It is a bit of an exaggeration to say that backhaul is the purpose of a fixed network. After all, as many generations of engineers have been trained, “access” is the purpose of a fixed network, allowing customers to use the apps and features of the core network.
On the other hand, one often hears app providers called “edge providers,”defined by the Federal Communications Commission as “any individual or entity that provides any content, application or service over the Internet, and any individual or entity that provides a device used for accessing any content, application, or service over the Internet.”
That is going to strike some of you--rightly--as being excessively broad. If all users and app, content or service providers are “edge providers,” then the concept has almost no meaning, as there are virtually no instances of any entity connected to the internet other than edge providers.
In other words, our language now suggests “everything” is “edge,” and nothing is “core.” That is wrong at the physical level, and also a topsy turvy inversion of networking elements.
So the first objection to the notion of “edge provider” is that it refers to “everyone” and “everything” connected to an IP network or the internet. In a broad sense, the “role” of a consumer, the role of a content or app provider and the role of an “internet access provider” remain distinct.
Big hyperscale data centers, central offices, private and public servers operated and used by enterprises, content, app and service providers are one thing. End users are another, and the networks that connect users are different from each of those categories.
Still, in a functional sense, whatever we choose to call the facilities called the “access network,” those facilities functionally provide backhaul (or “fronthaul,” services): cell tower to switching center; radios to controllers; phones to switches or servers; PCs to servers; sensors to servers.
Functionally, it is all backhaul, even if, technically, backhaul connects the mobile network to the wired network, while fronthaul connects radios with controllers. In other words, all access is backhaul.
That is especially true now that most human being get “access” to servers and switches from a mobile device connected to cellular network radios or a Wi-Fi router. For a telecom or network engineer, “access” is a specific part of the wired network, distinct from the “distribution” or “trunking” network and the “transport” or wide area network.
In a different functional sense, access is the radio link between a device and the wired network. But the last few miles of the wired network represent as much as 80 percent of all network investment.
That has huge implications in facilities-based competitive markets, as stranded fixed network assets become a key part of the business model. “Stranded assets” are “access lines” which have no paying customers on them. In facilities-based competitive markets such as the United States, that means no single supplier typically has a paying customer on more than 40 percent of deployed facilities.
Put another way, up to 60 percent of the invested access network capital is “stranded.”
On the other hand, fixed access assets used for backhaul become more important, as small cell architectures place a premium on dense backhaul networks. So it is a safe prediction that, in coming years, the value of fixed networks will be a contest between the cost of stranded assets and the value of dense backhaul assets.