Bart Braem

Contact information

Contact Address:   PATS Research Group - IBBT / University of Antwerp - Department of Mathematics and Computer Science Middelheimlaan 1 B-2020 Antwerpen Belgium

Phone: +32 (0)3 265.38.82. Fax: +32 (0)3 265.37.77. e-mail: bart.braem@ua.ac.be Office: G.3.27

Short biography

Courses

Publications

2010

• A Survey on Wireless Body Area Networks
  Benoît Latré, Bart Braem, Chris Blondia, Ingrid Moerman & Piet Demeester
  Accepted for publication in Wireless Networks, Springer, 2010.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @article{bbraem10wbansurvey,
  author = {Beno{\^i}t Latr{\'e} and Bart Braem and Chris Blondia and Ingrid Moerman and Piet Demeester},
  title = {A Survey on Wireless Body Area Networks},
  journal = {Accepted for publication in Wireless Networks},
  publisher = {Springer},
  year = {2010},
  url = {content/publications/2010/bbraem10wbansurvey.pdf},
  abstract = {The increasing use of wireless networks and the constant miniaturization of electrical devices has empowered the development of Wireless Body Area Networks (WBANs). In these networks various sensors are attached on clothing or on the body or even implanted under the skin. The wireless nature of the network and the wide variety of sensors offer numerous new, practical and innovative applications to improve health care and the Quality of Life. The sensors of a WBAN measure for example the heartbeat, the body temperature or record a prolonged electrocardiogram. Using a WBAN, the patient experiences a greater physical mobility and is no longer compelled to stay in the hospital. This paper offers a survey of the concept of Wireless Body Area Networks. First, we focus on some applications with special interest in patient monitoring. Then the communication in a WBAN and its positioning between the different technologies is discussed. An overview of the current research on the physical layer, existing MAC and network protocols is given. Further, cross layer and quality of service is discussed. As WBANs are placed
  on the human body and often transport private data, security is also considered. An overview of current and past projects is given. Finally, the open research issues and challenges are pointed out.
  }
  
  Abstract:
  The increasing use of wireless networks and the constant miniaturization of electrical devices has empowered the development of Wireless Body Area Networks (WBANs). In these networks various sensors are attached on clothing or on the body or even implanted under the skin. The wireless nature of the network and the wide variety of sensors offer numerous new, practical and innovative applications to improve health care and the Quality of Life. The sensors of a WBAN measure for example the heartbeat, the body temperature or record a prolonged electrocardiogram. Using a WBAN, the patient experiences a greater physical mobility and is no longer compelled to stay in the hospital. This paper offers a survey of the concept of Wireless Body Area Networks. First, we focus on some applications with special interest in patient monitoring. Then the communication in a WBAN and its positioning between the different technologies is discussed. An overview of the current research on the physical layer, existing MAC and network protocols is given. Further, cross layer and quality of service is discussed. As WBANs are placed the human body and often transport private data, security is also considered. An overview of current and past projects is given. Finally, the open research issues and challenges are pointed out.

• A Secure Cross-layer Protocol for Multi-hop Wireless Body Area Networks
  Dave Singelée, Benoît Latré, Bart Braem, Michael Peeters, Marijke De Soete, Peter De Cleyn, Bart Preneel, Ingrid Moerman & Chris Blondia
  Ad-Hoc and Sensor Wireless Networks, Vol. 9, No. 1, pp. 53-72, Old City Publishing, 2010.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @ Article{bbraem08securewbanprotocol,
  author = {Dave Singel{\'e}e and Beno{\^i}t Latr{\'e} and Bart Braem and Michael Peeters and Marijke De Soete and Peter De Cleyn and Bart Preneel and Ingrid Moerman and Chris Blondia},
  title = {A Secure Cross-layer Protocol for Multi-hop Wireless Body Area Networks},
  journal = {Ad-Hoc and Sensor Wireless Networks},
  year = {2010},
  pages = {53-72},
  volume = {9},
  number ={1},
  publisher = {Old City Publishing},
  URL = {content/publications/2008/bbraem08securewbanprotocoljournal.pdf},
  abstract = {The development of Wireless Body Area Networks (WBANs) for
  wireless sensing and monitoring of a person's vital functions, is
  an enabler in providing better personal health care whilst
  enhancing the quality of life. A critical factor in the acceptance
  of WBANs is providing appropriate security and privacy protection
  of the wireless communication. This paper first describes a
  general health care platform and pinpoints the security challenges
  and requirements. Further it proposes and analyzes the CICADA-S
  protocol, a secure cross-layer protocol for WBANs. It is an
  extension of CICADA, which is a cross-layer protocol that handles
  both medium access and the routing of data in WBANs. The CICADA-S
  protocol is the first integrated solution that copes with threats
  that occur in this mobile medical monitoring scenario. It is shown
  that the integration of key management and secure, privacy
  preserving communication techniques within the CICADA-S protocol
  has low impact on the power consumption and throughput.},
  }
  
  Abstract:
  The development of Wireless Body Area Networks (WBANs) for sensing and monitoring of a person s vital functions, is enabler in providing better personal health care whilst the quality of life. A critical factor in the acceptance WBANs is providing appropriate security and privacy protection the wireless communication. This paper first describes a health care platform and pinpoints the security challenges requirements. Further it proposes and analyzes the CICADA-S a secure cross-layer protocol for WBANs. It is an of CICADA, which is a cross-layer protocol that handles medium access and the routing of data in WBANs. The CICADA-S is the first integrated solution that copes with threats occur in this mobile medical monitoring scenario. It is shown the integration of key management and secure, privacy communication techniques within the CICADA-S protocol has low impact on the power consumption and throughput.

