Wireless communication system, communication control method and communication node

Abstract

A technique is disclosed which achieves both a reduction of the power consumption and an efficient access control at each of wireless nodes in a wireless communication system. According to this technique, a given period at the beginning of which a beacon is transmitted from a gateway (GW) (100) is specified that it is divided into an active interval during which each wireless node (P2P tag) transmits / receives frames and a sleep interval during which the frame transmission / reception operations are inactive. Further, the active interval is divided into a plurality of timeslots having a fixed length, and in particular, divided into intervals during which different types, that is, the GW, fixed nodes (P2P-S tags) and mobile nodes (P2P-M tags) may perform their respective frame transmissions. Each P2P tag selects, from the intervals of its own type, a timeslot at random and uses the selected timeslot to be on standby for a random standby time and then transmit a frame including information to be used for determining the ID of that P2P tag, the selected timeslot and the standby time.

Description

technical field [0001] The present invention relates to a wireless communication system, a communication control method and a communication node. In particular, the present invention relates to a wireless communication system, a communication control method, and a communication node for realizing Medium Access Control (MAC) with low power consumption in the case of bi-directional exchange of data by a mobile communication node. Background technique [0002] In wireless hardware of a wireless system, reduction of power consumption is an important factor. Specifically, in a wireless communication system, as examples of applications requiring a power saving mechanism, there are active electronic tag systems, sensor network systems, and the like. For sensor nodes in active electronic tags, or in sensor networks, portability and easy and flexible installation are important characteristics. Typically, it is a battery type node with a small size battery. [0003] Applications su...

AI Technical Summary

Problems solved by technology

The star topology lacks flexibility in its structure, and it has the disadvantage that it is used under the assumption of the topology when the mobile node performs communication

[0020] In the case of periodically transmitting short data (data of small data volume), there is a limit to the amount of information exchanged between two nodes by a single data transmission and reception

In this case, the amount of information transferred through multiple data transfers and receptions can be increased, however, it must be ensured that wireless communication does not cause collisions in data transfers

However, the simplified protocol was not structured to avoid the possibility of collisions in data transfers and cannot guarantee reliable maintenance of wireless communication routes

[0021] Also, according to IEEE 802.15.4, GTS's guarantee of slots is defined in a superframe period, and the problem arises in that there is a limit (upper limit) to the number of slots reserved for slots within a single superframe period

Also, a regulator for managing slot reservations is required, and there is also the problem that there may be constraints on the network structure

The network topology limited by IEEE 802.15.4 is not suitable for the case of performing data transmission and reception between MNs by P2P (Peer-to-Peer)

[0022] According to the system disclosed in Patent Document 1, the startup time of the receivers of the peripheral nodes can be synchronized uniformly by defining the wake-up signal to ensure data transmission and reception, but the problem is that the channel occupation period (from transmitting the wake-up signal to During the channel occupation period, the wake-up signal transmitted by a node before the start of data transmission occupies the channel

As a result, the probability of signal collision may increase, and it is difficult to have sufficient access control (collision avoidance control) between transmission nodes

Images