Subject: Power control

From: Felix Ko <[email-masked]>
Date: Wed, 02 May 2001 16:08:51 +0200

Hi!

I have searched the mailinglist archive but I haven't found
anything:

I am working on my diploma thesis and I am looking
for anything about power control in ad-hoc networks in
order to increase the network's capacity.

I searched the web and the IEEE database, but I found
only two publications about this subject:

- Jeffrey P. Monks "Transmission Power Control for Multiple
Access Wireless Packet Networks"
- Nicholas Bambos, Sunil Kandukuri, "Power Controlled Multiple
Access (PCMA) in Wireless Communication Networks"

From my point of view, research has primarily focused on
energy-conserving MAC/Routing protocols, is this correct?

ANY HELP on this subject is greatly appreciated!!!!!

With kind regards

Felix

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From: vikas kawadia <[email-masked]>
Date: Wed, 2 May 2001 14:10:49 -0500 (CDT)

Hi Felix,
We have a project undergoing for implementing a power control protocol for
adhoc networks. Its called COMPOW.
The idea is illustrated in this paper :
http://black1.csl.uiuc.edu/~prkumar/ps_files/two_protocols_cdc_2001.ps

We are currently working on implementing this idea in latops running linux
and using Cisco aironet 350 as the wireless client adapters.
Thanks.
..Vikas

 > ANY HELP on this subject is greatly appreciated!!!!!

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From: Miguel Sanchez <[email-masked]>
Date: Wed, 02 May 2001 10:35:57 -0700

Hi Felix,

I have been researching this topic for a while.  What I've seen is  that
most of the transmission power control study was done with cellular
systems in mind. Ad-hoc networks do not rely on basestations and
therefore some algorithms are not applicable here.

There are (at least three) different areas of interest for manet:
* Energy-aware routing.
* Power saving mechanisms.
* Network capacity improvement.

When you consider transmission power control you can think of three
different approaches:
* Network-wide power control (all nodes use the same tx power that may
change over time)
* Node-based power control (each node uses a different tx power value
for all transmissions)
* Link-based power control (each node uses a different tx power when
transmitting to each of its neighbors)

The network capacity improvement that could be expected from reducing
the transmission power levels may or may not turn into higher network
capacity. The problem is that by reducing transmission power we are
increasing the average number of hops for each application traffic flow.
More hops mean more packets and more contention, so the posible extra
capacity can be consumed by the higher number of packets. So network
capacity increase may not turn into higher network throughput.

An important issue on transmission power control is that its effect
spans to several layers in the communication architecture:
* Link layer (MAC)
* Network Layer (routing)

On the other hand, some power saving mechanisms are not related to power
control but to swithing on and off the nodes using some clever
synchonization mechanisms. Of course this could be combined with power
control too.

Lastly, when you look at the full picture of an ad-hoc network you see
that using 802.11 technology (or other spread-spectrum radios) the power
used for a node to receive a packet is of the same order of magnitud
than the power used for transmitting a packet. Given that ad-hoc
networks will usually require a node to have more than one neighbor to
guarantee connectivity, then you can expect that most of the power in
the network will be spent by nodes receiving packets. Therefore a node
that is reducing its transmission power will reach a lower number of
neighbors and this may mean an energy saving beyond the energy saved at
the transmitter only.

