Issue link: https://www.e-digitaleditions.com/i/1476549
12 I ICT TODAY The PoE switches generate more heat and often have different power requirements than their predecessors. While the power and cooling needs within the TR are easily addressed in greenfield deployment, they pose a unique challenge when one must overcome them in an existing TR. As wireless is called upon to support more and more other systems, including building automation systems (BAS) or access control, there may be a need to provide wireless in areas of the building, such as mechanical pent- houses and electrical rooms, where there can be greater radio frequency (RF) interference. As owners move away from wired connections and desire more robust wireless networks, deploying wireless infrastructure with the ability to scale up is beneficial. Power The extra radios and processor capabilities means these new generations of WAPs require more power. At a minimum, 802.3at (PoE Plus) is required to enable all functionality. Where tri-frequency Wi-Fi 6E WAPs are deployed, 802.3bt power is necessary because 802.3at is no longer sufficient. Furthermore, 802.3bt is the most current PoE standard that defines per-port power-source capabilities of 45 watts (W), 60 W, 75 W, and even 90 W. When a WAP is not fully powered, its functionality may be downgraded. Different vendors approach down grading capabilities differently. Some may turn off 2.4 GHz radios while others disable other network inter- faces, such as a Bluetooth low energy radio. It is important to research what will not be functioning when deploying WAPs with less than full power. Cabling Initially thought of as a way to future-proof cabling, the benefit of category 6A has been publicized for years. Some may not have adopted category 6A because of the increase in cost, perceived installation challenges, or because of not having a current use case for the increased transmis- sion rate. If not making a wholesale move to category 6A, it has been advised to use the advanced cable, at a minimum, for the WAPs. These generations of WAPs benefit from two class EA/category 6A or higher hori- zontal cables to each Wi-Fi location. Two cables allow for increased bandwidth through link aggregation; they also could provide increased PoE if that becomes necessary. Deploying Type 4 PoE Plus to remotely power WAPs can cause heat to build up in cable bundles. Select cables that are qualified for reliability up to 75°C (167°F), which enables support of the Type 4 PoE application over the entire operating temperature range of -20°C to 60°C (-4°F to 140°F). Shielded systems are more thermally stable and support longer channel lengths when deployed in high temperature environments (e.g., ceilings) and larger number of shielded cables may be bundled without concern for excessive heat build-up within the bundle. Use solid conductor cords that exhibit better thermal stability and lower insertion loss than stranded conductor cords for equipment connections in the ceiling where higher temperatures are likely to be encountered. FIGURE 4: Installing cables in a zone enclosure. The TRs are venturing out to the edge and may benefit from a zone cabling topology. The zone topol- ogy moves the heat and cable density from the TR into distributed telecommunications enclosures (TEs). Having a distributed zone approach, where the TE is near the WAPs, allows for rapid reconfiguration of the WAPs. It shortens the length of copper cables being installed and reduces the number of cables within pathways approaching the TE. It is important to reserve additional capacity within the TE so that cabling for extra WAPs can be installed to enhance wireless coverage (Figure 4).