5G Will Affect Network Architectures

Before the advent of mobile communications, networking architectures all were simple. Public networks (telcos) supplied wide area communications to a premises, while inside buildings customers created their own internal distribution networks.

Architectures are less clear now that new platforms such as Citizens Broadband Radio Service and spectrum sharing and aggregation are emerging. One might argue that “mobile” architectures might, in many cases, take the older fixed network form.

The classic example is the consumer in-home network or any business local area network, with a clear physical and logical point of demarcation between the WAN and the LAN.

The WAN consists of assets owned by the service provider and the LAN facilities are owned by the consumer, tenant or building owner.

source: Router-Switch

That became more complicated with the advent of mobile networks, which theoretically provide direct connection to the end user device, no matter where it is located. In practice it sometimes is more complicated.

A smartphone can be used as a Wi-Fi hotspot, which then creates a private network within a premises or any other local area. In that case, the public network (WAN) terminates at the device acting as the hotspot, all other potential devices connected to the hotspot then constituting the LAN.

In other cases a multi-radio Wi-Fi network with repeaters also creates a more-substantial LAN.

Indoor coverage, always an issue since 3G, is going to become a bigger challenge in the 5G era, when higher frequencies in the mid-band and millimeter wave region will be employed. And that is going to recreate the space within which LANs make sense.

Signal propagation is the reason: many 5G signals, while adequate outdoors, will have signal strength issues indoors. One way to illustrate this, shown below, is that signal propagation through walls, from the public network (cell towers), decreases with an increase in frequency.

source: Surecall

Another illustration illustrates the principle that cell site signal loss increases with frequency, while coverage decreases.

source: Look Far

All of that means there is potential new terrain for 5G and subsequent mobile networks to use the WAN-LAN framework, where private networks might assume greater roles inside buildings. That, in turn, means there might be new roles created for connectivity providers.

As Boingo and others have specialized in creating private Wi-Fi networks for venues, so it might happen that entities also provide 5G mobile coverage indoors. Whether that is the mobile operators, neutral-host providers or enterprises and consumers themselves remains to be seen.

CBRS, for example, can provide indoor coverage or traditional access to premises for 4G mobility services. The former use case is most likely with enterprise venues; the latter will be most common in consumer settings. CBRS can be used to create indoor private 4G networks. CBRS also might be used to support small cell or wireless fixed access networks.

Indoor 5G coverage methods already are available. In some cases service providers with licensed spectrum will deploy the systems. In other cases, third parties might use unlicensed spectrum to create their own indoor networks.

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The point is that from both a business model and technology standpoint, heterogeneous mobile networks are coming. In some cases, service providers directly will deploy indoor infrastructure in the form of small cells.

In other cases they may partner with third parties to install and operate such infrastructure. In yet other cases enterprises or consumers might create their own LANs.