5 key wireline network improvements needed for 5G
Ask an end-user about how their phone connects to the network, and they’ll likely only talk about cellular or wireless technology, which is also where most of the current 5G industry hype is focused, and for good reason, as this is the first part of the network to be upgraded. However, the reality is that RAN only makes up a small portion of the end-to-end path that data from a connected device must travel to provide connectivity. The rest of the path is primarily a fiber-optic transport network.
With 5G coming soon, featuring data rates as much as 100 times faster than what’s currently available, the wireline infrastructure that connects end-users (man and machine) to accessed content residing in data centers, must be ready to support upwards of 1,000 times more data flowing across it.
How can network operators prepare? Well, here are five key areas within the wireline network that will need to be upgraded and modernized to support 5G.
Fronthaul is part of the network connecting multiple Remote Radio Heads (RRH) to Centralized Baseband Units (BBU) where the baseband processing takes place (see What is mobile fronthaul?). It’s the transport component of Centralized/Cloud RAN (C-RAN).
Traditionally, BBUs processing signals were located at the base of macro cell towers, connected to the radio heads on top of the towers by copper cables. These copper connections continue to be replaced by fiber because it’s lighter, more power-efficient, less expensive, more secure, and more resilient to the elements. Fiber also supports far longer distances and much higher transmission rates, giving network operators the ability to centralize multiple geographically separated baseband units from multiple towers into a single physical location.
Centralization unlocks multiple benefits for service providers, including intelligent traffic coordination between multiple remote radios, a single secure site to manage, and access to web-scale benefits from centralizing the processing functions. Of course, the availability of fiber to/from RRHs and centralized BBUs can be a challenge in some environments, as is the strict latency requirements between the two.
5G promises to make available to the end-user a massive amount of bandwidth that will need to be aggregated and placed on the wireline networks. On the RAN side, a 20MHz 5G MIMO antenna array can generate upwards of 64 Gb/s of data, a massive increase in fronthaul traffic.
On the backhaul side, a model of 5G specifications can assume that 75% of users/sites will get 500 Mb/s, 20% at 1 Gb/s, and 5%% at 10 Gb/s. This will create an order of magnitude increase in backhaul traffic generated that will need to be aggregated and delivered to the wireline network.
All that bandwidth increases in both the fronthaul and backhaul network will be passed along to the metro, regional, and long haul networks all the way back to the data centers. The answer to this issue is fiber, and lots of it.
Today’s 4G macro cells are in big towers that typically serve a 20-30 km radius. To support the higher speeds of 5G carried over higher parts of the wireless frequency spectrum, network operators must make the cells much smaller and move them closer to the end-users. This will come in the form of “user-deployed” indoor cells—known as femto, micro, and pico cells—as well as operator-deployed small cells
The capacity of these small cells is such that each will require a fiber-based connection. There’ll be some radio-based backhaul in cases where the network operator cannot get right of way or is simply impractical, but fiber is always the preferred option due to its inherent security, capacity, and ability to scale. Score two for fiber.
Virtualization has allowed network operators to move from custom networking appliances to virtual applications run over x86 server clusters that can be moved around the mobile network depending on the application required.
Enhanced mobile broadband, for example, could have a cloud-evolved packet core sitting in a metro hub site, cloud RAN at an aggregation site, and numerous sites with IP/optical back to the access point feeding into the data center. This is essentially today’s broadband mobile network architecture, albeit on steroids!
For ultra-reliability and low latency, however, network operators could move network functions closer to the radios. A shorter path to process the data over less network equipment will produce much lower latency, much higher reliability that open a new range of possible use cases.
5) Network Slicing
Many of the use cases for 5G will all use the network in very different ways. For example, streaming very high-definition video over mobile broadband, telemedicine applications connecting to a mobile network using WiFi access, or low-capacity and periodic access from an IoT device will all have their own requirements in terms of speed, latency, availability, packet loss, and more.
Network operators will want to support all these types of applications on a common infrastructure for a variety of reasons related to economies of scale, security, simplicity, and reliability. Each will require distinct and guaranteed Service Level Agreements (SLAs), and each will need to be orchestrated from end-to-end. Providing different network attributes to different applications requires network operators to perform what’s known as network slicing. That makes network slicing a key enabler for creating new and valuable network services.
Enter Ciena 5G Boot Camp
The move to 5G won't be a simple network upgrade. It's a long journey with a high-performance wireline network as the critical component to commercial success for both 4G strategies and the evolution toward 5G. Trying to digest the vast amounts of information available online related to 5G is like drinking from a fire hydrant, which is why we’ve created 5G Booth Camp a series of blogs over 2018 aiming to concisely explain the most important aspect of 5G written by several experts at Ciena across various disciplines.
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