Before revision:  For its end users, such type of direct file transfer does not result in cellular data charges and allows to keep their primary Wi-Fi interface up concurrently with a dedicated Wi-Fi P2P interface, which is commonly provided by the default wireless module of the mobile phone .
After revision:  For its end users, such type of direct file transfer does not incur cellular data charges and allows to keep their primary Wi-Fi interface up concurrently with a dedicated Wi-Fi P2P interface, which is commonly provided by the default wireless module of the mobile phone .