2009

• anyMAC: adapting the Sun SPOT architecture for MAC development
  Daniel van den Akker, Bart Braem & Chris Blondia
  16th Annual Symposium on Communications and Vehicular Technology in the Benelux, Louvain-la-Neuve, Belgium, 2009.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @INPROCEEDINGS{ieee_cvt_16,
  author = { Daniel van den Akker and Bart Braem and Chris Blondia},
  title = {anyMAC: adapting the Sun SPOT architecture for MAC development},
  booktitle = {16th Annual Symposium on Communications and Vehicular Technology in the Benelux},
  year = {2009},
  month = {NOV},
  location = {Louvain-la-Neuve, Belgium},
  URL = {content/publications/2009/dvdakker09anyMAC.pdf},
  abstract = {The Sun SPOT platform allows sensor network nodes to be programmed in Java and is therefore well suited for prototyping new sensor network protocols. The design of the Sun SPOT network stack however, makes it hard to replace the default IEEE 802.15.4 based MAC implementation. We therefore introduce the `anyMAC project': a number of alterations to the default Sun SPOT network stack. The resulting `anyMAC network stack' allows MAC implementations to be easily interchanged and provides the exibility needed to allow new MAC implementations to be developed, as demonstrated by a proof of concept `DemoMAC' MAC implementation. Performance tests show that this exibility is achieved with a very acceptable performance loss. At MAC level, the round trip time of the anyMAC network stack differs by only 12% from that of the Sun SPOT network stack, while the throughput is only marginally
  affected.}
  }
  
  Abstract:
  The Sun SPOT platform allows sensor network nodes to be programmed in Java and is therefore well suited for prototyping new sensor network protocols. The design of the Sun SPOT network stack however, makes it hard to replace the default IEEE 802.15.4 based MAC implementation. We therefore introduce the anyMAC project : a number of alterations to the default Sun SPOT network stack. The resulting anyMAC network stack allows MAC implementations to be easily interchanged and provides the exibility needed to allow new MAC implementations to be developed, as demonstrated by a proof of concept DemoMAC MAC implementation. Performance tests show that this exibility is achieved with a very acceptable performance loss. At MAC level, the round trip time of the anyMAC network stack differs by only 12% from that of the Sun SPOT network stack, while the throughput is only marginally

• TinySPOTComm: Facilitating communication over IEEE 802.15.4 between Sun SPOTs and TinyOS-based motes
  Daniel van den Akker, Kurt Smolderen, Peter De Cleyn, Bart Braem & Chris Blondia
  The 1st International Conference on Sensor Networks Applications, Experimentation and Logistics, Athens, Greece, 2009.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @INPROCEEDINGS{sensappeal,
  author = { Daniel van den Akker and Kurt Smolderen and Peter De Cleyn and Bart Braem and Chris Blondia},
  title = {TinySPOTComm: Facilitating communication over IEEE 802.15.4 between Sun SPOTs and TinyOS-based motes},
  booktitle = {The 1st International Conference on Sensor Networks Applications, Experimentation and Logistics},
  year = {2009},
  month = {SEP},
  location = {Athens, Greece},
  URL = {content/publications/2009/dvdakker09tinyspotcomm.pdf},
  abstract = {The increasing popularity of sensor network has spawned a wide range of platforms and frameworks for sensor network development. While in theory nodes based on different frameworks should provide radio stack compatibility, in practice this is rarely the case. We explore this problem by providing a case study and introduce TinySPOTComm, a customized radio stack for the Sun SPOT platform which allows for radio communication between IEEE 802.15.4 based TinyOS motes and Sun SPOTs. The TinySPOTComm radio stack remains fully compatible with the Sun SPOT radio stack and its network performance is only marginally affected in comparison to the default Sun SPOT radio stack. Performance tests have shown good results when communicating between TinyOS motes and Sun SPOTs. The round trip time, when measured between a Sun SPOT and a TinyOS mote, is affected by no more than 15%, in comparison to the RTT between two TinyOS motes. In the same scenario an increase in throughput of more than 50% has been measured.}
  
  Abstract:
  The increasing popularity of sensor network has spawned a wide range of platforms and frameworks for sensor network development. While in theory nodes based on different frameworks should provide radio stack compatibility, in practice this is rarely the case. We explore this problem by providing a case study and introduce TinySPOTComm, a customized radio stack for the Sun SPOT platform which allows for radio communication between IEEE 802.15.4 based TinyOS motes and Sun SPOTs. The TinySPOTComm radio stack remains fully compatible with the Sun SPOT radio stack and its network performance is only marginally affected in comparison to the default Sun SPOT radio stack. Performance tests have shown good results when communicating between TinyOS motes and Sun SPOTs. The round trip time, when measured between a Sun SPOT and a TinyOS mote, is affected by no more than 15%, in comparison to the RTT between two TinyOS motes. In the same scenario an increase in throughput of more than 50% has been measured.

