Warehouse robots could use 5G and Wi-Fi at the same time.

Autonomous robots with multiple sensors and capabilities could take advantage of 5G / Wi-Fi network convergence.

The case for 4G/5G and Wi-Fi network convergence has never been stronger but what is the role of the MNO and what does this mean for industry?

By Drazen Vitez

Private 4G/5G networks are on the rise

Private 4G networks are not new. They have been around for a long time, but until now they were few and far between. From a current estimate of about one thousand¹ private 3GPP networks, their numbers are expected to grow to 10’s of thousands due to:

the availability of localized² private spectrum and cost efficient cloud based 4G/5G core deployments
the increased demand, as enterprises strive to increase productivity through automation and digitalization of their processes
MNO’s actively pushing private 5G networks in an attempt to capture their share of this growing market segment

At this point, MNO’s are putting a lot of focus on enterprise use cases in order to justify 5G investments. A variety of use cases are being driven by MNO’s. However, as the market matures, we believe that only some use cases and some verticals will remain viable for MNO’s. There are many other use cases and verticals that can benefit from private 4G/5G networks which will require other industry players to make their own arrangements. This can be seen from announcements that industrial automation experts such as Siemens³ are developing their own private 5G equipment and deployment capabilities. Domain know-how, flexibility, commitment and cross-domain integration beyond connectivity, needed in versatile campus networks will come from various system integrators and service providers.

Adding one more network to the list…

When we move from public communication networks into campus networks, we will find a huge variety of specialized equipment, protocols and use cases that are inconceivable for MNO’s operating a pure 3GPP network. Combinations of wired and wireless connectivity will remain viable options in campuses / enterprises and private 4G/5G networks will be one of the overlay networks, similar to enterprise Wi-Fi today. Private 5G network properties will be used for dedicated use cases and in some use cases (e.g. those requiring mobility), connected devices (e.g. robots, automated vehicles or smartphones) will roam between different networks. This could mean private 4G/5G, Wi-Fi, even public 4G/5G when moving out of campuses or on remote sites not covered by private 5G.

Moving in and out of network coverage can cause service interruption which might not be acceptable for some enterprise use cases (e.g. automated vehicles in logistic warehouses). In both 3GPP and non-3GPP networks, the connected device makes the decision as to which cell or AP it will attach to. It is not possible to control UE attachment from the network, rather we are dependent on the connected devices to make the right decision to roam. This creates difficult situations in “edge-of-coverage” areas where connected devices have better connectivity options available, but do not detach from the current (bad) connection to a cell/AP which can provide better connectivity.

In “handover” situations and in “edge-of-coverage” areas, the best connectivity can be achieved by connecting devices to all available networks simultaneously and making all connectivity options available at the same time to upper application layers. This is achieved by the introduction of ATSSS4, a 3GPP network function, defined in Rel16 and with further enhancements coming in future releases.

“Overlay ATSSS” based multipath connectivity

This variety of 5G use cases is an important factor in understanding the need for the “Overlay ATSSS” approach. 3GPP Rel16 and subsequent releases will define the ATSSS function, but its implementation by device vendors and 5GC suppliers is critical for the introduction of this convergence capability in commercial networks. As a consequence of the variety of use cases, there will be diversification of equipment vendors, integrators and service providers. Connected devices will also follow the diversification trend. This will make the ubiquitous native implementation of the ATSSS function, as part of the 5G Core, more difficult.

Difference between the 3GPP and Tessares approaches to ATSSS. Tessares overlay approach works now and in the future with 4G, 5G and fixed core.

On the left, the ATSSS function in the 5G core supports the convergence of 5G and Wi-Fi but is still years away. On the right, the Tessares solution which puts the ATSSS function into a Hybrid Access Gateway which supports the convergence of 4G, 5G and the fixed core today.

“Overlay ATSSS” proposed by Tessares, will allow for OTT deployment of this convergence function, regardless of the 5GC vendor and their roadmap. This approach is agnostic of underlying networks and flexible enough to adapt to various enterprise / campus network use cases. The standardized ATSSS convergence approach will have advantages over various proprietary implementations of similar functionality since it is based on open standards defined by the IETF, 3GPP and others. Its interoperability is rooted in the 3GPP ATSSS standard.

Use cases for multipath connectivity in private networks

Below, we can see how Deutsche Telekom sees use cases for ATSSS based multipath convergence in private/campus networks:

Deutsche Telekom view of campus networks benefitting from 5G Wi-Fi convergence.

Slide from: https://www.linkedin.com/posts/alex-jinsung-choi-dr-48a8b61_campusnetwork-atsss-activity-6746419255182471168-ZHII

Of course, those generic use cases will be broken down into more specific use cases as technology hits the production floor and new features become available both with upcoming Wi-Fi Alliance and 3GPP releases.

As technologies such as uRLL, MEC, AR and others find their foothold in the enterprise environment, connectivity in “handover” situations and in “edge-of-coverage” areas will become only more critical and a convergence solution more necessary.

Conclusion

The long running debate over the prevalence of 5G or Wi-Fi is a false narrative. Both technologies have their respective strengths and combined, they will be able to connect even more devices, creating benefits for mission critical IoT devices in manufacturing, healthcare, energy, and more⁵.

A new initiative⁶ that is exploring ecosystem requirements for efficient convergence of Wi-Fi and 5G in private networks will define early high impact use cases, convergence architectures and define early trials for this technology. Tessares is committed to supporting this important project.