Medium access control method for prolonging network lifetime in wireless body area network

Abstract

The invention discloses a medium access control method for prolonging network lifetime in a wireless body area network, which mainly solves the problem that network topology lacks the self-adaptive adjustment capability based on the current residual energy of a node in the existing research on the medium access control of the wireless body area network. The method is implemented by the steps as follows: under a normal communication state, a node immediately requests a relay towards a network coordinating point when detecting the current residual energy is lower than an energy threshold value; the network coordinating point selects the relay for the relay request node in the whole network through a relay selection superframe structure; the network topology is changed from a star structure into a tree structure; and a medium access control layer adjusts a next-hop superframe structure in accordance with the topology. Compared with the existing method for prolonging network lifetime in a wireless body area network, the invention can realize the self-adaptive adjustment of the network topology without increasing additional relay nodes, thereby prolonging the network lifetime of the whole wireless body area network.

Description

technical field [0001] The invention belongs to the technical field of communication, and relates to a media access control method, in particular to a media access control method used in a wireless body area network. prolong network lifetime. Background technique [0002] Wireless Body Area Network (WBAN, Wireless Body Area Network) is a wireless communication network centered on the human body and composed of various nodes and personal terminals distributed on the human body, clothing, and even inside the body. In the field of short-range wireless communication, although WPAN technology exists, the concept of body area network further extends short-range wireless communication technology to the communication between various sensors deployed on and inside the human body, so its The transmission distance is shorter. WBAN has a wide range of applications, ranging from remote medical monitoring, to human computing interaction, education and entertainment, etc., especially bec...

AI Technical Summary

Problems solved by technology

[0006] 2. The wireless devices in WBAN are applied around the human body, and the path loss around the human body is much larger than the loss in the case of free space propagation, especially when the link between the communication parties is non-line-of-sight NLOS, for example, transmitting The terminal is located on the back of the human body and the receiving terminal is placed on the chest of the human body. Even if the transmission power is high, direct communication between these nodes may not be feasible.

IEEE 802.15.4MAC layer can support two topological structures of star network and peer-to-peer network. However, most of the contents of the IEEE802.15.4 standard are about the operating specifications of the star network, and the working process standards of the peer-to-peer network The content is limited, for example: Regarding the multi-hop superframe structure used under the peer-to-peer network, the IEEE 802.15.4 standard only mentions that the media access control sublayer management entity MLME of the common coordination point must ensure that the superframe sent by each common coordination point The outgoing superframe must be completed within the inactive period of the incoming superframe received by the superframe. The standard does not involve the issue of how to avoid collisions between the outgoing superframes of each ordinary coordination point when there are multiple ordinary coordination points in the same sublayer of the peer-to-peer network

In addition, because it is beyond the scope of the standard, the standard does not involve the issue of how the MAC coordinates when the network switches between two different topologies

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