Communication method and communication apparatus

A communication method, comprising:

• monitoring a plurality of predetermined frequency points to determine whether a target group has been established;
• establishing the target group in response to no target group being established;
• determining a first transmission time slot for a terminal device from a plurality of transmission tune slots for the target group;
• and
• transmitting, by the terminal device, a data message in the first transmission time slot,
• joining, by the terminal device, the target group in response to the target group being established,
• wherein the terminal device's joining of the target group in response to the target group being established comprises:
• determining whether a number of terminal devices that have joined the target group exceeds a number of terminal devices that can he accommodated in the target group;
• and
• joining, by the terminal device, the target group in response to the number of terminal devices that have joined the target group not exceeding the number of terminal devices that can be accommodated in the target group,
• wherein a number N of terminal devices that can be accommodated by the target group is calculated as:
• N
• =
• T
• s
• d
• c
• +
• b
• A
• *
• T
• s
• b
• P
• wherein, Ts represents a length of the plurality of transmission time slots for the target group, d represents a communication distance, c represents a speed of light, bA represents a data encoding rate, and bp represents a data transmission rate.