Resolving the Antenna Misalignment Dilemma
By Philip Oxley, Director, Site Information Solutions • Fulcrum Technologies and
Landon Eason, VP of Business Development • Sunsight Instruments

Consider the evolution we have experienced in the wireless industry: 3G and 4G broadband services are here. These networks are being designed with sophisticated simulation tools and will deploy smart, dynamic antennas to maximize quality of service and throughput. Why then, does the wireless industry continue to accept the discrepancies between RF design specifications and the reality of misaligned antennas that are installed with the same compass-based alignment methodologies used in the initial days of analog cellular service?

The horse-and-buggy days of antenna alignment are over. Using proven technologies, there is now a solution that approaches the sophistication of the antennas it is designed to install. A US method patent was granted to the inventor, Christian Boucher, earlier in this decade for GPS-aided antenna alignment. Fulcrum Technologies is the exclusive licensee of the patent rights in the US and has partnered with Sunsight Instruments to develop a solution that brings precision, repeatability and an auditable data trail to the basic but critical task of antenna alignment.

An Industry-Wide Challenge

The challenges of aligning an antenna accurately with a compass are many: the precarious nature of simply being on a tower, the lack of adequate landmarks, the magnetic influence of nearby metals, inclement weather and even darkness - given maintenance window requirements – to name just a few. The difficulty in capturing accurate information is compounded with inconsistent means of data recording and data management, adding more opportunities for human error. It should be no surprise that Fulcrum’s audit results of thousands of antennas reveal significant variances between assumed antenna orientation and the real world:

• 46 percent of all Fulcrum-surveyed cell sites in the US have at least one sector with an azimuth variance of more than 10°
• 31 percent of all Fulcrum-surveyed antennas in the US have a mechanical tilt variance greater than 1°; 11 percent greater than 2°.

Independent studies have demonstrated that inaccurate antenna installations will have a negative impact on the KPIs of broadband network performance. Additionally, millions of dollars are misspent every year as contractors make return trips to sites to make corrections to antenna alignment errors, as determined by yet another contractor using the same inadequate methods.

The good news is that progress is being made. Wireless operators are beginning to recognize that 3G and 4G networks will require better results from the civil portion of their network deployment investments. Both carriers and contractors have begun to adopt the Fulcrum Alignment Solution as a best practice in building and managing their networks.

The Fulcrum Alignment Solution – How it Works

The Fulcrum Alignment Solution pairs its proven CATS Web software with Sunsight Instruments’ AntennAlign Alignment Tool (AAT). The AAT is a commercially available tool that can be used to determine the exact attitude of a device in three axes (azimuth, tilt, and roll). It can also record height with an accompanying laser range finder device that is connected to the AAT via cable. The AAT is a battery operated tool to be used to make highly accurate measurements of antenna positions. It can be used during initial installation and alignment of an antenna or when an antenna is audited or re-oriented for preventative maintenance and network optimization respectively.

The AAT uses GPS carrier phase measurements to accomplish the azimuth alignment (aka heading). The GPS signal is also used to record the location of the antenna system being aligned, as well as the current date and time. Two highly accurate inclinometers are used to determine the tilt and roll positions of the antenna being measured. In addition to its measuring capabilities, the AAT can be programmed with specific records of desired alignments, called Alignment Profiles. These profiles identify the site, sector, and antenna position being aligned and can include detailed descriptions of the antenna and other important information. Alignment Profiles are used by the AAT during the alignment process to provide easy targets for the installer. When aligning to an Alignment Profile, the installer is presented with visual cues that indicate when the antenna being aligned is within a specified alignment tolerance. When the installer is satisfied with the results depicted on the AAT screen, a capture function is used to save the measured alignment data.

The accuracy of the AAT is supplemented with the data management capabilities of Fulcrum Technologies’ CATS Web Software-as-a-Service (SaaS). Authorized access is available wherever an internet connection is available. The end-to-end process is outlined below:

1. RF engineers populate a CATS Web form to build Alignment Profiles (mentioned above) that contain antenna orientation specs and tolerance requirements.
2. CATS Web will then produce downloadable files to be assigned to field crews.
3. Field crews retrieve Alignment Profiles from CATS Web to be loaded onto the AAT (via an encrypted data file on an SD flash memory card).
4. Following completion of an antenna alignment project, capture records are uploaded to CATS Web for automated report generation.

Reports can be included in a contractors’ close out package or routed to databases that support RF planning tools.

Data integrity for an antenna alignment methodology relies on two components; an accurate tool for aligning an antenna and a data management process that minimizes the opportunity for human error. The Fulcrum Alignment Solution moves RF design data from the engineer’s desktop to the field and back, providing the engineer with the confidence that the reported data is sound (Figure 1).

The problems and costs of misaligned antennas are well known and beyond debate. The promise of improved data rates with 3G and 4G technologies will not be realized if the implementation of physical network design does not also improve. An accurate tool that provides repeatable results and a sound data management process is the foundation for best practices in antenna orientation. Fulcrum Technologies and Sunsight Instruments have packaged these attributes in the industry’s first comprehensive antenna alignment solution.

Philip Oxley is a wireless industry veteran of 25 years. Recent roles have included Business Development positions with cutting edge vendors in the wireless industry including his current role with Fulcrum Technologies, Inc. Philip can be reached at poxley@fulcrum.net.

Landon Eason has 15 years of product development experience in the telecom industry, and has been a key contributor at several technology start-ups. A founding partner and now VP of Business Development , Landon acts as Sunsight's representative to the Antenna Interface Standards Group (AISG), and is currently authoring protocol standards for antenna alignment monitoring devices. Landon can be reached at Landon.eason@sunsight.com.

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