面向移动环境的服务提供框架研究与实现

发布时间：2019-03-20 11:01

【摘要】：随着近年来移动计算技术的迅猛发展,移动终端用户越来越多以服务的方式去共享移动终端及其周边设备的处理能力和计算资源。目前智能手机越来越普及,计算能力、存储能力也得到了极大增强,同时现在的移动通信网络越来越快速,智能手机集成了大量的传感器组件,这使得智能手机可以提供丰富的含有环境上下文信息(例如,GPS位置信息、加速传感器信息)的Web服务。移动Web服务同时反过来也增强了移动应用程序的能力,例如移动群智感知、实时移动健康监测、基于位置的移动社交网络和医疗定位系统等。虽然近年来,智能手机发展迅猛,处理器向多核化发展、RAM/ROM容量不断增大,随着4G/5G技术的发展,移动环境下的网络带宽也随之提高,但是毫无疑问,作为移动环境的网络服务提供者相比于传统的服务器或者工作站,资源受限和电池能耗是明显的短板。移动终端的资源受限性和移动性等特征使得面向移动计算环境的服务提供、服务发现场景存在着一些特殊的问题,例如移动终端资源消耗、网络环境变化引起的失效问题等。因此,本论文针对资源受限的移动环境,设计和实现了一个轻量级的面向移动环境的服务提供框架。本论文主要从三个方面对移动服务提供框架进行了研究。针对应用场景的不同,移动服务提供框架共分为三个模块：CoAP协议栈模块、基于BLE的服务广播和发现模块以及基于RSD的广域服务发现模块。CoAP协议栈模块负责服务调用过程的数据传输,BLE服务广播为邻域内提供服务发现,RSD服务器实现了广域内的服务发现。然后,针对各模块分别进行了设计与实现。CoAP (Constrained Application Protocal)是一种应用层的通信协议,建立在UDP (User Datagram Protocal)网络协议与Web技术之上。在协议栈模块中重点研究了CoAP协议的基本通信原理,同时对其双层架构和超时重传机制进行了深入探索,实现了一套基于REST模式的CoAP协议栈。对于邻域内的服务发现,采用了低功耗蓝牙协议实现服务的广播和发现。同时,基于SpringMVC框架实现了远程服务目录服务器,提供服务注册、查询、更新和删除功能,实现了基于服务注册机制的广域内的服务发现。最后,根据本论文所设计的面向移动环境的服务提供框架实现了一个原型系统,并基于Android平台进行了系统的服务发现效率和性能测试。
[Abstract]:With the rapid development of mobile computing technology in recent years, more and more mobile terminal users share the processing power and computing resources of mobile terminal and its peripheral devices in a service manner. At present, smart phones are becoming more and more popular, and their computing and storage capabilities have been greatly enhanced. At the same time, the current mobile communication network is getting faster and faster, and smart phones integrate a large number of sensor components. This allows smartphones to provide rich Web services that contain environmental context information (e.g., GPS location information, acceleration sensor information). Mobile Web services, in turn, enhance the capabilities of mobile applications, such as mobile community awareness, real-time mobile health monitoring, location-based mobile social networks and medical positioning systems. Despite the rapid development of smart phones in recent years, the development of processors to multi-core, the increasing capacity of RAM/ROM, with the development of 4G/5G technology, the network bandwidth in mobile environment is also increased, but there is no doubt. As a network service provider in mobile environment, resource constraints and battery energy consumption are obviously weak compared with traditional servers or workstations. The resource limitation and mobility of mobile terminal make the service delivery for mobile computing environment. There are some special problems in service discovery scenario, such as the resource consumption of mobile terminal, the failure caused by the change of network environment, and so on. Therefore, this paper designs and implements a lightweight service providing framework for mobile environment, aiming at the resource-constrained mobile environment. This paper mainly studies the framework of mobile service provision from three aspects. According to the different application scenarios, the mobile service delivery framework is divided into three modules: the CoAP protocol stack module, BLE-based service broadcast and discovery module and RSD-based wide-area service discovery module. Coap protocol stack module is responsible for the data transmission of the service invocation process, and BLE service broadcast provides service discovery in the neighborhood. The RSD server implements service discovery in the wide area. Coap (Constrained Application Protocal) is an application layer communication protocol based on UDP (User Datagram Protocal) network protocol and Web technology. In the module of protocol stack, the basic communication principle of CoAP protocol is studied emphatically. At the same time, the double-layer architecture and retransmission mechanism of CoAP protocol are deeply explored, and a set of CoAP protocol stack based on REST mode is realized. For the service discovery in the neighborhood, the low power Bluetooth protocol is used to realize the broadcast and discovery of the service. At the same time, the remote service directory server is implemented based on SpringMVC framework, which provides the service registration, query, update and delete functions, and realizes the service discovery in the wide area based on the service registration mechanism. Finally, according to the mobile environment-oriented service providing framework designed in this paper, a prototype system is implemented, and the service discovery efficiency and performance of the system are tested based on the Android platform.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP311.52

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