Dynamic polling medium access control method of emergency response supported sensor network

Abstract

The invention discloses a dynamic polling medium access control method of an emergency response supported sensor network, which mainly solves the problems of great access delay, low bandwidth utilization rate and high system expense of the traditional polling mode. The method comprises the following steps of: (1) polling a working node list by a sink node, firstly sending downlink data, then sending uplink data while sending an acknowledgment frame, dynamically distributing packet size and bandwidth for a working node, and controlling the time of the working node using an uplink; (2) polling an idle node list through a short frame sending / short frame response by the sink node; and (3) preemptively scheduling sudden events when the sink node polls the working node list and the idle node list. The invention has the advantages of small system expenses, low delay, high bandwidth utilization rate and emergency response to sudden events. The method is applicable to wireless sensor network channel access with high requirements on bandwidth and delay.

Description

technical field [0001] The invention belongs to the technical field of network communication, and relates to a medium access control (MAC: Medium Access Control) method of a wireless sensor network. The method improves network performance through dynamic polling, and handles emergencies in the network through a preemptive scheduling algorithm. , which is suitable for the field of wireless sensor networks with high requirements on bandwidth and delay. Background technique [0002] Wireless Sensor Networks (WSN: Wireless Sensor Networks) is composed of a large number of cheap micro sensor nodes deployed in the monitoring area, and forms a multi-hop self-organizing network system through wireless communication. Cover some specific physical quantities in the area, process the collected information, and then send it to the observer. Due to the large number, sensor nodes are usually placed randomly in the monitoring area, and it is difficult to replace the power supply. Usually ...

AI Technical Summary

Problems solved by technology

[0006] 1 In the traditional DTMP polling method, the same polling frame is sent to each node. However, due to the different service types and bandwidth requirements of the nodes, some need to send data, some do not need to send data, and some data The amount of data is large, and some have small amount of data, so if the same polling is performed for each node, bandwidth will be wasted

[0007] 2 In the traditional DTMP polling method, when the working node receives the polling command from the sink node, it first sends the uplink data and then receives the downlink data. This working method will make the radio frequency of the sensor node receive->send->receive three times Switching, RF switching is frequent; in addition, in the traditional polling MAC method, it is necessary to send a special confirmation frame, the transmission efficiency is low, and the system overhead is large

[0008] 3. The traditional DTMP polling method cannot handle the sudden data business in the network very well. The access delay of the emergency node is large and cannot be processed in time. Therefore, the emergency handling ability is poor and the service quality is low.

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