Friday, July 1, 2011

IBM launches Mote Runner for sensor networks



Memsic Iris sensor moteMemsic Iris sensor mote
(Credit: Memsic)

IBM on Monday rolled out a software development kit for an application dubbed Mote Runner with the aim of spurring the adoption of sensors in various devices, products, and systems. The real goal is to enable the so-called Internet of things by making sensor networks easier to deploy and manage.

Mote Runner is a free download. IBM made the announcement at the 2010 Sensors Expo & Conference. The Mote Runner moniker refers to motes--or wireless sensor nodes--that gather information including temperature, movement, and light and refer back to a network.
Meanwhile, Memsic, which makes these micro sensor systems, will include Mote Runner on one of its Iris sensors. The Memsic Iris is a 2.4GHz wireless sensor mote used for enabling low-power wireless sensor networks in buildings or traffic patterns at an intersection.

New wearable wireless sensors can improve healthcare


Members of the public could form the backbone of powerful new mobile internet networks by carrying wearable sensors.
According to researchers from Queen's University Belfast, the novel sensors could create new ultra high bandwidth mobile internet infrastructures and reduce the density of mobile phone base stations.


The engineers from Queen's renowned Institute of Electronics, Communications and Information Technology (ECIT), are working on a new project based on the rapidly developing science of body centric communications.
Social benefits from the work could include vast improvements in mobile gaming and remote healthcare, along with new precision monitoring of athletes and real-time tactical training in team sports.


The researchers at ECIT are investigating how small sensors carried by members of the public, in items such as next generation smartphones, could communicate with each other to create potentially vast body-to-body networks (BBNs).
The new sensors would interact to transmit data, providing 'anytime, anywhere' mobile network connectivity.


Dr Simon Cotton, from ECIT's wireless communications research group said: "In the past few years a significant amount of research has been undertaken into antennas and systems designed to share information across the surface of the human body. Until now, however, little work has been done to address the next major challenge which is one of the last frontiers in wireless communication - how that information can be transferred efficiently to an off-body location.
"The availability of body-to-body networks could bring great social benefits, including significant healthcare improvements through the use of bodyworn sensors for the widespread, routine monitoring and treatment of illness away from medical centres. This could greatly reduce the current strain on health budgets and help make the Government's vision of healthcare at home for the elderly a reality.


"If the idea takes off, BBNs could also lead to a reduction in the number of base stations needed to service mobile phone users, particularly in areas of high population density. This could help to alleviate public perceptions of adverse health associated with current networks and be more environmentally friendly due to the much lower power levels required for operation."

Dr Cotton has been awarded a prestigious joint five-year Research Fellowship by the Royal Academy of Engineering and the Engineering and Physical Research Council (EPSRC) to examine how the new technology can be harnessed to become part of everyday life.

He added: "Our work at Queen's involves collaborating with national and international academic, industrial and institutional experts to develop a range of models for wireless channels required for body centric communications. These will provide a basis for the development of the antennas, wireless devices and networking standards required to make BBNs a reality.

"Success in this field will not only bring major social benefits it could also bring significant commercial rewards for those involved. Even though the market for wearable wireless sensors is still in its infancy, it is expected to grow to more than 400 million devices annually by 2014."

'Body-to-body' networks could serve healthcare, make Internet more mobile

Researchers at the Institute of Electronics, Communications and Information Technology at Queens University in Belfast, Northern Ireland, are studying how wearable sensors might not only help keep elderly and chronically ill patients out of nursing homes, but also form the backbone of future mobile "body-to-body networks." Says Simon Cotton, one of the researchers, "If the idea takes off, BBNs could also lead to a reduction in the number of base stations needed to service mobile phone users, particularly in areas of high population density. This could help to alleviate public perceptions of adverse health associated with current networks and be more environmentally friendly due to the much lower power levels required for operation." 

Wednesday, January 20, 2010

Central pattern generators

Even simple insects can generate quite different movement patterns with their six legs. The animal uses various gaits depending on whether it crawls uphill or downhill, slowly or fast. Scientists from Göttingen have now developed a walking robot, which -- depending on the situation -- can flexibly and autonomously switch between different gaits. The success of their solution lies in its simplicity: a small and simple network with just a few connections can create very diverse movement patterns.

