According to the International Telecommunications Union's (ITU) latest “Trends in Telecommunication Reform” report, ongoing capital investments related to fiber infrastructure are expected to total a staggering $144.2B between 2014 and 2019. One of the primary drivers for this immense capital investment into fiber infrastructure deployments comes out of thin air, in the form of tomorrow's 5G radios.

5G mobile networks will significantly affect both the wireless side (obviously!) and the wireline side of the global network infrastructure, as airborne bits jump to and from terrestrial wireline networks. In a previous post, I summarized the main aspirational performance goals of 5G, which are listed below. These formidable network performance goals are heavily predicated on the availability of fiber, and lots of it, to the cell sites.

Up to 1000 times increased in bandwidth, per unit area
Up to 100 times more connected devices
Up to 10Gbps connection rates to mobile devices in the field
A perceived network availability of 99.999%
A perceived 100% network coverage
Maximum of 1ms end-to-end round trip delay (latency)
Up to 90% reduction in network energy utilization

Traditionally, 2G and 3G mobile networks often used copper-based Time Division Multiplexing (TDM) circuits, such as multiple bonded T1s or E1s, to connect cell sites to a nearby Mobile Switching Center over the Mobile Backhaul (MBH) network. Although this now legacy MBH architecture has indeed served the industry well for decades, it’s quickly showing its age with the advent of 4G. MBH upgrades are taking place all over the world converting legacy copper-based MBH serving cell sites to packet-based transport over fiber, which enables far higher capacities to best future-proof MBH networks. The increased adoption of 4G LTE and LTE-Advanced mobile network technology is accelerating these MBH fiber upgrades, which can and will be leveraged by future 5G networks, given the almost unlimited bandwidth that fiber-based networks offer.

5 Key Wireline Network Improvements Needed for 5G

5G for Fixed Broadband
Another monkey wrench in the works is using fixed 5G access as a broadband replacement technology, which some carriers are considering. Although the “mobile” part is removed once the 5G radios are installed in a residential or business premise, they’ll still have a major effect on the RAN, and every part of the network between cell sites and data centers. Deployments of fixed 5G broadband access should be quicker and easier to deploy than running cables to premises meaning the rate that bandwidth can be turned up is accelerated, which will exacerbate bandwidth pressures on all parts of the global network. Although 5G fixed access will result in less fiber required to the premise, more bandwidth is turned up faster, meaning more RAN fiber.

Essentially all metro, regional, long haul, and submarine networks today are fiber-based, meaning they can already scale to voracious DCI growth by leveraging the very latest in optical transmission technologies. The access network, which includes the RAN, is the one part of the global network infrastructure that still has a significant amount of copper and wireless (microwave/millimeter wave) technology deployed, which will be a problem for 5G deployments, due to the promised speeds of this new technology. Areas targeted for 5G coverage require lots of fiber to be successful, and not just for capacity reasons, but also to meet the other rather formidable 5G performance goals related to network diversity, availability, and coverage, since all three of these goals are achieved through a greater number of interconnected paths, of fiber. It’s rather ironic that the projected performance goals of 5G wireless will depend on the availability of wireline fiber.

In fact, the only reason we don't have fiber connected right to our smartphones is because we'd be less mobile.