By Monica Paolini, Principal, Senza Fili
Enterprises increasingly see the benefits of a pervasive wireless environment which connects not only people on the premises – staff, tenants, contractors, visitors – but also sensors, cameras, machinery, vehicles, goods and pretty much anything within the confines of the business’s physical location. Wireless networks today primarily allow people to communicate with each other through data and voice. With 5G and Wi-Fi, wireless technologies will take on a central role in enterprise core operations, either replacing the wireline infrastructure at the edge or adding connectivity to processes that today are still done manually by humans.
Are new wireless technologies such as 5G or Wi-Fi 6 ready to meet the performance, reliability and safety requirements that are necessary to support IIoT enterprise processes? 4G and legacy Wi-Fi can support many enterprise processes, and they have been instrumental in attracting the enterprise attention to wireless. Wi-Fi networks are ubiquitous in enterprises of all sizes and in verticals, and almost all employees use a cellular device at work.
But to move further in the adoption of wireless, the enterprise needs a combination of low latency and high reliability that 5G and Wi-Fi 6 jointly bring in a scalable, affordable and secure framework. In applications such as manufacturing automation, remote healthcare, or vehicle control, high or variable latency or insufficient reliability can cause product and asset damage, safety hazards, and even fatalities. The deeper wireless goes in the enterprise, the more crucial the performance, reliability and security of the wireless infrastructure becomes.
As 5G evolves with Releases 16 and 17, URLLC is going to be more scalable, manageable and reliable. Crucial to this evolution is the fact URLLC needs more than low latency in the RAN. The major source of latency in wireless networks is not in the RAN interface, but in the transport – and, when usage is high, in the contention within the RAN. A 1 ms latency in the RAN is of little help when the end-to-end latency for an application is 100 ms.
Still, the reduction of RAN air interface latency in 5G’s NR is the first enabler of URLLC. The other two crucial ingredients are edge computing and network slicing. Edge computing keeps the processing and data storage of latency-sensitive applications close to the RAN – in the enterprise case, this usually means on prem – and thus the 1 ms RAN latency shines, because edge computing eliminates the transport component from the end-to-end application latency.
In some cases, however, an application may not be run entirely at the edge, because it requires data that is available only remotely. For instance, a manufacturing application may require data or control from a remote branch or a source external to the enterprise. A healthcare application may require the participation of a provider in a remote location. In those cases, a combination of distributed, centralized and cloud processing may be necessary to ensure that latency and all other application requirements are met. A single application may require multiple traffic streams that have to be managed separately. This is where more-advanced traffic management tools such as network slicing come in, to provide the flexibility needed in allocating network resources.
Also essential to URLLC is the use of network slicing and advanced traffic management to manage contention. While 5G can support extremely low latencies, it is still challenging and expensive to support them at scale. Delivering most traffic at URLLC levels would be wasteful and result in lower reliability, even in an enterprise environment (in public networks, mobile operators are very careful not to commit to wide URLLC availability).
To benefit from the URLLC capabilities of 5G, the enterprise has to carefully select the applications that need both low latency and high reliability, and give that traffic the priority it needs in the RAN and beyond – for instance, by allocating it to a dedicated URLLC network slice. Network slicing not only allows the enterprise to give priority to URLLC traffic, it also makes it possible to run all the other applications on the same network. This increases the utilization of the network and, as a result, its cost efficiency and scalability. Without this capability, the enterprise would have to deploy a separate network for URLLC to control latency and reliability, and that would make URLLC too expensive for most applications.
Wi-Fi 6 is the next enabler, especially with the contribution of WiGig (IEEE 802.11ay) at 60 GHz and, eventually, with the expected extension of Wi-Fi 6 to the 6 GHz band. The new Wi-Fi 6 interface supports latencies that are comparable to 5G NR, and so in environments where traffic contention can be managed, Wi-Fi can support applications that require very low latencies with the desired level of reliability, possibly at a much lower cost than 5G. But because it uses unlicensed spectrum, Wi-Fi cannot guarantee the same consistency in performance that 5G can provide in licensed bands in environments where the enterprise does not have complete control of the Wi-Fi channels. In these cases, however, Wi-Fi can play a very important role in complementing and strengthening URLLC applications, especially where access to licensed 5G spectrum is limited, coverage is insufficient, or the 5G infrastructure is at capacity. The use of edge computing in an enterprise network makes it possible for the enterprise to manage traffic loads locally and allocate them to the best-suited resources, based on availability. For example, if, or when, a 5G cell is at capacity, a collocated Wi-Fi access point may be better for URLLC applications.
In 5G, the combination of low latency with edge computing, network slicing and Wi-Fi creates a new wireless framework that meets the performance, reliability and safety requirements of the enterprise for URLLC applications. Just as important, it uses the network resources with efficiency and scalability. Not only can wireless URLLC now gain the confidence of the enterprise, it also strengthens the overall business case for the enterprise to move to wireless and automated processes.