• Characterization of On-Body Communication Channel and Energy Efficient Topology Design for Wireless Body Area Networks
  Elisabeth Reusens, Wout Joseph, Benoît Latré, Bart Braem, Günter Vermeeren, Luc Martens, Ingrid Moerman & Chris Blondia
  Accepted for publication in IEEE Transactions on Information Technology in BioMedicine, IEEE, 2009.
  Permalink | BibTeX | Abstract
  
  Bibtex:
  @article{bbraem2009titb,
  author = {Elisabeth Reusens and Wout Joseph and
  Beno{\^i}t Latr{\'e} and Bart Braem and G{\"u}nter Vermeeren and Luc Martens and Ingrid Moerman and Chris Blondia},
  title = {Characterization of On-Body Communication Channel and Energy Efficient Topology Design for Wireless Body Area Networks},
  journal = {Accepted for publication in IEEE Transactions on Information Technology in BioMedicine },
  abstract = {Wireless Body Area Networks (WBAN) offer many promising new applications in the area of remote health monitoring. An important element in the development of a WBAN is the characterization of the physical layer of the network, including an estimation of the delay spread and the path loss between two nodes on the body. This paper discusses the propagation channel between two half-wavelength dipoles at 2.45~GHz, placed near a human body and presents an application for cross-layer design in order to optimize the energy consumption of different topologies. Propagation measurements are performed on real humans in a multipath environment, considering different parts of the body separately. In addition, path loss has been numerically investigated with an anatomically correct model of the human body in free space using a 3D electromagnetic solver.
  Path loss parameters and time domain channel characteristics are extracted from the measurement and simulation data. A semi-empirical path loss model is presented for an antenna height above the body of 5~mm and antenna separations from 5~cm up to 40~cm. A time domain analysis is performed and models are presented for the mean excess delay and the delay spread.
  As a cross-layer application, the proposed path loss models are used to evaluate the energy efficiency of single-hop and multi-hop network topologies.
  },
  publisher= {IEEE},
  year = {2009}
  }
  
  Abstract:
  Wireless Body Area Networks (WBAN) offer many promising new applications in the area of remote health monitoring. An important element in the development of a WBAN is the characterization of the physical layer of the network, including an estimation of the delay spread and the path loss between two nodes on the body. This paper discusses the propagation channel between two half-wavelength dipoles at 2.45~GHz, placed near a human body and presents an application for cross-layer design in order to optimize the energy consumption of different topologies. Propagation measurements are performed on real humans in a multipath environment, considering different parts of the body separately. In addition, path loss has been numerically investigated with an anatomically correct model of the human body in free space using a 3D electromagnetic solver. loss parameters and time domain channel characteristics are extracted from the measurement and simulation data. A semi-empirical path loss model is presented for an antenna height above the body of 5~mm and antenna separations from 5~cm up to 40~cm. A time domain analysis is performed and models are presented for the mean excess delay and the delay spread. a cross-layer application, the proposed path loss models are used to evaluate the energy efficiency of single-hop and multi-hop network topologies.

• Analyzing and Improving Reliability in Multi-hop Body Sensor Networks
  Bart Braem, Benoît Latré, Chris Blondia, Ingrid Moerman & Piet Demeester
  International Journal On Advances in Internet Technology, ISSN 1942-2652, pp. 152-162, 2009.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @INPROCEEDINGS{bbraem09improvingreliabilityinbsns,
  author = {Bart Braem and Beno{\^i}t Latr{\'e} and Chris Blondia and Ingrid Moerman and Piet Demeester},
  title = {Analyzing and Improving Reliability in Multi-hop Body Sensor Networks},
  booktitle = {International Journal On Advances in Internet Technology, ISSN 1942-2652},
  year = {2009
  pages = {152--162},
  URL = {content/publications/2009/bbraem09improvingreliabilityinbsns.pdf},
  abstract = {Body Sensor Networks are an interesting emerging application of wireless sensor networks to improve healthcare and the Quality of Life. Current research has mainly focused on single-hop networks, although some works clearly show advantages of multi-hop architectures. In this paper, we model probabilistic connectivity in such multi-hop body sensor networks. Instead of using a circular coverage area, a more accurate model is defined based on the path loss along the human body. Further, we propose improvements to CICADA, a cross-layer multi-hop protocol that handles both medium access and the routing of data in BSNs. CICADA is slot-based and uses schemes to allocate these slots. Results for two reliability improvements are given: randomization of the schemes and repeating the schemes received from a parent node. We show that these improvements positively affect the throughput of the network and lead to fewer retransmissions while the energy consumption of the nodes is hardly influenced.},
  }
  
