In order to support the same sort of device - to - device connection , USB requires additional support in dual - role devices to emulate a host and provide similar functionality , and was only standardized years later as part of USB On - The - Go system .
In order to support the same sort of device - to - device connection , USB requires additional support in dual - role devices to emulate a host and provide similar functionality . 
 This was only standardized years later as part of USB On - The - Go system .