胡　静　宋雪雁　孙济洲

(天津大学计算机科学与技术学院　天津 300072)



航行通告分发服务中间件的研究与设计

胡静宋雪雁孙济洲

(天津大学计算机科学与技术学院天津 300072)

摘要现有的航行通告处理系统采用C/S模式，客户端和服务器间耦合度很高，且基于广播的传送方式造成客户端大量冗余航行通告的产生。针对航行通告发生地明确、接收端可按需订阅的特点，结合数据分发服务DDS(Data Distribution Service)规范能够使通信双方在空间、时间和数据通信等方面实现松耦合的特征。提出基于DDS规范的发布订阅模型，设计了一个支持服务质量QoS(Quality of Service)的航行通告分发服务中间件，定义其中的数据结构、工作流程以及全局数据空间的管理策略。根据航行通告发布场景，使用CPN Tools工具进行建模和仿真。案例仿真结果表明，该中间件能够提供准确的基于主题的航行通告分发服务，从而证明了中间件设计方案的可行性和有效性。

关键词航行通告分发服务中间件服务质量着色Petri网

RESEARCH AND DESIGN OF NOTAM DISTRIBUTION SERVICE MIDDLEWARE

Hu JingSong XueyanSun Jizhou

(School of Computer Science and Technology,Tianjin University,Tianjin 300072,China)

AbstractExisting NOTAM processing system uses C/S model, the coupling degree between client and server is very high, and the broadcast-based transmission means makes a lot of redundant NOTAM generated at the client. In view of the features of NOTAM that their generation places are clear and the receiver can be subscribed on demand, and combining with the characteristics of data distribution service (DDS) specification that it enables two communicating parties to reach the loose coupling in space, time and data communications, in this paper we present a DDS specification-based publishing and subscribing model. We design a NOTAM distribution service middleware which supports the QoS policies, define the data structure and work flow of it, as well as the managerial strategy of global data space. According to NOTAM distribution scene, we use CPN Tools for modelling and simulation. Case simulation results show that the middleware can provide accurate subject-based NOTAM distribution services, so that proves the feasibility and validity of the design scheme of middleware.

KeywordsNotice to airmen (NOTAM)Distribution serviceMiddlewareQuality of serviceColoured Petri nets (CPN)

0引言

航行情报服务是空中交通管理的重要组成部分[1]。目前，我国正在使用的民航航行情报处理系统采用了基于客户端/服务器C/S的通信模型，实现国内外航行通告、雪情通告及其他电报的接收、处理和发布[2]。这种基于C/S模型的系统，使得客户端和服务器间的耦合程度很高，降低了系统的灵活性、扩展性和健壮性。为了解决上述C/S模型的缺陷，本文在航行通告分发服务中引入了发布/订阅模型[3]，在发布/订阅模型中，发布者和订阅者通过主题关联，两者不需同时在线，也不必知道对方的位置，从而实现了通信双方时间、空间和数据通信的多维松耦合。……