Open Source Firmware
OSS-7 is an open source implementation of the DASH7 Alliance protocol. The aim of the project is to provide a reference implementation of the protocol stack which allowing fast development and prototyping of DASH7 based products. This implementation focuses on completeness, correctness and being easy to use and understand. Performance and code size are less important aspects. For clarity a clear separation between the ISO layers is maintained in the code.
Developed by WizziLab, the WizziKit2 is a compact and affordable development kit for DASH7.
Containing 2 Endpoints (SH2050 modems+Sensors+Nucleo32 Application MCU) and one Gateway, the WizziKit2 is the perfect development kit to evaluate the technology and prototype your DASH7 application.
The WizziKit2 can be purchased directly from WizziLab here.
In this first session we introduce the DASH7 Alliance Protocol.
- Open Wireless Sensor Communication
- Frequency vs Range
- Technology comparison
- DASH7 Topology
- DASH7 Design choices
In this sessions four examples which are using DASH7 are explained:
- Parking guidance and information
- Location Aware Tablets
- Food Cart Tracking and Locating
- Presence detection (small birds)
This session of the DASH7 Academy explains how DASH7 is build around a file based communication methodology:
- Generic model
- Low Power Wake-up
- File Notification
- Dormant Sessions
Whitepapers and Academic Publications
Maarten Weyn, Glenn Ergeerts, Rafael Berkvens, Bartosz Wojciechowski, Yordan Tabakov
This paper presents the DASH7 Alliance Protocol 1.0. It is an industry alliance standard for wireless sensor and actuator communication using the unlicensed sub-1 GHz bands. The paper explains its historic relation to active RFID standards ISO 18000-7 for 433 MHz communication, the basic concepts and communication paradigms of the protocol. Since the protocol is a full OSI stack specification, the paper discusses the implementation of every OSI layer.
Glenn Ergeerts, Maciej Nikodem, Dragan Subotic, Tomasz Surmacz, Bartosz Wojciechowski, Paul De Meulenaere, Maarten Weyn
In this paper we introduce important aspects of the recently published DASH7 Alliance Protocol v1.0 specification for wireless sensor and actuator networks. The main contribution of this paper is the discussion of the different communication schemes and the accompanying trade-offs which can be used when designing a DASH7 network. Finally, we describe two practical use cases as examples of how DASH7 can be used to efficiently solve specific problems as well as the hardware developed that uses energy harvesting.
Ronald Pulvermacher, Krzysztof Berezowski, Maarten Weyn, and Michael Andre
Have you ever seen your developers struggle with outwardly simple distributed embedded application? Have you seen them deceived by its functional simplicity then combated and defeated by the complexity of power management, connectivity management, packet routing, message queuing, synchronization, you name it? DASH7 abstracts those nightmares away. This white paper illustrates how its file system based abstract take on the sensor network allows you to focus on the most important task of the connected embedded system you have at hand – producing and providing information.
Maarten Weyn, Glenn Ergeerts, Luc Wante, Charles Vercauteren, and Peter Hellinckx
433 MHz is getting more attention for Machine-to-Machine communication. This paper presents the DASH7 Alliance Protocol, an active RFID alliance standard for 433 MHz wireless sensor communication based on the ISO/IEC 18000-7. First, the major differences of 433 MHz communication compared to more frequently used frequencies, such as 2.4 GHz and 868/920 MHz are explained. Subsequently, the general concepts of DASH7 Alliance Protocol are described, such as the BLAST networking topology and the different OSI layer implementations, in a top-down method. Basic DASH7 features such as the advertising protocol, ad-hoc synchronization and query based addressing are used to explain the different layers. Finally, the paper introduces a software stack implementation named OSS-7, which is an open source implementation of the DASH7 alliance protocol used for testing, rapid prototyping, and demonstrations
On the suitability of the 433 MHz band for M2M low-power wireless communications: propagation aspects
Pere Tuset-Peiró, Albert Anglès-Vazquez, José López-Vicario and Xavier Vilajosana-Guillén
The 433 MHz band is gaining relevance as an alternative to the 2.4 GHz band for machine-to-machine communications using low-power wireless technologies. Currently, two standards are being developed that use the 433 MHz band, DASH7 Mode 2 and IEEE 802.15.4f. The article presents propagation models based on measurements conducted at the 433 MHz and 2.4 GHz bands that can be used for link budget calculations in both outdoor and indoor environments depending on node height. The results obtained show that the 433 MHz band has a larger communication range in both indoor and outdoor environments despite the negative effects of having a larger Fresnel zone. In addition, indoor propagation measurements are conducted in line-of-sight and nonline-of-sight conditions to determine the suitability of channel hopping to combat the effects of multipath propagation. Contrary to the 2.4 GHz band, the results show that channel hopping at 433 MHz does not provide any link robustness advantage because the channel coherence bandwidth is larger than the whole band bandwidth, and thus, all channels are highly correlated.
Performance Comparison of DASH7 and ISO/IEC 18000-7 for Fast Tag Collection with an Enhanced CSMA/CA Protocol
Hwakyung Lee, Sang-Hwa Chung, Yun-Sung Lee, Yoobin Ha
Abstract—ISO/IEC 18000-7 adopted Slotted ALOHA as MAC transmission protocol. However, this protocol cannot solve the collision problem when there is a need of collecting massive tags. To solve this problem, DASH7 adopted CSMA/CA for MAC protocol. It also proposed three kinds of collision avoidance models to implement the back off flexibly. AIND is the unsurpassed model as it can effectively use the contention period employing data transmission time back off. RAIND adopts random initialization and distribute access time of each tag in order to reduce the backoff. And the last, RIGD does geometric decaying slot backoff, minimizing the number of backoffs to reduce energy consumption. This paper presents tag collection scenario. We analyze the three CA models and Slotted ALOHA with tag collection time. We also suggest adaptive guard time method to improve the CA models. The aftermath of tag collection experiment is that CSMA/CA has exceptional performance than Slotted ALOHA. AIND has the best performance among CA models and its performance is 28.7% better than Slotted ALOHA. In addition, the adaptive guard time method enhances RAIND and RIGD which are based on random back-off. In particular, RIGD with adaptive guard time method(AG-RIGD) has similar performance as AIND. Besides, AG-RIGD is better than AIND in terms of energy efficiency because it consumes one third of energy than AIND during tag collection.