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Publikationen

Zeitschriftenartikel | Konferenzbeiträge | Dissertationen

Zeitschriftenartikel

Andreas Weigel, Martin Ringwelski, Volker Turau und Andreas Timm-Giel. Route-over forwarding techniques in a 6LoWPAN. EAI Endorsed Transactions on Mobile Communications and Applications, 14(5), Dezember 2014.
@Article{Telematik_EAI_6LowPAN_2014, author = {Andreas Weigel and Martin Ringwelski and Volker Turau and Andreas Timm-Giel}, title = {Route-over forwarding techniques in a 6LoWPAN}, journal = {EAI Endorsed Transactions on Mobile Communications and Applications}, volume = {14}, number = {5}, month = dec, year = 2014, }
Abstract: 6LoWPAN plays a major role within the protocol stack for the future Internet of Things. Its fragmentation mechanism enables transport of IPv6 datagrams with the required minimum MTU of 1280 bytes over 802.15.4-based networks. With the goal of a fully standardized WSN protocol stack currently necessitating a route-over approach, i.e., routing at the IP-layer, there are two main choices for any 6LoWPAN implementation with regard to datagram fragmentation: Hop-by-hop assembly or a cross-layered direct mode, which forwards individual 6LoWPAN fragments before the whole datagram has arrived. In addition to these two straightforward approaches, we propose enhancements based on adaptive rate-restriction for the direct forwarding and a retry control for both modes to reduce the number of losses of larger datagrams. An evaluation of these modes in a simulation environment and a hardware testbed indicate that the proposed enhancements can considerably improve PRR and latency within 6LoWPAN networks.

