When 5G comes to mind, most people think of service providers and equipment manufacturers like Verizon, AT&T, T-Mobile, Samsung, Apple and Ericsson. This is not an incorrect or misguided tendency. The big 3 carriers are leading the way toward a 5G future and device makers like Apple, Samsung and LG continue to release mobile devices that push the limits of the user experience.
On top of that, Samsung and Ericsson also make carrier infrastructure equipment such as the antennas and equipment shelters you come across along the highway while driving on I-95 on the east coast and I-5 on the west coast, and which sit atop the rooftops of hotels, apartment buildings and the like. Go a little further upstream to the network core, and names such as Cisco and Juniper crop up, providing the edge routers, aggregation routers, backend servers, switches, hubs and every other form of gear needed to assemble and power some of the most complex networks on the planet.
Research and Development
Before any of this can happen, however, focused research and development must come away with breakthroughs that improve upon existing paradigms. This has happened roughly every decade in cellular communications, resulting in successive generations of technology: 1G, 2G, 3G, 4G and, now, 5G, with 6G to follow before we know it. Developments can happen anywhere, from a researcher’s home office to a major breakthrough at a university which is published as open source and picked up by every applicable tech company to use for their own endeavors. They may be introduced at trade shows, demonstrated at annual conferences, or simply show up as consumer end products, straightaway, if derived in relatively final form.
When sufficient ground is broken, standards are established and published by organizations such as the 3GPP (3rd Generation Partnership Project) to provide consistency across equipment makers and network services. From Beta models to long term stable, supported releases and multiple tiers between the two. This has already happened with 5G. The standards have been set and deployments have begun in earnest across the major US carriers and across the world, with each carrier and each market looking to get an edge on competitors and blaze the trail for others to follow.
5G Promises Unfulfilled…So Far
While 5G arrived with great fanfare, it has faced significant technical issues. Chief among them is the usage of millimeter waves to power 5G networks. If unresolved, the initial promise of 5G bandwidth and low latency may never come to pass. Thought to be the future of wireless communications, frequencies at the 24-40 GHz range have run up against the laws of physics and the fundamental properties of electromagnetic waves. Simply put, they degrade quickly when traveling through open space and can barely penetrate any solid surface, such as a wall, tree or car.
A 5G small cell antenna broadcasting mmwaves from atop a 40’ utility pole may reach as far as 1000 feet from the source, but only if passing through wholly unobstructed open space. Add homes, buildings, trees, leaves and other obstacles to the scenario, and a 5G signal may not get much further than the intersection from which it emanates. This means, for the moment, that mmwave 5G is not a viable solution to provide blanket 5G coverage across large geographic areas. For the time being, Sub6 frequencies, such as the 600-2100 MHz used for 4G and recently auctioned C-band frequencies in the 3-4 GHz range are being used to just get some form of 5G out there to subscribers, to realize at least some of the benefits.
Existing towers and rooftops are able to broadcast Sub6 frequencies due to their superior propagation when compared to mmwaves. This allows for quick deployments on existing infrastructure. A quick patch. But industry leaders understand that Sub6 signals will not provide the glittering intersection of rich experiences, automated vehicles, and deep persistent extended reality envisioned as part of an encompassing 5G future.
Enter Chipmaker Qualcomm
While many wireless equipment makers have diverted their focus to doing the best they can with Sub6 frequencies, Qualcomm has doggedly pursued improvements to mmwave signal propagation in order to turn it back into a commercially viable spectrum range for 5G communications. First among Qualcomm’s efforts has been developing a mobile device modem chipset that can process both Sub6 and mmwave signals, or “spectrum aggregation”, as it is called in the industry. The 2021 Snapdragon x65 chip was a big step in that direction.
Their most recent push is along the FeMIMO, or Further Enhanced MIMO, line of effort. MIMO stands for Multiple Input, Multiple Output, and has been utilized in 4G networks, but is expected to come to full fruition in 5G networks. A crowded public way, with rapidly moving vehicles and pedestrians, as well as nearby homes and businesses, all connected to the 5G network and receiving advanced services, will require levels of coordination not yet seen in wireless networks. Qualcomm is unveiling advances on features such as beam management, ultra-reliable, low latency communication (URLLC), and synchronization between time division duplexing and frequency division duplexing.
They are also developing solutions to deal with signal reflection in urban outdoor settings, which results in network degradation and asynchronous signal processing. Why are they doing this? Why haven’t they and others given up on the higher frequencies due to the physical challenges they present?
Simple Answer: Speed and Capacity
In a recent project with Chinese company ZTE, 5G download speeds on mmwave signals reached levels never seen before: 2.43 gigabits per second on a single device. This test is already a year old and Qualcomm has since exceeded its results, with speeds in excess of 10-20 GB per second in the future. For these reasons, do not expect the industry to permanently settle on the less capable Sub6 spectrum. Expect to see mmwave 5G reappear in the near future as these developments trickle down to enterprise ready equipment.