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On the ( In ) Feasibility of Fine Grained Transmit Power Control
| Content Provider | Semantic Scholar |
|---|---|
| Author | Shrivastava, Vivek Agarwal, Dheeraj Mishra, Arunesh Banerjee, Suman Nadeem, Tamer |
| Abstract | Spectral efficiency has been a major focus of research in wireless networks. Recent theoretical work has shown that ideal medium access protocol using optimal power control can improve channel utilization by up to a factor of √ ρ, where ρ is the density of nodes in the region [2]. Although power control mechanisms have been extensively studied in theory and simulations, their practical evaluation has not been done throughly. Most of the power control mechanisms proposed in literature [4, 6, 5] assume a very fine grained handle on transmit power of wireless nodes and exercise this control to provide sophisticated mechanisms of sharing wireless medium among competing flows. In this work, we investigate the (in)feasibility of fine-grained power control in wireless networks using real testbed experiments. We perform detailed experiments to highlight fundamental issues with power control mechanisms , that cannot be captured by using a network simulator. Our experiments indicate that fine grained power control may not be a viable solution for indoor wireless networks and most power control mechanisms may need to be adapted to be suitable for practical settings. Implementation of fine grained power control mechanisms has been limited by the hardware support in current 802.11 wireless cards which have only limited number of discrete power levels. As shown in [1] , most of the wireless cards support only 4 to 5 power levels at the hardware, which is in stark contrast to the fine grained power control assumed by most power control schemes. This being a limitation of current state of the art hardware, can be resolved in future wireless cards that may support fine grained power levels. However we argue that there are fundamental limitations to power control mechanism in wireless networks, which limits the number of feasible power levels that can be used in such mechanisms. Multipath and fading effects of the wireless medium are well studied [3]. Due to such multipath and fading effects, received signal strength (RSS) can vary significantly in an indoor environment , even in the absence of explicit interference from other flows. A difference of an order of wavelength in the paths taken by the wireless signals from the transmitter, can lead to the two signals being out of phase [3], resulting in variations in the signal strength at the receiver. In addition to multipath and fading effects, external interference from other flows in the network can also contribute … |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://pages.cs.wisc.edu/~viveks/power-abstract.pdf |
| Alternate Webpage(s) | http://www.cs.wisc.edu/~viveks/power-abstract.pdf |
| Alternate Webpage(s) | http://www.cs.odu.edu/~nadeem/papers/power_mobicom_page.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
