无线Mesh网络路由尺度问题研究
摘要
无线Mesh网络(Wireless Mesh Network)简称WMN,是一种新型的无线通信网络。无线Mesh网络具有自组织性和自愈的特点,并具有有效的移动用户管理和跟踪机制,是一种多跳的宽带无线网络,也是一种高容量、高速率的分布式网络。路由协议是无线Mesh网络的关键技术之一,而路由尺度是影响路由协议性能的关键参数。其中基于何种尺度进行路由选择是提高网络性能的关键。因此路由尺度问题的研究一直以来都是无线Mesh网络路由协议研究领域的热点问题。
本文首先阐述了无线Mesh网络的体系结构,对无线Mesh网络中典型的路由尺度进行了研究与分析,并重点研究了近期提出的期望吞吐量尺度-ETP。针对ETP尺度所存在的缺陷,本文考虑了链路的干扰范围,同时提出了Mesh网络中节点负载的定义,并将这两者与ETP尺度相结合,提出了改进的期望吞吐量尺度-METPLB。其次对动态源路由协议DSR中的路由建立过程进行了修改,利用RREQ报文中的保留字段建立了路由尺度表,并将本文所提出的METPLB尺度应用于DSR协议中,详细描述了基于METPLB尺度的DSR协议的工作过程,并将ETP与METPLB尺度的路径选择过程进行了比较。最后,通过仿真实验研究了METPLB尺度中权值系数β的取值对网络性能的影响,并分析比较了ETP和METPLB尺度的性能。实验证明:在数据流量较大,网络负载较重的多射频多信道无线Mesh网络中,与ETP相比,METPLB尺度更倾向于选择那些运行在相同信道上的链路间干扰较小且更加独立的路径来作为路由路径,从而提高了网络吞吐量,降低了数据包端到端延迟,有效地实现了网络的负载平衡。
The Wireless Mesh Network (WMN) is a new type of wireless communication network. WMN has features of self-organization and self-healing, as well as its capability of mobile user management and tracing. It is a multi-hop broad bandwidth distributing wireless network with high capacity and high transmission rate. Routing protocol is one of the key technologies in WMN, while routing metrics is an important parameter that influences the performance of routing protocol. The routing selection based on which metrics is the key issue of improving the performance of network. Therefore, the research of routing metrics is a hot spot in the area of routing protocol research all the way.
Firstly, the dissertation describes the structure of wireless mesh network, then it studies and analyses the typical routing metrics, especially the expected throughput metric proposed recently. To the limitation of ETP, the interference range of link is taken into account, and a definition of node’s loading is proposed at the same time, then the METPLB metric is proposed by incorporating them into ETP metric in this paper. Secondly, the process of route foundation of DSR protocol is modified and the routing metrics table is established by making use of the reserved bit of RREQ datagram, then the METPLB metric is applied in DSR protocol, the process of DSR protocol based on METPLB metric is described in detail, METPLB and ETP metrics are compared. Finally, the impact ofβvalue to network is studied through simulating experiment, the performance of ETP and METPLB is analyzed and compared. The experiment proves that: comparing with ETP, METPLB metric is preferable to choose the path which is more disjoint and the interference of link is smaller when running on the same channel as its routing path in mutil-radio and multi-channel wireless Mesh network with heavy traffic and loading, thus to improve the throughput and reduce the end-to-end delay as well as to achieve the loading balance of network effectively.
本文首先阐述了无线Mesh网络的体系结构,对无线Mesh网络中典型的路由尺度进行了研究与分析,并重点研究了近期提出的期望吞吐量尺度-ETP。针对ETP尺度所存在的缺陷,本文考虑了链路的干扰范围,同时提出了Mesh网络中节点负载的定义,并将这两者与ETP尺度相结合,提出了改进的期望吞吐量尺度-METPLB。其次对动态源路由协议DSR中的路由建立过程进行了修改,利用RREQ报文中的保留字段建立了路由尺度表,并将本文所提出的METPLB尺度应用于DSR协议中,详细描述了基于METPLB尺度的DSR协议的工作过程,并将ETP与METPLB尺度的路径选择过程进行了比较。最后,通过仿真实验研究了METPLB尺度中权值系数β的取值对网络性能的影响,并分析比较了ETP和METPLB尺度的性能。实验证明:在数据流量较大,网络负载较重的多射频多信道无线Mesh网络中,与ETP相比,METPLB尺度更倾向于选择那些运行在相同信道上的链路间干扰较小且更加独立的路径来作为路由路径,从而提高了网络吞吐量,降低了数据包端到端延迟,有效地实现了网络的负载平衡。
The Wireless Mesh Network (WMN) is a new type of wireless communication network. WMN has features of self-organization and self-healing, as well as its capability of mobile user management and tracing. It is a multi-hop broad bandwidth distributing wireless network with high capacity and high transmission rate. Routing protocol is one of the key technologies in WMN, while routing metrics is an important parameter that influences the performance of routing protocol. The routing selection based on which metrics is the key issue of improving the performance of network. Therefore, the research of routing metrics is a hot spot in the area of routing protocol research all the way.
