車聯(lián)網(wǎng)MAC層退避算法與信道預(yù)留策略研究
發(fā)布時(shí)間：2018-10-08 12:42
【摘要】：隨著汽車在普通家庭中的普及,交通安全、效率以及行車體驗(yàn)慢慢得到了人們的關(guān)注。車聯(lián)網(wǎng)屬于智能交通,實(shí)現(xiàn)了車輛之間的相互通信,可以為用戶提供安全行車與舒適的行車體驗(yàn)。它不僅可以提供安全信息來減少事故的發(fā)生,而且可以為車輛用戶提供非安全的多媒體等娛樂信息。目前,它已經(jīng)成為了智能交通領(lǐng)域的重要研究課題。車聯(lián)網(wǎng)采用固定大小的競(jìng)爭(zhēng)窗口以及二進(jìn)制指數(shù)退避策略,不適應(yīng)于不同車流密度的車輛環(huán)境。當(dāng)車流密度較大時(shí),固定的窗口和退避策略會(huì)導(dǎo)致大量的碰撞,增大了時(shí)延,影響了安全信息的傳輸；當(dāng)車流密度較小時(shí),固定的窗口和退避策略又會(huì)導(dǎo)致大量的空閑時(shí)間,造成信道資源的浪費(fèi)。此外,在多信道協(xié)作方面,車聯(lián)網(wǎng)采用了固定的切換周期。當(dāng)車流密度較小時(shí),安全信息相對(duì)較少,產(chǎn)生了大量的空閑時(shí)隙,導(dǎo)致了信道資源的浪費(fèi)。 針對(duì)車聯(lián)網(wǎng)中固定窗口和傳統(tǒng)退避策略引起的信道接入問題,本文設(shè)計(jì)了一種自適應(yīng)窗口的退避算法。通過建立廣播的一維馬爾科夫鏈模型,利用飽和吞吐量公式計(jì)算最優(yōu)競(jìng)爭(zhēng)窗口與節(jié)點(diǎn)數(shù)量的關(guān)系,設(shè)計(jì)基于節(jié)點(diǎn)數(shù)量自適應(yīng)窗口的退避算法。仿真結(jié)果表明,該算法可以有效降低車聯(lián)網(wǎng)的通信時(shí)延,增大了系統(tǒng)的吞吐量,并適用于不同的車流密度環(huán)境。針對(duì)信道切換引起的資源浪費(fèi)問題,本文提出了一種基于信道預(yù)留的RCMAC協(xié)議。為了提高車流密度較少時(shí)信道資源的利用率,通過劃分業(yè)務(wù)的優(yōu)先級(jí),建立信道狀態(tài)表,利用空閑的控制信道時(shí)隙對(duì)服務(wù)信道進(jìn)行預(yù)約,實(shí)現(xiàn)一種近似無競(jìng)爭(zhēng)的服務(wù)信道接入方式。仿真結(jié)果表明,在車流密度小的情況下,該協(xié)議可以有效增加服務(wù)信道的吞吐量,降低不同優(yōu)先級(jí)業(yè)務(wù)的傳輸時(shí)延。
[Abstract]:With the popularity of cars in ordinary families, traffic safety, efficiency and driving experience gradually get people's attention. The network of cars belongs to intelligent transportation, which realizes the mutual communication between vehicles, and can provide users with a safe and comfortable driving experience. It can not only provide safety information to reduce accidents, but also provide non-safe multimedia and other entertainment information for vehicle users. At present, it has become an important research topic in the field of intelligent transportation. The fixed size competition window and binary exponent Backoff strategy are used in the vehicle networking, which is not suitable for the vehicle environment with different traffic density. When the traffic density is high, the fixed window and Backoff strategy will lead to a large number of collisions, increase the delay, affect the transmission of security information, when the traffic density is small, the fixed window and Backoff strategy will lead to a lot of idle time. Causes the waste of channel resources. In addition, in the aspect of multi-channel collaboration, vehicle networking adopts a fixed switching period. When the traffic density is small, the security information is relatively less, resulting in a large number of idle time slots, resulting in a waste of channel resources. In order to solve the channel access problem caused by fixed window and traditional Backoff strategy in vehicle networking, an adaptive window Backoff algorithm is designed in this paper. By establishing a one-dimensional Markov chain model of broadcasting and calculating the relationship between the optimal competition window and the number of nodes by using the saturation throughput formula, a Backoff algorithm based on the adaptive window of the number of nodes is designed. The simulation results show that the proposed algorithm can effectively reduce the communication delay and increase the throughput of the system, and it is suitable for different traffic density environments. In order to solve the problem of resource waste caused by channel switching, a channel reservation based RCMAC protocol is proposed in this paper. In order to improve the utilization of channel resources when the traffic density is low, the channel status table is established by dividing the traffic priority, and the service channel is reserved by the idle control channel time slot. A kind of service channel access method without competition is realized. The simulation results show that the proposed protocol can effectively increase the throughput of the service channel and reduce the transmission delay of different priority services under the condition of low traffic density.
