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Faculty of Electronics, Communications and Automation | Department of Communications and Networking |
| Current Notes | Research Interests | Theses | Projects | Teaching | Publications | Some Useful Links | Contact |
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Jörg Ott Jörg Ott holds a Diploma in Computer Science and in Industrial Engineering He received his Doctor in Engineering (Dr.-Ing.) in 1997 from Technische Universität Berlin. Since March 2005, he is Professor for Networking Technology with a focus on Protocols, Services and Telecommunications Software in the Department of Communications and Networking in the Faculty of Electronics, Communications and Automation at Helsinki University of Technology. From 1997 through early 2005, he was Assistant Professor in the Computer Networks group at the Universität Bremen and member of the Center for Computing Technologies (TZI). From 1992 through 1997 he worked as a research staff member with teaching responsibilities at TU Berlin. His research interests are in Internet technologies, protocol design, and protocol and system architectures for multipoint communications, content distribution, IP telephony, and multimedia conferencing. His current research focus is on communication in challenged networks, particularly on disruption/delay-tolerant networking. In the IETF, he has been co-chair of the MMUSIC working group since 1997 and co-chaired the SIP working group from its foundation in 1999 to October 2002. In the ITU-T, he was one of the core designers of H.323 from the very beginning in 1995 and editor of two of its Annexes. Jörg has co-founded Tellique Kommunikationstechnik GmbH in 1998 which has provided solutions for IP multicast-based content distribution and performance enhancements for satellite and other challenged networks. He is co-founder of Lysatiq GmbH which provides solutions for disconnection tolerance and performance optimizations for challenged networks and mobile Internet access. |
| Current Notes |
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Teaching: Delay-tolerant Networking in the 1st period.
Travel: I will be at ACM MobiArch at MobiSys 2009 in Krakow from 22 through 24 March 2009.
Travel: I will be at TU Braunschweig on 2 and 3 July 2009 to give an invited talk.
Travel: I will be at the 75th IETF from 27 through 31 July 2009.
Vacation: I will be on vacation without email access from 1 through 23 August 2009.
My previous home (1997-2005) was at
University of Bremen TZI.
| Research Interests |
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Delay/disruption-tolerant
Networking |
Diverging from today's usual approaches towards supporting mobile users by providing ubiquitous and seamless connectivity across several networks, the goal of this research area is to accept the non-permanent nature of connectivity experienced and achievable today. My primary interest is to investigate architectures, protocols, and applications to maximize the gain a user a draw even from rare and short-lived connectivity as one aspect and to minimize the impact of connectivity interruption when commuting or traveling. One key example is the introduction of Drive-thru Internet &mdash an application scenario where we provide WLAN-based short range connectivity islands to users traveling at potentially high speeds on the road. |
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Interactive Interpersonal
Multimedia Communications |
Design and implementation of control protocols for interpersonal (multiparty) (multimedia) communications such as teleconferences, support for face-to-face meetings, etc. This particularly includes system architectures for multimedia communication systems — endpoints as well as infrastructure components. I am also interested in transport aspects of real-time (RTP, RTCP) and/or multiparty communications (reliable multicast). |
| IP Telephony | Research and development in the area of signaling protocols for IP telephony as well as architectures for and implementation of endpoints and infrastructure components and endpoint integration with personal/desk area environment. Of particular interest are also concepts and architectures architectures for intra- and inter-domain IP telephony deployments, including scalable, decentralized call routing and addressing infrastructures. |
|
IP Multicast-based
Content Distribution and Media Streaming |
Publication of the availability of content (related but not restricted to) Electronic Program/Service Guides (EPGs/ESGs) and distribution of media via IP-based networks. My particular interests include (reliable) multicast transport protocols and service architectures for content dissemination (real-time streaming, reliable data delivery) for unidirectional and bidirectional network infrastructures: multicast-enabled IP networks, satellite (DVB-S), digital terrestrial broadcast (DVB-T), and cable (DVB-C) as well as hybrid networks using wireline and wireless networks as back channels. I am also working on specific enhancement protocols and middleboxes (performance enhancing proxies) for accelerated on-demand access to content and/or receiver-specific content delivery. Finally, I am working on a framework for disseminating Internet Media Guides (IMGs), a generalization of EPGs/ESGs. |
|
Specific Link
Layer Technologies |
Research for IP-based multimedia communications and content distribution tailored to deal with specific aspects of access and distribution networks: my primary interests are in satellite (DVB-S) and terrestrial broadcast (DVB-T) networks as well as wireless LANs (802.11) and, to some degree, 3G networks. |
