By Josh Simer,  AFL Market Manager for Service Providers and MSOs

In my last blog entry, I talked about the “collision” of “Cloud” and “Edge” computing, the one trend pushing computing capability away from the user, toward more centralization and the other pushing it toward the user. I concluded by saying that it was unpredictable where and indeed whether this collision would occur, but that network operators could prepare for any scenario by building an expandable, accessible, and flexible network. In this blog, let’s look at one likely-to-be-common scenario and talk about how those characteristics help the network operator address it.



Macro sites developing into C-RAN Hubs and Edge Data Centers

Scenario: a C-RAN Hub/Macro Cell site-based Edge Computing Center

As discussed in the previous blog, placing a miniature data center (DC) in a Centralized or Cloud Radio Access Network (C-RAN) Hub is one possible scenario for edge computing. It minimizes the physical distance traveled by any packet until reaching a server that can do something with the information, and therefore minimizes “network-induced” latency. Verizon, for example, has specifically said that their edge computing "can and will be getting to C-RAN locations."

In this scenario, the wireless network operator takes an existing C-RAN hub and expands it (both physically and logically) to become a miniature edge data center. This could range from simply adding a few devices to an existing rack or cabinet, to adding multiple additional racks in a walk-in shelter.

Here is how the key network characteristics help address this scenario:

Expandability

The first characteristic to address here is expandability. This further breaks down into two elements: connections to the edge DC and connections within the DC.

For connections to the DC, in this scenario, there may be a requirement for additional fibers to handle increased bandwidth needs. While the edge DC should, all else equal, reduce the bandwidth requirements for backhaul by handling some traffic at its level, in reality all else is not equal. If someone is putting an edge DC in that C-RAN Hub, it’s because there is or will be more total traffic being generated in that hub’s coverage area. That means there is, or will be, more front haul and backhaul traffic. But it can be expensive to install new fiber connections to and from this hub. That is particularly true in the dense urban areas in which this this scenario is most likely. Also, wireless operators may “densify” their networks by adding more small cell sites which will then need connection back to that C-RAN Hub. Network operators need to prepare for this from the start by ensuring they have the fiber capacity available.

Fortunately, AFL helps network operators address this by making it more economical to deploy this capacity up front. AFL’s Wrapping Tube Cable provides the most fibers in a given cross-section of any ribbon cable available today. This allows operators to deploy more fiber in the same or even smaller sized ducts, conduits, handholes, etc. The result is that they can deploy additional fiber without increasing construction costs. For example, doubling the amount of fiber deployed while increasing total costs by less than 5%.  AFL’s Apex™ Fiber Optic Splice Closure, when combined with Wrapping Tube Cable, enables the most splicing capability in a given sized handhole within the industry. This means that installing the capacity to manage those additional fibers and handle new connections can also be done without increasing construction costs.

Within the C-RAN Hub/Edge DC, expandability is also important. In this scenario, there may be dozens or hundreds of new fiber connections internally. AFL’s ASCEND® Modular Platform is an example of how operators can plan for this capacity, by having a fiber management panel that can readily accept new modules, convert from simplex to duplex to MPO connectivity, and more. It is even capable of accepting passive WDM filters to further expand the capacity of internal and external connections.

Flexibility

Now that we’ve talked about how to use the expandability characteristic to ensure that the network is capable of handling the bandwidth, we have to discuss having the flexibility to make use of that capacity where and when it’s needed. To make an analogy, it’s one thing to build a new 10-lane highway, but you need to make sure you can add on and off ramps where the traffic occurs. In this case, a wireline operator doesn’t necessarily know in advance which existing macro cell sites may be used as C-RAN hubs in the future, which of those may become Edge DCs, and where new C-RAN hubs and Edge DCs might be added.

Fortunately, AFL products help here as well. For example, AFL’s Wrapping Tube Cable with Spider Web Ribbon® (SWR) technology, combined with the Apex splice closure, allows for the maximum flexibility in a given space. By fitting the capability to handle more fibers in the same or even smaller size handhole, we give the network operator more options on placing that handhole, and a greater ability to bring in future connections. 

The ASCEND’s modular platform is another example of allowing the operator to redesign inside the hub to accommodate more internal connections, and different numbers and types of external connections (simplex, duplex, CWDM, DWDM with various channel counts, etc.).  In short, these products give the wireline network operator a wide range of options to address changing future needs.

Accessibility

Having the flexibility to redesign a network to accommodate future needs is one thing. Somebody actually has to go out and implement those changes. This can be a real challenge with an already installed, fiber-rich network. Technicians deal with congested cable environments, reopening enclosures, identifying the right fibers, and have to do all this in any type of environment and weather.

AFL has solutions for this as well. The design of SWR enables technicians to readily pull out and splice any number of fibers, not just multiples of 12. SWR also is ribbonized at a 250μm pitch, which means that it allows for the compact cable designs enabled by 200μm fiber without requiring special tools for mass fusion splicing to 250μm fibers and ribbons. AFL has even innovated the labeling of fibers and ribbons to better allow technicians to identify the correct ones to use. The Apex splice closure is designed to be easily re-enterable and re-sealable. It also has a standard splice tray design, as opposed to separate ribbon and single-fusion splice trays, meaning the technician only needs to have a single type of tray available. Inside the C-RAN Hub/Edge DC, AFL has designed the ASCEND modular platform to make changes and upgrades in a snap (literally).

Sometimes the Cloud and the Edge will collide. Sometimes they won’t. The only universal statement we can make is that it will depend on the specifics of a given location or area, combined with future trends in technologies and applications that we can’t predict. But even with that sort of vague prediction, a network operator can prepare for future opportunities by building a network that is expandable, flexible, and accessible. AFL’s products are designed to deliver these capabilities to networks, and AFL’s network services personnel are the world’s experts at engineering and building such networks.