Packet suppression protocol for a regional protection system using a wireless ad-hoc network

Abstract

We are currently developing a Regional Protection System in which children have terminals, and transponders installed at various locations receive packets sent from these terminals via a Specified Low-Power Radio System. The packets are then transmitted to a server so the positions of the children can be inferred from that information. With the ARIB STD-T67 access protocol used in this system, collisions frequently occur at locations where there are many terminals. Therefore, the authors improved a protocol in which frequent collisions do not occur, even when as many as 150 terminals gather in the same place. However, it was impossible to prevent frequent collisions when many terminals are concentrated in one place, such as in a school. A new access protocol was developed in this research to deal with this problem. In this protocol, transmission by terminals is suppressed at specific locations, and then resumed after the terminal moves away from those locations. However, the position of a terminal must not be lost when its transmission is being restricted. In this presentation, we propose this new access protocol, and evaluate its effectiveness.

A Pseudo-TDMA MAC Protocol Using Randomly Determined Transmission Times for Landslide Prediction Wireless Sensor Networks

“…In order to get our network up and running, we used the same protocol as is used in the Regional Protection System [3]. This protocol is based on the Japanese ARIB Standard STD-T67 protocol.…”

“…As an example of one of these projects, our research group has developed an ad-hoc wireless network that can continue to operate even after a large-scale disaster [1]- [3]. This is accomplished by powering the communications equipment with batteries charged by solar cells.…”

Construction and evaluation of a regional protection system employing power-saving wireless terminals without using GPS modules.

“…However, based on the operation experiments we conducted, there was confirmed to be an increase in packet loss due to problems specific to this regional protection system. Therefore, the protocol was used after making our own improvements [2].…”