Communications method and apparatus, and computer-readable storage medium

A communications method, applied for a first network device and comprising:

• sending an uplink data transmission threshold and a downlink signal quality threshold to a terminal device, wherein the terminal device performs random access to the first network device, the uplink data transmission threshold indicates a maximum size of a data packet and is used in determining to transmit, in a non-connected state, uplink data packet on a first uplink carrier or a supplementary uplink (SUL) carrier, and a frequency of the first uplink carrier is higher than that of the SUL carrier;
• receiving, on the first uplink carrier or the SUL carrier which is determined based on the downlink signal quality threshold in a case that a data volume of a to-be-transmitted uplink data packet is less than or equal to the uplink data transmission threshold, an uplink data packet transmitted by the terminal device in the non-connected state;
• and
• sending first information to the terminal device, wherein the first information indicates a first next hop chaining count (NCC) for determining a first key used for transmitting the uplink data packet in the non-connected state, wherein the first key is a key derived horizontally in a case that the first NCC is the same as a second NCC, and the second NCC is a NCC used before the first NCC is received,
• wherein the first key is determined by the terminal device based on at least one of:
• a key used by the terminal device for a second network device, cell information of a first network device, or a next hop chaining count (NCC) value, the second network device is a network device that configures the terminal device to enter the non-connected state, the cell information comprises frequency channel number information and/or a physical cell identifier of a cell of the first network device, and the first network device is a target network device to which the terminal device performs random access,
• wherein the method further comprises:
• receiving a second message sent by a second network device, wherein the second message comprises a receiving address of the uplink data packet;
• and
• forwarding, to the second network device based on the receiving address, the received uplink data packet transmitted by the terminal device.

A communications apparatus comprising:

• at least one processor;
• and
• a memory configured to store computer readable instructions that, when executed by the at least one processor, cause the apparatus to perform operations comprising:
• receiving an uplink data transmission threshold and a downlink signal quality threshold from a first network device, wherein the first network device is a target network device to which the communications apparatus performs random access, the uplink data transmission threshold indicates a maximum size of a data packet supported by a terminal device and is used in determining to transmit, in a non-connected state, uplink data packet on a first uplink carrier or a supplementary uplink (SUL) carrier, and a frequency of the first uplink carrier is higher than that of the SUL carrier;
• in a case that a data volume of a to-be-transmitted uplink data packet is less than or equal to the uplink data transmission threshold, selecting, based on the downlink signal quality threshold, the first uplink carrier or the SUL carrier to transmit, in the non-connected state, the uplink data packet;
• and
• receiving first information, wherein the first information indicates a first next hop chaining count (NCC) for determining a first key used for transmitting the uplink data packet in the non-connected state, wherein the first key is a key derived horizontally in a case that the first NCC is the same as a second NCC, and the second NCC is a NCC used before the first NCC is received,
• wherein the operations further comprise:
• receiving a random access configuration from the first network device;
• and
• the selecting, based on the downlink signal quality threshold, the first uplink carrier or the SUL carrier to transmit, in the non-connected state, the uplink data packet comprises:
• determining to transmit, in the non-connected state, the uplink data packet on the first uplink carrier or the SUL carrier of the first network device based on the random access configuration,
• wherein the random access configuration comprises at least one random access configuration corresponding to at least one coverage enhancement level, and
• wherein the uplink data transmission threshold comprises at least one uplink data transmission threshold corresponding to the at least one coverage enhancement level.