Firstly, the dissertation describes the structure of wireless mesh network, then it studies and analyses the typical routing metrics, especially the expected throughput metric proposed recently. To the limitation of ETP, the interference range of link is taken into account, and a definition of node’s loading is proposed at the same time, then the METPLB metric is proposed by incorporating them into ETP metric in this paper. Secondly, the process of route foundation of DSR protocol is modified and the routing metrics table is established by making use of the reserved bit of RREQ datagram, then the METPLB metric is applied in DSR protocol, the process of DSR protocol based on METPLB metric is described in detail, METPLB and ETP metrics are compared. Finally, the impact ofβvalue to network is studied through simulating experiment, the performance of ETP and METPLB is analyzed and compared. The experiment proves that: comparing with ETP, METPLB metric is preferable to choose the path which is more disjoint and the interference of link is smaller when running on the same channel as its routing path in mutil-radio and multi-channel wireless Mesh network with heavy traffic and loading, thus to improve the throughput and reduce the end-to-end delay as well as to achieve the loading balance of network effectively.
引文
[1] 姜红旗,康凯,林孝康. 拓展宽带接入的无线 Mesh 网技术[J]. 电信科学,2005,1:24-30
[2] F. Akyildiz, Xudong Wang, Weilin Wang. Wireless mesh networks: a survey[J]. Computer Networks, 2005,5(47):445-487
[3] Rendong Bai and Mukesh Singhal. DOA: DSR over AODV Routing for Mobile Ad Hoc Networks[J]. IEEE Transactions on Mobile Computing, 2006, 5(10):1403-1416
[4] Can Emre Koksal and Hari Balakrishnan. Quality-Aware Routing Metrics for Time-Varying Wireless Mesh Networks[J]. IEEE Press,2006,24(11):1984-1994
[5] Jun Cheol Park and Sneha Kumar Kasera. An Accurate High-Throughput Path Metric For Multi-Hop Wireless Routing[white paper]. University of Utah, 2007
[6] Devu Manikantan Shila and Tricha Anjali. Load-aware Traffic Engineering for Mesh Networks[C]. In: Proceedings of 16th International Conference on Computer Communications and Networks. IEEE Press,2007,1040-1045
[7] Anand Prabhu Subramanian and Milind M. Buddhikot and Scott Miller. Interference aware routing in multi-radio wireless mesh networks[C]. In: 2nd IEEE Workshop on Wireless Mesh Networks. New York: IEEE Press, 2006, 55-63
[8] Wei Zhou, Dongbo Zhang, and Daji Qiao. Comparative Study of Routing Metrics for Multi-Radio Multi-Channel Wireless Networks[C]. In: Wireless Communications and Networking Conference. New York: IEEE Press, 2006,1, 270-275
[9] 范涛,张燕. 无线 Mesh 网络的组网及其相关标准[J]. 数据通信,2005,4:40-42
[10] 李娅. 无线网状网技术研究[J]. 电脑知识与技术,2006,1:56-57
[11] 沈强,方旭明,宋文. 无线 Mesh 网络路由协议研究[J]. 数据通信,2005,4:30-33
[12] Zhingming Zhang,Xiaofeng Zhong and Weirong Jiang. High Throughput Routing in Large-Scale Multi-Radio Wireless Mesh Networks[C]. In:WCNC proceedings. New York: IEEE Press, 2007,1, 3601-3605
[13] Yun Hu and ShouBao Yang. A New Routing Metric for Multi-Radio and Multi-Channel Wireless Mesh Network[C]. In: International Conference on Wireless Communications, Networking and Mobile Computing (WICCOM).NewYork: IEEE Press, 2006,22(24):1-4
[14] 张瑞,洪佩琳,等. MEIL_一种高吞吐量的无线网状网路由协议[J]. 中国科学院研究生院学报,2007,24(4):473-479
[15] Shenghui Wang, Zhengding Qiu. a link type aware routing metric for wireless mesh networks[C]. In:The 8th International Conference on Signal Processing. Beijing: IEEE Press, 2006,1701-1704
