Add revenue, not copper: 
Double copper plant capacity on existing twisted pair

The DuaLine Plus™ System multiplexes two 64 Kbps Clear channel POTS lines and transports them over a single twisted pair utilizing noiseless, low power HDSL (2B1Q) line coding. The digital subscriber line (DSL) is then demultiplexed at the Remote Terminal (RT), providing two POTS lines. 

System components include Central Office Terminal (COT) line cards, Remote Terminals (RT) and 300 series shelves common for DuaLine Plus™  and QuadPOTS™.

For Internet and other high-speed data applications, Charles manufactures two speciality versions of the DuaLine System that multiplex one POTS line and one high-speed data line over a single twisted pair.  These units include:

D56K COT Line Card
POTS+BRI COT Line Card and RT

• CLASS^® services compatible
• Spectrally compatible with ISDN and other protected services
• NEBS Level 3 certified
  
  

	Central Office Terminal (COT) Line Card Provides 2:1 Digital Pair-Gain (DPG) 2B1Q line coding Line powered Mounts in 300 series shelves Enhanced Pre-Provisioning (EPREP) for easy one person turn-up of additional lines Compatible with AML/Seiscor/SLC 4TEL or MLT line testing signatures Rugged design for use at -40° to +65° C (-40° to +149° F)
	300 Series Shelf 23" DML301 shelf; maximum 36 lines  (19 slots, 18 COT line cards) 19" DML305 shelf; maximum of 30 lines  (16 slots, 15 COT line cards) Shelves use 5.25" of vertical rack space  (three 1.75" rack spaces)
	Remote Terminal (RT) RT2 Drops up to two POTS lines Line powered Electronics mount in enclosure base Enhanced Pre-Provisioning (EPREP) for easy one person turn-up of additional lines Rugged design for use at -40° to +65° C (-40° to +149° F)
	Alarm Card One card per 300 series shelf Visual alarms Major alarm LED (red) occurs when all DSLs within the shelf are out of service or there is a power outage Minor Alarm LED (yellow) occurs with loss of service on one or more DSLs within the shelf
	MX-4000 Mounting Assemblies Eight position shelf Wall or rack mount
	Single-Slot Mounting Assemblies Mount vertically or horizontally on wall or desk

Configuration
System Capabilities
Transmission Format Channelization Range of Digital Subscriber Line	2B1Q, 160 Kbps full duplex Two, 64 Kbps Clear channel POTS lines Distance: 22 Kft on 24 AWG and 18 Kft on 26 AWG