Channel Modes; Encoding - Motorola Canopy T1/E1 User Manual

Canopy T1/E1 Multiplexer
1.5.1 Channel Modes
T1 Channel Mode
While in T1 mode, the Canopy T1/E1 Multiplexer operates as a DSX-1 interface in a DSU
channel mode. There are no user options to change this mode. The DSU channel mode
can operate within five line lengths, each providing compensation for the length of the T1
line. The line lengths are:
◦
0-133 ft. / 0.6dB
◦
134-266 ft. / 1.2dB
◦
267-399 ft. / 1.8dB
◦
400-533 ft. / 2.4dB
◦
534-655 ft. / 3.0dB
E1 Channel Mode
While in E1 mode, the transmit line build-out meets the short haul requirements specified
in Recommendation ITU G.703.
1.5.2 Encoding
The Canopy T1/E1 Multiplexer transparently passes all T1/E1 bits, including framing,
encoding and zero suppression, through to the far end T1/E1 using the Canopy BH
Module Ethernet port.
For T1 mode, no user settings are required for D4 or Extended Superframe (ESF)
framing types, or for T1 signaling bits. Both 56-kbps and 64-kbps channels are
transparently passed. The user must identify which type of T1 is being used; Alternate
Mark Inversion (AMI) or Binary Eight Zero Substitution (B8ZS) in order for the Canopy
T1/E1 Multiplexer to properly ascertain bipolar violations (BPV). A bipolar violation is a
non-zero signal element in an AMI signal that has the same polarity as the previous non-
zero signal element.
For T1 mode, the Canopy T1/E1 Multiplexer supports the following:
◦
Transparent support of the T1 channel, including
−
D4
−
Extended Superframe (ESF)
−
56-kbps and 64-kbps channels
−
Zero suppression
◦
AMI
◦
B8ZS
◦
up to four ports
For E1 mode, no user settings are required for framing types or for E1 signaling bits. The
user must identify which type of E1 is being used; Alternate Mark Inversion (AMI) or High
Density Binary Three Bit Zero Substitution (HDB3) in order for the Canopy T1/E1
Multiplexer to properly ascertain bipolar violations (BPV). A bipolar violation is a non-
zero signal element in an AMI signal that has the same polarity as the previous non-zero
signal element.
Issue 3 Page 19 of 73
T1/E1 Multiplexer FPGA Version 3.4
September 2004