## 5 Simulations and Discussions
### Evaluation of Detection Capability
The best situation is when the PS of each orbit is in the same logical position in the orbit, that is, only AOLs are used. The worst situation is that the difference between the ID of PS in the orbit 1 (\(ID_{sat}^{PS}\)) and the ID of PS in the orbit 6 (\(ID_{sat}^{PS}\)) is the half number of satellites per orbit (\(ID_{sat}^{PS1}-ID_{sat}^{PS6}=5\), in this case), that is, AOLs and IOLs with the maximum number of hops are used. In this case, the _Link delay obtaining_ time can be calculated as 2 \(\times\) 13.5 = 27 ms (delay of round-trip links between adjacent satellites), the _LSAs to PS_ time can be calculated as 5 \(\times\) 13.5 = 67.5 ms (link delay between PS and the satellite farthest from it), the shortest _S-LSA exchange_ time can be calculated as 5 \(\times\) \((9+0.98)\)\(\approx\) 50 ms (best case scenario, time cost of 5 AOLs link transmissions), the longest _S-LSA exchange_ time can be calculated as 5 \(\times\)\((9+0.98)\)\(+\) 5 \(\times\)\((13.5+0.98)\)\(\approx\) 123 ms (worst case scenario, time cost of 5 AOLs and 5 IOLs transmissions), the _RT distribution_ time can be calculated as 5 \(\times\) 13.5 + 1.16 \(\approx\) 73 ms (time cost for PS to send the routing table to the satellite farthest from it), and the average _S-LSA exchange_ time can be calculated as \((50+123)/2=86.5\) ms. Under the SN situation, the additional routing convergence time consisted mainly of the following parts: the RIB download time (_RIB download_) and the routing table upload time (_RT upload_). In this example, we assume that we have detected a wrong RIB that can cause a SH. The _RIB download_ time can be calculated as 14.94 + 6 \(\approx\) 21 ms (downlink transmission delay of RIB and average propagation delay of the satellite-ground link), and  
Figure 21: The total routing convergence time under different situations. Figure 20: Changes in file transmission delay with transmission rate. the _RT upload_ time can be calculated as \(11\times 1.73+6\approx 25\) ms (uplink transmission delay of RT and average propagation delay of the satellite-ground link). In other words, if an RIB of a PS has an error, the RTs of 11 satellites in this orbit need to be uploaded additionally. Under the GN situation, the additional routing convergence time consists mainly of the following parts: the routing table download time (_RT download_) and the routing table upload (_RT upload_) time. In this example, we assume that we have detected a wrong RT that can cause a GH. The _RT download_ time can be calculated as \(11\times 3.46+6\approx 44\) ms (downlink transmission delay of RT and average propagation delay of the satellite-ground link), and the _RT upload_ time can be calculated as \(1.73+6\approx 8\) ms (uplink transmission delay of RT and average propagation delay of the satellite-ground link). In other words, the PS sends the routing tables of all satellites in this orbit to the ground station, and the ground station uploads the correct RT according to the ID of the affected RT. Under the SGN situation, if the wrong RTs are included in RTs generated according to the wrong RIB, the additional routing convergence time is the same as that of SN. If the wrong RTs are not included in the RTs generated according to the wrong RIB (this is the case in Figure 21), the additional routing convergence time consists mainly of the following parts: the RIB download time (_RIB download_), routing table download time (_RT download_), and routing table upload time (_RT upload_). In this example, we assume that we have detected a wrong RIB that can cause a SH and a wrong RT that can cause a GH.