One of the biggest challenges that operators have identified for deploying Open RAN in macro networks is optimal integration with Massive MIMO antenna arrays. Massive MIMO are a central feature of many operators’ 5G strategies – to a far greater extent than predicted just a few years ago. In many cases, the antenna arrays – which feature between 16 and 128 (or even 256 in future) transmit and receive elements – have taken the role once foreseen for densification, in greatly boosting the capacity of a cell, and Massive MIMO can also improve cell range and the quality of experience at the cell edge. Clearly, then, the technology is important to many operators as they seek to provide…