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All private microwave companies licensed in the 2-GHz RF frequency band have been appreciably concerned that their microwave systems may have to move else- where to make room for personal communications network growth. Coexistence with PCN is also an issue. The major concern, of course, is what will it cost? As discussed in Section 1, almost everything associated with a microwave system becomes a factor to evaluate and requires a decision involving cost.
The Problem Resolution Process Andrew Corporation; the antenna, waveguide, tower, shelter and fild services people can help you evaluate your current situation. They have designed, manufac- tured and installed microwave site equipment in brand new and older operating microwave systems for more than 35 years. Andrew can assist in evaluating your present site installation and equipment for suitability in any RF band. In Section 1, we discussed the major technical issues that need to be addressed when RF systems are moved upward in frequency. In this Sec- tion, we will discuss physical plant and site issues that exist with presently used towers, antennas, lines, equip- ment location, etc. Reuse of what you have will make any transition to another RF band easier. Andrew can provide expert evaluations and recommendations after our site inspections; evaluations that may save you considerable cost. |
A number of different improvement/evaluation issues are discussed. How many of these will apply to your situation? While many of these will apply, not all issue evaluations will result in complete replacement and costs for brand new items. Contact Andrew Corporation, Mr. Jerry Moravec, 708- 349-5163, for further discussion and request for quota- tion. Initiate your site evaluation before the finality of any FCC decision. Not all phases need to be explored at any given time. Converting Your Equipment Tower Modifications At each site, a structural analysis determination should be made to determine whether or not the tower can handle the current and future loading from the antennas and transmission lines. For very old towers, and where tower drawings are not available, the sizes of the steel tower members must be measured. The Andrew crew is in a good position to not only inventory all equipment mounted to the tower, but also to measure the size of the tower members, if requested. This tower member information will be used in the tower structural analysis. Once reactions are determined for the expected wind loading, the adequacy of the old foundation design for the new tower loading should be determined. Guyed towers may require new guy cables and/or new torque stabilizers or existing torque stablizers may need to be moved. These may be required to provide for the new wind loading and/or for the necessary rigidity at the higher frequency. In some situations, analysis of the existing tower design, examined under the new EIA-222-E criteria, may offer load relief compared with older specificatins. Conversion of the Existing Antenna (Antenna Retrofit If the existing antennas were manufactured by Andrew, |
