无线自组网协议网关设计与实现.pdf

摘要摘要无线自组织网是一种无中心、多跳、临时组织的对等网络,由于它具有无需基础设施、快速组网的能力,因而被广泛应用于军事行动、地震等自然灾害或者偏远地区的救援行动等场合。最初对自组网的研究只是将其作为一个独立的网络,将自组网与Intemet相连,可以扩展自组网的应用,同时自组网的多跳通信特点为无线接入提供更大的覆盖范围。然而二者的协议栈不一样,要实现互联,中间需要进行协议转换。为了解决这一需求,我们设计了自组网协议网关,实现了自组网与Intemet的互联。首先,本文对自组网协议栈的体系架构从整体上进行规划,协议网关在链路层实现。在实现方法上对链路层进行软硬件实现划分:MAC子层在FPGA中实现,RLC和PDCP子层在PowerPC中实现。设计并实现高速通信接口口核,解决了FPGA与PowerPC之间的通信问题。其次,本文通过构造Ad Hoe虚拟网卡,对进入无线自组网的m数据包进行统一的封装,同时将该虚拟网卡和以太网卡通过网桥进行桥接,获得以太网卡中的数据,减少设计难度。通过虚拟网卡的设计,为后续RLC的实现提供平台。再次,通过研究3GPP中RLC AM实体的工作原理,设计本文RLC的帧结构、差错控制、队列操作等,并在虚拟网卡的基础上实现RLC层的具体功能。实验结果表明,RLC能正常工作,信息。最后,为了提高无线自组网的带宽效率,拟在PDCP子层进行ROHC报头压缩。本文详细分析了ROHC报头压缩的原理和工作机制后,对其在Linux平台上进行实现。测试表明,ROHC能够达到84%压缩率,且适合于无线链路,为下一步在RLC层的基础上添加ROHC压缩技术提供理论依据。关键词:无线自组网;网关;ROHC Abstract Abstract grtreless Ad work iS al(indofpeer-to- ofthe capability of no infrastructure and working,it haswidely used inmilitary operations,earthquakes andothernaturaldisastersand remote areas. The research ofAd hocinitially isonly connected Ad Hoc、析th Intemet willhave more widely willexpand the application ofAdHoc,and meanwhile themulti-hop Ad workwill provide the Interactgreater coverage itneeds protocol conversion between them. In this paper,we focus on designing the protocol gateway to address the ,we analyze Ad work architecture,and propose todesign the protocol gateway therealization ofsoftwareandhardware oflink layer:MAC sub-layer isimplemented inFPGA,RLC and PDCP sub-layer in we design andimplement IPCOre ofhigh-munication interface tosolvetheproblem munication between FPGA and PowerPC. Secondly,by constructing a work card toencapsulate thepackets which arewant bridge work cardand Ethemet card to access carddataand reduce work cardprovides aplatform forthe RLC. Again,by studying theprinciple of3GPP RLC AM entities,wedesign thefrdme structure,error control andqueue manipulation ofthisRLC,and implement the specific function on thebaseofthe w