Everyone is demanding bandwidth and more bandwidth, and they want it now. Optical fiber supports these bandwidth requirements and is increasingly being used wherever possible in telecom access networks, with examples such as fiber-to-the-antenna (FTTA) and distributed antenna systems (DAS) for wireless fronthaul, and fiber-to-the-home (FTTH) for residential, and small and medium businesses (SMBs). However, optical fiber must be deployed rapidly—if not, customers will go elsewhere. If the deployment is not carried out correctly, customers will have to wait for more bandwidth and/or experience outage when the poor-quality optical construction leads to a link-down condition.
The three basic steps to fiber deployment are as follows:
- Plan the deployment (often with contractors/subcontractors).
- Manage the deployment (as contractors perform the work).
- Verify the results (upon receipt from the contractors).
As easy as ABC, right? And with all the importance on rolling out fiber quickly and correctly, you would think that fiber deployments would be as efficient and high-tech as the services that they will eventually be supporting.
Step A (Plan the Deployment)
Many telecom providers create methods and procedures (M&Ps) documents detailing how to construct and test fiber links to their exacting standards, with this documentation often specifying what fiber IDs and test-result file names must be used. However, these M&Ps are typically out-of-date by the time they are completed, and the task of ensuring that all contractor/subcontractor technicians have the correct versions is monumental, especially considering the high turnover and internal transfers associated with contractors and their technicians. M&P documents are often well over 50 pages in length, making them cumbersome to use in the field; imagine a technician flipping through the pages at the top of a windy cellular tower! Even in cases where the telecom provider has figured out a way to share the document digitally with the technicians’ fiber test instruments (i.e., those used to test the fibers in step B and provide results for verification in step C), toggling back and forth between the M&Ps and test applications is no easy task, nor is ensuring that each technician has completed all of the mandatory steps using the correct parameters.
Step B (Manage the Deployment) For FTTA wireless tower deployments, the fiber IDs typically remain the same, but the site ID and several other parameters change from job to job. However, DAS and FTTH deployments are highly variable, relying on technicians to accurately enter even more data. If you have had experience with such field deployments, you may not be surprised to learn that over 90% of test results contain data-entry errors leading to the following problems:
- Results are not saved.
- Results cannot be found.
- Results are associated with the wrong fiber, cable or location, etc.
- The wrong test is performed.
- The test is performed with the wrong thresholds.
- Some of the tests required for full qualification of installation are not performed.
Under these conditions, managing fiber construction compliance to appropriate test thresholds while ensuring quality is challenging, but there’s more. Up to 50% of technicians’ time is spent on bookkeeping (e.g., entering and keeping track of test-point identification and reporting). As such, not only do technicians invalidate most of their test results with poor data entry, they also spend half their time doing so.
Although technicians try to avoid making mistakes, repetitive data entry is difficult in the field, especially when all of the necessary tests must be performed using a test set with two or more user interfaces, and the technicians have two or more different test sets to deal with.
Step C (Verify the Results)
Four out of five fiber deployment project managers say that although contractors have to submit reams of test-result documents to prove that they have correctly tested the fiber installation, most closeout packages (some of which contain thousands of results files) are not reviewed in their entirety, with only spot checks being performed to validate compliance and quality. This is not surprising, considering that many documents are only provided in a human-readable PDF format (i.e., are not easily machine-readable), and that any telecom provider trying to review all of the results would need an army of infallible auditors—which would not be terribly cost-effective. In addition, the results analysis is frequently not automated, and therefore project managers spend a lot of time trying to understand why the deployments are delayed, and what problems are occurring and why—all while trying to document the data.
In summary, it is safe to assume that you will have issues if you stick to the manual method of maintaining process compliance, because you will have no way to ensure that technicians are following the right process or using the right test thresholds in the correct sequence, and will have to rely on non-automated processes to retrieve test results from contractors in order to validate successful fiber deployment.
EXFO recommends a combination of fiber inspection and fiber characterization using optical time-domain reflectometry (OTDR) technology. And for FTTA and newer DAS deployments, where the construction crew also install and power on the remote radio equipment, EXFO recommends CPRI (the technology used to carry digitized RF signals over fiber) emulation tests. In addition, FTTA and DAS construction crews may also have to perform radio frequency (RF) testing using a spectrum analyzer.
Many service providers believe in the benefits of testing in order to assure a compliant and quality installation. In fact, many contractors and subcontractors do not get paid until they hand over the closeout package (construction documentation that includes design layouts, photos and test results). But, as mentioned previously, providers face significant issues in ensuring that installation was completed correctly and to the right specifications/thresholds. EXFO has some of the best and easiest-to-use test equipment available, but for many fiber deployments, technicians must perform anywhere from a minimum of 40 to a hundred or more tests using two or more test applications, while making sure that they use the correct test configurations and thresholds (to obtain the right pass/fail indication). They must also identify the cables and fibers properly (plus other reference data such as the job ID and site location), and save the results using a file name that can be searched, filtered, found at a later date and quickly shared with the contractor’s project management team and the service provider.
