Berlin Roof Net Technologies
(Seminar 2 SWS)

Instructor: Dipl-Inf. Anatolij Zubow
Monday, 13:15-14:45, RUD 25, 4.113

Computer Science Department
Systems Architecture Group

Abstract: 'Berlin Roof Net' is a project run by volunteer students of the Computer Science Department at Humboldt University Berlin. The project's goal is to construct a network of nodes (access points) which share Internet access over wireless radio connections. The access points are run independently by the students with their own equipment. The project was inspired by the MIT RoofNet project in Boston, USA. In this seminar we will study the core technologies of the Berlin RoofNet project, ranging from wireless communication in general, over the 802.11 MAC protocol, to (opportunistic) routing protocols for wireless multi-hop networks; but also including software development tools for the Netgear MIPS router hardware, and network simulator(s).


  • Seminar, Praktische Informatik, Hauptstudium.
  • 2h each week, over one semester (2 SWS).
  • Target Audience: Students who are interested in the technologies behind the Berlin Roof Net project and who want to acquire the basic knowledge necessary to participate in the project.

Credits and grading:

     In order to obtain credits for this seminar, participants are expected to:

  • Attend regularly (at least 90%).
  • Read each paper before the seminar, to be adequately prepared for discussion.
  • Research an assigned subject; present major findings (45 min presentation; 30 min discussion).
  • Presentations will be evaluated by two members of the audience at the end of each class (Bewertungskriterien-Seminarvortrag.pdf).
  • Presenters summarize their presentation and relevant discussion on the Seminar's WIKI page within 2 weeks.
  • Presentations may be given in English or German. All documents are in English (exceptions may be granted).


  • Successful completion of PI-1,2,3.


