A Reliable Peer-to-Peer Protocol for Multi-Robot
Operating in Mobile Ad-Hoc Wireless
Networks
Tarek Dandashy1,
Mayez Al-Mouhamed2, and Irfan Khan2
1Department of Computer Science, Balamand
University, Lebanon
2Department of
Computer Engineering, King Fahd University of Petroleum and Minerals, KSA
Abstract: Cooperative behaviour in multi-robot systems are based on
distributed negotiation mechanisms. A set of autonomous robots playing soccer
may cooperate in deciding a suitable game strategy or role playing. Degradation
in broadcast and multicast services are widely observed due to the lack of
reliable broadcast in current IEEE 802.11. A reliable, Peer-To-Peer (P2P), fast
auction-based broadcast is proposed for a team of robots playing soccer
interconnected using an ad-hoc wireless mobile network. Auction broadcast
includes a sequence order to determine the reply order of all nodes. This helps
minimizing the potential of Medium Access Control (MAC) conflicts. Repeated
back-off are not desired especially at low load. Uncoordinated negotiation lead
to multiple outstanding auctions originated by distinct nodes. In this case,
the sequence order becomes useless as auction times are interleaved. An
adaptive MAC is proposed to dynamically adjust the reply. Protocols are
implemented as symmetric multi-threaded software on an experimental Wireless
Local Area Network (WLAN) embedded system. Evaluation reports the distribution
of auction completion times for peer-to-peer operations for both static and
mobile nodes. Protocol trade-offs with respect to auction response time,
symmetry and fairness, and power consumption are discussed. Proposed protocols
are embedded as a library for multi-robot Cooperative Behaviours (CBs).
Evaluation shows the proposed protocol preferences versus the behavioural
primitives with specific communication patterns.
Keywords: Auction communication, cooperative
multi-robot, distributed intelligence, peer-to-peer, wireless protocol.