Of course, such a solution does exist. EXFO has combined years of field experience and test expertise into the functionality and design of its TestFlow solution. In comparison with the existing manual process, test setup is confined to powering on the test set and connecting fiber test leads, with no need to configure each test and enter identification data. The overall M&P is digitized as a sequence on the test set (including generic tasks such as inserting the SFP into RRH port), and the technician is guided through the process; if a technician needs to jump ahead when collaborating with other technicians, the TestFlow test-set application prevents the technician from finishing without completing mandatory steps, and progress is visually apparent in the unified application. In addition, there’s no need to switch between test applications, because each test is launched automatically with the correct configuration and thresholds to ensure process compliance. After completion, test results are automatically consolidated and uploaded to the TestFlow server, eliminating several report administration tasks for the technician and project manager.
Results are centrally stored and available for viewing by contractor managers and the service provider, with full analytics capabilities to assess contractor efficiency, compliance, quality and progress as compared to deployment schedules. Results can be analyzed automatically, since TestFlow removes most, if not all, of the reference-ID data-entry and file-naming issues associated with the existing manual process.
The process starts with the conversion of a static M&P document into a digitized and automated task sequence as part of step A (planning the deployment). The sequence comprises the requisite fiber inspection and characterization tests (in addition to CPRI for FTTA/DAS), cable/fiber/connector IDs, step-by-step instructions (including diagrams and videos) and applicable test configurations, including pass/fail thresholds per test point. The sequence is defined on the TestFlow server providing sequence definition capability, centralized storage of all test sequences (including instructions, videos and test configurations), uploaded test results, reporting and analytics, as well as application-programming-interface (API) connectivity to external operations support systems (OSS). The server provides the service provider with secure, segregated access to data, which can optionally be extended to their contractor partners. From the technician’s perspective, EXFO’s FTB-1v2 Pro offers the most advanced fiber and datacom (including CPRI) field test set available, and this unit also runs the TestFlow test-set application incorporating all test applications, test sequence downloading and test-results uploading. For technicians who only perform fiber inspection (e.g., FTTA tower top), EXFO offers a battery-powered wireless probe that is controlled by a smartphone and equipped with the capability to share results with the TestFlow server using the EXFO Link Android application.
Once defined, the TestFlow template is pushed directly to the assigned technicians (from the TestFlow server to their units). TestFlow templates can be shared with different technician groups, contractors and subcontractors, depending on the job types they need to perform. If a template is updated, it can be pushed again the next time the relevant test sets connect back to the server; technicians do not need to manage template versions.
The test sequence is job-specific, and can therefore be customized to the specific needs required by the job. For example, based on the antenna vendor in an FTTA deployment, the cell tower can be equipped with a single or multiple junction boxes, thus requiring additional test points. In a DAS environment, the architecture will be adapted depending on whether it is operated by a neutral host with a multitenant architecture, or a single mobile network operator. In either case, there is no single methodology that can be applied across the board. TestFlow addresses the challenge of controlling and guiding work in the field (step B, managing the deployment) with the objective of permitting the right level of adaptation. This is achieved by providing the flexibility needed to modify the test sequence. On one end of the spectrum, a test sequence can be locked, in which case the user will follow the test sequence order in a wizard-like fashion. On the other end of the spectrum, the user can add or remove test points on the go in order to properly represent the as-built conditions. In this case, the test sequence acts as a dynamic framework that drives the appearance of the user-interface display, in turn deciding what tasks need to be achieved at which point in time, while automatically selecting the correct pass/fail criteria for the appropriate test. As such, it reduces the number of decisions that need to be made by the technician while enhancing overall process efficiency
As the user progresses through the test sequence, each fiber inspection, intelligent Optical Link Mapper (iOLM) fiber characterization and CPRI emulation test will be properly documented and organized. Whenever Internet connectivity is available, it will be possible to upload and centralize test results to the TestFlow database directly from the test set, thus avoiding any fi le-naming errors of results, or time wasted transferring the information via USB device and e-mail. To provide accurate geolocation tagging for test results, technicians can utilize their smartphone’s GPS and location acquisition capability (the phone must be running the EXFO Link application) to transmit this information to the TestFlow application running on the EXFO FTB-1v2 Pro test set. If the technician needs to upload third-party test results (e.g., from RF spectrum analyzers for FTTA and DAS deployments), the EXFO Link application also supports the uploading of these results, along with key metadata such as job ID and pass/fail indication, directly from a smartphone to the TestFlow server.
When it comes to fiber deployments that support new access technologies (FTTA, DAS, FTTH) and the high-value services running over them, telecom service providers and their contractors are faced with many challenges. As previously discussed, many field issues necessitate testing verification during construction in order to prevent costly deployment delays and future service outages. However, this involves highly manual and error-prone management tasks, and is further complicated by the many levels of contractors/ subcontractors involved. Building a golden process is one thing, but ensuring that a varied and ever-changing set of contractor companies and technicians are following it correctly is another. In addition, the task of analyzing and interpreting reams of test results that are full of ID and file-naming data-entry errors is something else entirely. EXFO is currently the only company on the market offering the state-of-the-art fiber and datacom test instrumentation needed to properly qualify all aspects of fiber deployment within these growth markets, and also supplies the only solution (TestFlow) capable of fully addressing the process compliance and analytics requirements for successful deployments. Through this combined approach, contractors and their technicians are able to benefit from higher efficiency and better job quality with minimal training required; service providers are able to gain control of their fiber deployments, maximize return on investment through on-schedule project delivery, and proactively prevent future service issues.