How to build a private 5G network architecture
A private 5G network could provide organizations with greater control over their wireless environments. But cost and complexity could be critical deterrents.
Just as previous generations of wireless technology had their honeymoon phases, 5G networking was introduced with great fanfare to a range of potential constituents. Verizon, AT&T and their contemporaries made early 5G pitches to their enormous consumer bases. But another 5G story has also simmered in the background.
A growing list of vendors and potential enterprise customers are contemplating how private 5G networks might reshape organizational wireless connectivity in the years to come. Let's explore the high-level why and how of private 5G network architecture.
Define your 5G requirements
5G networking has been marketed heavily as a transformational technology for both public and private spaces. 5G follows 4G LTE and is supposed to yield vast improvements in performance by comparison. The promise of 5G sounds impressive, but the realization of benefits on the grand scale hasn't exactly been rapid or consistent yet. Understanding the tradeoffs that are required to get there is important to anyone interested in implementing a private 5G network architecture.
Smaller cells, and often more of them, may complicate the potential in-house deployment of private 5G. At the same time, the control and power of a private 5G network may be compelling.
But why invest in private 5G networking? The technology is expensive, and it probably won't fully displace Wi-Fi or LAN for most environments. So, it simply could be another system for the budget to accommodate.
Wi-Fi and private 5G similarities
As with Wi-Fi, company requirements drive 5G network design. But, before enterprises can proceed to the design phase of either Wi-Fi or 5G, they need to understand what they want from the network. Wi-Fi and private 5G have the following characteristics in common:
- Requirements drive design. If an enterprise can't define what it needs the network to do for the business in detail, then it's almost impossible to get the design right.
- Design skills matter. In-house network design is possible but only if those charged with the task have specialized training. Otherwise, it's best left to a third party that specializes in system design for the specific technology.
- Integration is integral. Both Wi-Fi and private 5G are just part of the overall network picture and require thoughtful integration with the LAN and possibly WAN environments to be successful.
- Don't forget the wires. Both Wi-Fi and private 5G have their own cabling and pathway needs to consider.
Wi-Fi and private 5G differences
Wi-Fi has been around for more than 20 years. It's well established in nearly all corners of the enterprise network environment. By comparison, private 5G, and even private LTE, are relative newcomers. Key differences between Wi-Fi and private 5G include the following:
- Device density. Wi-Fi-compatible devices are everywhere, but not many device types and models can benefit from private 5G, even when it's the better service for a given application.
- Access hurdles. The private 5G paradigm is subscription-based, just like public 5G. Unlike Wi-Fi, it's difficult to just let anyone on a private 5G network. Users need to have a capable device and be registered for access.
- Cells and coverage. Enterprises should be able to overlay more ground with private 5G cells compared to Wi-Fi when it comes to simple coverage. But, if the blazing speeds promised by private 5G are desired, then cell sizes need to be carefully managed.
Private 5G deployment considerations
Once you have defined the why for private 5G, the how becomes important. Most environments need outside help to get it right. As with any network design -- and especially for wireless networks -- different network sites could have vastly different requirements. While private networks may boil down to simple line diagrams, they can be complicated depending on several factors.
Small cell hardware, such as gNodeB devices and remote radio heads and their associated interconnect cabling -- form the access edge of the 5G private network. These devices need strong upstream connectivity to the LAN and likely out to the internet as well. Clients obviously access the network as 5G radio devices, but what goes on upstream may rely on fiber, copper, microwave links, satellite or any combination of them all.
To support the strongest 5G networks, upstream connectivity needs to be scaled accordingly -- generally measured in the tens of gigabits for interfaces. The entire paradigm needs to dovetail with your existing network. As a result, switching, routing, security and core services, like Dynamic Host Configuration Protocol and DNS, that are tailored per organization are all in play.
Private 5G is part of a company's network, while the carriers' versions of 5G rely on their own core services. Hybrid topologies combine both private and public 5G for flexibility -- and complexity.
Public 5G networks should overlap 4G for many years. Mass-scale 5G simply can't be rolled out quickly given the size and diversity of coverage areas that need to be accounted for. By contrast, private 5G networks may well see a faster rollout rate if their ROI models solidify and more enterprises buy in.
Remember, this is not a one-size-fits-all paradigm, and there are countless permutations to the constructs of private 5G networks depending on what purpose they serve and what frequencies are in play.
How to build a private 5G network
Regardless of the particular size and setting of a new private 5G network, the following steps are required:
- Define requirements and scope of usage for the network.
- Identify client devices that should meet the requirements.
- Find a private 5G service. Any request for proposal would likely garner responses from leading system providers and other vendors that specialize in complete private 5G services.
- Design the network, which may come before or after the vendor selection process, but it's a key milestone in building the system.
- Build out the physical layer.
- Implement system turnup.
- Integrate the private 5G network with the rest of the network.
- Perform testing and tuning.
Though most private 5G deployments still require a significant amount of outside help, a growing number of Wi-Fi professionals are morphing into "wireless generalists" and getting skilled on private 5G and other technologies, like Long Range WAN, as the overall wireless landscape evolves.
Editor's note: This article was updated to provide more comprehensive information on building a private 5G network and to explore the similarities and differences between Wi-Fi and private 5G.
Lee Badman is a network architect specializing in wireless and cloud technologies for a large private university. He's also an author and frequent presenter at industry events.