ADTRAN 5045 system manual INSTALLING/TROUBLESHOOTING the Tracer Hardware

Section 6 Troubleshooting Guide TRACER 5045 System Manual

5.INSTALLING/TROUBLESHOOTING THE TRACER HARDWARE

1.Perform a detailed path profile and link budget for each TRACER 5045 microwave link. A thorough path study can be used to estimate signal power budgets, fade margins at each receiver, identity potential line-of-site obstacles, properly size antenna dishes, and determine minimum antenna dish heights above the earth.

ADTRAN provides a wireless link planning tool on our website. This link budget tool is constructed as an easy to use spreadsheet with dropdown menus so that the user can quickly change any of the link parameters (antenna size, coaxial cable type and length, frequency band, link distance, etc) and instantly see how the microwave path availability is affected. This tool is available at www.adtran.com/wireless and can be used online or downloaded for standalone use.

2.Setup all of the TRACER hardware on a workbench. ADTRAN recommends that the actual cables used in the permanent installation be used in the workbench setup. A rigorous workbench “simulation” of the link will help alleviate and avoid time-consuming errors.

3.Examine the PLAN A and PLAN B LEDs on the front panel of each unit. These LEDs indicate the frequency plan for each TRACER 5045 unit. The frequency plan (Plan A, Plan B) LED should be the opposite on the TRACER 5045 units.

4.Attach the RF coaxial cables to be used in the permanent installation to the N-type connectors on the back of the TRACER 5045 unit. Attach the other end of the coaxial cable(s) to an RF power meter or spectrum analyzer, if either is available. The power measured by the meter/analyzer will be the RF power available at the input of the antenna. The TRACER 5045 unit is programmed at the factory to output approximately 100 mW (20 dBm) of RF power. The actual power level measured by the meter/analyzer will be less than 100 mW due to RF losses through the coaxial cable, and is a function of the cable type and length being used. In any event, the power level at the output of the coaxial cable should be a significant fraction of 100 mW. A power meter/analyzer reading that is not on the order of at least tens-of-milliwatts could be an indication of any combination of either unsuitable RF, faulty, or unreasonably long coaxial cable.

5.Resolve all RF coaxial cabling errors before proceeding.

6.Attach the RF coaxial cables to a high-quality attenuator, if possible. If you do not have an attenuator, attach the coaxial cables to the antennas to be used in the permanent installation. If the installation antennas are not available, small, inexpensive dipole or patch antennas can be used for verification purposes. If an adjustable attenuator is being used, dial in the amount of attenuation that corresponds to the path loss value expected for the microwave link in which the TRACER hardware will be installed. The path loss value can be calculated from a knowledge of the path length, or provided by a path study. Remember to subtract both antenna gain values from the attenuator level if these values have not already be accounted for.

7.After setting up the RF pieces, examine the RF DOWN LED on the front panel of each TRACER 5045 unit. If the RF DOWN LED is illuminated (red), the corresponding TRACER 5045 is not receiving a suitable RF signal from the other TRACER 5045 unit. In this case, the receiving TRACER 5045 is either receiving a very weak signal, or no signal at all. If the RF DOWN LED is not illuminated, then the TRACER 5045 units are receiving a suitable RF signal. Suitable RF power levels for low error rate communication will range from -30 dBm to -78 dBm measured at the N-type connector input on the TRACER 5045 unit.

8.Resolve any signal level issues before proceeding.

54 © 2003 ADTRAN, Inc. 612805045L1-1A