To this end, the robot uses a mechanism for "chaos control." This interdisciplinary work was carried out by a team of scientists at the Bernstein Center for Computational Neuroscience Göttingen, the Physics Department of the Georg-August-University of Göttingen and the Max Planck Institute for Dynamics and Self-Organization.

In humans and animals, periodically recurring movements like walking or breathing are controlled by small neural circuits called "central pattern generators" (CPG). Scientists have been using this principle in the development of walking machines. To date, typically one separate CPG was needed for every gait. The robot receives information about its environment via several sensors -- about whether there is an obstacle in front of it or whether it climbs a slope. Based on this information, it selects the CPG controlling the gait that is appropriate for the respective situation.

One single pattern generator for many gaits

The robot developed by the Göttingen scientists now manages the same task with only one CPG that generates entirely different gaits and which can switch between these gaits in a flexible manner. This CPG is a tiny network consisting of two circuit elements. The secret of its functioning lies in the so-called "chaos control." If uncontrolled, the CPG produces a chaotic activity pattern. This activity, however, can very easily be controlled by the sensor inputs into periodic patterns that determine the gait. Depending on the sensory input signal, different patterns -- and thus different gaits -- are generated.

The connection between sensory properties and CPG can either be preprogrammed or learned by the robot from experience. The scientists use a key example to show how this works: the robot can autonomously learn to walk up a slope with as little energy input as possible. As soon as the robot reaches a slope, a sensor shows that the energy consumption is too high. Thereupon, the connection between the sensor and the control input of the CPG is varied until a gait is found that allows the robot to consume less energy. Once the right connections have been established, the robot has learned the relation between slope and gait. When it tries to climb the hill a second time, it will
immediately adopt the appropriate gait.

In the future, the robot will also be equipped with a memory device which will enable it to complete movements even after the sensory input ceases to exist. In order to walk over an obstacle, for instance, the robot would have to take a large step with each of its six legs. "Currently, the robot would not be able to handle this task -- as soon as the obstacle is out of sight, it no longer knows which gait to use," says Marc Timme, scientist at the Max Planck Institute for Dynamics and Self-Organization. "Once the robot is equipped with a motor memory, it will be capable to use foresight and plan its movements."

Friday, September 18, 2009

Wireless Sensor Networks: Security Requirements

1. Security Requirements

As mentioned in the previous articles (Introduction and Limitations), sensor networks are used in a number of domains that handle sensitive information. Due to this, there are many considerations that should be investigated and are related with protecting sensitive information traveling between nodes (which are either sensor nodes or the base station) from been disclosure to unauthorized third parties.

The scope of this article is to analyze basic security concepts before moving into a detail discussion of the various security issues. It is essential to first understand the security requirements that are raised in a sensor environment; by doing so, we could apply appropriate security techniques to ensure the protection and safety of data and systems involved in a more spherical approach. By knowing what we are trying to protect, we could develop a comprehensive and strong security approach to overcome possible security breaches; after all, in order to protect something you must first know that is in danger. Since sensor networks are still a developing technology. Researchers and developers agree that their efforts should be concentrated in developing and integrating security from the initial phases of sensor applications development; by doing so, they hope to provide a stronger and complete protection against illegal activities maintaining at the same time the stability of the system, rather than adding on security functionality after the application is finished.

Moving on, next section analyzes the security requirements that constitute fundamental objectives based on which every sensor application should adhere in order to guarantee an appropriate level of security.

1.1 Confidentiality

Confidentiality requirement is needed to ensure that sensitive information is well protected and not revealed to unauthorized third parties.

The confidentiality objective is required in sensors’ environment to protect information traveling between the sensor nodes of the network or between the sensors and the base station from disclosure, since an adversary having the appropriate equipment may eavesdrop on the communication. By eavesdropping, the adversary could overhear critical information such as sensing data and routing information. Based on the sensitivity of the data stolen, an adversary may cause severe damage since he can use the sensing data for many illegal purposes i.e. sabotage, blackmail. For example, competitors may use the data to produce a better product i.e. safety monitoring sensor application. Furthermore, by stealing routing information the adversary could introduce his own malicious nodes into the network in an attempt to overhear the entire communication.

