The Research Of Location Management Technology For LEO Satellite System

In the field of satellite communication system,the LEO satellite system has been a hot research field for many years because of the advantages of low power consumption,low delay and high efficiency in the transmission of low-earth satellite communication system.The satellite user's location management technology is the key technology in LEO satellite system,which guarantees the high performance operation and user satisfaction of the whole network.Due to the LEO satellite system's high operating speed,and the short visual time of the LEO satellite system users.And as the number of LEO satellite subscribers continues to grow,the types of subscribers continue to diversify,the complexity of location management continues to increase,and the impact of location management on the entire network becomes more significant.A good location management technology can reduce the cost of the entire system and improve system performance.How to balance the cost of location updating and location paging and ensure user satisfaction is the main problem of location management research.This thesis first studies and analyzes the location updating and location paging technologies in the existing location management field at home and abroad,and then improves the shortcomings of existing location updating and location paging technologies respectively.The main work has the following two points:(1)Aiming at the disadvantage of the existing LEO satellite system's location updating strategy that the overhead of the location updating strategy is high and the overall QoS of the users are low when multiple types of users exist simultaneously,a dynamic k-step user location updating strategy for the LEO satellite system is proposed,When the location is updated,the visitor location register is dynamically adjusted to update the length of the pointer chain according to user characteristics and user priorities.The simulation results show that this strategy not only reduces the total cost of location management,but also ensures the different needs of various users and improves the overall QoS of users.(2)In view of the problem of large paging overhead and paging prolongation when the user location paging strategy of the existing LEO satellite system is deployed,a user location paging strategy based on user location prediction is proposed.The system pre-sets the number of different sub-paging areas according to users with different delay limits.When the user places a page,according to the user's speed and priority,the area where the user is located is probabilistically predicted,and then the areas are paged in descending order of the predicted probability.Simulation results show that this strategy not only reduces the paging overhead,but also ensures the paging delay requirements of different priority users and users of different speed types.