Research Of Multi-agent Technologies For Multimedia Communication Task In Next Generation Networks

The next-generation network (NGN), based on IP, will converge all telecom traffic as public switched telephone network (PSTN), wireless networks and computer networks into one. There are many complex computing tasks and communication tasks in NGN. Based on the cooperation, coordination, communication of agents, Multi-agent System (MAS) can be employed to accomplish the complex task that is difficult or even impossible to accomplish for a sole-agent system. Therefore, we mainly discuss how to apply multi-agent technologies to accomplish the complex computing tasks and communication tasks in NGN.At present, agent technologies are mainly employed to accomplish the knowledge sharing and manipulating that does not require high real-time and interactive proceeding. They are not suitable for the switching mass information too. So, how to extend the capability of communication between agents, and to have agents to be able to deal with real-time, interactive, multi-level and multi-round task? How to have agents to be able to deal with switching mass information, especially such as multimedia information? And how to have agent technologies to be employed in NGN to achieve complex its computing task? There are many difficulties in theory and realization to address them. It should be researched in depth.It's a complex communication task for multimedia communication to traverse NAT/Firewall in NGN. As bundled-session communication, multimedia communication can't traverse NAT/Firewall directly, which is a global difficult problem for audio and video application to be really deployed in NGN. Although several solutions has been proposed separately by Microsoft, Cisco, 3Com and some international standardization organization, they can't resolve the problem very well at all by now. Softswitch needs to accomplish signaling switch, call control and service control etc. It is a complex computing task in NGN.This dissertation focuses on proposing a new Agent Communication Language and its executing model to have Multi-agent system to support the multimedia communication task in NGN. Furthermore, we use it to resolve the problem of multimedia communication traversing NAT/Firewall, and design multi-agent based Softswitch.Concretely, the main research works are as follows:(1) This dissertation proposed a new specification of Agent Communication Language for multimedia communication (ACLMC) task. The primitives of ACLMC are designed by referring to ITU-T Q.931, KQML and FIPA ACL. This design is also fully taken account of the message mapping between ACLMC and MoIP protocols such as H.323, SIP etc. The semantic of ACLMC are defined. Compared with KQML, ACLMC can directly express the intention of interaction of agents by providing the interactive primitive. Therefore, it can support the real-time interaction among agents. The communication structure is also presented. Take account of the requirement of agents interacting with periphery entity based on MoIP protocol, the mappings between ACLMC primitive and MoIP protocol, including message mapping, message sequence mapping, media coding format and call addresses mapping, are also presented. The using KIF (Knowledge Interchange Format) as content language of ACLMC is discussed. The way of call knowledge expression and format of knowledge exchange arc also presented.(2) Based on the BDI (Belief Desire> Intention ) agent model, the dissertation defines the interpreting and executing model of ACLMC. As to describe the Belief, Desire and Intention, a new agent (describe) language MC-agentspeak is proposed. Its format and semantic are defined. MC-agentspeak looks an agent as an object composed of a group of static sets and operations that are on behalf of the events, beliefs, plans, intentions, actions goal of agent. The ESA rules are given to plan the actions of agents. The executing model is described by using Operational Semantics of MC-agentspeak.(3) The multi-agent system for multimedia communication traversing NAT/Firewall is designed. Through the communication based on ALCMC among agents, the system converts the bundled session communication into non-bunlded session communication in NAT/Firewall, and non-bunlded session can traversing multi-level NAT/Firewall directly. The theory of this traversing way is also proved. The security and performance of the system are discussed too. The system has better capability than that of the other solutions. It can meet the traversing of all MoIP protocols. It can traverse multi-level NAT/Firewall. Its implementation does not need to update the installed NATs/Firewalls. The experiment verified the design of the system.(4) The multi-agent based Softswitch is presented. The architectureof the system and function model of agents has been designed. The communication method and procedure of interaction has also been discussed. The simulation results verified the thinking of the dissertation.This dissertation proposed the ACLMC language and its interpreting and executing model, which is the fist-step for multi-agent technologies being used in NGN to accomplish those complex multimedia-concered tasks. Besides resolving the two problems of this paper, the ACLMC language can be also used to implement the intelligent, distributed and personalized service control and management in company with mobile agent technologies in the future.