long reach Ethernet (LRE)
Long Reach Ethernet (LRE) is a method developed by Cisco for the connection area with symmetrical bandwidth for the outward and return channels, which is transmitted via the normal copper twisted pairs.
The LRE technology is comparable to the symmetrical DSL methods and also uses the same frequency bands defined by the European Telecommunications Standards Institute( ETSI). LRE connections can be used to transmit data, video services such as streamingmedia, and voice services such as Voice over IP( VoIP) in real time, and to implement VPNs beyond metro networks to the end user. This technology is the basis for fiber-based Ethernet to the Home( ETTH).
The advantage of LRE technology is that Ethernet extends end-to-end to the end user and the end user has an 802.3 Ethernet connection. Distances of up to 1.5 km can be bridged via LRE at data rates of 5 Mbit/s; for cable lengths of less than 1 km, the data rate is even 15 Mbit/s. Existing infrastructures for the telephone network( POTS), ISDN or private branch exchanges are supported by Long Reach Ethernet, which can be used to establish point-to-point connections in half- duplex and full-duplex.
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As a transmission method, LRE technology uses complex quadrature amplitude modulation( QAM) to transmit signals in the available frequency range of 300 Hz to 3.4 kHz. LRE also relies on Frequency Division Duplex ( FDD) to separate the different data from telephone, ISDN or extension.
Long-reach Ethernet is particularly suitable for hotels, convention centers and airports, as well as for residential complexes and companies with several offices.