[16] Lingyun Jiang,Guangzeng Feng. A MAC Aware Cross-Layer Routing Approach for Wireless Mesh Network[C]. In:International Conference on Wireless Communications, Networking and Mobile Computing (WICCOM). NewYork: IEEE Press, 2006,22(24):1-5
[17] Tehuang LIU and Wanjiun Liao. Capacity-Aware Routing in Multi-Channel Multi-Rate Wireless Mesh Networks[C]. In:IEEE International Conference on Communications. Istanbul: IEEE Press, 2006,5:1971-1976
[18] 吴 笑 萍 . Ad hoc 网 络 隐 藏 / 暴 露 终 端 问 题 的 研 究 [J]. 微 计 算 机 信息,2006,22(10-3):35-37
[19] 朱隽. 无线网状网路由判据研究[J]. 电子工程师,2007,33(8):73-77
[20] D. De Couto, D. Aguayo, J. Bicket, and R. Morris. A high-throughput path metric for multi-hop wireless routing[C]. In: Proceedings of the 9th annual international conference on Mobile computing and networking. San Diego:ACM press,2003,134-136
[21] Richard Draves, Jitendra Padhye and Brian Zill. Routing in Multi-Radio, Multi-Hop Wireless Mesh Networks[C]. In: Proceedings of the 10th annual international conference on Mobile computing and networking. Philadelphia: ACM press, 2004,114-128
[22] Yaling Yang, Jun Wang, and Robin Kravets. Designing Routing Metrics for Mesh Networks[R]. In:IEEE Workshop on Wireless Mesh Networks. Santa Clara ,2005
[23] Yaling Yang, Jun Wang, and Robin Kravets. Interference-aware Load Balancing for Multihop Wireless Networks[R]. In: Department of Computer Science, University of Illinois at Urbana-Champaign, 2005
[24] R. Draves, J. Padhye, and B. Zill. Comparison of Routing Metrics for Static Multi-Hop Wireless Networks[C]. In: Proceedings of the 2004 conference on Applications, technologies, architectures, and protocols for computer communications. NewYork: ACM press, 2004, 133-144
[25] Martin Heusse, Franck Rousseau, Gilles Berger-Sabbatel and Andrzej Duda. Performance anomaly of 802.11b[J]. In: Twenty-Second Annual Joint Conference of the IEEE Computer and Communications Societies. NewYork: IEEE Press,2003,2,836-843
[26] S. Choi, K. Park and C. Kim, On the performance characteristics of WLANs: revisited[J]. In: ACM SIGMETRICS Performance Evaluation Review. NewYork: ACM Press,2005,33(1):97-108
[27] Vivek P.Mhatre and Henrik Lundgren. MAC-aware routing in wireless mesh networks[C]. In: Fourth Annual Conference on Wireless on Demand Network Systems and Services. Oberguyrgl: IEEE Press,2007,46-49
[28] Vivek P.Mhatre and Henrik Lundgren. Joint MAC-aware Routing and Load Balancing in Mesh Networks[C]. In: International Conference On Emerging Networking Experiments And Technologies. NewYork: ACM Press,2007,10-13
[29] 802.11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications[S]. ANSI/IEEE, 1999
[30] Can Emre Koksal, Hisham Kassab, Hari Balakrishnan. An analysis of short-term fairness in wireless media access protocols[C]. In: ACM SIGMETRICS Performance Evaluation Review. NewYork: ACM Press,2000,28(1):118-119
[31] Jitendra Padhye, Sharad Agarwal, et al. Estimation of Link Interference in Static Multi-hop Wireless Networks[C]. In: Proceedings of the 5th ACM SIGCOMM conference on Internet measurement. Berkeley, California: ACM Press,2005
[32] K. Jain, J. Padhye, V. Padmanabhan and L. Qiu. Impact of interference on multi-hop wireless network performance[C]. In: Proceedings of the 9th annual international conference on Mobile computing and networking. San Diego: ACM Press,2003,66-80
