It sounds encouraging:
"It is backward-compatible, meaning deployed Zigbee Green Power devices will still be interoperable years down the line."
"The Zigbee mesh network standard runs over IEEE 802.15.4, and green power has been part
of Zigbee for more than 10 years. The Zigbee Green Power protocol defines compressed,
secure, and highly optimized message traffic for ultra-low-power devices. It allows these
devices to send messages, in a reliable way, to destinations in the mesh network that may
be well beyond the range of these ultra-low power devices. The Zigbee network is always
on, and can receive and forward Zigbee Green Power messages at any time."
"The non-negotiable rule in the Zigbee Alliance is interoperability and backwards
compatibility. This means that your deployed Zigbee Green Power products will still be
interoperable in 20 years."
Looking forward to hearing more . . .