【作者】 叶剑； 李锦涛； 朱珍民； 顾晓光； 史红周；

【Author】 YE Jian1,2+,LI Jin-Tao1,SHI Hong-Zhou1,ZHU Zhen-Min1,GUO Jun-Bo1,2,Gu Xiao-Guang1 1(Institute of Computing Technology, Chinese Academy of Sciences, Beijing, 100080, China) 2(Graduate School of Chinese Academy of Sciences, Beijing, 100049, China)

【机构】 中国科学院计算技术研究所；

【摘要】 本文提出了一种自组织计算环境中的情境共享模型——DCSM模型。DCSM模型针对自组织网络终端分布式和资源受限的特点,通过情境空间划分,在终端上实现基于注册-查询机制的情境管理模型;在终端间通过发现广播消息和远程注册消息,实现分布式情境访问代理的远程注册,最终面向察觉计算应用业务需求,构建自组织计算环境中的情境共享融合机制。DCSM模型通过消息通信和情境存储优化技术,有效的解决了分布式计算模型固有的通信开销大和存储冗余问题。更多还原

【Abstract】 The peer-to-peer (P2P) computing is a common architecture of computing in a mobile wireless network environment. In such a ubiquitous wireless network, sentient computing applications, which can change their behaviors based on a model of the environment they construct using sensor data, will form a more intelligent environment for services running to provide users with the best experience of ubiquitous computing. The sentient computing applications rely on some distributed contexts to make decisions. How to build up the channel between sentient computing applications and distributed context information is an awkward problem to solve. The building of the channel involves the sharing of contexts among terminals and presentation of distributed contexts to applications. The Distributed Contexts Sharing Model (DCSM), a peer-to-peer computing-oriented context sharing model, is put forward in this paper. Based on gathering, inference, storage of contexts on terminals, the DCSM model is focused on intercommunication, sharing and fusing of contexts among terminals. Besides, the DCSM model offers a context presentation platform with the design of context presentation engines to construct a context awareness framework for contexts sharing and fusing. The architecture of the DCSM model is divided into three components, including Registration Center (RC), Context Database Agent (CDA) and Context Presentation Engine (CPE). These three components are mapped respectively into context manager, context provider, and context query. The mechanism of distributed contexts sharing is a model of constructing intercommunication among terminals. An Emphasis is placed on the maintenance of resident contexts and peripheral contexts sharing. As the context model of a peer-to-peer computing environment, the contexts in the DCSM model should be classified as resident context, neighbor context and out-of-group context. Context resident environment is an environment for interaction between CDAs and CPEs on the same terminal, and is the foundation of distributed peer-to-peer terminal context management. Based on the Registration-Query scheme, the environment implements the registration of CDAs and the access interface of resident contexts. The whole procedure of management of contexts in the context resident environment is divided into the registration of a CDA and context query. The context sharing is aimed at the context intercommunication among distributed network terminals. The context sharing message is the most important to the design of the RC. The context sharing message comprises two types of messages. One is broadcast message used for detecting the peer RC, the other is unicast message used for the registration of remote CDAs. The DCSM model is a kind of distributed model. In a distributed system, the cost of synchronization and communication as well as the redundancy of storage and communication will be elevated. To realize the tradeoff between the distributi更多还原