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
Figure 4 illustrates the predicted OPB associated with the three transceivers series specified in this data sheet at the Beginning of Life (BOL). These curves repre- sent 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 losses.
Agilent LED technology has produced 800 nm LED and 1300 nm LED devices with lower aging characteristics than normally associated with these technolo- gies in the industry. The industry convention is 3 dB aging for 800 nm and 1.5 dB aging for 1300 nm LEDs. The 1300 nm HP LEDs are specified to experience less than 1 dB of aging over normal commercial equipment mission life periods. Contact your Agilent sales representative for additional details.
Figure 4 was generated for the 1300 nm transceivers with an Agilent fiber optic link model containing the current industry conventions for fiber cable specifications and the draft ANSI T1E1.2. These optical 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 T1E1.2 committee, to establish the optical performance requirements for various fiber
5
optic interface standards. The cable parameters used come from the ISO/IEC JTC1/SC 25/WG3 Generic Cabling for Customer Premises per DIS 11801 docu- ment and the EIA/TIA-568-A Commercial Building Telecommunications Cabling Standard per SP-2840.
The HFBR-5203 series 800 nm transceiver curve in Figure 4 was generated based on extensive empirical test data of the 800 nm transceiver performance. The curve includes the effect of typical fiber attenuation, plus receiver sensitivity loss due to chromatic and metal dispersion losses through the fiber.
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 symbol time. Data rate (bits/ sec) is the symbol rate divided by the encoding factor used to encode the data (symbols/bit).
| 12 |
|
| |
| 10 |
| ||
(dB) |
|
| ||
| ||||
| 62.5/125 µm | |||
BUDGET |
| |||
8 |
|
| ||
|
| |||
|
| 50/125 µm | ||
POWER | 6 | |||
| ||||
| 50/125 µm |
| ||
4 |
| |||
OPTICAL |
| |||
| 62.5/125 µm | |||
|
| |||
2 |
| |||
|
|
| ||
|
|
| 50/125 µm | |
0 | 0.5 | 1.0 | 1.5 | 2.0 | 2.5 |
0.3 |
FIBER OPTIC CABLE LENGTH (km)
Figure 4. Optical Power Budget vs. Fiber Optic Cable Length.
When used in 155 Mbps SONET
The transceivers may be used for other applications at signaling rates different than 155 Mbps with some variation in the link optical power budget. Figure 5 gives an indication of the typical performance of these products at different rates.
These transceivers can also be used for applications which require different Bit Error Rate (BER) performance. Figure 6