  Abstract:
  Body Sensor Networks are an interesting emerging application of wireless sensor networks to improve healthcare and the Quality of Life. Current research has mainly focused on single-hop networks, although some works clearly show advantages of multi-hop architectures. In this paper, we model probabilistic connectivity in such multi-hop body sensor networks. Instead of using a circular coverage area, a more accurate model is defined based on the path loss along the human body. Further, we propose improvements to CICADA, a cross-layer multi-hop protocol that handles both medium access and the routing of data in BSNs. CICADA is slot-based and uses schemes to allocate these slots. Results for two reliability improvements are given: randomization of the schemes and repeating the schemes received from a parent node. We show that these improvements positively affect the throughput of the network and lead to fewer retransmissions while the energy consumption of the nodes is hardly influenced.,

2008

• A Low-Delay Protocol for Multihop Wireless Body Area Networks
  Benoît Latré, Bart Braem, Ingrid Moerman, Chris Blondia & Piet Demeester
  KEIO and Gent University G-COE Joint workshop for future network, Ghent, Belgium, pp. 38-45, 2008.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @INPROCEEDINGS{Latre08Keio,
  author = {Beno{\^i}t Latr{\'e} and Bart Braem and Ingrid Moerman and Chris Blondia and Piet Demeester},
  title = {A Low-Delay Protocol for Multihop Wireless Body Area Networks},
  booktitle = {KEIO and Gent University G-COE Joint workshop for future network},
  year = {2008},
  pages = {38--45},
  location = {Ghent, Belgium},
  month = {26-27 September},
  URL = {content/publications/2007/bbraem07cicada.pdf},
  abstract = {Wireless Body Area Networks (WBANs) form a new and interesting area in the world of remote health monitoring. An important concern in such networks is the communication between the sensors. This communication needs to be energy efficient and highly reliable while keeping delays low. Mobility also has to be supported as the nodes are positioned on different parts of the body that move with regard to each other. In this paper, we present a new cross-layer communication protocol for WBANs: CICADA or Cascading Information retrieval by Controlling Access with Distributed slot Assignment. The protocol sets up a network tree in a distributed manner. This tree structure is subsequently used to guarantee collision free access to the medium and to route data towards the sink. The paper analyzes CICADA and shows simulation results. The protocol offers low delay and good resilience to mobility. The energy usage is low as the nodes can sleep in slots where they are not transmitting or receiving.}
  }
  
  Abstract:
  Wireless Body Area Networks (WBANs) form a new and interesting area in the world of remote health monitoring. An important concern in such networks is the communication between the sensors. This communication needs to be energy efficient and highly reliable while keeping delays low. Mobility also has to be supported as the nodes are positioned on different parts of the body that move with regard to each other. In this paper, we present a new cross-layer communication protocol for WBANs: CICADA or Cascading Information retrieval by Controlling Access with Distributed slot Assignment. The protocol sets up a network tree in a distributed manner. This tree structure is subsequently used to guarantee collision free access to the medium and to route data towards the sink. The paper analyzes CICADA and shows simulation results. The protocol offers low delay and good resilience to mobility. The energy usage is low as the nodes can sleep in slots where they are not transmitting or receiving.

• Improving Reliability in Multi-hop Body Sensor Networks
  Bart Braem, Benoît Latré, Chris Blondia, Ingrid Moerman & Piet Demeester
  Sensor Technologies and Applications, 2008. SENSORCOMM 08. Second International Conference on, Cap Esterel, France, pp. 342-347, 2008.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @INPROCEEDINGS{bbraem08improvingreliabilityinbsns,
  author = {Bart Braem and Beno{\^i}t Latr{\'e} and Chris Blondia and Ingrid Moerman and Piet Demeester},
  title = {Improving Reliability in Multi-hop Body Sensor Networks},
  booktitle = {Sensor Technologies and Applications, 2008. {SENSORCOMM} '08. Second International Conference on},
  year = {2008},
  pages = {342--347},
  location = {Cap Esterel, France},
  month = {AUG},
  day = {25--31},
  URL = {content/publications/2008/bbraem08improvingreliabilityinbsns.pdf},
  abstract = {Body Sensor Networks are an interesting emerging application of wireless sensor networks to improve healthcare and the Quality of Life. Current research has mainly focused on singlehop~networks, although some works clearly show advantages of multihop~architectures. In this paper, we model probabilistic connectivity in such multihop~body sensor networks. Instead of using a circular coverage area, a more accurate model is defined based on the path loss along the human body. Further, we propose improvements to CICADA, a cross-layer multihop protocol that handles both medium access and the routing of data in BSNs. CICDA is slot-based and uses schemes to allocate these slots. Preliminary results for two reliability improvements are given: randomization of the schemes and repeating the schemes received from a parent node. We show that these improvements positively affect the throughput of the network and lead to fewer retransmissions. In both cases, the energy consumption of the nodes is hardly influenced.},
  doi = {10.1109/SENSORCOMM.2008.47},
  }
  