[33] 郭嘉丰,张信明,谢飞等. 基于节点空闲度的自适应移动 Ad Hoc 网络路由协议[J]. 软件学报,2005,16(5):960-969
[34] Yigal Bejerano,Seung-Jae Han,Amit Kumar. Efficient load-balancing routing for wireless mesh networks[J]. Computer Networks: The International Journal of Computer and Telecommunications Networking,2007,51(10):2450-2466
[35] Hossam Hassanein and Audrey Zhou. Routing with Load Balancing in Wireless Ad hoc Networks[C]. In: Proceedings of the 4th ACM international workshop on Modeling, analysis and simulation of wireless and mobile systems. Rome, Italy : ACM Press,2001,89-96
[36] Xiaojing Tao, Thomas Kunz and David Falconer. Traffic balancing in wireless MESH networks[C]. In: International Conference on Wireless Networks, Communications and Mobile Computing. NewYork: IEEE Press,2005,1,169-174
[37] Han Zhang and Danny H.K. Traffic Oriented Topology Formation and Load-balancing Routing in Wireless Mesh Networks[C]. In: Proceedings of 16th International Conference on Computer Communications and Networks . Honolulu, HI: IEEE Press,2007,1046-1052
[38] Wen Song and Xuming Fang. Routing with Congestion Control and Load Balancing in Wireless Mesh Networks[C]. In: 2006 6th Intertional Conference on ITS Telecommunications Proceedings. ChengDu: IEEE Press,2006,719-724
[39] 陈祥. 无线自组织网络负载均衡路由研究[D]. 成都:电子科技大学. 2007,6:20-23
[40] Kyu-Han Kim and Kang G. Shin. On Accurate Measurement of Link Quality in Multi-hop Wireless Mesh Networks[C]. In: Proceedings of the 12th annual international conference on Mobile computing and networking. Los Angeles: ACM Press, 2006,38-49
[41] Geetha Jayakumar, and G. Gopinath. Ad Hoc Mobile Wireless Networks Routing Protocols – A Review[J]. Journal of Computer Science, 2007,3(8):574-582
[42] Josh Broch, David A. Maltz, et al. A performance comparison of multi-hop Wireless Ad hoc network routing protocols[C]. In: Proceedings of the 4th annual ACM/IEEE international conference on Mobile computing and networking. Dallas: ACM Press,1998,85-97
[43] Turgay Kormaz, Wei Zhou. On Finding Optimal Paths in Multi-radio, Multi-hop Mesh Networks using WCETT Metric[C]. In: Proceedings of the 2006 international conference on Wireless communications and mobile computing. Vancouver, British Columbia, Canada: ACM Press,2006,1375-1380
[44] D.Johnson, Y. Hu, and D.Maltz. The Dynamic Source Routing Protocol(DSR) for Mobile Ad Hoc Networks for IPv4. RFC4728. http://www.rfc-editor.org/rfc/rfc4728.txt, 2007
[2] F. Akyildiz, Xudong Wang, Weilin Wang. Wireless mesh networks: a survey[J]. Computer Networks, 2005,5(47):445-487
[3] Rendong Bai and Mukesh Singhal. DOA: DSR over AODV Routing for Mobile Ad Hoc Networks[J]. IEEE Transactions on Mobile Computing, 2006, 5(10):1403-1416
[4] Can Emre Koksal and Hari Balakrishnan. Quality-Aware Routing Metrics for Time-Varying Wireless Mesh Networks[J]. IEEE Press,2006,24(11):1984-1994
[5] Jun Cheol Park and Sneha Kumar Kasera. An Accurate High-Throughput Path Metric For Multi-Hop Wireless Routing[white paper]. University of Utah, 2007
[6] Devu Manikantan Shila and Tricha Anjali. Load-aware Traffic Engineering for Mesh Networks[C]. In: Proceedings of 16th International Conference on Computer Communications and Networks. IEEE Press,2007,1040-1045
[7] Anand Prabhu Subramanian and Milind M. Buddhikot and Scott Miller. Interference aware routing in multi-radio wireless mesh networks[C]. In: 2nd IEEE Workshop on Wireless Mesh Networks. New York: IEEE Press, 2006, 55-63
