2. 4g Outdoor Wireless Bridge

 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 70s, discrete fourier transform was put forward to simplify system structure and OFDM technology became practical. In 80s applying OFDM technology on high rate MODEM was under research. Since 90s, 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.