Chain-type wireless sensor network-oriented hybrid media access control method

A chain-type wireless sensor network-oriented hybrid media access control method, wherein

• in a wireless sensor network, if a proportion of cluster heads arid cluster members which simultaneously transmit data reaches a certain value, a time division access control Pipelined TDMA is used, comprising:
• in every time slot, cluster heads in the network acquire sensor data of all cluster members in subsequent clusters;
• and
• cluster heads that acquire sensor data forward acquired sensor data;
• in the wireless sensor network, if a proportion of cluster heads and cluster members which simultaneously transmit data does not reach a certain value, a contention access control S-XMAC is used, in which wake-up time scheduling is based on position information, comprising:
• waking up cluster heads and cluster members in order based on geographical positions of cluster heads and cluster members in the network;
• and
• the S-XMAC is realized by:
• each cluster head and cluster member periodically sleeping and waking up by a duty cycle Tduty-cycle;
• a cluster head waiting to transmit data does not activate a radio frequency to transmit preamble codes, but instead transmits preamble codes containing address information of a transmitting end cluster head and of a destination receiving end cluster head at a time ½ Tpreamble ahead of a wake-up time of the destination receiving end cluster head, Tpreamble representing the maximum time required for transmitting the preamble codes;
• after transmission of the preamble codes, the cluster head waiting to transmit data waits for a preamble codes acknowledgment ACK from the destination receiving end cluster head, and repeats transmission of the preamble codes until a preamble codes acknowledgment ACK is received, the cluster head waiting to transmit data will not transmit data until a preamble codes acknowledgment ACK is received;
• a receiving end cluster head is periodically woken up;
• if the awoken receiving end cluster head is receiving preamble codes containing address information while awake, the receiving end cluster head judges whether the address information of the destination receiving end cluster head in the preamble codes agrees with the awoken receiving end cluster head address information;
• if there is a judgment that the address information is in agreement, then the awoken receiving end cluster head sends a preamble codes acknowledgment ACK notifying the transmitting end cluster head to transmit data;
• if there is not a judgment that the address information is in agreement, then the awoken receiving end cluster head does not send back a preamble codes acknowledgment ACK and goes into dormancy immediately.