Future-Proofing 5G Architecture with Open-RAN
The RAN (Radio Access Network) architecture for mobile networks includes a remote radio unit (RRU) located at the top of a cell tower, which communicates with a baseband unit (BBU) at the base of the tower. The hardware and communication interfaces are owned by a specific vendor, and its software-driven functionality is tightly coupled within the hardware.
Traditionally, this has worked well for mobile network operators (MNOs). However, there are several drawbacks to consider – for instance, upgrading or changing the wireless network demands physical hardware replacements throughout the network, which is cost-inefficient, labor-intensive, and time-consuming. Furthermore, the equipment and interfaces that connect the hardware are owned by the vendors that originally supplied them, which locks MNOs into existing relationships with them.
What is Open-RAN?
To fully grasp the concept of Open-RAN (O-RAN), a thorough understanding of virtual RAN (vRAN) is beneficial. vRAN comprises the same RRU as RAN – however, a stark difference is found in the BBU with the decoupling of the software-driven functionality from the proprietary hardware. This replaces purpose-built hardware with a programmable RAN infrastructure, which was built in a low-cost manner and could serve as general-purpose hardware.
O-RAN takes virtualization to the next level through disassociating software applications from the underlying, proprietary hardware. The proprietary communication interfaces between the baseband parts – the centralized units (CU), the distributed unit (DU), and the radio units (RU) – are replaced with open, standardized interfaces. This enables operators to utilize the radio, baseband, and software from various vendors.
It is important to differentiate the decisions of virtualizing and opening RANs. A virtual RAN may not be open, as the software functionality can be segregated from the hardware and uploaded to a cloud-native architecture without opening and standardizing the communication interfaces. Some have argued that virtualization is a required precursor to a full opening of RAN. So long as the interfaces remain closed and tied to a specific vendor, new entrants are unable to dive into the market.
How Open-RANs can Future-Proof 5G Infrastructures
5G technology poses a challenge to mobile network providers to squeeze more data into much faster and more efficient, yet less expensive offerings, while average revenue per user (ARPU) drops rapidly.
Here are four reasons why O-RANs play a critical role in future-proofing 5G infrastructures:
Lower Upfront Infrastructure Costs
For its predecessor, 4G, providers need to only construct infrastructure to fulfill its 200 megabits/second speed requirement. However, the new generation of 5G promises a speed of up to 1000 megabits/second. With big targets come to an even bigger infrastructure requirement – up to four times more cell sites and greater network density. By allowing multiple operators to utilize a single virtualized BBU to support multiple radios, O-RAN allows a reduction in the cost of building new towers and attaining vendor-proprietary hardware. Instead, O-RANs enable a smaller, simpler, and more energy-efficient installation footprint.
Lower Operational Expenses
Traditionally, software upgrades and changes need to be done manually, which proved to be less efficient and labor-intensive. Software-mediated and programmable RAN infrastructures allow for a simpler and more cost-effective solution to roll out new upgrades and features at various RAN locations. Furthermore, open interfaces grant new network features and functions to operate on hardware from any vendors without having to deploy engineers and technicians of a specific vendor. Hence maintenance, upgrades, and optimizations of networks can be automated remotely.
Virtual Baseband Units (vBBUs) Can Aid Dynamic RAN Adaptation
By allowing a single vBBU to act as the brain behind multiple RRUs, they are able to learn and become smarter. The baseband processing centralization enables and boosts dynamic RAN adaptation, which will increase the reliability of the network.
O-RANs Encourages Innovation
Research tests and trials are more easily done when all aspects can be monitored virtually, which will increase market participation and decrease the entry barrier. O-RANs allow mobile network providers to gain and utilize insights from their other towers, in order to improve overall network performance. Although market participants will most likely lead to more innovations, tight competition could also arise, which will push current market leaders to maintain the quality of offerings.
In conclusion, many have argued that open-RANs could accelerate and future-proof 5G infrastructures based on the reasons stated above. Although there is more to finalize to reach successful worldwide 5G implementations, VIAVI Solutions’ industry-leading offerings deliver complete 5G solutions for validation, verification, and visibility.