If we consider eavesdropping to be a network level threat, then a local level threat could be a compromised node that an adversary has in his possession. Compromised nodes are a big threat to confidentiality objective since the adversary could steal critical data stored on nodes such as cryptographic keys that are used to encrypt the communication.


Monday, August 24, 2009

THE FUTURE OF SENSOR NETWORKS

From thermostats in building automation to computer numerical controls in factory automation, device and sensor information is traveling over the same technology that is powering our e-world. But how well is it working, and where is the trend taking us?

Mark Fondl, ICT and Lynn Linse, Lantronix, Inc.


The volume of data carried on a network increases as the devices on it become more sophisticated. Low-end devices may transmit data in 1 bit increments, indicating a simple on/off condition. High-end sensors, on the other hand, contain local intelligence and transmit complex data types measured in bytes (see Figure 1.)

To meet the need for more complex data communications, the industry has looked to other networks. In the process, many have asked: Can Ethernet/TCP/IP be used to replace some of these networks? Can some of the networks be integrated into higher level Ethernet architectures (e.g., DeviceNet over Ethernet, Interbus-S over Ethernet, LonWorks over Ethernet)? Some of the answers to these questions can be found in an examination of implementation costs, ease of use, performance, and vendor support.

Implemention Costs

Ethernet costs are not inherently lower than the other networks. For the foreseeable future, cost can be justified only by concentrating multiple sensors on one Ethernet interface.

Other factors contributing to the cost of implementation are the CPU resources. Here, Ethernet does not compare favorably with an architecture such as DeviceNet. For example, DeviceNet can run on a CPU with 4000 bytes of code and 176 bytes of RAM. Ethernet, though, requires a minimum of 64,000 bytes of code and 64,000 bytes of RAM. Here, many implementers insist the minimum is more like 256 KB each, but they would prefer 2–4 MB of code and RAM. If the volumes are low and the margins are high, the simpler software offsets Ethernet’s greater CPU requirements. But as volumes rise and margins shrink, the lower resource needs of something like DeviceNet will force a price premium for Ethernet with the same sales volumes.

Consideration of connection costs—especially for bit-level sensors in industrial environments—causes some to favor ASI and DeviceNet wiring. Optimized for machines in which many discrete sensors are located in a relatively small area (50 m), these sensor networks are ideal. But extending their range poses some difficulty, and based on response times of these clusters, bridging with Ethernet may provide value.

Ease of Use

Here the focus is on long-term support of software configuration. This has multiple facets:

TCP/IP ease of use is based on the wide availability of skilled technicians and tools.
But TCP/IP (at the moment) lacks the high-level standards that allow auto-replacement, which is supported in DeviceNet and ASI.
The complexity of the options found in TCP/IP can overwhelm inexperienced users.
Systems such as DeviceNet and ASI are well suited for applications in which the communications are kept on a local scale. But when the data travel into extended areas and applications in which specialized network skills are required, then a commercial TCû/IP network becomes attractive. Network evaluation can be as simple as a “ping” from almost any computer. Commercial technologies aimed at simple diagnostics will eventually become common. Training individuals to support TCP/IP will be much easier. Device networks feeling this pressure will undoubtedly develop simpler and even browser-based tools.

Performance

With a well-designed network, TCP/IP will perform quite well. But the network must be well designed. An isolated subnet with limited or master/slave functions can expect reliable 2–5 ms times. But the instant you add routers or other noncontrol traffic (including Web servers), you can expect delays of 500 ms or more. So Ethernet performs only as well as the user designs it to perform.

A sparsely designed Ethernet, which underuses its capacity, can rival or beat any deterministic control network. But a poorly designed Ethernet can be an operational nightmare.

Web access via TCP/IP is a common unrealistic hope. With control traffic running at 5–10,000 Bps, users often overlook the fact that a Web page can attempt to force millions of bytes of data through a network at the same time that control data are being transmitted, dwarfing the control traffic. Users and vendors still have to learn the tradeoffs here. Some Web access is wonderful, but this needs to be shared/supplemented with Web resources stored off the control network.

To improve performance on the sensor level, automation companies are experimenting with UDP and variations of limited TCP/IP stacks. These stacks listen only to certain types of transmissions, ignoring others and eliminating a retry structure for a high-speed master-slave structure. This is similar to how I/O has worked for years with PLCs. The architecture and wiring are Ethernet, but the openness is traded for performance.

