History

Ambient Systems was founded in 2004 by senior researchers from Twente University who had been leading the European research project EYES on energy efficient sensor networks. This project conducted breakthrough research on the architecture and technology needed to build self-organizing and collaborative sensor networks using reconfigurable smart sensor nodes, which are self-aware, self-reconfigurable and autonomous. During EYES and subsequent research projects, the principles of Ambient’s wireless mesh networks were developed:

•Multi-hop - Ambient Networks are multi-hop, enabling the communication of two nodes that are not in each other’s radio range by relaying data through intermediate nodes.

•Self-organizing - The network is self-organizing, meaning that the whole network setup is automated. MicroRouters and SmartPoints have the ability to discover and join the network without configuration. Also, the network dynamically adapts to changes like moving nodes or adjusted range due to environmental interference.

•Self-healing - The network is self-healing, which means that when a relaying MicroRouter fails, alternative paths are used to deliver data at the destination.

•Energy-efficient - The network is energy-efficient. MicroRouters maximize their sleep time -and therefore increase battery lifetime - by communicating only at certain highly synchronized time intervals.

How Does It Work?

The 3000 Series at its core is a so-called Dynamic Wireless Sensor Network (DWSN). Unlike other Wireless Sensor Network (WSN) technologies, the Ambient Network is specifically designed for highly dynamic application scenarios, such as Supply Chain applications, and characterizes itself due to its capability to scale to up to dozens of MicroRouters and hundreds of SmartPoints and remain energy-efficient enough to operate on batteries and solar-power only. Furthermore, unlike traditional Active Radio Frequency Identification (RFID) and Real-time Location Systems (RTLS), a WSN builds on low-power networking technology enabling every part of the network to operate at minute energy levels, whereas Active RFID and RTLS infrastructure is very energy consuming.

The 3000 Series is based on the IEEE 802.15.4 PHY standard which has specifically been designed for large-scale and low-energy DWSNs, and operates at the world-wide license-free 2.4 GHz band. The wireless network consists of two main layers: 1) an infrastructure layer that comprises of a Gateway and MicroRouters that are spread out across a location offering radio coverage for 2) SmartPoints that are deployed throughout a location and/or attached to objects that move through the network and in & out of networks.

The infrastructure layer is fixed. SmartPoints can be both fixed as well as mobile, depending on the type of SmartPoint and its intended operation. In the overview it can be seen that infrastructure devices communicate with each other and with SmartPoints, whereas SmartPoints only communicate with infrastructure devices. SmartPoints can not communicate with each other. All communication in an Ambient network is bi-directional, meaning that every device can send and receive messages. As such, it is always possible, for example, to reconfigure a SmartPoint while it is already installed.

Ambient Protocol Stack

Ambient’s Product Series 3000 is based on the IEEE 802.15.4 standard. This standard is designed for low-cost communication between physical objects and devices (in contrast with more user-oriented networks, such as Wi-Fi). IEEE 802.15.4 is not a complete network protocol stack, and only provides the lower level network layers (in the OSI reference model the physical layer and the medium access layer). As defined in the IEEE 802.15.4 standard, the Ambient Product Series 3000 operates in the globally available 2.44 GHz bandwidth. The Ambient protocol stack includes a number of additional protocols, which were specifically designed to meet the requirements from transport & logistics applications.

Some of the important protocols are described below:

• Reliable Transport Protocol (RTP) – The Reliable Transport Protocol is an optional mechanism that notifies the sender of data whether that data is actually received by the destination, also in multi hop communication. The protocol is able to setup a streaming connection. A connection between source and destination is setup and the source can continuously stream messages through this connection reliably until it has no more data to send.

• Remote Update Protocol (RUP): The Remote Update Protocol runs in parallel to the routing and transport protocols. It is used to communicate a large amount of data throughout the network to each node. It can be used to perform a system-wide firmware upgrade. The transferred data is the new firmware image and every MicroRouter receiving it can use it to reprogram itself.

• Device Driver Interface (DDI): The Device Driver Interface allows users, applications and nodes to access resources in a standardized manner. Resources are made accessible by implementing drivers for them. Using DDI, it is possible to access these drivers and, in that way, obtain information from them or send information to them. The latter might be the case when a driver needs to be configured.