Chapter 1 Introduction FOM-E1/T1 Installation and Operation Manual
1-2 Overview
Application In the application illustrated, each FOM-E1/T1 receives E1 or T1 signals that are
equalized to overcome electrical link distortion. FOM-E1/T1 then converts the E1
or T1 signals into an optical signal.
PBX FOM-E1/T1 FOM-E1/T1
DACS
E1/T1 E1/T1 E1/T1
Coax Fiber Optic Coax
Figure 1-1 FOM-E1/T1 Application
Features Fiber Optic Interface
Table 1-1 details fiber optic interface types supported by FOM-E1/T1.
Table 1-1. Fiber Optic Interface Types
Wavelength
[nm]
Fiber Type
[µm]
Transmitter
Type
Power
[dBm]
Receiver
Sensitivity
[dBm]
Typical Max.
Range
[km/miles]
850 62.5/125
multimode
VCSEL -18 -38 5/3
1310 9/125 single
mode
LED -18 -40 38/24
1310 9/125 single
mode
Laser -12 -40 50/31
1550 9/125 single
mode
Laser -12 -40 100/62
E1/T1 Interface
• The electrical interface meets requirements of ITU G.703, G.824, G.921 and
G.935 standards for E1 and T1.
• FOM-E1/T1 supports both balanced and unbalanced interfaces.
• FOM-E1/T1 conforms to all relevant ITU standards.
When FOM-E1/T1 detects electrical interface levels below G.703 electrical levels,
the modem transmits an “All 1 signal” (AIS) to the optical interface.
Test and Diagnostics Capabilities
• FOM-E1/T1’s built-in diagnostics comply with the V.54 standard.
• FOM-E1/T1 features a dry contact alarm port for attaching an external alert
device.
• When an AIS is detected at the optical or electrical interface, the modem
transparently converts the signal and alerts the user via front panel LEDs.