Research And Implementation On The Behavior Of CoAP Under The Conditional Observe

With the rise of the Internet,the Internet of Things are followed,it did not stop the pace of development.HTTP runs on the transport layer of the Internet,however HTTP shows no flexibility upon constrained objects in the Internet of Things.Because for constrained objects,the overhead of HTTP is relatively large,it will occupy too many resources of the constrained objects.Therefore,working group CoRE of IETF defined a new protocol can be applied on the transport layer of the Internet of Things--CoAP.CoAP defines a way of observing resources based on the observer pattern,and on the basis of this observation,people also proposed an enhanced constraint condition observation--conditional observe.The conditional observe does not involve all the terminals in the CoAP system,which means that there is only one terminal,such as server,intermediary or client to determine whether the conditions are met can make the system work properly.The work carried out on a different terminal cause different effects on the entire system.However,the conditional observe draft does not specify which terminal to do the work.Therefore,under the guidance of this idea,this paper will propose viable solutions to the various scenarios of CoAP system,and compare the burden of the corresponding terminal in different scenarios,and thus to compare different solutions.In order to compare the burden of the terminals in each scenario,there is a chapter for theoretical analysis and describing the establishment of "CoAP Conditional Observe System".In this system each case in the theoretical analysis section is put into practice,the burden of each terminal is calculated on the basis of experimental data,and then on the basis of the actual data a further verification of the correctness of the theory is conducted.Finally,a performance analysis of "CoAP Conditional Observe System" is conducted,the analysis is based on the data of the theoretical analysis section,and on an experimental basis a verification of the correctness and the robustness of the entire system within an acceptable range of deviation is performed.