Piggy-back Network to Enable Beyond 5G Society Supported by Autonomous Mobilities: Application of MAB Algorithm for Data Synchronization Between Distributed Collaborative Robots

This paper proposes a technique for pre-negotiation of transfer data for a millimeter-wave (mmW) Store-Carry-Forwarding (SCF) data transfer network called the Piggy-back network between autonomous mobile robots. Each robot has its own database on this network, and the purpose is to synchronize the entire network when a part of the data is updated from time to time. While mmW communication is capable of high-speed and large-capacity data communication, the communication range is short and the communication time is extremely limited when the robots are moving. In order to make the best use of communication time and transfer data, it is appropriate to decide in advance which data to receive or transmit. Therefore, by using medium-speed communication, which has a relatively large communication range, and exchanging meta information of each data before the robots approach each other, it is decided which data should be handled. This paper models the difference and update check of data managed in segments for data synchronization as the Multi Armed Bandit (MAB) problem, which is a bandit problem and propose a Tug-of-War (TOW) dynamics-based data query scheme, which is a MAB algorithm. In order to verify the effectiveness of the proposed method, some simulations are performed on the data hit rate, which means the detection rate of update data with a limited number of queries in the situation where the update data occurs randomly. The results show that when the data consists of 10 segments and there is a large bias in the update frequency of each data, the data query method using TOW achieves detection of updated data up to about 40% higher than the random query method.