[8] Wei Zhou, Dongbo Zhang, and Daji Qiao. Comparative Study of Routing Metrics for Multi-Radio Multi-Channel Wireless Networks[C]. In: Wireless Communications and Networking Conference. New York: IEEE Press, 2006,1, 270-275
[9] 范涛,张燕. 无线 Mesh 网络的组网及其相关标准[J]. 数据通信,2005,4:40-42
[10] 李娅. 无线网状网技术研究[J]. 电脑知识与技术,2006,1:56-57
[11] 沈强,方旭明,宋文. 无线 Mesh 网络路由协议研究[J]. 数据通信,2005,4:30-33
[12] Zhingming Zhang,Xiaofeng Zhong and Weirong Jiang. High Throughput Routing in Large-Scale Multi-Radio Wireless Mesh Networks[C]. In:WCNC proceedings. New York: IEEE Press, 2007,1, 3601-3605
[13] Yun Hu and ShouBao Yang. A New Routing Metric for Multi-Radio and Multi-Channel Wireless Mesh Network[C]. In: International Conference on Wireless Communications, Networking and Mobile Computing (WICCOM).NewYork: IEEE Press, 2006,22(24):1-4
[14] 张瑞,洪佩琳,等. MEIL_一种高吞吐量的无线网状网路由协议[J]. 中国科学院研究生院学报,2007,24(4):473-479
[15] Shenghui Wang, Zhengding Qiu. a link type aware routing metric for wireless mesh networks[C]. In:The 8th International Conference on Signal Processing. Beijing: IEEE Press, 2006,1701-1704
[16] Lingyun Jiang,Guangzeng Feng. A MAC Aware Cross-Layer Routing Approach for Wireless Mesh Network[C]. In:International Conference on Wireless Communications, Networking and Mobile Computing (WICCOM). NewYork: IEEE Press, 2006,22(24):1-5
[17] Tehuang LIU and Wanjiun Liao. Capacity-Aware Routing in Multi-Channel Multi-Rate Wireless Mesh Networks[C]. In:IEEE International Conference on Communications. Istanbul: IEEE Press, 2006,5:1971-1976
[18] 吴 笑 萍 . Ad hoc 网 络 隐 藏 / 暴 露 终 端 问 题 的 研 究 [J]. 微 计 算 机 信息,2006,22(10-3):35-37
[19] 朱隽. 无线网状网路由判据研究[J]. 电子工程师,2007,33(8):73-77
[20] D. De Couto, D. Aguayo, J. Bicket, and R. Morris. A high-throughput path metric for multi-hop wireless routing[C]. In: Proceedings of the 9th annual international conference on Mobile computing and networking. San Diego:ACM press,2003,134-136
[21] Richard Draves, Jitendra Padhye and Brian Zill. Routing in Multi-Radio, Multi-Hop Wireless Mesh Networks[C]. In: Proceedings of the 10th annual international conference on Mobile computing and networking. Philadelphia: ACM press, 2004,114-128
[22] Yaling Yang, Jun Wang, and Robin Kravets. Designing Routing Metrics for Mesh Networks[R]. In:IEEE Workshop on Wireless Mesh Networks. Santa Clara ,2005
[23] Yaling Yang, Jun Wang, and Robin Kravets. Interference-aware Load Balancing for Multihop Wireless Networks[R]. In: Department of Computer Science, University of Illinois at Urbana-Champaign, 2005
[24] R. Draves, J. Padhye, and B. Zill. Comparison of Routing Metrics for Static Multi-Hop Wireless Networks[C]. In: Proceedings of the 2004 conference on Applications, technologies, architectures, and protocols for computer communications. NewYork: ACM press, 2004, 133-144
[25] Martin Heusse, Franck Rousseau, Gilles Berger-Sabbatel and Andrzej Duda. Performance anomaly of 802.11b[J]. In: Twenty-Second Annual Joint Conference of the IEEE Computer and Communications Societies. NewYork: IEEE Press,2003,2,836-843
[26] S. Choi, K. Park and C. Kim, On the performance characteristics of WLANs: revisited[J]. In: ACM SIGMETRICS Performance Evaluation Review. NewYork: ACM Press,2005,33(1):97-108
[27] Vivek P.Mhatre and Henrik Lundgren. MAC-aware routing in wireless mesh networks[C]. In: Fourth Annual Conference on Wireless on Demand Network Systems and Services. Oberguyrgl: IEEE Press,2007,46-49
