Wireless operators are devoting significant attention to deployments of indoor 5G coverage for large venues, transportation hubs, commercial developments and other high-density public or semi-public spaces. Since the majority of cellular traffic originates indoors, this is hardly surprising; macro networks have difficulty penetrating indoor spaces, and 5G’s bands are even more challenged by glass, steel and concrete than older technologies.
The traditional distributed antenna system (DAS) that provides this coverage needs radios with a baseband unit connected to the core network outside, but these options come with a lot of baggage, a reputation for complexity and significant demand on resources — not only space for the headend and potentially miles of analog coaxial cable, but also in the power required to operate and cool the system. For operators and venue owners alike, these can be an indulgent price to pay, even more so as society has turned its attention to the importance of sustainability in everyday living — and this includes how we connect to our digital lives.
Operators and owners are left with some hard decisions as they race to bring 5G networks indoors. However, O-RAN technology and intelligent architecture can help solve these challenges.
The infrastructure difference — less space, less power
One of the most cumbersome parts of traditional DAS deployments is the amount of headend equipment needed to convert analog fronthaul signals to digital baseband signals. The space occupied by this equipment is substantial and it requires a great deal of power to operate — and then more power to keep cool. O-RAN specifications call for digital fronthaul infrastructure and therefore require no analog-to-digital conversion — and no bulky, energy-intensive converter equipment. Many of the network’s features can be driven by software instead of hardware.
Secondly, O-RAN, being based on the idea of open compatibility and interoperability, also specifies standard Ethernet cabling instead of bulky, single-purpose coaxial cabling. By leveraging existing (or easily installed) structural copper and fiber-optic infrastructure, O-RAN reduces the amount of material used in the deployment of the DAS.
In fact, some O-RAN-based DAS solutions can reduce the headend’s rack and floor space requirement by nearly 90 percent as compared to traditional analog DAS. These offerings also consume 50 percent less operating power and require 50 percent less HVAC power to cool. In addition, O-RAN-based DAS solutions reduce the need for new cabling, as they can operate completely on standard Ethernet cabling — a highly sustainable shared infrastructure approach that’s not only efficient but also reduces the amount of material needed to deploy the DAS.
Reduced complexity and fewer components simplifies installation
A related benefit of an O-RAN-based digital DAS network is the relative simplicity of its structure. The reduced number of components afforded by the all-digital nature of the solution means fewer potential points of failure; the use of familiar infrastructure to drive the system means less reliance on hard-to-find specialized labor to install and maintain cabling; the ability to reduce the necessary fiber count by more than 80% when innovative technology, such as coarse wavelength division multiplexing (CWDM) is employed, simplifies cabling requirements; and the vastly reduced headend space requirements expand the variety of locations where it can be installed. In fact, the all-digital fronthaul means it’s possible to locate the headend outside the venue — or even miles away if necessary. Intelligent management even allows the DAS to allocate power where needed, as needed, and even power down the network when idle, further reducing electricity consumption.
This deployment flexibility is a boon for operators who must work with all kinds, shapes and sizes of enterprises, venues and other indoor spaces — and it also means that O-RAN’s more sustainable footprint can replace less-green options for venue owners.
Multi-operator capabilities multiply its sustainability advantage
The capacity to connect baseband radios from multiple OEMs means a single system can drive the digitalization of multiple operator networks on a single platform. Traditionally, operators have had different radio requirements that necessitated different connections to a DAS, some digital, some analog. O-RAN removes this necessity and enables multiple networks, regardless of radio preference, to operate digitally on shared infrastructure. This means that we can take the space and energy savings delivered by O-RAN DAS and multiply it for each operator that connects to the DAS, driving even more cost sustainability savings.
AI enters the mix
Because all-digital O-RAN DAS networks handle so much of the workload in software rather than hardware, there also exists the potential for even greater efficiencies through advanced AI management. A well-trained AI can perform real-time monitoring of traffic levels and constantly optimize the DAS network, even to the extent of enabling and disabling network features depending on conditions.
For large venues with variable traffic levels — such as stadiums that may host 70,000 football fans one weekend and even more concert fans the next, or airports where clusters of high demand can appear, disappear and shift as passengers come and go — this kind of intelligent and automated management of the O-RAN DAS can drive entirely new energy efficiencies based solely on smarter deployment of network resources.
Indoor O-RAN is the green key to a more sustainable future
As with outdoor macro networks, there exists a significant opportunity for O-RAN deployments in indoor environments. Digital DAS networks can fully leverage O-RAN’s agility to deliver a more compact, more efficient and (with AI assistance) more powerful way to deliver consistent indoor 5G coverage.
The development of all-digital DAS platforms has ushered in an exciting new chapter in the O-RAN story — one that requires less power, less copper and less carbon release to power our increasingly connected digital lives in the indoor spaces where we spend most of our time.
