Beat bottlenecks in WLANs and retain legacy copper infrastructure

May 07, 2015 // By Kamal Dalmia, Freescale Semiconductor
Wireless connectivity is transforming enterprise network topology everywhere except in one critical area: the infrastructure carrying wireless traffic from access points to network switches.

In most cases, that infrastructure is dominated by 1-Gigabit per second copper cables that transport access point signals back to Ethernet switches. But connectivity demands and next-wave technology standards require greater bandwidth than 1Gbps.

Increasing the ability of the existing infrastructure to accommodate higher transmission rates promises to alleviate this infrastructure bottleneck and accommodate the growth in enterprise wireless connectivity in the most cost-effective, least disruptive way.

Enterprise local-area-network (LAN) technology deployed in most offices and campuses around the world has remained static at 1-Gbps transmission speeds for more than a decade. The broad proliferation of mobile devices generating traffic through these networks demands capacity well beyond this rate.

Figure 1. Copper cables in the walls and drop ceilings of enterprise campus buildings represent the current status quo of access network infrastructure and support 1-Gigabit per second data rates.

However, a variety of next wave technologies, such as 802.11ac access points, demand greater bandwidth.

802.11ac Wi-Fi access points (APs), and Wave 2 in particular, demand Ethernet backhaul bandwidth of up to 6.9 Gbps on the wired infrastructure side, but the copper cables that connect these WiFi APs to enterprise switches have reached their design limits. The vast majority of these UTP cable connections are either Category 5e or Category 6. Replacing these cables with higher speed 10Gbps links of Category 6a or above is costly, labour intensive, disruptive, and requires a monumental effort to upgrade billions of installed connections. Upgrading to fibre optic connections would be even more expensive and intrusive. Theoretically, enterprise and campus network administrators might upgrade these connections to 10 Gbps or higher as soon as possible. In reality, the prevailing attitude is to leave the legacy cable infrastructure in place for as long as possible because it is still functional and reliable and the cost of replacing it is prohibitive.