[28] Vivek P.Mhatre and Henrik Lundgren. Joint MAC-aware Routing and Load Balancing in Mesh Networks[C]. In: International Conference On Emerging Networking Experiments And Technologies. NewYork: ACM Press,2007,10-13
[29] 802.11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications[S]. ANSI/IEEE, 1999
[30] Can Emre Koksal, Hisham Kassab, Hari Balakrishnan. An analysis of short-term fairness in wireless media access protocols[C]. In: ACM SIGMETRICS Performance Evaluation Review. NewYork: ACM Press,2000,28(1):118-119
[31] Jitendra Padhye, Sharad Agarwal, et al. Estimation of Link Interference in Static Multi-hop Wireless Networks[C]. In: Proceedings of the 5th ACM SIGCOMM conference on Internet measurement. Berkeley, California: ACM Press,2005
[32] K. Jain, J. Padhye, V. Padmanabhan and L. Qiu. Impact of interference on multi-hop wireless network performance[C]. In: Proceedings of the 9th annual international conference on Mobile computing and networking. San Diego: ACM Press,2003,66-80
[33] 郭嘉丰,张信明,谢飞等. 基于节点空闲度的自适应移动 Ad Hoc 网络路由协议[J]. 软件学报,2005,16(5):960-969
[34] Yigal Bejerano,Seung-Jae Han,Amit Kumar. Efficient load-balancing routing for wireless mesh networks[J]. Computer Networks: The International Journal of Computer and Telecommunications Networking,2007,51(10):2450-2466
[35] Hossam Hassanein and Audrey Zhou. Routing with Load Balancing in Wireless Ad hoc Networks[C]. In: Proceedings of the 4th ACM international workshop on Modeling, analysis and simulation of wireless and mobile systems. Rome, Italy : ACM Press,2001,89-96
[36] Xiaojing Tao, Thomas Kunz and David Falconer. Traffic balancing in wireless MESH networks[C]. In: International Conference on Wireless Networks, Communications and Mobile Computing. NewYork: IEEE Press,2005,1,169-174
[37] Han Zhang and Danny H.K. Traffic Oriented Topology Formation and Load-balancing Routing in Wireless Mesh Networks[C]. In: Proceedings of 16th International Conference on Computer Communications and Networks . Honolulu, HI: IEEE Press,2007,1046-1052
[38] Wen Song and Xuming Fang. Routing with Congestion Control and Load Balancing in Wireless Mesh Networks[C]. In: 2006 6th Intertional Conference on ITS Telecommunications Proceedings. ChengDu: IEEE Press,2006,719-724
[39] 陈祥. 无线自组织网络负载均衡路由研究[D]. 成都:电子科技大学. 2007,6:20-23
[40] Kyu-Han Kim and Kang G. Shin. On Accurate Measurement of Link Quality in Multi-hop Wireless Mesh Networks[C]. In: Proceedings of the 12th annual international conference on Mobile computing and networking. Los Angeles: ACM Press, 2006,38-49
[41] Geetha Jayakumar, and G. Gopinath. Ad Hoc Mobile Wireless Networks Routing Protocols – A Review[J]. Journal of Computer Science, 2007,3(8):574-582
[42] Josh Broch, David A. Maltz, et al. A performance comparison of multi-hop Wireless Ad hoc network routing protocols[C]. In: Proceedings of the 4th annual ACM/IEEE international conference on Mobile computing and networking. Dallas: ACM Press,1998,85-97
[43] Turgay Kormaz, Wei Zhou. On Finding Optimal Paths in Multi-radio, Multi-hop Mesh Networks using WCETT Metric[C]. In: Proceedings of the 2006 international conference on Wireless communications and mobile computing. Vancouver, British Columbia, Canada: ACM Press,2006,1375-1380
[44] D.Johnson, Y. Hu, and D.Maltz. The Dynamic Source Routing Protocol(DSR) for Mobile Ad Hoc Networks for IPv4. RFC4728. http://www.rfc-editor.org/rfc/rfc4728.txt, 2007