Motorola SG 2000 ユーザーズマニュアル
2 - 1 2 O v e r v i e w
SG 20 00 Ins tal la tion and O pera tion M anua l
D ig ita l Re tu rn P a th
The digital return transmitter series (DS-SG2-DRT*) converts a broadband analog RF return-path
signal into digital optical signals with 10-bit resolution.
signal into digital optical signals with 10-bit resolution.
The transmitters used for digital return applications are divided into two families: DS-SG2-DRT/A
and DS-SG2-DRT-2X/A.
and DS-SG2-DRT-2X/A.
Seven digital return transmitters per family are available to meet the needs of most digital return
applications.
applications.
Table 2-2 identifies the fourteen optical digital return transmitters:
T a b l e 2 - 2
D i g i t a l r e t u r n t r a n s m i t t e r s
D i g i t a l r e t u r n t r a n s m i t t e r s
DS-SG2- DR T/ A DS-SG2- DR T- 2X/ A
DS-SG2-DRT/A-1310 FP
DS-SG2-DRT-2X
(1)
/A-1310 FP
DS-SG2-DRT/A-1310 DFB
DS-SG2-DRT-2X/A-1310 DFB
DS-SG2-DRT/A-1470 DFB
DS-SG2-DRT-2X/A-1470 DFB
DS-SG2-DRT/A-1490 DFB
DS-SG2-DRT-2X/A-1490 DFB
DS-SG2-DRT/A-1550 DFB
DS-SG2-DRT-2X/A-1550 DFB
DS-SG2-DRT/A-1510c
(2)
DFB
DS-SG2-DRT-2X/A-1510c DFB
DS-SG2-DRT/A-1530c DFB
DS-SG2-DRT-2X/A-1530c DFB
DS-SG2-DRT/A-1550c DFB
DS-SG2-DRT-2X/A-1550c DFB
DS-SG2-DRT/A-1570c DFB
DS-SG2-DRT-2X/A-1570c DFB
DS-SG2-DRT/A-1590 DFB
DS-SG2-DRT-2X/A-1590 DFB
DS-SG2-DRT/A-1610 DFB
DS-SG2-DRT-2X/A-1610 DFB
(1) 2X in the model number denotes time division multiplexing (TDM)
(2) c in the model number denotes coarse wave division multiplexing (CWDM)
To prepare for an anticipated increase in return traffic, provisioning for CWDM is built into the
transmitters. The CWDM option consists of lasers at predefined wavelengths. This option is
available to support multiplexing in the optical domain, using eight-wavelength wave division
multiplexing (WDM) in the DS-SG2-DRT/A-15XX DFB and DS-SG2-DRT-2X/A-15XX DFB
windows.
transmitters. The CWDM option consists of lasers at predefined wavelengths. This option is
available to support multiplexing in the optical domain, using eight-wavelength wave division
multiplexing (WDM) in the DS-SG2-DRT/A-15XX DFB and DS-SG2-DRT-2X/A-15XX DFB
windows.
DS-SG2-DRT/A
The DS-SG2-DRT/A digitizes a single analog 5-42 MHz return path signal to produce a 1.6 Gbps
data stream. This data stream is then routed to a digital laser for transmission to a corresponding
digital return receiver. The node can be configured with one or two DS-SG2-DRT/A transmitters,
with dual transmitters providing redundancy. In conjunction with these transmitters, the node must
also be configured with the SG2 Return Path Module/Combined (SG2-RPM/C). The return signals
from all four ports are combined and fed to the optical transmitters.
data stream. This data stream is then routed to a digital laser for transmission to a corresponding
digital return receiver. The node can be configured with one or two DS-SG2-DRT/A transmitters,
with dual transmitters providing redundancy. In conjunction with these transmitters, the node must
also be configured with the SG2 Return Path Module/Combined (SG2-RPM/C). The return signals
from all four ports are combined and fed to the optical transmitters.