Cellular vs. Wi-Fi
The cellular and Wi-Fi worlds have always maintained somewhat of a love-hate relationship. I’ve personally lost count of how many times I’ve heard about convergence, offload, integration and complementarity technology.
The reality? Development and sales in certain market segments were primarily determined by three factors: maximum radiated power, the use of licensed/unlicensed frequencies (which are then two concepts linked together) and the support of mobility (static, nomadic and full mobility). Leaving aside niche cases and specific applications, Wi-Fi has in fact become the standard technology for short-range access (now) at very high speeds and within everyone’s reach. In contrast, 4G – and the future 5G – are still considered a wide-area coverage mobile technology, available only to operators with access to certain licensed frequencies.
Why is convergence such a popular topic? There are applications – in particular high-density applications – where a cellular approach requires a very precise design. Examples include stadiums where offloading over Wi-Fi networks is necessary and requires very small radio cells and strong directional antennas. This equipment ensures the necessary throughput to support applications such as video streaming to thousands of devices densely concentrated within a few hundred square meters. In addition, MVNOs with a large geographical footprint that lack access to cellular spectrum have used Wi-Fi to offer data and voice access (thanks to Wi-Fi calling) and pay fees to their MNO only when strictly necessary.
Convergence: Limited use cases
However, even if the technologies to implement an effective and seamless convergence have been around for some time (such as Passpoint), real use cases are still quite limited. A definitive explanation isn’t immediately apparent, although it is clear that economic and political interests continue to play a prominent role. This is because 4G technology has benefited from enormous industry investment over the years and lucrative market opportunities remain focused on cellular technology. It is no coincidence that the best example of “convergence” was achieved on the device front, rather than the network side. Specifically, all modern smartphones can switch painlessly between Wi-Fi and cellular networks by automatically selecting the best connection (ABC, Always Best Connected).
5G and network slicing
What will happen on the 5G front? Well, that is a good question indeed. Huge investments are being made in 5G (some pundits estimate it to be an order of magnitude higher than 4G) to support a technology that promises very high throughput, very low latency and innovative features to support IoT, VR, automotive and enterprise applications.
One fascinating concept related to the advent of 5G is network slicing, which incorporates advanced concepts of NFV, SDN and Cloud. One potential application would be to ’outsource’ the deployment of LANs and delegate them to remote delivery over a 5G network. One could therefore be forgiven for wondering why the industry should continue investing in enterprise structured cabling and wireless LANs when everything can be offered from outside, via 5G.
This is an interesting question, albeit with several underlying question marks:
- Current WLAN technologies – such as Wi-Fi 6 and multi-gigabit connectivity – already offer performance levels that most cellular networks can’t match in the short term. The advantages of WLAN will be further bolstered by additional 6GHz spectrum rolling out in multiple regions throughout 2020 and 2021.
- From the perspective of CAPEX savings, outdoor-indoor radio penetration is optimal in a minimum subset of cases – and would still require investments in in-building wireless systems, even for 5G.
- LAN has historically been perceived as a very physical domain that is well- controlled by on-premise staff. Is the market genuinely ready for outsourcing?
- How will all the devices – such as servers, printers and phones – that do not have cellular connectivity connect? Will the cost of putting 5G NR radios in these devices be feasible? And is such an approach sustainable even in developing countries, especially considering the low cost of Wi-Fi?
Currently and in the foreseeable future, it is somewhat difficult to imagine this scenario materialize. Before these 5G technologies are implemented and achieve mass market penetration, Wi-Fi will continue to evolve at a faster pace and with more agile processes. Indeed, we will likely see the availability of 6 GHz and perhaps even Wi-Fi 7 before 5G deployments ramp on a massive and global scale. It should also be noted that Wi-Fi technology already includes features such as NFV, multitenancy, SDN and the segmentation of resources.
Perhaps a more realistic way of understanding the future of convergence revolves around devices playing a key role by taking advantage of the best of both worlds: maximum range and throughput, as well as minimum latency. Put simply, 5G will not make Wi-Fi irrelevant and Wi-Fi 6 will not jeopardize 5G. Rather, we may even see complimentary and parallel convergences.