Nortel Networks DCT1900 manual Ltu

Technical Product Manual - DCT1900

System Description, Radio Exchange Boards

4.9Line Termination Unit - LTU (REX-BRD0007 or ROFNB 157 02/6) LTU2 (REX-BRD0019A or ROFNB 157 25/2)

LTUs are used only in Standalone configurations. The LTU provides the analog interface between the PBX and the RE. Every LTU board contains 8 Line Termination Circuits (LTC, see Figure 4-8). An LTC interfaces to the PBX through a two–wire analog subscriber line. Every analog line is dedicated to a specific Portable Telephone number. The LTC terminates the line to the PBX like an ordinary wired analog telephone.

The main tasks of the LTU board are:

zTo establish physical connection between the PBX and RE

zOn/Off hook detection

zRing signal detection

zR–button function handling

zPulse dialing (not currently supported)

zAnalog to digital speech processing [PCM (Pulse Code Modulation)] and vice versa

BC

	Peripheral
LTC	P8	Analog
		Telephone
8
		Line

		Peripheral	Analog
	LTC	P1
			Telephone
1			Line

Fig. 4-8 LTU

System-DCT1900/R8/mw	4-9
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