| IETF Standardization | I have been participating in the IETF since 1993 focussing on the areas outlined above, particularly control and transport protocols for multimedia conferencing. I am co-chair of the MMUSIC WG since 1997 and maintain the informal MMUSIC web page as well as of the SIP WG since 1999 (informal page). I am also interested in closely related areas such as security, QoS, mobility, mapping IP to various link layers, satellite communications and dealing with middleboxes. |
| ITU-T Standardization | In a former life, from 1994 through 2000, I have been active in the Telecommunication Sector of the International Telecommunication Union (ITU-T, formerly known as CCITT). Particular interests included the infrastructure for data conferencing (T.120) which was developed by Study Groups 8 and later 16 and the design of the H.323 series of Recommendations for IP-based multimedia conferencing (in local area networks) and IP telephony which I accompanied from the the very beginning in early 1995, first in SG15 and later in SG16. |
| Theses and Special Assignments |
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| I am offering a range of subjects in the context of my research interests listed above for special assignments and master theses. While I also accept theoretical work and simulations, my focus is clearly on engineering, meaning that I expect a workable product (e.g., a piece of code running on a PC or an embedded device). Hence, you may require well-developed coding, debugging, and possibly other practical skills. For practical reasons, I can only supervise theses that are written in English language. |
Specific subjects for master theses presently on my radar
include (but are definitely not limited to):
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| A sample of subjects for special assignments is available here. Further subjects can be found and agreed on upon request. |
| Your thesis can also be connected to your day job in a company. It just should fit roughly into my general field of Internet technologies, communications, and distributed systems. |
| Important: For writing a thesis, the general rules of Netlab apply. Please take particular note of the thesis process instructions and the thesis content guidelines. |
| Research Projects |
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| MoViE |
Jan 2008 –
Dec 2008 |
Mobile Video Enhancements: A project funded directly by the industry that investigates adaptive error and rate control for mobile video applications (conversational and streaming media). We also investigate RTP/RTCP for peer-to-peer media streaming. |
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| CATDTN |
Jan 2008 –
Dec 2008 |
Connectivity, Applications, and Trials of Delay-tolerant Networking: A project funded directly by the industry in which we are developing a few trial applications for mobile users, for which we also set up a small (partly virtual, partly physical) trial network. We investigate resource management for mobile devices in conjunction with security mechanisms. |
| CHIANTI | 2008 – 2009 | Challenged Internet Access Network Technology Infrastructure: An EC FP7 project on supporting personal and vehicular mobility as well as nomadic computing incrementally in today's Internet. The base assumption is that mobility and nomadicity will lead to challenged networking conditions due to (unforeseeable) disconnections. The project develops technical solutions to support robust communications in such challenged networks with and without infrastructure assistance. |
| Multicast IPTV |
Jan 2008 –
Dec 2008 |
Adaptive Error Measurement, Concealment, and Repair for IP Streaming Video: A joint project with University of Glasgow (Colin Perkins) funded by Cisco Research on multicast-based IPTV media distribution and repair. The project addresses repair by intermediaries and peers and investigates diagnosing network characteristics from observing reception statistics across different receivers from individual and multiple media streams, for which suitable quality metrics will be derived. |
| REDI | 2007 – 2009 | Rethinking the Design of Internet Application Protocols for a Mobile Future: A project funded by a grant from Teknologiateollisuus ry on adapting and enhancing application protocol design to (a) support delay-/disconnection-tolerant operation to increase robustness and better support mobility and (b) to make application protocols aware of underlying networking characteristics so that they can take sensible decisions about their mode of operation and communication. |
| DISTANCE |
Jan 2007 – Dec 2009 |
A project funded by the Academy of Finland on generic support for application-specific functions in intermediate nodes in Delay-tolerant Networking (DTN) environments. Concrete examples include the distributed storage and retrieval of contents using hints from the application as well as opportunistic support for application-specific routing and forwarding policies. |
| SINDTN |
Jan 2007 – Dec 2007 |
Security Infrastructure for DTN: A project directly funded from industry on security for DTN applications and DTN-based forwarding in ad-hoc networks and their realization for the DTNRG protocol specifications. The project also investigates leveraging Identity-based Cryptography (IBC) and the 3G infrastructure for mobile user authentication. |
| AVoW |
May 2007 – Dec 2007 |
Adaptive Video over Wireless: A project directly funded from industry focusing on mobile video communications in heterogenous (wireless) networks. The project extends the ns-2 simulator for 3GPP specific scenarios and analyzes different options for increasing error resilience for mobile video communications. |
