Parent node device, terminal device for wireless network and data transmission method thereof

A parent node device for a wireless network, comprising:

• a non-transitory computer readable storage medium configured to store instructions comprising a network layer module and a Media Access Control (MAC) layer module;
• and
• a processor,
• wherein the processor is configured to execute the network layer module to calculate an estimated arrival time of a next poll data request of a terminal device according to a receipt time of a poll data request that is received from the terminal device, and transmit data for the terminal device to a cache of the MAC layer module at a time point which is a predetermined time length ahead of the estimated arrival time, responsive to a determination that the data for the terminal device is in the network layer module, and
• wherein the processor is further configured to execute the MAC layer module to transmit, to the terminal device, an acknowledgement packet indicating that the data for the terminal device is in the cache of the MAC layer module, and the data for the terminal device, responsive to receiving the next poll data request.

A terminal device for a wireless network, the terminal device comprising:

• a processor;
• and
• a memory, the processor configured to execute instructions residing in the memory to perform operations comprising:
• modifying a time interval of transmitting a poll data request from a first time interval to a modified time interval according to a preset condition responsive to receiving, from a parent node device, data for the terminal device and an acknowledgement packet indicating that the data for the terminal device is present on the parent node device;
• and
• transmitting at least three poll data requests to the parent node device at the modified time interval.