What are O-RAN, Open RAN and OpenRAN?
I thought in this month’s column, I’d provide a definitive definition, along with a succinct explanation, of what O-RAN, Open RAN and OpenRAN are. This, if you like, is a “behind the scenes” peek into the objectives, as defined by the O-RAN Alliance, the Telecom Infra Project (TIP) along with a look at how others in the industry perceive these terms.
Establishing standardization and solidifying the supply chain infrastructure
In the past few weeks, I have spoken to several service providers and network operators and there still seems to be some confusion surrounding O-RAN, Open RAN and OpenRAN (written with no space) where these three terms are often muddled and have been used interchangeably which, of course, isn’t correct. Some of you may recall my previous column where I talked about the radio access network (RAN) in A brief history of the radio access network. Clearly, I didn’t dig deep enough, so this time I will delve further into the subject matter and offer you additional clarity regarding the differences between O-RAN, Open RAN and OpenRAN.
Firstly, let me clarify some of the confusion that surrounds the terminology. So, O-RAN (hyphenated) specifically refers to the O-RAN Alliance, although it has been used without the hyphen, that is, “ORAN.” With or without the hyphen, the term emerged to specifically acknowledge the Alliance and its initiative. Similarly, “Open RAN” with a space is a reference to the Alliance’s publication of numerous RAN architecture specifications, where the group’s initiatives include the use of artificial intelligence (AI) ideologies and application programming interfaces (APIs) all of which aid in establishing standardization and solidifying the supply chain infrastructure. This is the Alliance’s core theme and a foundation in its mission to offer an open architecture in the RAN ecosystem.
We have a “cloud” for most things …
Now “OpenRAN” without a space, refers to the Telecom Infra Project (or TIP), which is a group dedicated to building 2G, 3G and 4G RAN solutions using general purpose vendor-neutral software and hardware technology. Additionally, the group is also focused on developing 5G New Radio (NR) architecture. I assume some of the confusion has emerged due to how hashtags are created and used across social media, and it may confuse the wider audience too, where #ORAN, #OpenRAN and other denominations, for example, are used. Naturally, as the terms become more mainstream, better understood and used in a specific context, then I have no doubt we’ll come to accept them in our everyday “tech-speak.”
The concept as defined by the O-RAN Alliance is to simply establish successful interoperability and standardization of the components that form the RAN ecosystem, which can be sourced from multiple vendors irrespective of manufacturer and all of which harmoniously interoperate. You see, the legacy or traditional provision of network and infrastructure equipment in establishing and, in turn, supporting a cellular ecosystem, whether that’s 2G, 3G, 4G or 5G has become costly and restrictive, but there’s network functions virtualization (NFV) and a cloud for that!
Open RAN encourages openness in its approach by disaggregating both the software and hardware elements.
Disaggregating the hardware and software
In the meantime, most cellular infrastructures are composed of vendor-specific proprietary software and hardware systems, as well as proprietary interfaces, which limits access and ease of repair, along with upgrades to other vendors’ equipment and software. So, a traditional RAN infrastructure would ordinarily comprise numerous RF antennas connected to a base station via fiber that has signal processing and permits network access. The RAN infrastructure also includes a remote radio unit (RRU) and a baseband unit (BBU), where the communication between these two would be done over proprietary hardware and software using vendor-specific interfaces (or APIs). In a virtualized RAN (vRAN) strategy, for example, the RRU remains proprietary, whereas the BBU is proprietary software with virtualized functions, but runs on a commercial off-the-shelf (COTS) server. Nevertheless, the interface between the RRU and BBU still uses proprietary interfaces, and let’s not forget that vRAN is not necessarily Open RAN.
Anyway, the Open RAN approach is to overcome the restrictions imposed by utilizing vendor-specific software, hardware and their interfaces. As such, Open RAN encourages openness in its approach by disaggregating both the software and hardware elements, where the RRU becomes COTS-based hardware which, in turn, can be purchased from any ODM/OEM or RAN provider. However, the topology of the BBU largely remains the same as the vRAN approach, but now the interfaces between the BBU and RRU are open, allowing software and hardware vendors to easily interoperate with each other, which is the new approach as conceived by the O-RAN Alliance and its numerous Open RAN architecture specifications.
Until next time …
This philosophy or new way of working in building cellular infrastructures permits vendors to interchange, easily swap in and out defective equipment, and allows simpler upgrades. So this modular approach in the Open RAN infrastructure naturally reduces both capital and operational expenditure, something which most network operators and providers are striving to do in light of the flexibility now being afforded to their consumers through competitive, cost-effective and data-driven packages.
Perhaps next month, I’ll take a look at how the Open RAN strategy and its approach to disaggregating the traditional RAN infrastructure which helps in building a more cohesive strategy when developing cellular infrastructure, especially now we are ramping up 5G rollout and for those already looking ahead to 6G!
So, this is where your “cellular-enabled” Dr. G signs off.
Originally published in Technically Speaking.