| DTNPREP |
Oct 2006 – Dec 2006 |
A project directly funded from industry on exploring end-user security functionality in Delay-tolerant Networking environments by building a small demonstrator for mobile devices. |
| IVIHUT |
Mar 2006 – Dec 2006 |
A project directly funded from industry that deals with Interactive VIdeo applications and researches error-resilient packet video communications with a particular focus on mixed wired-wireless environments, aspect of the implementation and system integration of video codecs, and multiparty multimedia communications. |
| VIVALDI |
Jan 2006 – Dec 2007 |
An EC FP6 project on the development and validation of (call signaling protocol-independent) QoS and admission mechanisms for enabling flexible deployment scenarios of IP telephony bi-directional satellite networks (using DVB-RCS). TKK's focus areas are in protocol analysis, QoS-enabled media stream handlng, and overall testing and validation. |
|
Drive-thru
Internet |
Since 2003 | Exploiting short-lived Internet connectivity for mobile users on the road by means of connectivity islands provided by 802.11 wireless LANs as inexpensive yet powerful communications infrastructure. The research project has shown that vehicles traveling at speed of 180km/h and more can be supported with off-the-shelf equipment today — provided that appropriate Drive-thru Services are available to the mobile users that conceal the intermittent nature of connectivity from the user's general purpose applications. Ongoing research in this self-funded project investigates the use of more general concepts of Delay-tolerant Networking (DTN) to mobile ad-hoc communications. |
| Information on past research projects is available from my previous homepage . |
| Teaching |
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| 2008/2009 |
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4th period
S-38.3157 |
Protocol Design | This course will review architectural and protocol design principles from theory as well as from practical experience over the past decades. We will discuss building blocks and (design) patterns for protocols and assess their applicability and their limitations. We will validate how the various design principles fit with and how they impact recent and foreseeable future developments in communications and (inter)networking at large and discuss how such principles may be to be restated or adapted for new environments. While a clear focus is on architectures and principles from the Internet and for internetworking we will also consider lessons from other networking technologies. |
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3rd period
S-38.3155 |
Postgraduate seminar on Challenged Networks | This seminar addresses communications in environments with unusual caracteristics, i.e. properties that traditional design of communication protocols has not taken into account. Such "challenged networks" may exhibit, e.g., long communication delays, unpredictable link availability, and may not even provide an end-to-end path at all. Sparse sensor networks, interplanetary communications, and networks employing physical information carriage belong to this category, but so does mobile communication in the Internet. We will investigate novel networking architectures dealing with such specific environments and address issues of routing, reliability, security, and application protocols and services. We will pay particular attention to the DTN architecture developed in the DTNRG of the Internet Research Task Force. Sources for the seminar will primarily come from conferences and dedicated workshops on this subject area. The course Delay-tolerant Networking (S-38.3151) is not strictly a prerequisite, but provides the necessary background. |
|
3rd period
S-38.4043 |
Postgraduate Seminar in Network Economics | I am involved with a minor role in this seminar run by the chair in Network Economics (Prof. Heikki H?mm?inen) on the Techno-economic analysis of Internet architecture evolution. It investigated the impact of relative technology and pricing evolution over time (ratios), e.g. cost for link capacity vs. cost for storage, on the Internet and the roles of its stakeholders. |
|
2nd period
S-38.3152 |
Network Multimedia Protocols and Services | Starting with a review of the basics of IP-based multimedia communications, we will explore the details of media annoucements (SAP, SDP), Internet Media Guides (IMG), media streaming (RTSP), and as the focus of the Session Initiation Protocol (SIP) as defined in RFC 3261. We will discuss concepts, protocol details, numerous extensions, and SIP's service creation architecture. Specific application scenarios to be discussed include telephony as well as instant messaging and personal presence. We will also address security and NAT/firewalls traversal. Finally, system design aspects (for endpoints as well as for infrastructures) will be investigated. Lectures will be complemented by two or three coding assignments. |
|
1st period
S-38.3151 |