  1. Introduction
    • Berlin RoofNet - Overview
  2. Properties of the Wireless Medium
    • [1] Architecture and evaluation of an unplanned 802.11b mesh network, J. Bicket, D. Aguayo, s. Biswas, and R. Morris, AcM Mobicom 2005 (link)
    • [2] Link-level measurements from an 802.11b mesh network, D. Aguayo, J. Bicket, S. Biswas, G. Judd, and R. Morris, Proc. of ACM SIGCOMM, September 2004 (link)
    • [3] Capacity of Ad Hoc Wireless Networks, Jinyang Li, Charles Blake, Douglas S. J., Hu Imm Lee and Robert Morris, Proceedings of the 7th International Conference on Mobile Computing and Networking, July 2001 (link)
    • [4] Multi-Channel Link-level Measurements in 802.11 Mesh Networks, Mathias Kurth, Anatolij Zubow and Jens-Peter Redlich, IWCMC, July 2006 (link)
  3. Network Structures [IEEE 802.11]
    • Traditional 802.11 (infrastructure/ad-hoc mode, 802.11 frame structure, encryption)
    • Ad-hoc multi-hop mesh networks (de-centralized, ...)
  4. Medium Access Control
    • [5] MACAW: A Media Access Protocol for Wireless LAN's, Vaduvur Bharghavan, Alan J. Demers, Scott Shenker and Lixia Zhang, SIGCOMM, 1994 (link)
    • [6] MACA - A New Channel Access Method for Packet Radio, Phil Karn (link)
    • 802.11 MAC (RTS/CTS, DCF/PCF) [4.3]
    • [7] A Multi-channel MAC Protocol for Ad Hoc Wireless Networks, J. So and N. Vaidya, Technical report, Dept. of Comp. Science, Univ. of Illinois at Urbana-Chamapign, June 2003 (link)
  5. Routing
    • [8] Dynamic Source Routing in Ad Hoc Wireless Networks, David B Johnson and David A Maltz, Mobile Computing, Kluwer Academic Publishers, 1996 (link)
    • [9] Ad-hoc on-demand distance vector routing, C. Perkins, MILCOM 1997 (link)
    • [10] Opportunistic Routing in MultiHop Wireless Networks, Sanjit Biswas and Robert Morris, Proceedings of the Second Workshop on Hot Topics in Networking (HotNets-II), Cambridge, Massachusetts, November 2003 (link)
    • [11] Opportunistic Routing in Multi-Hop Wireless Networks, Sanjit Biswas and Robert Morris, SIGCOMM 2005, Aug. 2005 (link)
    • [12] A Routing Protocol for Utilizing Multiple Channels in Multi-Hop Wireless Networks with a Single Transceiver, Jungmin So and Nitin Vaidya, Technical Report, October 2004 (link)
  6. Network Simulation [6.1]
    • Java in Simulation Time (JiST) / Scalable Wireless Ad hoc Network Simulator (SWANS)
    • Network Simulator (NS2)
    • Radio model (Ns2), MAC-layer, Routing (DSR, AODV, comparison in NS2), topology realization in JiST
    • [13] Connectivity in the presence of Shadowing in 802.11 Ad Hoc Networks, Patrick Stuedi, Oscar Chinellato and Gustavo Alonso, IEEE Communications Society / WCNC, 2005 (link)
  7. TCP/IP in Wireless Multi-Hop Networks
    • [14] Analysis of TCP Performance over Mobile Ad Hoc Networks, Gavin Holland and Nitin Vaidya, Wireless Networks, Kluwer Academic Publishers, 2002 (link)
    • [15] Split TCP for Mobile Ad Hoc Networks,  Swastik Kopparty, Srikanth V. Krishnamurthy, Michalis Faloutsos and Satish K. Tripathi, Proceedings of IEEE GLOBECOM, 2002 (link)
    • TCP/IP realization in JiST
  8. Evaluation
    • [16] The Click Modular Router (link)
    • [17] MultiMAC - An Adaptive MAC Framework for Dynamic Radio Networking, Christian Doerr, Michael Neufeld, Jeff Fifield, Troy Weingart, Douglas C. Sicker, and Dirk Grunwald (link)
    • [18] MultiMAC - An Adaptive MAC Framework for Dynamic Radio Networking, Christian Doerr, Michael Neufeld, Jeff Fifield, Troy Weingart, Douglas C. Sicker, and Dirk Grunwald (link)
    • [19] Click for Measurement, Eddie Kohler, Technical Report, February 2006 (link)
  9. Information Distribution in Wireless Multi-Hop Networks
    • [20] The Broadcast Storm Problem in a Mobile Ad Hoc Network, Sze-Yao Ni, Yu-Chee Tseng, Yuh-Shyan Chen, and Jang-Ping Sheu, Mobicom, 1999 (link)
    • [21] Chord: A Scalable Peer-to-peer Lookup Service for Internet Applications, Ion Stoica, Robert Morris, David Karger, M. Frans Kaashoek and Hari Balakrishnan, SIGCOMM’01, August 2001, (link)
    • [22] DART: Dynamic Address RouTing for Scalable Ad Hoc and Mesh Networks, Jakob Eriksson, Michalis Faloutsos and Srikanth Krishnamurthy, INFOCOM (link)
  10. Network coding
    • [23] Network Coding: The Case of Multiple Unicast Sessions (link)
    • [24] Practical Network Coding, P. A. Chou, Y. Wu, and K. Jain, October 2003 (link)
    • [25] Efficient Operation of Wireless Packet Networks Using Network Coding, Desmond S. Lun, Muriel Medard, and Ralf Koetter, IWCT, 2005 (link)
    • [26] Network Coding for Wireless Applications: A Brief Tutorial, Supratim Deb, Michelle Effros, Tracey Ho, David R. Karger, Ralf Koetter, Desmond S. Lun, Muriel Medard, and Niranjan Ratnakar (link)

Assignments (Themenvergabe):




 24.Apr   A. Zubow  Introduction (Berlin RoofNet) 

   official holiday

 08.May   Florian L., Andreas W.  Properties of the Wireless Medium 
 15.May   Matthias B.  Network Structures 
 22.May   Maria Ts., Artur Fröhlich  Medium Access Control 
 29.May   Robert Hildrich, Ronald Kluth  Routing (ExOR, MCRP) 
 05.Jun   official holiday  
 12.Jun   O. Friedrich  Network Simulation 
 19.Jun   N.Seyer, T.Kalaydjiev  TCP/IP 
 26.Jun   Robert G.  Evaluation 
 03.Jul   Denitsa Ivanova, Juan N.  Information Distribution 
 10.Jul   Robert Sombrutzki  DHT-based Services 
 17.Jul   Network Coding 
Roof Net (home page)
Berlin (Community)
Berlin Roof Net
Project Home Page
Click Modular Router

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