Application Information
The Applications Engineering
group in the Agilent Fiber
Optics Communication Division
is available to assist you with
the technical understanding
and design trade-offs
associated with these trans-
ceivers. You can contact them
through your Agilent sales
representative.
The following information is
provided to answer some of
the most common questions
about the use of these parts.
Transceiver Optical Power Budget
versus Link Length
Optical Power Budget (OPB) is
the available optical power for
a fiber optic link to
accommodate fiber cable losses
plus losses due to in-line
connectors, splices, optical
switches, and to provide
margin for link aging and
unplanned losses due to cable
plant reconfiguration or repair.
Figure 4 illustrates the pre-
dicted OPB associated with the
transceiver series specified in
this data sheet at the Beginning
of Life (BOL). These curves
represent the attenuation and
chromatic plus modal
dispersion losses associated
with the 62.5/125 µm and 50/
125 µm fiber cables only. The
area under the curves
represents the remaining OPB
at any link length, which is
available for overcoming non-
fiber cable related losses.
Agilent LED technology has
produced 1300 nm LED
devices with lower aging
characteristics than normally
associated with these
technologies in the industry.
The industry convention is 1.5
dB aging for 1300 nm LEDs.
The Agilent 1300 nm LEDs will
experience less than 1 dB of
aging over normal commercial
5
equipment mission life periods.
Contact your Agilent sales
representative for additional
details.
Figure 4 was generated with a
Agilent fiber optic link model
containing the current industry
conventions for fiber cable
specifications and the FDDI
PMD and LCF-PMD optical
parameters. These parameters
are reflected in the guaranteed
performance of the transceiver
specifications in this data
sheet. This same model has
been used extensively in the
ANSI and IEEE committees,
including the ANSI X3T9.5
committee, to establish the
optical performance require-
ments for various fiber optic
interface standards. The cable
parameters used come from
the ISO/IEC JTC1/SC 25/WG3
Generic Cabling for Customer
Premises per
DIS 11801 document and the
EIA/TIA-568-A Commercial
Building Telecommunications
Cabling Standard per SP-2840.
12
AFBR-5803, 62.5/125 µm
OPTICAL POWER BUDGET (dB)
encoding factor used to encode
the data
(symbols/bit).
When used in Fast Ethernet,
FDDI and ATM 100 Mb/s
applications the performance
of the 1300 nm transceivers is
guaranteed over the signaling
rate of 10 MBd to
125 MBd to the full conditions
listed in individual product
specification tables.
2.5
TRANSCEIVER RELATIVE OPTICAL POWER BUDGET
AT CONSTANT BER (dB)
2.0
1.5
1.0
0.5
0
0.5
0
25
50
75
100
125
150
175 200
SIGNAL RATE (MBd)
CONDITIONS:
1. PRBS 2
7
-1
2. DATA SAMPLED AT CENTER OF DATA SYMBOL.
3. BER = 10
-6
4. T
A
= +25˚ C
5. V
CC
= 3.3 V to 5 V dc
6. INPUT OPTICAL RISE/FALL TIMES = 1.0/2.1 ns.
Figure 5. Transceiver Relative Optical Power
Budget at Constant BER vs. Signaling Rate.
10
8
6
4
2
0
1.
0.3 0.5
0
1.5
2.0
FIBER OPTIC CABLE LENGTH (km)
AFBR-5803
50/125 µm
2.5
Figure 4. Optical Power Budget at BOL versus
Fiber Optic Cable Length.
The transceivers may be used
for other applications at
signaling rates outside of the
10 MBd to 125 MBd range
with some penalty in the link
optical power budget primarily
caused by a reduction of
receiver sensitivity. Figure 5
gives an indication of the
typical performance of these
1300 nm products at different
rates.
These transceivers can also be
used for applications which
require different Bit Error
Rate (BER) performance.
Figure 6 illustrates the typical
trade-off between link BER
and the receivers input optical
power level.
Transceiver Signaling Operating
Rate Range and BER Performance
For purposes of definition, the
symbol (Baud) rate, also called
signaling rate, is the reciprocal
of the shortest symbol time.
Data rate (bits/sec) is the
symbol rate divided by the
AGILENT [ AGILENT TECHNOLOGIES, LTD. ]