  Abstract:
  Body Sensor Networks are an interesting emerging application of wireless sensor networks to improve healthcare and the Quality of Life. Current research has mainly focused on singlehop~networks, although some works clearly show advantages of multihop~architectures. In this paper, we model probabilistic connectivity in such multihop~body sensor networks. Instead of using a circular coverage area, a more accurate model is defined based on the path loss along the human body. Further, we propose improvements to CICADA, a cross-layer multihop protocol that handles both medium access and the routing of data in BSNs. CICDA is slot-based and uses schemes to allocate these slots. Preliminary results for two reliability improvements are given: randomization of the schemes and repeating the schemes received from a parent node. We show that these improvements positively affect the throughput of the network and lead to fewer retransmissions. In both cases, the energy consumption of the nodes is hardly influenced.

• A Secure Cross-layer Protocol for Multi-hop Wireless Body Area Networks
  Dave Singelée, Benoît Latré, Bart Braem, Michael Peeters, Marijke De Soete, Peter De Cleyn, Bart Preneel, Ingrid Moerman & Chris Blondia
  Ad-hoc, Mobile and Wireless Networks, Sophia Antipolis, France, Lecture Notes in Computer Science, Vol. 5198, pp. 94-107, Springer Berlin / Heidelberg, 2008.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @inproceedings{bbraem08securewbanprotocol,
  author = {Dave Singel{\'e}e and Beno{\^i}t Latr{\'e} and Bart Braem and Michael Peeters and Marijke De Soete and Peter De Cleyn and Bart Preneel and Ingrid Moerman and Chris Blondia},
  title = {A Secure Cross-layer Protocol for Multi-hop Wireless Body Area Networks},
  booktitle = {Ad-hoc, Mobile and Wireless Networks},
  publisher = {Springer Berlin / Heidelberg},
  issn = {0302-9743 (Print) 1611-3349 (Online)},
  isbn = {978-3-540-85208-7},
  abstract = {The development of Wireless Body Area Networks (WBANs) for wireless sensing and monitoring of a persons vital functions, is an enabler in providing better personal health care whilst enhancing the quality of life. A critical factor in the acceptance of WBANs is providing appropriate security and privacy protection of the wireless communication. This paper first describes a general health care platform and pinpoints the security challenges and requirements. Further it proposes and analyzes the CICADA-S protocol, a secure cross-layer protocol for WBANs. It is an extension of CICADA, which is a cross-layer protocol that handles both medium access and the routing of data in WBANs. The CICADA-S protocol is the first integrated solution that copes with threats that occur in this mobile medical monitoring scenario. It is shown that the integration of key management and secure, privacy preserving communication techniques within the CICADA-S protocol has low impact on the power consumption and throughput.},
  volume = {5198},
  series = {Lecture Notes in Computer Science},
  year = {2008},
  month = {SEP},
  pages = {94--107},
  location = {Sophia Antipolis, France},
  subject_collection = {Computer Science},
  doi = {10.1007/978-3-540-85209-4_8},
  URL = {content/publications/2008/bbraem08securewbanprotocol.pdf}
  }
  
  Abstract:
  The development of Wireless Body Area Networks (WBANs) for wireless sensing and monitoring of a persons vital functions, is an enabler in providing better personal health care whilst enhancing the quality of life. A critical factor in the acceptance of WBANs is providing appropriate security and privacy protection of the wireless communication. This paper first describes a general health care platform and pinpoints the security challenges and requirements. Further it proposes and analyzes the CICADA-S protocol, a secure cross-layer protocol for WBANs. It is an extension of CICADA, which is a cross-layer protocol that handles both medium access and the routing of data in WBANs. The CICADA-S protocol is the first integrated solution that copes with threats that occur in this mobile medical monitoring scenario. It is shown that the integration of key management and secure, privacy preserving communication techniques within the CICADA-S protocol has low impact on the power consumption and throughput.

