Research On Media Access Control Technology In UAV Formation Networking

The usage scenarios of UAV groups are developing towards the trend of formation and the number of them keeps on a low level.The UAV formation maintains a relatively constant formation for a long time during flight,but it will also change formation and topology according to changes in the environment and target requirements.In this kind of ad hoc network,services with different priorities need to be sent,of which with higher priority need to be sent earlier to require lower delay.Moreover,the MAC protocols of most UAV networks have the problem in data channel of exposing terminals which has a negative impact on the delay and throughput of different services.In distributed TDMA,the static allocation of control slots is not fair,which will cause starvation of low-priority services,and the random dynamic allocation ignores the delay sensitivity of high-priority services.So,thesis proposes a dynamic algorithm about control slots allocation.In the algorithm every node can decide their order to send reservation requests without conflict based on services situation of themselves and their two-hop neighbors,so that higher nodes can reserve enough data slots.Thesis verifies by simulations the effectiveness of the dynamic algorithm for control slots allocation in terms of delay and throughput.To solve exposed nodes problem in data channels to the degree of reusing more channel resource,thesis designs a new FSM for data slots reservation which helps nodes to reuse more data slots and designs two algorithms oriented to slot for slots reservation based on TDMA in case for different scenarios.Besides,most TDMA protocols work in static network topology.Once topology changes,the conflict of use of data slots may happen.To solve the problem,thesis propose a scheme that nodes can resolve the conflict of two neighbors which are going to be neighbors by predicting their locations and velocities,reducing the probability of conflict of data slots between nodes and improving the packet delivery rate.In the end,thesis verifies by simulations the effectiveness of algorithms oriented to slot for slots reservation in terms of delay and throughput,and the effectiveness of conflict resolve scheme in terms of the probability of conflict of data slots.