Research And Implementation Of Light-Weight Ip

With the development of Internet technologies, communications and networks are being embedded into our living environment and more and more equipments have the needs to communicate. Many of them are small devices, which exist with constrained resources such as8-bit microprocessors, limited memory and low power. The constraint of devices makes the realization of Internet Protocols more difficult and it is not always easy to embed all the necessary features of traditional technologies. It is expected to research light-weight protocols and implementations. The study of application protocols is an important direction, and it can be very helpful for the implementations of various applications on small devices.This thesis firstly introduces the background and present research situation of lightweight IP. The existing protocol standards in the IETF (Internet Engineering Task Force) working groups and the research progress of applications in other organizations are introduced. Based on the analysis of protocol standards, a lightweight application protocol which is called CoAP (Constrained Application Protocol) is analyzed in detail. The basic features, communication model, messaging model, message format and interactive processes are described. And this thesis combines the protocol standard with wireless network scenario, proposing an application scenario in which the protocol is applied to the M2M (machine-to-machine) services and mobile communication networks are used for serving as a bearing to explore the new problems and needs and analyze the optimization of the standard.In order to indicate the identification of applications, the thesis proposes the extensions to CoAP, adding an option. By reading this option some function entities in transport networks could distinguish different applications and do some differentiated processing. Furthermore, this thesis complements the security considerations of CoAP. The endpoints make security negotiation to whether the lower layer security in an intermediate network could secure CoAP data. If the lower layer security standards could fulfill the security requirements of CoAP, in this network DTLS (Datagram Transport Layer Security) could be disabled to avoid DTLS datagram overhead and we just mark a security flag to indicate that CoAP data is secured by lower layer. Thus different security modes are realized in one transmission path between CoAP endpoints. It’s more flexible. Then this thesis implements CoAP on the simulation platform and verifies light-weight features and the validity of solutions.Finally, the shortcomings in the work and future possible research directions are summarized. Additionally, the works and achievements during my graduate study are described.