Mobile World Congress (MWC) was almost back at full scale in Barcelona this year, after a smaller event in 2022 in the aftermath of the pandemic.
About 85,000 attendees were recorded, and the Fira conference center’s eight halls were packed with robot dogs, drone taxis, ‘metaverse’ experiences and satellites. And of course, 5G – with support for all those eye-catching applications increasingly reliant on dense and ubiquitous connectivity, as enabled by small cells.
Successive MWCs suggest that the actual mention of the term ‘small cell’ declines in inverse proportion to the scale of their use to support advanced use cases. A large proportion of the demonstrations and launches related to key themes such as 5G-Advanced turned out, on closer inspection, to be running on small cell networks.
This was true of the areas where small cells would be expected to be present. As in 2022, there was a heavy focus on private networks, especially for sectors with advanced connectivity requirements such as manufacturing and transport (the sophistication of smart factory digital twin demos had increased significantly since last year). Here, small cells are foundational to most deployments, enabling self-contained RANs with their own packet cores, operated by neutral hosts, MNOs or private network specialists.
But there were other prominent themes in which small cells were unexpectedly prominent. Most large vendors, and some operators, presented their roadmaps for 5G-Advanced, which still start to become commercially real at the end of this year once 3GPP Release 18 standards are frozen. Among 5G-A capabilities that were deemed to have most immediate usefulness, many were very dependent on dense capacity and universal coverage. Examples included 5G Positioning, edge/AI/5G convergence and advanced IoT use cases – all of them dependent on a level of localized capacity and connectivity that the macro network cannot provide alone.
Despite the talk of 5G-A, the overall tone of the show was a pragmatic one, focused on making 5G deployable in the near term rather than dwelling on bluesky visions (surprisingly little talk of 6G or even metaverse compared to some industry events). In this respect, there were two particular areas of focus that are deeply relevant to small cells – Open RAN and 5G IoT. Both have, at different stages in the 5G journey so far, been held up as silver bullets that would transform the operators’ cost base, agility and revenue diversity.
Both, it was openly acknowledged, have failed to deliver on their promises so far. This was not a message of despair, but a call for all interested parties to cooperate in a fully practical way to address the challenges. In both cases, these attempts to ensure deployable systems that offer clearly quantifiable commercial benefits are being driven initially by small cells.
Many of the biggest barriers to at-scale adoption of Open RAN platforms relate to the macro network, and particularly the complexity of integrating multiple vendors’ elements, especially when Massive MIMO is involved. Small cell networks have the same challenges to match the performance of integrated base stations with a disaggregated, virtualized and potentially multivendor platform. But it is somewhat easier to address them in a small cell environment, partly because the workloads are lighter than in an urban macrocell, but also because the small cell industry was built on an open ecosystem to start with. 
So small cell specialists were innovating alongside big names in addressing the challenges of openness, in a way that could be built upon for the macro network in future. In the chip layer, big names like Qualcomm and AMD/Xilinx showed off small cell offerings alongside specialists like Picocom, and Qualcomm, in particular, demonstrated one of Small Cell Forum’s significant contributions to the development of open networks, the FAPI interface.
The other big 5G disappointment to date has been the IoT, which has been slower than hoped in delivering strong business cases for cellular operators. MWC saw a concerted effort to rekindle the 5G IoT fire, based on the coming delights of Release 18, which introduces a four-layered pyramid of IoT capabilities. At the bottom is new support for 5G-connected passive IoT tags, which could replace RFID and barcodes at a cost of just 30 cents each. Above this layer are low-power WAN (the 5G iteration of NB-IoT), 5G Reduced Capacity (RedCap, also known as 5G NR Light), and finally full broadband 5G, for video-rich IoT applications.
There were many examples of products that could turn all this into commercial gold. Askey Computer, one of the Taiwanese ecosystem vendors that are so important to mass-scale small cells, included its small cell designs in demoes devoted to private 5G networks, ‘civil IoT’ and ‘Internet of vehicles’. It included millimeter wave and sub-6 GHz cells, with integration with WiFi and with short-range connections under the Matter platform.
And there were fascinating demoes of how traffic could be steered dynamically between the layers for the optimal network efficiency and user experience, all of which were dependent on access to connectivity in every corner, based on ubiquitous, low-cost small cells, often integrated with a sliver of edge compute and a dose of AI.
Indeed, AI was everywhere – according to the MWC app, more than 10% of exhibitors identified themselves as AI companies, and AI was inherent to the launches and applications of many others. Operators like NTT Docomo and Orange showed AI increasingly embedded into the infrastructure, enhancing the business case in at least three ways – by enriching the analytics applied to all the data generated by the dense 5G/edge networks; by enabling new user experiences and customer services; and by adding intelligence and prediction to the management of the networks themselves. All of these are of interest in small cell environments, but the ability not just to automate operation of networks with large numbers of small cells, but to ensure they are intelligent, will be business-critical.
While many of the most interesting discussions related to the broader environment and platform surrounding small cells, there were plenty of innovations in the products themselves. All the top equipment vendors, including Ericsson and Nokia, launched new urban small cells and in-building solutions as part of their obligatory MWC portfolio refresh. Small cell-focused suppliers broadened their offerings by incorporating support for some of the key trends – increased Open RAN and AI capabilities in Airspan’s designs, for instance.
A particular area of innovation was in the ‘network-in-a-box’, which has the potential to enable new services for operators and neutral hosts, whether for temporary networks for disaster recovery, or simple enterprise systems. One of the most eye-catching was from Vodafone, which has a history of developing its own-branded small cells, such as the recent OpenCell, and has now prototyped an open RAN network-in-a-box powered by a Raspberry Pi.
These are just a few examples of the innovations that were on display to enrich the small cell platform and the increasingly broad platform that surrounds it, promising to take deployers and vendors into new adjacent markets and applications.