Wireless, opportunistic, sensor network

Topic Category

Microcontroller, Wireless Opportunistic Sensor Network

Topic Keywords

Microcontroller, Sensor, Network

Preamble

Opportunistic networks are (usually) asynchronous wireless networks, with nodes consisting (typically) of handheld devices carried by people.  No infrastructure is required. Nodes discover each other automatically when the network is deployed and communicate directly with each other with no user intervention.  Some opportunistic networks are also wireless sensor networks. One can get an idea of the power of opportunistic networks by looking at a recent example of research report published at the University of Cambridge, UK, http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-617.html  & http://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-617.pdf . This research relies on the use of the Intel i-Mote. However, it is possible to experiment with opportunistic networks for a low cost, with inexpensive nodes.

A possible opportunistic network may consist of nodes able to measure temperature, light, motion, etc, and collaborating to “identify” the state of a room. It is possible to start with small existing wireless modules (e.g. eZ430-RF2500, http://focus.ti.com/docs/toolsw/folders/print/ez430-rf2500.html, i.e. USB stick interface and two 2.4GHz wireless target boards). There is actually an application note documenting in some detail the wireless temperature-sensor network demonstration application provided with the eZ430-RF2500 development tool (http://www.ti.com/litv/pdf/slaa378a) and some code example (http://www.ti.com/litv/pdf/slaa325). Similarly, a motion detector example exists at http://www.designmsp430.com/Login.aspx?ReturnUrl=%2fsamples/Display.aspx%3fUserSampleId%3dc5eaea35-c5e8-4437-be7e-dc4495e3e980 and many other examples of simple functions for a node (http://www.designmsp430.com/View.aspx). The existing proprietary wireless network is called SimpliciTI (http://focus.ti.com/docs/toolsw/folders/print/simpliciti.html?DCMP=hpa_rf_general&HQS=Other+OT+simpliciti ). It needs to be modified for use in an opportunistic network. Its current operation is the one of a central node talking to many (about 100+) peripheral nodes.

Objective

            Design, build, and test a small, hand-held, wireless opportunistic network of 5 nodes capable of self configuration and reporting to a notebook computer. At power up each node must look for neighbouring nodes. Operation with 1, 2, 3, 4, and 5 nodes must be tested. Each node shall perform its task, e.g. measure temperature, measure presence/absence of light, detect motion, etc. Each node shall inform its neighbours of its own measurement. The node closest a chosen notebook computer shall report the results of all other nodes to the computer.

If this project is developed well, results could be publishable in a practical magazine such as the “Circuit Cellar”, http://www.circuitcellar.com/, or, if new theoretical results are achieved, in a conference such as the “International Conference for Upcoming Engineers”. It should be a strong objective of the student team to produce results of publishable quality.

Partial Specifications

As a minimum develop a small 5 node opportunistic, hand held, wireless sensor network capable of measuring temperature at up to 5 different points of a room and reporting to a notebook computer the results. It must operate with 1, 2, 3, 4, and 5 nodes. The network must function while the persons holding the nodes move in the room. The network must reconfigure itself when one or more nodes are turned off and on.

Suggested Approach

The work can be divided into the following tasks:

  1. Collect the literature about the above mentioned eZ430-RF2500
  2. Study the SimpliciTI network protocol to check if it can be modified to implement an opportunistic network
  3. If the answer to (2) is “YES”, prepare a design of the new opportunistic protocol
  4. If the answer to (2) is “NO”, design your own design from scratch (consider using a protocol akin to the multidrop of wired connections)
  5. Prepare a design and bill of materials for the 5 nodes network
  6. Purchase the pre-assembled components (estimated cost $ 120)
  7. Deploy the SimpliciTI network and verify its operation with 1, 2, 3, 4, and 5 nodes (this will be a network measuring temperature and battery voltage at each node; probably, it should also measure the approximate distance between nodes). A blow dryer and a freezing mist should be carefully used to quickly change temperature without damaging the hardware.
  8. Implement and test either the design of the above (3) or (4)
  9. Write your report.

Group Responsibilities

The group is responsible for making the complete system working including the report writing and meeting milestones.

Student A Responsibilities

To be defined.

Student B Responsibilities

To be defined.

Student C Responsibilities

To be defined.

Prerequisite

Basic knowledge of sensors microprocessor based systems and small networks