Most systems don’t need this level of performance and should stay with standard Ethernet. As the technology continues to improve, you can imagine a time when a conventional approach will surpass proprietary methods.

Service and Support
Support for Ethernet TCP/IP systems is good, but the actual media (e.g., cables, connectors, and power) are rather unindustrial. Many TCP/IP experts have an IT mentality, not a plant-floor mindset, so they misunderstand what users want or modify existing systems in ways that hurt the industrial user in an effort to improve the system according to other criteria.

«o users still need to learn about the technology and watch over the shoulders of the experts. Ask questions, and make sure the IT experts learn how you view the problem.

Openness

Ethernet TCP/IP systems provide an open network platform, but high-level application standards are still in flux. TCP/IP is often viewed as a false open standard because its higher layers are proprietary. Modbus/TCP and some of the new encapsulations of òeviceNet, Foundation Fieldbus, and Profibus will help in this area by providing interfaces that will allow different protocols to communicate with each other. But that still leaves a lot of application standards that are not interoperable.

Many of these network architectures encapsulate other protocols, but the interoperability does not extend to the physical and transport layers. This prevents the various buses from communicating with each other. So there is still a great deal of work to be done in this area.

Flexibility

Just about anything is possible with global TCP/IP, but the reliability of its performance depends on the skill of the implementer. However, there is still a need for a more industrial and optimized sensor bus.

As data requirements increase, hybrid and direct Ethernet systems will become commonplace. High-level sensors with serial ports are already being linked over Ethernet. The protocols are transported transparently on top of TCP/IP and delivered to a host, which in some cases is unaware that they were carried over a LAN.

Monday, November 10, 2008

Mobile Sensors

Mobile Sensor Cam

We were asked by a colleague in Environmental Science about using a mobile phone to relay pictures back of one of there remote sites every half hour for hopefully about a month. We have created not only bespoke mobile application that allows any suitable mobile camera phone to be used for functionality but is programmable for a variety of operating parameters time of operation, frequency etc. The resultant images can be viewed as a series of time lapse photographs at the project site

 Mobile sensor cam project in ealy test phase using additional solar panel
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Mobile sensor cam project in ealy test phase using additional solar panel

River Flow Monitoring

River flow monitoring system
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River flow monitoring system

Our influence on the changing natural environment poses many challenges for future generations. One obvious environmental change relates to the increasing regularity of flooding. Monitoring river and stream velocity enables the accurate modelling of flood planes, river bank erosion, and mans influence over the natural environment. The remote monitoring unit developed for this project gives the environmental science community a ‘real time’ cost effective data collection system, freeing up large amounts of time spent out in the field gathering data and eliminating the potential for human error during the recording process. The system incorporates a sensor placed in the river that users Doppler shift to esimate the flow rate of the river. A unit on the bank relays the sensor reading plus a GPS time stamp to a central server using a GPRS connection to the celluar network. With cellular coverage now extended to even the most remote rural of areas systems this project highlights that mass monitoring of stream and river networks is now a practical solution.


Bus ETA

 Application showing ETA of bus at selected stop
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Application showing ETA of bus at selected stop

Whilst it is readily accepted that mobile phones enable users to obtain information quickly and easily in any location, there are a great many ways in which this information can be accessed and provided. Although mobile phone manufacturers are embracing standardization of mobile phone operating systems, as yet there is no clear market leader, which coupled with extremely variable phone feature sets, make porting applications to different platforms a challenging experience. Further to this, is the fact that even within technologically advanced societies large sections of the population are technologically naïve. Thus, the development of information systems that can be accessed by large numbers of the general public from mobile phones, can be problematic, and all too often such systems provide only a single mode access solution, which limits both their acceptance and usefulness. In this project we developed a mobile information system which has been designed so that it can accommodate both the variation in mobile phone features and the technical sophistication of individual users and can be easily deployed for a wide variety of services. The system was demonstrated through an example service which demonstrated information related to the Estimated Time of Arrival (ETA) of vehicles in a metro-bus public transport system. The solution illustrates that information can be provided in different forms, to suit individual users preferences, from the same mobile information system, without significant increases in the underlying infrastructure.