|Toward Energy-efficient Communication in Wireless Sensor Networks|
Sensor-Actor Testbed:This testbed comprises 16 sensor devices and 2 actor devices. The sensor devices are based on Crossbow mica2 motes and dots from two MOTE-KIT5040 professional kits. The Professional Kit, MOTE-KIT5040, is a combination 8 node kit for Mote Development. It features Crossbow’s latest generation MICA2 and MICA2DOT Motes. Both Motes are compatible with TinyOS. The Kit includes:
- 4 MICA2 Processor/Radio Boards
- 4 MICA2DOT Quarter-Sized Processor Radio Boards
- 3 MTS310 Sensor Boards (Acceleration, Magnetic, Light, Temperature, Acoustic, and Sounder)
- 2 MDA500, MICA2DOT Prototype and Data Acquisition Boards
- 1 MIB510 Programming and Serial Interface Board
- Operates at 915MHz
The mica2 motes and dots have a transmission range of 2-6 feet at the lowest power setting, and about 100 feet at the highest power setting. Thus, there are a total of 6 sensor motes and 9 other motes that act as relays to the sink. The figure attached below illustrates the sensor network testbed.
The two actors are composed of a combination of laptop, attached to a Devasys USB I2C/IO board, attached to a light source. The USB I2C/IO interface board provides a simple, "drop-in", solution for customers that need to connect hardware to a P.C. The board provides 20 bits of user-configurable digital I/O, a 90Kbps I2C interface, and an 8 bit wide data bus for fast FIFO transfers. The laptop, Devasys USB I2C/IO board combination acts as a wireless transceiver and microcontroller to turn on or off the light source depending on the values reported by the sensor network.
Sensor Communication Testbed:The testbed implementation contains one sender and one receiver. The sender sends information to the receiver via a efficient communication strategy designed for wireless sensor networks. Both the sender and the receiver are transceiver modules with microcontrollers that are programmed to realize the communication strategy. Each module contains one CC1010 chip and related peripheral circuits.
The CC1010 is a true single-chip UHF transceiver with an integrated high performance 8051 microcontroller with 32 kB of Flash program memory. The RF transceiver can be programmed for operation in the 300 - 1000 MHz range, and is designed for very low power wireless applications.
Using this testbed, we will implement and test the proposed communication strategy, and show the effectiveness of the solution. Different power modes of the CC1010 chip (awake, idle and sleep)can also be incorporated into the experiment, enabling us to evaluate various ways of energy savings possible in sensor communications.
Heterogeneous Sensor Network Testbed
It consists of clusters of motes connected through a gateway (such as a Stargate node) to other clusters. These gateway connected clusters co-exist and work in concert with an independent collection of more powerful (iPAQ class) nodes that form their own ad hoc network together with the gateway nodes. The hierarchical nature of this testbed goes hand in hand with the envisioned research in IDS. A gateway node naturally behaves as a cluster head, while forming a mesh network with the more powerful (iPAQ class) nodes.
The testbed lends itself to the transport of both high bitrate (such as video) and low bitrate (such as humidity values) stream data. This is our first-cut deployment of the testbed and we will enhance it as the research progresses to allow dynamic clustering of the nodes and dynamic selection of cluster head.
Last modified 18 April 2006 at 3:21 pm by Rajnish Kumar
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