Research Of Adaptive Routing Based On Dijkstra Algorithm In Optical Networks-on-Chip

The number of cores are gradually increasing in a single processor core.It is easy to obtain excellent performance through paraller computing.With the continuous improvement and integration of Complementary metal oxide semiconductor(CMOS)on-chip technology,the number of on-core processing chips is increasing dramatically.Hundreds of cores will be integrated on a single chip,and multi-core processors with high performance advantages have developed into a very attractive platform.However,as more cores are intergretd into the chip,the data rate of processors will soon reach tens of GHz,which means that the demand of the bandwidth is increasing.The traditional electronic network uses electrical signals to transmit information,which has lower bandwidth and higher energy consumption.Electronic interconnection networks on-chip are only adequate for the communication needs of today's applications.However,as the number of cores and memory requirements of the application expands,the performance expansion of the electrical interconnection of No Cs cannot be matched with the equivalent communication improvement requirements.Optical network-on-chip(ONoCs)can not only meet the bandwidth requirements of future systems,but also have the advantages of low delay and small power consumption.So optical interconnection of No Cs is increasingly becoming an attractive solution to the problems faced by today's electronic chip-level interconnection networks.In the multi-core architecture based on ONoCs,the optical router is an important part of the ONoCs communication system.It consists of the basic optical switching elements,waveguide cross and optical terminal.The switching elements,waveguide crossing and transmission waveguide in optical routers could cause transmission loss.However,larger transmission losses lead to more power consumption,which greatly limits the scale of ONoCs.There are three common architectures of optical networks,namely Mesh topology,Torus topology and Fattree topology.X-Y dimensional routing protocol is adopted to achieve concurrent communication in the network,but the transmission loss of each link cann't be minimized.Besides,the transmission loss of link will gradually increase with the expansion of the network size,which will lead to the increasing of power consumption of the whole network and the decreasing of network performance.In order to ensure the normal communication of links,the traditional power control will allocate power to other links according to the maximum loss of all links,which will cause a lot of redundancy in the power allocation of other links.In order to solve the above problems,a new adaptive routing based on Dijkstra algorithm is proposed in this paper,which can realize the selection of the minimum transmission loss routing path in the mesh topology and realize the minimize the link transmission loss in the network.The power control can be optimized under the premise of keeping the sensitivity of the receiver constant.In addition,compared with the traditional power control and adaptive power control,the proposed routing algorithm has no significant reduction in network performance on the premise of reducing the link loss and optimizing the network power control,which also verifies the practicability of theadaptive routing based on Dijkstra algorithm.The main contents of this paper are as follows:(1)The basic theory of ONoCs is described,the physical architecture and implementation principle of basic silicon-based photonic devices are given.The loss estimation model of optical waveguide and the coupling theoretical model of microresonator based on SOI are proposed,and the output power on different ports of basic optical switching elements are analyzed.(2)The traditional power control model and the adaptive power control model are analyzed,and the optimized power control model based on Dijkstra algorithm is established.(3)The mathematical analysis models of power loss at router level and network level are established respectively.The design and implementation scheme of adaptive routing in optical network on Mesh architecture based on Dijkstra algorithm are proposed.And the switching mechanism of optical circuit is explained.(4)Finally,it is concluded that the link transmission loss of the adaptive routing based on Dijkstra algorithm is smaller than that based on the traditional dimensional routing with the aid of Matlab numerical simulation software.The optimized power control realized by the adaptive routing based on Dijkstra algorithm has a greater advantage in reducing the network power consumption than that of the traditional power control and the adaptive power control.Based on OPNET simulation platform,the end-to-end delay(ETE delay)and network throughput of dimensional routing and adaptive routing based on Dijkstra algorithm in different network scales are compared under Mesh based on ONoCs.The results show that the adaptive routing based on Dijkstra algorithm has no obvious decreasing trend in terms of ETE delay and throughput compared with the traditional dimensional routing,which also verifies that the adaptive routing based on Dijkstra algorithm can reduce the link transmission loss in terms of physical performance,and the optimized power control could reduce network power consumption without sacrificing network performance.