To be known as Optus 11, the new satellite will be deployed in 2023 at the current Optus D1 orbital location of 160° East.
In this context, "software defined" means the satellite's location, coverage, bandwidth and capacity can be changed in orbit to meet changing demands.
Optus 11 will make the company the first satellite operator in Asia Pacific to launch a software-defined satellite capable of providing flexible concurrent broadcast and broadband services via a very high throughput satellite (VHTS) design.
Optus 11 will provide coverage from Antarctica to the Cocos Islands, including the bulk of the Pacific region. Tracking spot beams will deliver coverage to planes and vessels anywhere within its footprint.
It will also carry a satellite-based augmentation system (SBAS) that can be used to increase the precision of GPS and other positioning systems across the ANZ region to within 0.1m.
The new satellite will be used by Sky New Zealand, among others.
"Today's exciting news is a testament to Optus's commitment to invest in cutting-edge next generation technology to enhance our world-class communication networks," said Optus CEO Kelly Bayer Rosmarin.
"Optus 11 cements our scale and leadership in the trans-Tasman satellite industry, and will enable us to provide unique, flexible services and customer experiences tailored to our customers' needs."
Optus wholesale satellite and strategy managing director Ben White said: "Optus 11's software-defined technology marks a paradigm shift in how satellite communication will be delivered across Australia and New Zealand and it will offer unparalleled flexibility for our satellite customers.
"Telecom markets don't stand still and the ability to re-configure payloads in-orbit is a game-changer. It allows us to adapt to shifting business landscapes and tailor the delivery of services and capacity through dynamic beam-forming technologies."
He added "Optus 11 will add capacity and resilience to our satellite fleet and its unique capabilities will give our broadcast customers the option to tailor their dynamic video delivery via IP streaming, and our broadband customers can benefit from better performance and higher individual throughputs. In addition, it will support the Optus mobile network using satellite backhaul and the Government's Mobile Black Spot Programs."