2007

• The Need for Cooperation and Relaying in Short-Range High Path Loss Sensor Networks
  B. Braem, B. Latré, I. Moerman, C. Blondia, E. Reusens, W. Joseph, L. Martens & P. Demeester
  Sensor Technologies and Applications, 2007. SensorComm 2007. International Conference on, Valencia, Spain, pp. 566-571, 2007.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @INPROCEEDINGS{bbraem07needcooperationrelaying,
  author = {B. Braem and B. Latr{\'e} and I. Moerman and C. Blondia and E. Reusens and W. Joseph and L. Martens and P. Demeester},
  title = {The Need for Cooperation and Relaying in Short-Range High
  Path Loss Sensor Networks},
  booktitle = {Sensor Technologies and Applications, 2007. SensorComm 2007. International Conference on},
  year = {2007},
  month = {OCT},
  location = {Valencia, Spain},
  pages = {566-571},
  URL = {content/publications/2007/bbraem07needcooperationrelaying.pdf},
  abstract = {This paper focuses on the energy efficiency of communication in small-scale sensor networks experiencing high path loss. In particular, a sensor network on the human body or BASN is considered. The energy consumption or network lifetime of a single-hop network and a multi-hop network are compared. We derive a propagation model and a radio model for communication along the human body. Using these models, energy efficiency was studied analytically for a line and a tree topology. Calculations show that single-hop communication is inefficient, especially for nodes far away from the sink. There however, multi-hop proves to be more efficient but closer to the sink hotspots arise. Based on these findings, we propose to exploit the performance difference by either introducing extra nodes in the network, i.e. dedicated relay devices, or by using a cooperative approach or by a combination of both. We show that these solutions increase the network lifetime significantly.},
  }
  
  Abstract:
  This paper focuses on the energy efficiency of communication in small-scale sensor networks experiencing high path loss. In particular, a sensor network on the human body or BASN is considered. The energy consumption or network lifetime of a single-hop network and a multi-hop network are compared. We derive a propagation model and a radio model for communication along the human body. Using these models, energy efficiency was studied analytically for a line and a tree topology. Calculations show that single-hop communication is inefficient, especially for nodes far away from the sink. There however, multi-hop proves to be more efficient but closer to the sink hotspots arise. Based on these findings, we propose to exploit the performance difference by either introducing extra nodes in the network, i.e. dedicated relay devices, or by using a cooperative approach or by a combination of both. We show that these solutions increase the network lifetime significantly.,

• A Low-delay Protocol for Multihop Wireless Body Area Networks
  B. Latré, B. Braem, I. Moerman, C. Blondia, E. Reusens, W. Joseph & P. Demeester
  Accepted at Mobile and Ubiquitous Systems: Networking & Services, 2007 Fourth Annual International Conference on, Philadelphia, Pennsylvania, USA, 2007.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @INPROCEEDINGS{bbraem07cicada,
  author = {B. Latr{\'e} and B. Braem and I. Moerman and C. Blondia and E. Reusens and W. Joseph and P. Demeester},
  title = {A Low-delay Protocol for Multihop Wireless Body Area Networks},
  booktitle = {Accepted at Mobile and {U}biquitous {S}ystems: {N}etworking & {S}ervices, 2007 {F}ourth {A}nnual {I}nternational {C}onference on},
  year = {2007},
  month = {AUG},
  location = {Philadelphia, Pennsylvania, USA},
  URL = {content/publications/2007/bbraem07cicada.pdf},
  abstract = {Wireless Body Area Networks (WBANs) form a new and interesting area in the world of remote health monitoring. An important concern in such networks is the communication between the sensors. This communication needs to be energy efficient and highly reliable while keeping delays low. Mobility also has to be supported as the nodes are positioned on different parts of the body that move with regard to each other. In this paper, we present a new cross-layer communication protocol for WBANs: CICADA or Cascading Information retrieval by Controlling Access with Distributed slot Assignment. The protocol sets up a network tree in a distributed manner. This tree structure is subsequently used to guarantee collision free access to the medium and to route data towards the sink. The paper analyzes CICADA and shows simulation results. The protocol offers low delay and good resilience to mobility. The energy usage is low as the nodes can sleep in slots where they are not transmitting or receiving.},
  }
  
  Abstract:
  Wireless Body Area Networks (WBANs) form a new and interesting area in the world of remote health monitoring. An important concern in such networks is the communication between the sensors. This communication needs to be energy efficient and highly reliable while keeping delays low. Mobility also has to be supported as the nodes are positioned on different parts of the body that move with regard to each other. In this paper, we present a new cross-layer communication protocol for WBANs: CICADA or Cascading Information retrieval by Controlling Access with Distributed slot Assignment. The protocol sets up a network tree in a distributed manner. This tree structure is subsequently used to guarantee collision free access to the medium and to route data towards the sink. The paper analyzes CICADA and shows simulation results. The protocol offers low delay and good resilience to mobility. The energy usage is low as the nodes can sleep in slots where they are not transmitting or receiving.,

