How to assess and calculate the cost of critical wireless connectivity options

Why private wireless networks are a compelling choice over wi-fi

Modern industrial enterprises have a variety of connectivity requirements, including those related to the conduct of their business and machinery. At most sites, there is a combination of two different requirements:

• Administrative functions: Office teams need to be able to use their phones, for which a traditional mobile operator’s coverage is sufficient, while IT teams are responsible for land connectivity and wi-fi.
• Critical applications: These are driven more by the operational technology (OT) side of the business, with a higher set of requirements for reliability and security.

Private wireless technology focuses on the OT side of communication and applications, while the IT side is handled more by familiar tech such as ethernet or wi-fi.

In an era when there is a need to connect increasing numbers of assets, the OT team expects from wireless the same level of performance and reliability that used to be delivered by wired connectivity.

While wi-fi has improved significantly with the advent of the wi-fi 6 standard, but that has focused mostly on increased capacity and user performance. There are still some significant challenges when it comes to meeting OT requirements. In terms of reliability of performance, private wireless networks make a major difference. 

Not all applications need extremely low latency, but it needs to be stable. When you plug a LAN cable into a machine, you are almost guaranteed to get 100mg performance – and OT teams expect that from wireless technology.

Private wireless delivers added value in security and mobility

4G and 5G technology has raised security standards, which – allied with the use of SIM cards and end-to-end encryption – makes for extremely robust systems.

Another aspect that is important for OT is the ability to have a single wireless network for all applications. This is especially beneficial in industrial sites that have multiple networks for different applications.

The final important consideration is mobility. At a location such as a port or a mine, the mobile credentials of 4.9G LTE networks are crucial when it comes to reliability, low latency and a high data rate.  

Whereas wi-fi is geared for IT and office communications, private wireless is better suited to the critical OT piece.

Three reasons why wi-fi is still seen as a contender

1. OT connectivity projects often involve the IT team, who bring their own technology to the table.
2. Vendors of wi-fi technology do not always understand the difference that private wireless networks can make.
3. The perception remains that wi-fi is a low-cost solution.

The tipping point at which private wireless makes sense from a cost perspective

The picture is complex, but our research suggests that the increased cost in terms of spectrum, sales and the core network are offset once you have an industrial site of more than 25,000 square metres of indoor space.

However, at any industrial site of any size that has a challenging radio environment, a private wireless network is clearly a superior solution…

Case study 1: A deployment that offered a point of comparison

We worked on a deployment in North America at a very large manufacturing plant with an extremely high ceiling and many large, long metal machines.

We learned anecdotally that the planning and network design aspect of the proposed rival wi-fi solution was more expensive than our complete offer for private wireless network. There were two principal reasons:

1. Wi-fi uses a licensed spectrum that is limited in terms of output power. Wi-fi access points had to be placed very high on the ceiling and use directional antennae to create coverage on the floor below for the whole network. While we were able to do our radio survey in a couple of days, it took almost a month to plan the wi-fi coverage.
2. Another challenge was posed by interference. The prevalence of metal machinery causes reflection and refraction – which is not good for wi-fi at all – whereas private wireless still works when there is interference.

The enduring assumption that wi-fi is a simple, plug-and-play technology is erroneous, especially in complex industrial environments.

Case study 2: Challenges in the open pit mining space

This was another example of a complex radio environment. While there is a slightly steeper learning curve on private wireless – despite the considerable amount of work Nokia has done in this space – ultimately it is a far more compelling choice.

In a difficult, fast-moving environment with metal machines, partitions and a mine that expands due to explosions, drilling and digging, a private wireless network is a deploy-and-forget solution.

In contrast, wi-fi in such a location requires constant management. The teams maintaining the wi-fi had to return to the site on an almost weekly basis to readjust the network in line with the new topology of the mine.

This was another context where the ability of a private wireless network to be the single wireless network for all the applications on site was highly valuable.

That includes legacy P25 or TETRA critical voice systems, which can be upgraded with private wireless.

For more information: Private wireless | Nokia

To listen to our other episodes: Nokia Private Wireless audio library | Nokia