Associate Professor
Bjorn Landfeldt, Ph. D. SMIEEE, MACM, MCOMSOC



I have left School of Information Technologies , at the University of Sydney


I now work at Lund University, Sweden. To contact me, please email:

bjorn.landfeldt (at)


To find out more about me, follow the relevant links to the right.

Contact Details:

Phone: +61 2 9351 8962

Internet filtering in Australia

I have been heavily involved in the debate surrounding mandated filtering of the Internet at the ISP level in Australia. I was hired as an expert consultant to a group investigating the feasibility of carrying out filtering at the ISP level. The report from that study is available from the Department (DBCDE) web site and also here. There were two parts to report, one was never released to the general public as it included some sensitive information.

I also appeared before the Australian parliament joint select committee on cyber-safety on March 24, 2011. I made the following submission to the committee before the hearing.

Current Research Projects 


Modeling of and Forwarding in Highly Dynamic Networks

Some emerging wireless networks such as vehicular networks introduce a new property of extremely dynamic topologies and densities. In such networks, the notion of links become out dated, and many of the well established ways of viewing networks become obsolete. In this project, we focus on the fundamental modeling of the behaviour of selected highly dynamic networks and try to understand their properties so that efficient forwarding and routing mechanisms can be properly devised. PhD student - Saeed Bastani


Modeling risk levels in road traffic networks to optimise efficiency/safety

Current road traffic networks are planned and deployed based on acquired experiences of accident and risk levels. Since traditionally, there has been no way of treating different road users differently, the curse of averaging has been the natural approach. However, this is about to change with the introduction of vehicular wireless communication systems such as DSRC/WAVE radios. In this project, we work with the modeling of drivers, vehicles and the environment to be able to determine dynamic risk levels and from that determine appropriate flow parameters such as velocity and density to maximise the road utility while manitaining a desired risk level. PhD student - Emma Fitzgerald.


Avoiding interference and maximising capacity in collaborative access networks

In this project we investigate ways of overcoming the problems asociated with wireless access points overlapping in coverage and contending for resources in densly deployed areas. It has been shown that the performance of WLAN (802.11) suffers greatly when there are many acess points contending for resources. We are working on alleviating this problem using collaborative algorithmic techniques. PhD student - SuparerkManitpornsut.

Mobility Management in unstructured wireless networks
Traditional wireless networks can be viewed as hierarchical constructs and it is easy to determine the apropriateanchorpoints and gateways in such neteorks. In unplanned and unstructured networks however, this does not hold true. Such networks (e.g. wireless mesh networks) have unstructured connectivity graphs which makes the optimum location of anchorpoints difficult to determine. PhD student working on topic - Paul Wu. locations of mobility

Effects of inaccuracy of location estimation on DSRC based services
DSRC based vehicular services include road safety applications such as collision avoidance. These applicationachieveable accuracy of sensed data trough sensor fusion and data filtering and determine the flow on effects on application peformance. PhD student - Quincy Tse

Old projects

Device Auto-configuration

This project is looking at translations of resource reservations between different access networks as mobile nodes move between accesses. The project has two parts ,mapping/admission control and modeling of queuing systems under self-similar traffic input. 


A function based communication stack

This project looks at decoupling individual functions in the communication stack instead of bundling them into static protocols. The major advantage is that using only the components necessary to support a given service, the stack implementation can be optimised. This is useful for saving complexity and power usage in sensor nodes etc.


Power aware routing for sensor networks

This project aims at developing methods for maximising network lifespan by equalising power in routing nodes. If critical nodes fall off the network, entire sub trees can become unavailable. Therefore, equalisation will maximise network lifespan rather than individual node lifespan.


Presence and notifications in infrastructure-less environments

This project aims at providing presence, location and notification services in networks where known addresses for servers etc. are unavailable. Networks such as ad-hoc networks inherently have the problem that resources are at best difficult to locate so that traditional server based approaches fail.

Load balancing of asymmetric access channels with asymmetric traffic

It is well known that asymmery is an important factor to consider when balancing load over communication networks. In this project, we investigate an additional dimension, asymmetric traffic mapping onto asymmetric access links to achieve maximum network utilisation.


Optimised Location Management

This project aims at minimising the cost associated with maintaining knowledge about mobile hosts in cellular networks (or extrapolations thereof). Currently, there has been  a strong focus on dynamically determining optimal location areas/paging areas to improve on the pretty inefficient static model current cellular networks use. In this work we take this work further by optimising the cost on an individual basis rather than the network aggregate for all hosts.


An optimized PCF for QoS in IEEE 802.11

In this project we are investigating different methods of improving the QoS provisioning in IEEE 802.11. We are trying to maximise the number of supported terminals with QoS sensitive traffic while improving the service differentiation.









Research and Publications

Dive Blog



Fun stuff


PhD Comics



Big Bang Theory

Current research students



Saeed Bastani

Quincy Tse

Rezwan Khan

Emma Fitzgerald


Suparerk Manitpornsut (PhD 2009)

Mohsin Iftikhar (PhD 2008)

Dan Cutting (PhD 2008)

Khaled Matrouk (PhD 2008)

Kaushalya Premadasa (PhD 2007)

Apichan Kanjanavapastit (PhD 2005)
Sanchai Rattananon (PhD 2005)

James Cowling (University Medalist, won the Soprano Prize for best Thesis in 2004, Fullbright Scholar, Allan Bromley prize for best honours thesis in University of Sydney and the University of Sydney medal of Convocation)

Florian Vehrein (University Medalist, the best EIE thesis 2004, Co-supervised with Dr. Sanjay Chawla)

Natalie Kolodziej (Honours, won the Singtel prize for best Telecoms project in 2003)

Ezequiel Muns (Hons 1)

Yuri Tselishchev (Hons 1)

T. J. Singh (Hons 1) now with Microsoft Redmont

David Helstroom (Hons 1) now with Google Mountainview

Future Projects

I am always interested in working with good students. However, I am a busy person and have limited time to spare. Before you send me your CV, please read the future student requirements. If you don't meet these requirements, I am not able to supervise.