• Path-Loss Models for Wireless Communication Channel along Arm and Torso: Measurements and Simulations
  E. Reusens, W. Joseph, G. Vermeeren, L. Martens, B. Latré, B. Braem, C. Blondia & I. Moerman
  2007 IEEE Antennas and Propagation Society International Symposium, Sheraton Waikiki, Honolulu, Hawaii, USA, pp. 345-348, 2007.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @INPROCEEDINGS{reusens07aps,
  author = { E. Reusens and W. Joseph and G. Vermeeren and L. Martens and B. Latr{\'e} and B. Braem and C. Blondia and I. Moerman},
  title = {Path-Loss Models for Wireless Communication Channel along Arm and Torso: Measurements and Simulations},
  booktitle = {2007 IEEE Antennas and Propagation Society International Symposium},
  year = {2007},
  month = {JUN},
  day = {10-15},
  isbn = {ISBN 1-4244-0878-4},
  pages = {345-348},
  location = {Sheraton Waikiki, Honolulu, Hawaii, USA},
  url = {content/publications/2007/bbraem07APSReusens.pdf},
  abstract = { A Wireless Body Area Network (WBAN) connects independent nodes (e.g., sensors and actuators) that are situated in the clothes, on the body or under the skin of a person. The network typically expands over the whole body and the nodes are connected through a wireless communication channel. A WBAN offers many promising new applications in home/health care, medicine, sports, and many other areas. An important step in the development of a WBAN is the characterization of the physical layer and the description of the electromagnetic wave propagation and antenna behavior near the human body. Propagation near flat, homogeneous and layered phantoms has been investigated in [2]. In this paper, measurements are performed on a real human using two half-wavelength dipoles, considering different parts of the human body separately. Path-loss models are developed for the on-body channels along the arm and torso. The measurement results are verif{}ied with FDTD (Finite-Difference Time-Domain) simulations, using an anatomically correct conf{}iguration of the arms.
  }
  }
  
  Abstract:
  A Wireless Body Area Network (WBAN) connects independent nodes (e.g., sensors and actuators) that are situated in the clothes, on the body or under the skin of a person. The network typically expands over the whole body and the nodes are connected through a wireless communication channel. A WBAN offers many promising new applications in home/health care, medicine, sports, and many other areas. An important step in the development of a WBAN is the characterization of the physical layer and the description of the electromagnetic wave propagation and antenna behavior near the human body. Propagation near flat, homogeneous and layered phantoms has been investigated in [2]. In this paper, measurements are performed on a real human using two half-wavelength dipoles, considering different parts of the human body separately. Path-loss models are developed for the on-body channels along the arm and torso. The measurement results are verified with FDTD (Finite-Difference Time-Domain) simulations, using an anatomically correct configuration of the arms.

2006

• The Wireless Autonomous Spanning Tree Protocol for Multihop Wireless Body Area Networks
  B. Braem, B. Latré, I. Moerman, C. Blondia & P. Demeester
  Mobile and Ubiquitous Systems: Networking & Services, 2006 Third Annual International Conference on, San Jose, California, USA, pp. 1-8, 2006.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @INPROCEEDINGS{bbraem06wasp,
  author = { B. Braem and B. Latr{\'e} and I. Moerman and C. Blondia and P. Demeester},
  title = {The Wireless Autonomous Spanning Tree Protocol for Multihop Wireless Body Area Networks},
  booktitle = {Mobile and {U}biquitous {S}ystems: {N}etworking & {S}ervices, 2006 {T}hird {A}nnual {I}nternational {C}onference on},
  pages = {1--8},
  year = {2006},
  month = {JUL},
  location = {San Jose, California, USA},
  URL = {content/publications/2006/bbraem06wasp.pdf},
  abstract = {Wireless body area networks (WBANs) have gained a lot of interest in the world of medical monitoring. Current implementations generally use a large single hop network to connect all sensors to a personal server. However recent research pointed out that multihop networks are more energy-efficient and even necessary when applied near the human body with inherent severe propagation loss. In this paper we present a slotted multihop approach to medium access control and routing in wireless body area networks, the Wireless Autonomous Spanning tree Protocol or WASP. It uses crosslayer techniques to achieve efficient distributed coordination of the separated wireless links. Traffic in the network is controlled by setting up a spanning tree and by broadcasting scheme messages over it that are used both by the parent and the children of each node in the tree. We analyze the performance of WASP and show the simulation results.},
  doi = {10.1109/MOBIQ.2006.340421}
  }
  
  Abstract:
  Wireless body area networks (WBANs) have gained a lot of interest in the world of medical monitoring. Current implementations generally use a large single hop network to connect all sensors to a personal server. However recent research pointed out that multihop networks are more energy-efficient and even necessary when applied near the human body with inherent severe propagation loss. In this paper we present a slotted multihop approach to medium access control and routing in wireless body area networks, the Wireless Autonomous Spanning tree Protocol or WASP. It uses crosslayer techniques to achieve efficient distributed coordination of the separated wireless links. Traffic in the network is controlled by setting up a spanning tree and by broadcasting scheme messages over it that are used both by the parent and the children of each node in the tree. We analyze the performance of WASP and show the simulation results.

