Reserch Of The Licklider Transmission Protocol In Delay Tolerant Deep Space Network

The deep space communication is the radio communication in deep spacecommunication environment for the object of spacecraft. The deep space environment isthe space beyond Earth within the solar system and is characterized by a big differencewith the terrestrial environment. So the deep space communication has its own uniquecharacteristics. Deep space communications is another development following thesatellite communications in the field of aviation tasks. Deep space communications hasits unique characteristics to the ground, so the TCP/IP protocol can’t be applied in thedeep space environment. New concept called delay tolerant network (DTN) caused agreat deal of attention in recent years. More in depth research about DTN in the deepspace exploration activities and a certain amount of research results have attained.In this paper, performance of the Licklider Transmission Protocol in delay tolerantnetwork has been researched. In this paper, communication theories and keytechnologies for deep space exploration have been introduced and the transmissiondelay variability and intermittent characteristics of the deep space communication linkhave been analyzed.The performance of the layer protocol and Licklider TransmissionProtocol have been focused on, which have special advantages in the deep spacenetwork and are different from the ground TCP/IP protocol. The operation mechanismof LTP in the deep space structure has been described theoretically. The performance ofthe LTP protocol has been emulated and tested on the interplanetary overlay network(ION).Using the special properties of the Lagrange point, the Earth and Mars Lagrangepoints are selected as relay points to build the backbone of the deep space networkforming a deep space network architecture model. On the ground, large antenna isdirectly used to send commands to the spacecraft and receive data from the deep space.On the Mars, the Mars satellite network is used to solve the link break of the Marsrotation. Relay ideas is used in the Earth to Mars communications links, and one or tworelay points are contained in the communications system. In the Earth to Marscommunication system, an effective communication link, the delay time and theinterrupt time of the link are obtained using the STK simulation in the communicationsenvironment. These parameters are loaded into the ION simulation platform. The simulation has come to the relationship between the data throughput of thecommunications system and the interrupt time and the relationship between theretransmission packet and the interrupt time.Based congestion control LTP protocol is divided into five stages the transfer ofinformation beam selection phase, the target node selection strategy based on the ERSrules, the measure selected by the destination node, the destination node to select andtransfer information beam to retrieve stage five parts, link interruption and endpointmemory full, select the first beam to transfer to neighboring eligible node until the linkrecovery or memory release then passes the information in the space after the beamtransfer back to reduce link congestion, lower packet loss rate.