While DC loop resistance and DC resistance unbalance can be a result of low-quality cables, DC resistance unbalance can also be caused by poor workmanship, such as inconsistent conductor terminations, exceeding bend radius requirements, or failure to maintain pair twists as close to the point of termination as possible. Extending certification testing to include DC resistance unbalance requires a certification tester capable of testing these parameters in the field. Testers with this capability automate the calculations to provide a PASS or FAIL rating. Ensuring support for PoE via DC resistance unbalance testing will become increasingly vital for newer Wi-Fi 7 APs with more spatial streams that demand more power via four-pair Type 4 PoE. TROUBLESHOOTING WI-FI: A STEP-BY-STEP GUIDE Even if the cabling infrastructure passed certification testing at the time of installation, including DC resistance unbalance testing, problems with Wi-Fi can still arise once the network is up and running. With wide-scale reliance on Wi-Fi across the enterprise and beyond, network operators must quickly identify and address complaints such as slow speeds, inability to connect, and dropped connections.
Problems with Wi-Fi are often blamed on cabling. While damaged cables can certainly cause issues, the problem might lie elsewhere in the network infrastructure. The following steps walk through a systematic approach to troubleshooting Wi-Fi problems, focusing on key areas like cabling, network configuration, PoE, and the Wi-Fi environment itself. STEP 1: VERIFY CABLING INTEGRITY The first step in troubleshooting Wi-Fi is to verify the connectivity of the link. This is achieved through simple wire map testing for opens, shorts, and miswirings. Using a cable tester with graphical display and analysis capabilities can simplify wire map testing (Figure 2). When wire map testing reveals an open and potentially damaged cable, locating the break can be difficult if cables are not easily accessible (i.e., behind walls or in conduit). Testers with a built-in tone generator are ideal for locating a break. For cabling infrastructure comprised of shielded twisted pair cabling, the problem could be a break in the continuity of the shield. Therefore, a cable tester with the ability to test shield integrity is a consideration.
FIGURE 2: Cable testers that graphically display and analyze wire map test results can facilitate identifying opens, shorts, or miswirings that prevent signals from reaching a connected device. (Source: Fluke Corporation)
I
January/February/March 2025
17
Made with FlippingBook - Online catalogs