Research On Satellite Internet Of Things Identification System Based On The Separation From Location

With the continuous development of network technology and mobile terminal equipment,the network scale is gradually expanding.Satellite Internet of things has the characteristics of large number of terminals,limited on-board resources and high-speed mobility.However,the traditional IP(Internet protocol address)address has dual semantics,which on the one hand will increase the burden of satellite network;on the other hand,it will limit the support of mobility and hardly adapt to the high-speed mobility of satellite.To solve the above two problems,the separation of location information and identification information in IP has become a widely studied topic in recent years.In the satellite Internet of things,there will be the following problems in the application of the method of separation of location and identification: the number of terminals is large,which conflicts with the limited storage resources of satellites;when the geographical location of terminals changes,the update delay of mapping information increases;the query delay of mapping information increases.To solve the above problems,this thesis designs an identification system based on sink node to separate the location and identification of Satellite Internet of things.A cache update method is also designed to speed up the mapping query.The main work of this thesis is as follows:1.To adapt to the high-speed mobility of satellites in the satellite Internet of things,a satellite Internet of things identification architecture including global sink node,local sink node,satellite and mobile terminal is constructed.The global sink node and the local sink node constitute a mapping system: the global sink node stores the mapping information in a distributed way to save memory space and binds with the satellite to reduce the delay and cost of satellite handover according to the predictability of satellite topology;the local sink node speeds up the mapping query by caching the mapping information.2.To solve the problem that the update delay of mapping information increases when the geographical location of mobile terminal changes,a mobility support protocol for Satellite Internet of things is designed.Especially when the terminal moves to the area covered by the satellite,the updating process of the mapping information is simplified by changing the message passing and the updating mode of the mapping information in the original protocol,and the updating of multiple mapping information can be carried out synchronously by using the push mode.The simulation results show that when 1000 terminals switch between domains,the handover delay can be reduced by 28.6% at most,and the signaling overhead can be reduced It reduces the number of packet loss by about21%.3.To reduce the query delay of mapping information,a cache update method based on Thompson sampling is designed.The higher the cache hit rate of local sink node for mapping information,the lower the query delay of mapping information.By modeling the cache problem of mapping information as a multi armed slot machine problem,the classic Thompson sampling algorithm is used to evaluate and replace each mapping information.The simulation results show that compared with the classic cache replacement algorithm,the proposed algorithm can improve the cache hit rate by about 10%.