Workshop and symposium talks

2009

• Teaching with Click Modular Router
  B. Braem, M. Voorhaen & C. Blondia
  Symposium on Click Modular Router, n.p., Ghent, Belgium, October 2009.
  Permalink | Abstract | PDF Available
  
  Abstract:
  This poster describes how we use Click to teach a telecommunications course. We show why Click was chosen and how it is used. We elaborate on the different projects students have to finish and discuss practical problems like the typical learning curve.
• Teaching with Sun SPOTs
  B. Braem & C. Blondia
  UK/Europe Sun SPOT Symposium, n.p., London, United Kingdom, February 2009.
  Permalink | Abstract | PDF Available
  
  Abstract:
  Recently, the PATS research group of the University of Antwerp introduced sensor networks into its research. Consequently, we also incorporated this topic into our teaching curriculum. Past experiences with traditional sensor network platforms however showed a steep learning curve to get familiar with the platform, which makes it hard to use them in time limited practical courses. Once we discovered the Sun SPOTS with an all Java approach, this hurdle was easily taken.
  This talk will introduce two implementations of education with Sun SPOTS. First, we teach the course "Sensor Network Lab". Here students learn to use Sun SPOTS and develop a specific network related sensory application in order to get some first hands on experience with sensor networks. We will describe the practicalities of this course, assignments students get and most important the reactions of students on this technology.
  The second part of this talk illustrates how Sun SPOTS are used to guide Master students towards research topics in internships and Masters theses. Ongoing work will be presented together with preliminary results and the personal opinions of our Master students about Sun SPOTS.

2007

• Challenges in Multihop Wireless Body Area Networks
  B. Braem & C. Blondia
  Second Benelux Workshop on Performance Analysis of Communication Systems, n.p., Antwerp, Belgium, February 2007.
  Permalink | Abstract | PDF Available
  
  Abstract:
  A Wireless Body Area Network (WBAN) is formed when sensors on the human body are connected using wireless technologies. Such a network can be used to monitor patients remotely as the costs of keeping them in a hospital just for monitoring are enormous. Another possibility is to assist in athlete coaching with real time measurements of their muscle performance. Connecting the sensors wirelessly largely improves comfort of the person wearing them, to monitor athletes unobtrusively is absolutely necessary. Research shows that radio signals sent close to the human body experience severe path loss compared to regular, free-space communication. To send over large distances, sensors on the body should have to transmit with a relatively high transmission power compared to the short distance. This means that multihop communication can result in less battery drain. A larger argument stems from the fact that radio signals can not pass through the human body. This means that sensors located at the back of a person can only use multihop routing to reach the other sensors at the front of the body. We discuss the challenges that arise when using a multihop network protocol for WBANs, relating this to existing technologies like sensor networks and ad-hoc networks.

Masters thesis information

Past projects

Past publications

2005

• Semantic Searching for SignWriting
  Steven Aerts, Bart Braem, Katrien Van Mulders & Kristof De Weerdt
  Actes de TALS 2005, Dourdan, France.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @INPROCEEDINGS{bbraem05semanticsearching,
  author = {Steven Aerts and Bart Braem and Katrien Van Mulders and Kristof De Weerdt},
  title = {Semantic Searching for SignWriting},
  booktitle = {Actes de TALS 2005},
  year = {2005},
  location = {Dourdan, France},
  URL = {http://euterpe.cmi.ua.ac.be/~bbraem/publications/tals.pdf},
  abstract = {In this paper we present the development results of an online sign searching system independent of manual annotations based on SignWriting. Lookup is done on an intuitive yet flexible basis and results are ordered by relevance. The system is currently active for the Flemish Sign Language dictionary containing over 7000 signs.},
  }
  
  Abstract:
  In this paper we present the development results of an online sign searching system independent of manual annotations based on SignWriting. Lookup is done on an intuitive yet flexible basis and results are ordered by relevance. The system is currently active for the Flemish Sign Language dictionary containing over 7000 signs.

2004

• Searching SignWriting Signs
  Steven Aerts, Bart Braem, Katrien Van Mulders & Kristof De Weerdt
  Sign Processing Workshop, LREC 2004, p. 79-81, Lisbon, Portugal.
  Permalink | BibTeX | Abstract | PDF Available
  
  Bibtex:
  @INPROCEEDINGS{bbraem04searchingsignwriting,
  author = {Steven Aerts and Bart Braem and Katrien Van Mulders and Kristof De Weerdt},
  title = {Searching SignWriting Signs},
  booktitle = {Sign Processing Workshop, LREC 2004},
  pages = {79--81}
  year = {2004},
  location = {Lisbon, Portugal},
  URL = {http://euterpe.cmi.ua.ac.be/~bbraem/publications/lrec.pdf},
  abstract = {At this moment the publication of the first written Flemish Sign Language (VGT) Dictionary is in progress. It consists of VGT glossaries and allows its users to lookup the signs for over 2000 Dutch words. The signs are written in SignWriting. We have established an electronic representation of this sign language dictionary. Searching for signs starting from a Dutch word works straightforward. The opposite, receiving results ordered by relevance, has never been develloped before. In this paper we explain how we have worked out such a system.},
  }
  
  Abstract:
  At this moment the publication of the first written Flemish Sign Language (VGT) Dictionary is in progress. It consists of VGT glossaries and allows its users to lookup the signs for over 2000 Dutch words. The signs are written in SignWriting. We have established an electronic representation of this sign language dictionary. Searching for signs starting from a Dutch word works straightforward. The opposite, receiving results ordered by relevance, has never been develloped before. In this paper we explain how we have worked out such a system.