Delay-tolerant Networking (DTN) | This lecture addresses communications in environments with large communication delay and/or high likelihood for disruptions. Examples include sparse sensor and mobile ad-hoc networks, networks with intermittent connectivity or disconnections, deep-space and underwater communications, and communication in environment without communication infrastructure such as remote areas, developing regions, or disaster areas. Delays and link availability in such "challenged networking environments" may be unpredictable, storage, energy, or very constrained link capacities may prevail, and and an "instant" end-to-end path between peers may not be available at all. Communication may also involve physical carriage of data (e.g., stored on a USB stick or a hard drive) over short or long distances. We will investigate novel networking architectures dealing with such specific environments and address the specific challenges arising from such environment for routing, reliability, security, and application protocols and services. We will pay particular attention to the DTN architecture developed in the DTNRG of the Internet Research Task Force. The lecture will include theoretical and practical (configuration and coding) assignments. |
| 2007/2008 |
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|
4th period
S-38.3157 |
Protocol Design | This course will review architectural and protocol design principles from theory as well as from practical experience over the past decades. We will discuss building blocks and (design) patterns for protocols and assess their applicability and their limitations. We will validate how the various design principles fit with and how they impact recent and foreseeable future developments in communications and (inter)networking at large and discuss how such principles may be to be restated or adapted for new environments. While a clear focus is on architectures and principles from the Internet and for internetworking we will also consider lessons from other networking technologies. |
|---|---|---|
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3rd period
S-38.3155 |
Postgraduate seminar on Challenged Networks | This seminar addresses communications in environments with unusual caracteristics, i.e. properties that traditional design of communication protocols has not taken into account. Such "challenged networks" may exhibit, e.g., long communication delays, unpredictable link availability, and may not even provide an end-to-end path at all. Sparse sensor networks, interplanetary communications, and networks employing physical information carriage belong to this category, but so does mobile communication in the Internet. We will investigate novel networking architectures dealing with such specific environments and address issues of routing, reliability, security, and application protocols and services. We will pay particular attention to the DTN architecture developed in the DTNRG of the Internet Research Task Force. Sources for the seminar will primarily come from conferences and dedicated workshops on this subject area. The course Delay-tolerant Networking (S-38.3151) is not strictly a prerequisite, but provides the necessary background. |
|
2nd period
S-38.3152 |
Network Multimedia Protocols and Services | Starting with a review of the basics of IP-based multimedia communications, we will explore the details of media annoucements (SAP, SDP), Internet Media Guides (IMG), media streaming (RTSP), and as the focus of the Session Initiation Protocol (SIP) as defined in RFC 3261. We will discuss concepts, protocol details, numerous extensions, and SIP's service creation architecture. Specific application scenarios to be discussed include telephony as well as instant messaging and personal presence. We will also address security and NAT/firewalls traversal. Finally, system design aspects (for endpoints as well as for infrastructures) will be investigated. Lectures will be complemented by two or three coding assignments. |
|
1st period
S-38.3151 |
Delay-tolerant Networking (DTN) | This lecture addresses communications in environments with large communication delay and/or high likelihood for disruptions. Examples include sparse sensor and mobile ad-hoc networks, networks with intermittent connectivity or disconnections, deep-space and underwater communications, and communication in environment without communication infrastructure such as remote areas, developing regions, or disaster areas. Delays and link availability in such "challenged networking environments" may be unpredictable, storage, energy, or very constrained link capacities may prevail, and and an "instant" end-to-end path between peers may not be available at all. Communication may also involve physical carriage of data (e.g., stored on a USB stick or a hard drive) over short or long distances. We will investigate novel networking architectures dealing with such specific environments and address the specific challenges arising from such environment for routing, reliability, security, and application protocols and services. We will pay particular attention to the DTN architecture developed in the DTNRG of the Internet Research Task Force. The lecture will include theoretical and practical (configuration and coding) assignments. |
| 2006/2007 |
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|
4th period
S-38.3157 |
Protocol Design | This course will review architectural and protocol design principles from theory as well as from practical experience over the past decades. We will discuss building blocks and (design) patterns for protocols and assess their applicability and their limitations. We will validate how the various design principles fit with and how they impact recent and foreseeable future developments in communications and (inter)networking at large and discuss how such principles may be to be restated or adapted for new environments. While a clear focus is on architectures and principles from the Internet and for internetworking we will also consider lessons from other networking technologies. |
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3rd period
S-38.2188 |
