Research On Fault-tolerance And Congestion Avoidance Routing Algorithm And Wireless MAC Protocol In WiNoC

The wireless network-on-chip(WiNoC)can achieve efficient on-chip long-distance communication,overcoming the problems of high energy consumption and high-latency communication bottleneck caused by the long-distance multi-hop transmission of the traditional metal interconnected network-on-chip.In a wireless network-on-chip,the wireless interface used for on-chip wireless communication occupies a large hardware overhead.Therefore,wireless network-on-chips often use wired and wireless hybrid hierarchical architecture.The hierarchical wireless network-on-chip divides the entire network into multiple subnets,and each subnet is equipped with one or more wireless routers(WR)for long-distance communication between subnets.In the hierarchical wireless network-on-chip,wireless router that handle a large number of long-distance data communication tasks between subnets,so it is easy to form congestion,and the failure of a wireless router will have a more serious impact on the reliability of the network-on-chip communication.Therefore,wireless network-on-chips require reasonable congestion control mechanisms and fault-tolerant solutions.In addition,in hierarchical wireless network-on-chip,only one wireless router can obtain the right to use the wireless channel to send wireless data at the same time.Therefore,on-chip wireless communication requires an efficient media access control(MAC)protocol to allocate the right to use wireless channels.To this end,this paper has conducted in-depth research on the failure and congestion of wireless communication and the wireless MAC protocol in the hierarchical wireless network-on-chip.The main work of the paper is as follows:1)Aiming at the problem of wireless communication congestion and failure,this paper proposes a routing algorithm for fault tolerance and congestion avoidance.First,a wireless router for wireless communication congestion and failure awareness is designed.The wireless router can sense the congestion and failure status of WR communication pairs,encode the congestion and fault status,and send the code to the routers in the subnet;then the router in the subnet judges whether the packet uses wireless transmission at the source node according to the received WR communication pair status information,and adopt congestion avoidance mechanism when wireless transmission is not used.Avoid a large number of packets passing near the wireless node to form congestion.Experiments show that the proposed scheme can ensure low packet average delay and high network throughput rate under small additional hardware area and power consumption overhead,and has efficient fault tolerance for permanent faults of WR communication pairs.2)Aiming at the problem of wireless channel allocation,this paper designs a wireless token MAC protocol based on the total time of packets waiting for wireless transmission,so that the allocation of wireless channels is fairer in different traffic modes.At the same time,the wireless interface sends its own status information to the remaining wireless interfaces by the methods of token flit carry,so as to realize the status awareness between different wireless interfaces,avoid sending data packets to the congested wireless interface,and ensure the reliability of wireless data transmission.Experiments show that the proposed scheme can significantly improve the efficiency of on-chip wireless communication in non-uniform traffic mode with a small additional hardware overhead.