on each sub-channel and the
signal band width is smaller than the appropriate band width of
channel, therefore interference among wave shape can be
decreased greatly. Due to quadrature one another for carrier
wave on each sub-channel in OFDM system, thus their spectrums
are overlapped one another which not only decreases interference
among sub-carrier waves but also boosts spectrum efficiency.OFDM
technology is Multi-Carrier Modulation, (MCM).Actually it is not
precise to mix OFDM and MCM in some articles. Usually MCM and
OFDM are available in wireless channel, the difference lies in:
OFDM stands for to divide channel into quadrature sub-channel
with high channel frequency; while MCM can be more channel
dividing modes.OFDM technology is designed to boost carrier wave
spectrum efficiency or improve multi-carrier modulation, its
feature is quadrature one another for every carrier wave to
overlap spectrum after spreading modulation one another and
therefore reducing interference one another among sub-carrier
waves. After completing modulation to each carrier wave, it
applies a processing technology named HomePlug to increase data
throughout and boost data transmission speed and therefore to
combined processing to all carrier waves to be sent data signal
bit to send a individual transmission signal combined numerous
single signal into a individual transmission signal. Otherwise
one of the reasons OFDM is paid attention specially is that it
can utilize Inverse Discrete Fourier Transform/Discrete Fourier
Transform (IDFT/DFT) to replace multi-carrier modulation and
demodulation.Can send large quantity of data in narrow band
width. At least 1000 digital signals can be divided
simultaneously, and the feature can operate safely surrounding
interfered signals will threaten directly CDMA technology be in
vogue to expand further, the special signal “penertating?does
make OFDM technology is interested deeply by European
communication operator and mobile manufacture, such as
California Cisco System Company, NewYork Flarion Industrial
Institute and Lucent Industrial Institute and Canada Wi-LAN
Industrial Institute.(2) OFDM technology can constantly monitor
abrupt change on transmission media, as data transmission
capability on communication path changes with time, OFDM can
adapt it dynamically, connect and cut appropriate carriers to
assure successful communication;(3) Can detect automatically
which special carrier under transmission media exists high
signal attenuation or interference pulse and then adopts
appropriate modulating to designate carrier under frequency to
communicate;(4) OFDM technology is suitable to high building,
high density residence and protrudenting geological place and
area to sow signals, the place where need to delete multi-path
interference for high speed data transmission and broadcasting.
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