Computer Networks | I will give a couple of lectures in Computer Networks. The responsible teacher is Jouni Karvo. For further details see the course home page. |
|
2nd period
S-38.3150 |
Network Multimedia Protocols and Services | Starting with a review of the basics of IP-based multimedia communications, we will explore the details of media annoucements (SAP, SDP), Internet Media Guides (IMG), media streaming (RTSP), and as the focus of the Session Initiation Protocol (SIP) as defined in RFC 3261. We will discuss concepts, protocol details, numerous extensions, and SIP's service creation architecture. Specific application scenarios to be discussed include telephony as well as instant messaging and personal presence. We will also address security and NAT/firewalls traversal. Finally, system design aspects (for endpoints as well as for infrastructures) will be investigated. Lectures will be complemented by two coding assignments. |
|
1st period
S-38.3155 |
Postgraduate seminar on Challenged Networks | This seminar addresses communications in environments with unusual caracteristics, i.e. properties that traditional design of communication protocols has not taken into account. Such "challenged networks" may exhibit, e.g., long communication delays, unpredictable link availability, and may not even provide an end-to-end path at all. Sparse sensor networks, interplanetary communications, and networks employing physical information carriage belong to this category, but so does mobile communication in the Internet. We will investigate novel networking architectures dealing with such specific environments and address issues of routing, reliability, security, and application protocols and services. We will pay particular attention to the DTN architecture developed in the DTNRG of the Internet Research Task Force. Sources for the seminar will primarily come from conferences and dedicated workshops on this subject area. |
| 2005/2006 |
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|
4th period
S-38.3157 |
Protocol Design | This completely revised course will review architectural and protocol design principles from theory as well as from practical experience over the past decades. We will discuss building blocks and (design) patterns for protocols and assess their applicability and their limitations. We will validate how the various design principles fit with and how they impact recent and foreseeable future developments in communications and (inter)networking at large and discuss how such principles may be to be restated or adapted for new environments. While a clear focus is on architectures and principles from the Internet and for internetworking we will also consider lessons from other networking technologies. |
|---|---|---|
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3rd period
S-38.2188 |
Computer Networks | I will just give a couple of lectures in Computer Networks. The responsible teacher is Jouni Karvo. For further details see the course home page. |
|
2nd period
S-38.3150 |
Network Multimedia Protocols and Services | Starting with a review of the basics of IP-based multimedia communications, we will explore the details of media annoucements (SAP, SDP), Internet Media Guides (IMG), media streaming (RTSP), and as the focus of the Session Initiation Protocol (SIP) as defined in RFC 3261. We will discuss concepts, protocol details, numerous extensions, and SIP's service creation architecture. Specific application scenarios to be discussed include telephony as well as instant messaging and personal presence. We will also address security and NAT/firewalls traversal. Finally, system design aspects (for endpoints as well as for infrastructures) will be investigated. Lectures will be complemented by three coding assignments. |
|
1st period
S-38.3119 |
Postgraduate seminar on Delay-tolerant Networking | This seminar addresses communications in environments with unusual caracteristics, i.e. properties that traditional design of communication protocols has not taken into account. Such "challenged networks" may exhibit, e.g., long communication delays, unpredictable link availability, and may not even provide an end-to-end path at all. We will analyze numerous challenged networking environments and their communication characteristics. We will investigate (network,) transport, session, and application layer solutions to delay-tolerant networking as well as novel networking architectures dealing with such specific environments and also look into potential consequences for applications and user interaction paradigms. We will pay particular attention to the DTN architecture developed in the DTNRG of the Internet Research Task Force. |
| Spring 2005 |
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| S-38.158 | Protocol Design, Practical Assignment | The practical assignment for Protocol Design will focus on implementation primarily following the lecture on TCP/IP. In practice, this means that the assignments should build on socket programming and design a small protocol using exither text (e.g., ASCII or UTF-8) encoding, XML, ASN.1 or XDR/RPC. |
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| Some useful links |
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| Contact |
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Helsinki University of Technology Faculty of Electronics, Communications and Automation Department of Communications and Networking (Comnet) Otakaari 5A FIN-02150 Espoo Finland |
office: SE 324 (reception: Wed 10–12) tel: +358 9 451-2460 tel: +358 9 451-2461 (secr.) fax: +358 9 451-2474 sip:joergott@iptel.org mailto:jo@netlab.hut.fi |
| © 2005-2008 Jörg Ott - Last modified: $Id: index.shtml,v 1.174 2009/06/22 13:15:09 jo Exp $ |