Konferenzbeiträge

Andreas Weigel und Volker Turau. Hardware-Assisted IEEE 802.15.4 Transmissions and Why to Avoid Them. In Conference proceedings of the 8th International Conference on Internet and Distributed Computer Systems, IDCS 2015, September 2015, pp. 223–234. Windsor, UK.
@InProceedings{Telematik_IDCS_2015_6LoWPAN, author = {Andreas Weigel and Volker Turau}, title = {Hardware-Assisted IEEE 802.15.4 Transmissions and Why to Avoid Them}, booktitle = {Conference proceedings of the 8th International Conference on Internet and Distributed Computer Systems, IDCS 2015}, pages = {223-234}, day = {2-4}, month = sep, year = 2015, location = {Windsor, UK}, }
Abstract: 6LoWPAN’s fragmentation mechanism enables transport of IPv6 datagrams with the required minimum MTU of 1280 bytes over IEEE 802.15.4-based networks. Testbed experiments showed disastrously bad datagram success rates for a collection traffic scenario with large, 6LoWPAN-fragmented datagrams, which significantly differed from the simulation results for a comparable scenario. In this paper we present an experimental setup that enables capturing the MAC and transceiver states of participating nodes in realtime. The results of our experiments show, that for the given fragmentation/collection scenario, the usage of the extended operating mode of the transceiver hardware, which provides CSMA/CA, ACKs and retransmissions in hardware, is responsible for nearly all datagram losses. Therefore, we strongly advise against using such hardware-assisted modes of operation in similar traffic scenarios.
Andreas Weigel und Volker Turau. An Analytical Model of 6LoWPAN Route-Over Forwarding Practices. In Conference proceedings of the International Conference on Ad-hoc, Mobile and Wireless Networks, ADHOC-NOW 2014, Juni 2014, pp. 279–289. Benidorm, Spain.
@InProceedings{Telematik_AdHocNow_2014_6LoWPAN, author = {Andreas Weigel and Volker Turau}, title = {An Analytical Model of 6LoWPAN Route-Over Forwarding Practices}, booktitle = {Conference proceedings of the International Conference on Ad-hoc, Mobile and Wireless Networks, ADHOC-NOW 2014}, pages = {279-289}, day = {22-27}, month = jun, year = 2014, location = {Benidorm, Spain}, }
Abstract: 6LoWPAN has been developed to bring IPv6 to even the smallest resource-constrained devices, enabling the vision of an Internet of Things. To be compliant to IPv6’s minimum MTU of 1280 Bytes, its fragmentation mechanism allows transmission of datagrams the size of up to 2048 Bytes. Within low power and lossy environments, fragmen- tation of datagrams can lead to an increase in end-to-end loss rates and to a waste of bandwidth by propagation of fragments of an already lost datagram. We present an extension to an existing analytical, bit-error- based model, which takes into account different route-over forwarding practices in the presence of fragmentation and use it to assess their in- fluence on the end-to-end success rate and the expected number of bits sent. While being not precisely accurate due to the neglect of effects like (self-induced) collisions, the model provides insight into the effects to be expected when using 6LoWPAN’s fragmentation mechanism.
Andreas Weigel, Christian Renner, Volker Turau und Holger Ernst. Wireless Sensor Networks for Smart Metering. In Energy Conference and Exhibition (ENERGYCON), 2014 IEEE International, Mai 2014, pp. 722–729. Dubrovnik, Croatia.
@InProceedings{Telematik_EnergyCon_2014_SmartMetering, author = {Andreas Weigel and Christian Renner and Volker Turau and Holger Ernst}, title = {Wireless Sensor Networks for Smart Metering}, booktitle = {Energy Conference and Exhibition (ENERGYCON), 2014 IEEE International}, pages = {722-729}, day = {13-16}, month = may, year = 2014, location = {Dubrovnik, Croatia}, }
Abstract: Smart metering will change the way we assess and control energy consumption. The necessary two-way communication between energy utilities and smart meters yet requires further research. In par- ticular, cheap, low-maintenance, and reliable alterna- tives to existing approaches must be analyzed. We believe that self-organizing wireless sensor networks are a promising candidate. In this paper, we perform a requirement analysis for smart metering using wireless sensor network technology; we propose an architecture including a set of protocols; and we conduct a real-world evaluation with a testbed of 64 smart meters. With regard to latency and network formation time, the sys- tem was able to fulfill the identified requirements. The results show that the attained reliability for some traffic patterns is low. Further analysis revealed the use of link-layer broadcasts for one-to-many communication as a cause
Andreas Weigel, Martin Ringwelski, Volker Turau und Andreas Timm-Giel. Route-Over Forwarding Techniques in a 6LoWPAN. In Proceedings of the 5th International Conference on Mobile Networks and Management (monami'13), September 2013, pp. 122–135. Cork, Irland.
@InProceedings{Telematik_ICMNM_2013_6LoWPAN, author = {Andreas Weigel and Martin Ringwelski and Volker Turau and Andreas Timm-Giel}, title = {Route-Over Forwarding Techniques in a 6LoWPAN}, booktitle = {Proceedings of the 5th International Conference on Mobile Networks and Management (monami'13)}, pages = {122-135}, day = {23-25}, month = sep, year = 2013, location = {Cork, Irland}, }
Abstract: 6LoWPAN plays a major role within the protocol stack for the future Internet of Things. Its fragmentation mechanism enables transport of IPv6 datagrams with the required minimum MTU of 1280 bytes over 802.15.4-based wireless sensor networks. With the envisioned goal of a fully standardized WSN protocol stack currently necessitating a route-over approach, i.e. routing at the IP-layer, there are two main choices for any 6LoWPAN implementation with regard to datagram fragmentation: Hop-by-hop assembly or a cross-layered direct mode, which forwards individual 6LoWPAN fragments before the whole datagram has arrived. In addition to these two straightforward approaches, we propose enhancements based on adaptive rate-restriction for the direct forwarding and a retry control for both modes to reduce the number of losses of larger datagrams. Our evaluation of the basic and enhanced forwarding modes within simulations and a hardware testbed indicate that the proposed enhancements can considerably improve packet reception rate and latency within 6LoWPAN networks.
Martin Ringwelski, Christian Renner, Andreas Reinhardt, Andreas Weigel und Volker Turau. The Hitchhiker's Guide to Choosing the Compression Algorithm for Your Smart Meter Data. In Proceedings of the IEEE International Energy Conference and Exhibition (EnergyCon'12), September 2012. Florence, Italy.
@InProceedings{Telematik_RRWRT_2012_CompressionGuide, author = {Martin Ringwelski and Christian Renner and Andreas Reinhardt and Andreas Weigel and Volker Turau}, title = {The Hitchhiker's Guide to Choosing the Compression Algorithm for Your Smart Meter Data}, booktitle = {Proceedings of the IEEE International Energy Conference and Exhibition (EnergyCon'12)}, day = {9-12}, month = sep, year = 2012, location = {Florence, Italy}, }
Abstract: Smart meters are increasingly penetrating the market, resulting in enormous data volumes to be communicated. In many cases, embedded devices collect the metering data and transmit them wirelessly to achieve cheap and facile deployment. Bandwidth is yet scarce and transmission occupies the spectrum. Smart meter data should hence be compressed prior to transmission. Here, solutions for personal computers are not applicable, as they are too resource-demanding. In this paper, we propose four lossless compression algorithms for smart meters. We analyze processing time and compression gains and compare the results with five off-the-shelf compression algorithms. We show that excellent compression gains can be achieved when investing a moderate amount of memory. A discussion of the suitability of the algorithms for different kinds of metering data is presented.
Stefan Unterschütz, Andreas Weigel und Volker Turau. Cross-Platform Protocol Development Based on OMNeT++. In Proceedings of the 5th International Workshop on OMNeT++ (OMNeT++'12), März 2012. Desenzano, Italy.
@InProceedings{Telematik_UWT_2012_CometOS, author = {Stefan Untersch{\"u}tz and Andreas Weigel and Volker Turau}, title = {Cross-Platform Protocol Development Based on OMNeT++}, booktitle = {Proceedings of the 5th International Workshop on OMNeT++ (OMNeT++'12)}, day = {23}, month = mar, year = 2012, location = {Desenzano, Italy}, }

Dissertationen

Andreas Weigel. Forwarding Strategies for 6LoWPAN-Fragmented IPv6 Datagrams. PhD Thesis, Hamburg University of Technology, Hamburg, Germany, 2017.
@PhdThesis{Telematik_Weigel_2017_Diss, author = {Andreas Weigel}, title = {Forwarding Strategies for 6LoWPAN-Fragmented IPv6 Datagrams}, publisher = {Cuvillier Verlag, G{\"o}ttingen, Germany}, school = {Hamburg University of Technology}, address = {Hamburg, Germany}, year = 2017, isbn = {978-3-7369-9667-0}, }
Abstract: This dissertation explores different implementation strategies for the fragment-forwarding aspect of the 6LoWPAN protocol for “low power and lossy networks” (LLNs). The performance in terms of latency and reliability for the LLN-typical collection traffic pattern is analyzed for several “direct” and “reassembling” strategies. A novel approach based on snooping and suspending transmissions is developed and it is shown that this approach improves the end-to-reliability significantly in most of the evaluated simulation and testbed scenarios.