报告题目：Robust and Efficient Broadcasting in Multihop Wireless Networks
报告日期及时间：2016年3月29日15：30
报告地点：B404报告厅
报告人：Prof. Thomas Kunz
报告人单位：Carleton University, Canada
报告摘要：
Broadcasting (communicating information from one to all or many to all nodes in a network) is an important communication primitive. It is used as a building block in many MANET routing protocols, for example. In addition, broadcasting is a key primitive in multihop networks to support applications of all-informed voice, group push-to-talk, situational information sharing etc. Supporting one-to-all and many-to-all communication patterns in multihop wireless networks efficiently is therefore important. The key metric we are interested in our work is the number of packet transmissions at the MAC layer: if a protocol can deliver data packets to all nodes with fewer packet transmissions at the MAC/PHY layer, this will lower energy and network resource consumption and mitigate the traffic congestion problem in the network, compared to simply flooding the network. Many researchers have addressed that problem by having only a subset of nodes re-broadcast data packets. For example, the recent IETF RFC 6621 describes SMF (Simplified Multicast Forwarding), a broadcast/multicast protocol that selects a subset of nodes, called MPRs, to re-broadcast the packets, establishing an approximation of the Minimum Connected Dominating Set for a given topology. However, such protocols need to learn at least the local 2-hop topology, and their selection of MPRs will be poor when this neighborhood changes due to mobility. In addition, packet transmission is highly unreliable as wireless links may suffer from fading and interference, and random access MAC protocols such as IEEE 802.11 may cause packet collisions. In this talk I will give discuss our work in this area, where we have studied both lower bounds and the efficiency and robustness of actual broadcasting protocols. The work has explored both routing/packet forwarding solutions as well as approaches based on network coding. I will particularly highlight our most recent work, exploring how broadcast protocols such as SMF are impacted by unreliable packet transmissions and topology changes. This will be contrasted with a broadcast protocol we developed, based on network coding, that performs consistently well, even under adverse conditions, and that is more efficient in many cases.
报告人简介：
Professor Kunz received his Diplom in Wirtschafts informatik in 1990 and his Dr.Ing. inInformatik in 1994, both from the Technische Hochschule Darmstadt, Germany. He is currently a full professor in the Departmentof Systems and Computer Engineering, CarletonUniversity, Ottawa, Canadaand visiting the Software Engineering Institute of East China Normal University, Shanghai, during his 2015/16 sabbatical. He heads the MobileComputing Group, researching wireless network architectures (Manets. wireless mesh networks, andwireless sensor networks), network protocols (for example MAC, routing, localization, clock synchronization, and OoS support), and middleware layers for innovative wireless applications. He also collaborates closely with Canada’s Centre of Excellence in Next Generation Networks (CENGN), a consortium of industry, academic and research leaders dedicated to accelerating the commercialization of next generation communications solutions, with emphasis on Software-Defined Networking and Network Function Virtualization. He hasserved on more than 70 TPCs of international conferencesand workshops in the mobile and wirelessdomain and has collaborated extensively with both industry and government research labs. He is the author or coauthor of more than 220 technical papers andreceived a number of awards and best paper prizes. Professor Kunz is a senior memberof both ACM and IEEE.
邀请人： 吴黎兵 教授
