ethernet

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Hello
Anyone can help me defining what the baseband ethernet and broadband ethernet ?

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Broadband versus baseband signaling
Two signaling methods used by LANs are broadband and baseband. In broadband signaling, the bandwidth of the transmission medium is subdivided by frequency to form two or more subchannels, with each subchannel permitting data transfer to occur independently of data transfer on another subchannel. In baseband signaling only one signal is transmitted on the medium at any point in time.

Broadband signaling
A broadband local area network uses analog technology, in which high frequency (HF) modems operating at or above 4 kHz place carrier signals onto the transmission medium. The carrier signals are then modified: a process known as modulation, which impresses information onto the carrier. Other modems connected to a broadband LAN reconvert the analog signal block into its original digital format: a process known as demodulation.
Baseband signaling
In comparison to broadband local area networks, which use analog signaling, baseband LANs use digital signaling to convey information. Typically, the methods used are UNZ, Manchester, etc. In the UNZ signaling method a positive voltage is used to represent a binary 1, whereas 0 voltage represents a binary 0. In Manchester encoding a timing transition always occurs in the middle of each bit, and an equal amount of positive and negative voltage is used to represent each bit. The IEEE 802.3 standard specifies the use of Manchester coding for baseband Ethernet operating at data rates up to 10Mbps.