Cabling for Wi-Fi

Editorial Type: Technology Date: 2019-09-01 Views: 1,366 Tags: Networking, Wi-Fi, 5G, Wireless Networking, Siemon
The latest design standard for Wi-Fi requires an intelligent approach to cabling in order to derive full benefit. Valerie Maguire, Director of Standards & Technology at Siemon offers an informed insight

Wi-Fi 6 (802.11ax) differs from previous generations of wireless technology in three major aspects. Firstly, it will initially deliver four times faster average throughput when compared to Wi-Fi 5 and with data rates in excess of 5 Gb/s expected, it will increase speed and capacity. Secondly, Wi-Fi 6 benefits from the provision of two wired high bandwidth IT cabling uplink connections that will enhance remote powering capability. Lastly, Wi-Fi 6 can operate at either 2.4 GHz or 5 GHz to support a larger volume of mobile devices within dense deployment environments.

Designers, consultants and installers tasked with the implementation of a Wi-Fi 6 network must be aware of these technological changes and fully understand the implications for the wired cabling uplink infrastructure. The potential of Wi-Fi 6 can only be fully unlocked if the wired infrastructure is properly specified, designed and deployed.

CONNECTING UPLINK
The ability of Wi-Fi 6 to support greater than 5 Gb/s data speeds has significant implications on wired media selection for uplink connections. Further, Wi-Fi 6 access points are outfitted with two copper ports with at least one of these Ethernet ports supporting either 2.5GBASE T or 5GBASE-T. Because Wi-Fi 6 technology is expected to eventually rely on aggregation of multiple 2.5G/5G/10GBASE-T capable uplinks, Standards organisations and design experts are adopting the recommended practice of deploying two minimum category 6A (or category 7A) drops to each wireless access point (WAP).

Wi-Fi 6 WAPs perform highly complex signal processing and are thus unable to operate within the 13-watt Power over Ethernet (PoE) budget that supported earlier generation Wi-Fi implementations. New Wi-Fi 6 WAPs must be supported by either a direct DC power connection or cables and connectors compatible with 30-watt Type 2 PoE. Support of PoE operation inherently requires additional attention to media selection.

PERFORMING AT TEMPERATURE
At an applied current of 600mA per pair, Type 2 PoE can increase the temperature in cable bundles by up to 10°C, leading to a loss in performance. A recommended practise is to select and install shielded cabling, which provides greater thermal stability. Category 6A or category 7A shielded systems that are qualified for mechanical operation up 75°C will further minimise the need to implement strategies, such as reducing bundle sizes or derating channel length to support necessary signal margin over the installation operating temperature range of -20°C to 60°C.

In addition, unless specifically designed to support remote powering applications, connectors are susceptible to contact erosion, which results in decreased reliability when cabling is disconnected from a live WAP. Selecting connecting hardware that complies with IEC 60512-99-001 will ensure that contact seating surfaces are not damaged when plugs and jacks are unmated under these PoE current loads.

CABLING IN THE ZONE
A cabling deployment topology that supports redundancy and equipment upgrades can alleviate pain points associated with Wi-Fi network management. A grid-based zone cabling architecture that uses zone enclosures and service concentration points (SCPs) will allow for maximum flexibility to interconnect wired cabling uplinks to WAPS while also enabling rapid reconfiguration of coverage areas as needed. It will also conveniently provide additional capacity for WAP upgrades with minimal disruption.

Wi-Fi 6 technology is not only required to support the rapidly growing number of new connected devices appearing on the IT network, but also to support the increased need for the speed and capacity required to ensure users can access ultra HD video, multimedia streaming and other business critical applications from their mobile devices. But the performance of the wired uplink connections is critical. A grid-based zone cabling design using thermally stable shielded category 6A or higher cabling solutions is the best choice to ensure support of Wi-Fi 6 and beyond. NC