Can you explain what you mean exactly by physical parameter?
if you mean the characteristics of physical layer (i.e. signal strength), the answer is yes. you can get a relation between distance and signal strength
if you mean the physical location of node, the answer is yes. for example, you can use triangulation triangulation, or GPS (if there is enough energy)
YES! It is possible using Physical layer or MIMO Techniques
In my opinion if physical parameter is related to interference (e.g. radio interference) it could be quite easy
thanks for suggestions sir.The signal parameter means RSSI, SNR and CSI.Let i want to know how do i combine this parameters for energy optimization?
PHY layer parameters is one of the essential information for the routing decision in WSN. the possible parameters is includes RSSI, Pr and LQI. so, the answer diffidently yes.
if you are considering a cross layer design, then others parameters should also be included for optimum routing decision.
you have to give more information on what are your objective.
good luck.
All of the advice given above is good. One of the early decisions the 802.15.4 committee made was to admit RSSI values (normally limited to the PHY layer) into upper layers to assist with routing decisions. And the Ricochet / Metricom system used GPS coordinates to help establish a mesh network.
So you can use RSSI and Pr and LQI and GPS coordinates as part of your routing strategy, but couple of warnings:
* Links are never exactly symmetrical: don't assume that just because node A can hear node B that B can hear A.
* Topography is not the same as topology (in the RF sense). The distance between nodes is only loosely correlated with their ability to send packets to one another.
Regarding asymmetry, One factor that designers often overlook is that there may be an interferer in the vicinity of node A. In that case, node B can hear A just fine, but A won't be able to hear B as well. Another factor is that receive sensitivity will vary by several db among otherwise identical radios. It's a good idea to characterize both of these factors in your simulations before committing anything to hardware.
When talking about outdoor environments, RSSI/LQI are not the optimal parameters to base the routing decision, since interference and other environmental factors affect seriously the assumed linear relation between distance and RSSI. However, since we are talking about cross-layer routing, one can use RSSI in combination with other parameters to have a better estimate of nodes' connectivity.
Please take a look at my work with measurements of real experiments with WSN outdoors cross-layer routing supporting tracking / monitoring applications.
1. S. Giannoulis, A. Prayati, C. Antonopoulos, G. Papadopoulos, “A.MO.R : An Adaptive Routing Mechanism for WSN Health Applications”, IEEE International Workshop on Wireless Pervasive Healthcare, March 2009
2. Tsenka Stoyanova, Fotis Kerasiotis, Aggeliki Prayati, George Papadopoulos, “Evaluation of Impact Factors on RSS Accuracy for Localization and Tracking Applications in Sensor Networks”, Special issue of Telecommunications Systems Journal, Springer, Volume 42, Issues 3-4, December 2009
3. A. Prayati, “Wireless Technology Applications in Environment and Health: Network Design Challenges”, IEEE Latin America Transactions, Volume 10, Issue 3, April 2012
Thanks to all give suggestions.I want to use a cross layerinformation(PHY,MAC&network) for coperative communication in terms of energy optimization.I forward your 's valuable suggestions.
It depends on your network topology too. You may be communicating through a nearest neighbor and only one node may be connecting to the AP/server....so it can be more complicated that you are envisioning... That being said, signal strength is often used as a rough locator.
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