Two phases of the leaching Protocol

We will not talk too much about the basic introduction of the leaching protocol. This is because it has been covered in previous articles. Now, we will mainly explain its basic algorithms, process stages, and features. We hope you can get useful materials.

The basic idea of this algorithm is to randomly select the first worker node in a circular manner, and evenly distribute the energy load of the entire network to each sensor node, this reduces network energy consumption and improves the overall survival time of the network. Simulation shows that, compared with the common multi-hop routing protocol and static layered algorithm, the leaching protocol can prolong the network life cycle by 15%.

During the running process, the Digest rebuild process is continuously executed cyclically. Each digest rebuild process can be described using the round concept. Each round can be divided into two phases: the establishment phase of the slave node and the stable phase of data transmission. To save resource overhead, the duration of the stable phase must be later than that of the build phase. The creation process of a worker can be divided into four stages: selection of the first node of the worker, broadcast of the first node of the worker, establishment of the first node of the worker, and generation of scheduling mechanism.

The selection of the primary node is determined by the total number of primary nodes required in the network and the number of times each node has become the primary node so far. The specific method is to randomly select a value between 0 and 1 for each sensor node. If the selected value is smaller than a threshold value, the node becomes the first node of the worker.

After the first node of the listener is selected, the whole network is notified through broadcast. Other nodes in the network determine the secondary Node Based on the signal strength of the received information, and notify the corresponding primary node to complete the establishment of the secondary node. Finally, the first node of the primary node uses the TDMA method to allocate a time point for each node in the primary node to transmit data to it.

In the stable phase, the sensor node transmits the collected data to the first node of the worker. The first node of the primary node fuses the data collected by all nodes in the primary node and then transmits the data to the aggregation node. This is a reasonable working model called low-traffic communication. After the stable phase lasts for a period of time, the network re-enters the establishment phase of the pipeline, reconstructs the pipeline in the next round, and repeats continuously, each worker uses different CDMA codes to communicate with each other to reduce interference from other inner nodes.

The Protocol is divided into two phases: setup phase and ready phase ). The total duration of the cluster creation and stable operation phases is one round ). To reduce protocol overhead, the duration of the stable operation phase is longer than that of the cluster creation phase.

In the cluster creation phase, the sensor node generates a random number between 0 and 1 at random and compares it with the threshold T (n). If the value is smaller than the threshold, the node is elected as the cluster header. In the stability phase, the sensor node transmits the collected data to the first cluster node. The first cluster node fuses the collected data before transmitting the information to the aggregation center. The aggregation center transfers the data to the monitoring center for data processing. After the stable phase lasts for a period of time, the network re-establishes the cluster, re-creates the next round of cluster, and repeats continuously.

The characteristics of the leaching protocol are as follows:

1. To reduce the amount of information transmitted to the aggregation node, the first node of the worker is responsible for integrating the data generated by different source nodes in the worker and sending the merged data to the aggregation point.

2. Leaching uses a MAC layer mechanism based on TDMA/CDMA to reduce intra-and intra-region conflicts.

3 because data collection is centralized and periodic, this protocol is very suitable for application systems requiring continuous monitoring.

4 for end users, because it does not need to obtain all the data immediately, the Protocol does not need to transmit data periodically, so as to limit the energy consumption of sensor nodes.

5. After a given interval, the Protocol re-selects the first node of the primary node to ensure that the wireless sensor network obtains the agreed energy distribution.

Although the existence time of the network can be improved by leaching, the assumptions used by the Protocol still have some problems worth discussing. The problems are mainly reflected in:

1. Because of the assumption that all nodes can communicate directly with the aggregation node, and each node has computing capabilities that support different MAC protocols, this protocol is not suitable for large-scale wireless sensor networks.

2. The Protocol does not explain how the number of first nodes of the primary node is distributed across the network. Therefore, it is very likely that the selected primary node is concentrated in a certain area of the network, so that some nodes are not surrounded by any primary node.

3. Because of the assumption that all nodes carry the same energy in the first selection of the primary node, each node that becomes the primary node consumes roughly the same energy. Therefore, the Protocol is not suitable for networks with unbalanced node energy.

After the node is elected as the primary node header, a notice is published to notify other nodes. Select the region to which other nodes are added based on the distance from the worker header node.