# Traffic-Predictive Routing Strategy for Satellite Networks
## 2 Related Research  
Due to the dynamic changes of satellite network topology, traditional terrestrial Internet routing protocols, such as Routing Information Protocol (RIP) and Open Shortest Path Protocol (OSPF), do not apply to satellite networks [6]. According to different triggering principles, the routing protocols applied to satellite networks can be divided into table-driven routing protocols and on-demand routing protocols. Typical table-driven routing protocols include Destination-Sequenced Distance-Vector (DSDV) and Optimized Link State Routing (OLSR) [7]. DSDV enables each node to advertise the routing table to its neighbors and maintain and update the routing table regularly, as well as when certain events occur, such as a disconnection [8]. [PERSON] et al. proposed a new heterogeneous routing protocol based on DSDV [9]. The protocol dynamically divides the network nodes into multi-hop clusters, the cluster heads are elected as backbone nodes in a distributed manner, and some long-distance high-capacity links are used as part of its routing. To meet the specific service requirements of large-scale star cluster systems, the literature [10; 11] improved OLSR, improved network performance and scalability, and reduced protocol overhead within the network. In the table-driven routing protocol, which has the characteristic of faster routing lookup by group, each node must maintain a constantly updated routing table. No matter whether the route in the routing table has data to be transmitted, each node must periodically generate a large number of control packets to maintain the route, which will consume a large amount of limited network bandwidth and reduce the transmission performance of the network. In addition, the rapid change of satellite network topology will make the \begin{table}
\begin{tabular}{c l} \hline \hline
**Abbreviations and Terms** & **Explanation of Abbreviations and Terms** \\ \hline \(Curr\_traffic_{i}\) & Current traffic load value. \\ \hline \(Next\_traffic_{i}\) & The traffic load value for the next moment \\ \hline \(L\) & Traffic threshold. \\ \hline \(hopS\) & The number of hops a data packet takes from the source node to the broken node. \\ \hline \(hopD\) & The number of hops required for a data packet to travel from the broken node to the destination node. \\ \hline \(STA_{i}\) & The stability of the node \(i\) \\ \hline _Pdelivery_ & Packet delivery rate. \\ \hline \(P_{R}\) & The number of data packets successfully reaching the destination node. \\ \hline \(P_{S}\) & The total number of data packets sent from the source node. \\ \hline \(A\)_vdelay_ & Average end-to-end delay. \\ \hline \(R_{time}(i)\) & The time when the \(i\)-th packet reaches the destination node. \\ \hline \(S_{time}(i)\) & The sending time of the \(i\)-th packet. \\ \hline _Ploss_ & Packet loss rate. \\ \hline \(P_{l}\) & The number of packets lost. \\ \hline TAG\_CONGEST & Route congestion status flag. \\ \hline RCS & Congestion control signal. \\ \hline RREQ & Request grouping defined in AODV protocol. \\ \hline RREP & The response packet defined in the AODV protocol for \\ responding to RREP. \\ \hline RERR & Packets used to notify errors defined in the AODV protocol. \\ \hline HELLO & Probe messages sent to neighbor nodes in the AODV protocol. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Mainly used abbreviations and terms. routing table information of table-driven routing protocol easily obsolete, resulting in a large amount of resource waste. As a result of these factors, the table-driven protocol is not suitable for the working environment of the satellite network. Typical on-demand routing protocols include Ad hoc On-Demand Distance Vector Routing (AODV), Dynamic Source Routing (DSR), etc. [12]. To verify the applicability of the AODV routing protocol to satellite networks, [PERSON] et al. compared the AODV routing protocol with flooding [13] and implemented a network simulator in C# language for routing selection of different satellites.