Transmission status applies only if you are manually syncing your ERP system with PhoneX, meaning you update your inventory, customers, orders, and more with spreadsheet uploads. If you use PhoneX as your system of record (no separate ERP) or have integrated your ERP with PhoneX via API, this article will not apply to you.
Transmission status helps keep your inventory counts accurate in PhoneX. When you create an order in your ERP, you will mark the order as transmitted in PhoneX. That lets us know not to continue holding the allocated inventory back from your available items.
See this video for more details.