2GHz ~ 5GHz frequency band affected by the impact of rain attenuation is very small, and under the same conditions of space transmission loss is also lower than LMDS, MMDS band so can be applied to tens of km radius of the large-scale coverage.
From the technical point of view adopted, MMDS down band width is generally 2MHz ~ 6MHz, using TDM the way, a sector of the users often share a data stream. TDMA uplink signals commonly used method, the minimum bandwidth for hundreds of kHz, up to a few MHz. In order to effectively manage wireless resources, need to use media access control protocol (MAC, MediaAc cessControl) control.
MMDS can provide data bandwidth and can use the same frequency band, using the modulation (QPSK, 16QAM or 64QAM) and the relevant number of sectors. Rough estimate, to provide the capacity share of the frequency bandwidth of about 3 to 4 times, that is, the frequency bandwidth of 100MHz can provide 300Mbit / s ~ 400Mbit / s data bandwidth, a base station within the coverage area for users to share.
Availability of products from the point of view, MMDS LMDS is weaker than some, but there are already several manufacturers. MMDS also can be used as IP, TDM and FrameRelay access to backbone networks such as broadband wireless access solutions. Users can achieve, such as Internet access, local users to exchange large amounts of data, voice, VoiceoverIP, VOD, data broadcasting and standard definition or high definition TV signals, and other business.
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