Grant-free transmission method, user equipment, access network device, and core network device

A method for grant-free transmission, the method comprising:

• receiving, by an access network device, a first request message from a user equipment, the first request message for indicating the user equipment supports grant-free transmission and for requesting a core network device to allocate, to the user equipment, a user equipment identifier and a key to be used for grant-free transmission;
• sending, by the access network device, the first request message to the core network device;
• receiving, by the access network device, a first response message sent by the core network device that carries the user equipment identifier and the key;
• sending, by the access network device, the first response message to the user equipment for encrypting and encapsulating data by using the key and the user equipment identifier;
• receiving, by the access network device, the data transmitted by the user equipment on a first contention transmission unit (CTU) resource in a grant-free transmission mode;
• and
• sending, by the access network device, the data to the core network device.

User equipment, comprising:

• an obtaining module, configured to obtain a user equipment identifier and a key allocated by a core network device to be used for grant-free transmission;
• an encryption module, configured to encrypt data using the key;
• an encapsulation module, configured to encapsulate the data by using the user equipment identifier;
• and
• a sending module, configured to transmit the encrypted and encapsulated data to an access network device on a first contention transmission unit (CTU) resource in a grant-free transmission mode.