【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：U495;TP391.44;TN929.5
本文編號(hào)：2256790
[Abstract]:With the popularity of cars in ordinary families, traffic safety, efficiency and driving experience gradually get people's attention. The network of cars belongs to intelligent transportation, which realizes the mutual communication between vehicles, and can provide users with a safe and comfortable driving experience. It can not only provide safety information to reduce accidents, but also provide non-safe multimedia and other entertainment information for vehicle users. At present, it has become an important research topic in the field of intelligent transportation. The fixed size competition window and binary exponent Backoff strategy are used in the vehicle networking, which is not suitable for the vehicle environment with different traffic density. When the traffic density is high, the fixed window and Backoff strategy will lead to a large number of collisions, increase the delay, affect the transmission of security information, when the traffic density is small, the fixed window and Backoff strategy will lead to a lot of idle time. Causes the waste of channel resources. In addition, in the aspect of multi-channel collaboration, vehicle networking adopts a fixed switching period. When the traffic density is small, the security information is relatively less, resulting in a large number of idle time slots, resulting in a waste of channel resources. In order to solve the channel access problem caused by fixed window and traditional Backoff strategy in vehicle networking, an adaptive window Backoff algorithm is designed in this paper. By establishing a one-dimensional Markov chain model of broadcasting and calculating the relationship between the optimal competition window and the number of nodes by using the saturation throughput formula, a Backoff algorithm based on the adaptive window of the number of nodes is designed. The simulation results show that the proposed algorithm can effectively reduce the communication delay and increase the throughput of the system, and it is suitable for different traffic density environments. In order to solve the problem of resource waste caused by channel switching, a channel reservation based RCMAC protocol is proposed in this paper. In order to improve the utilization of channel resources when the traffic density is low, the channel status table is established by dividing the traffic priority, and the service channel is reserved by the idle control channel time slot. A kind of service channel access method without competition is realized. The simulation results show that the proposed protocol can effectively increase the throughput of the service channel and reduce the transmission delay of different priority services under the condition of low traffic density.
【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：U495;TP391.44;TN929.5
【共引文獻(xiàn)】
相關(guān)期刊論文 前2條
1 荊濤;關(guān)明陽;;基于RFID技術(shù)的位置信息輔助系統(tǒng)[J];北京交通大學(xué)學(xué)報(bào);2014年05期
2 陶洋;李娜;臧文軒;;基于區(qū)域的車載自組織網(wǎng)絡(luò)節(jié)點(diǎn)分簇算法研究[J];廣東通信技術(shù);2015年02期
相關(guān)博士學(xué)位論文 前4條
1 揭志忠;高速公路環(huán)境VANET的高效路由算法研究[D];武漢大學(xué);2013年
2 張秀華;基于WLAN/RFID信息融合的移動(dòng)機(jī)器人自主定位算法研究[D];哈爾濱理工大學(xué);2013年
3 范存群;車聯(lián)網(wǎng)環(huán)境下基于可靠接入的高效數(shù)據(jù)傳輸機(jī)制研究[D];北京郵電大學(xué);2014年
4 梅穎;車聯(lián)網(wǎng)隱私保護(hù)研究[D];華中科技大學(xué);2014年
相關(guān)碩士學(xué)位論文 前4條
1 王勤龍;基于路側(cè)設(shè)備的車輛定位和交叉口防撞預(yù)警方法研究[D];北京交通大學(xué);2013年
2 劉慶;DTN網(wǎng)絡(luò)中基于概率的散發(fā)等待路由算法[D];華中師范大學(xué);2013年
3 張鶴丹;基于WiFi技術(shù)的井下人員定位系統(tǒng)研究[D];西安建筑科技大學(xué);2013年
4 關(guān)明陽;面向RFID-VANETs的位置信息輔助系統(tǒng)[D];北京交通大學(xué);2015年
，本文編號(hào)：2256790
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