There are other significant publications on this topic
*Chen, S.C., Bambos, N., Pottie, G.J. \char`\"{}Admission Control
Schemes for
Wireless Communication Networks with Adjustable Transmitter
Powers\char`\"
in IEEE INFOCOM, 1 (1994), pp.21--28.
*Chlamtac, I., Petroli, C. and Redi, J. \char`\"{}Energy-Conserving
Access Protocols
for Identification Networks\char`\"{} IEEE Transactions on Networking,
Vol.
7, No. 1, February 1999.
*Chockalingam, A., Xu W., Zorzi, M. and Milstein, L.B. \char`\"{}Energy
Efficiency
Analysis of a Multichannel Wireless Access Protocol\char`\"{} PIMRC' 98,
Boston,
Sep. 1998.
*Feeney L. {}``An Energy Consumption Model for Performance Analysis of
Routing
Protocols for Mobile Ad Hoc Networks{}'' presentation slides at IETF
\noun{manet}
group meeting, July 14th, 1999.
*Frodigh, M. and Zander, J. \char`\"{}Joint Power Control in Cellular
Radio Systems\char`\"{}
submitted to IEEE Veh. Tech. Transactions.
*Gauthier, P., Harada D. and Stemm, M. {}``Reducing Power Consumption
for the
Next Generation of PDAs: It's in the Network Interface!{}'', URL:
http://http.cs.berkeley.edu/
stemm/cs252/report/main/node1.html
*T.C. Hou and V.O.K. Li \char`\"{}Transmission Range Control in Multihop
Packet
Radio Networks,\char`\"{} in IEEE Transactions on Communications, Vol.
COM-34,
No. 1, pp.38-44, January 1986.
*P. Karn \char`\"{}MACA - A New Channel Access Method for Packet
Radio,\char`\"{}
in ARRL/CRRL Amateur Radio 9th~ Computer Networking Conference, pp.
134-140,
ARRL, 1990.
*A. LaMaire, Krishna and M. Zorzi, ``On the Use of Transmitter Power
Variations
to Increase Throughput in Multiple Access Radio Systems,'' Wireless
Networks,
vol. 4, n. 3, pp. 263-277, June 1998.
*Rulnick, J.M and Bambos, N. \char`\"{}Mobile power management for
wireless communication
networks\char`\"{} Wireless Networks No. 3,, Pages 3-14, Baltzer AG
Science
Publishers 1997.
*Singh, S. and Raghavendra, C.S. \char`\"{}PAMAS- Power Aware
Multi-Access protocol
with Signaling for Ad-hoc Networks\char`\"{} ACM ComputerCommunications
Review,
Vol. 28, No. 3, July 1998.
*Mark Stemm, Paul Gauthier, Daishi Harada, and Randy Katz. {}``Reducing
power
consumption of network interfaces in hand-held devices{}''. In
Proceedings
of the 3rd International Workshop on Mobile Multimedia Communications
(MoMuc-3),
pages 130--142, 1996.
*Wu, S.-L., Tseng Y--C. and Sheu, J.P. \char`\"{}Intelligent Medium
Access for
Mobile Ad Hoc Networks with Busy Tones and Power Control\char`\"{} in
International
Conference on Computer Communications and Networks, 1999.
\bibitem{17}Yener, A., Rose, C. and Yates, R.D. \char`\"{}Optimum Power
Scheduling for CDMA
Access Channels\char`\"{} WINLAB-TR 148, April 1997.

Not exactly dealing with this topic but connected with the fundamental
question is P.R.Kumar and P.Gupta paper on the capacity of wireless
networks.

I hope this helps.

Best regards,

--
Miguel Sanchez

International Computer Science Institute
1947 Center St, suite 636
Berkeley, CA, 94704
USA

voice: (510) 666 2906
email: [email-masked]

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From: vikas kawadia <[email-masked]>
Date: Wed, 2 May 2001 22:51:53 -0500 (CDT)

Hi Felix,
Here is a message from my advisor, Prof. Kumar in response to your query.
thanks.
..vikas

-------------------------------------------------------------------------
From: P. R. Kumar <[email-masked]>

Dear Felix,

We have developed a unified power control and routing solution.
We have also implemented it on our network of laptops.
We are currently doing testing.
A description of our algorithm as well as the architecture
of the implementation can be found in the paper:
V. Kawadia, S. Narayanaswamy, R. Rozovsky, R. S. Sreenivas and P.R. Kumar,
``Protocols for Media Access Control and Power Control in Wireless
Networks.''
This paper can be found at:
http://black.csl.uiuc.edu/~prkumar/postscript_files.html#Wireless Networks

As you rightly suggest, power control does impact on capacity.
A theoretical study of the problem of capacity of wireless networks
is presented in the paper:
Piyush Gupta and P. R. Kumar, ``The Capacity of Wireless Networks.'' IEEE
Transactions on Information Theory, pp. 388-404, vol.~IT-46, no.~2,
March 2000.
(Also downloadable from the same web site).
Also presented in this paper are scaling laws for wireless networks.

Best Regards,
Kumar

--------------
P. R. Kumar
Franklin W. Woeltge Professor of Electrical and Computer Engineering, and
Research Professor, Coordinated Science Lab

Campus Office: Room 163, C&SRL Bldg 	Campus Mail Code: MC-228
Mailing Address: 			Office: 217-333-7476
Univ. of Illinois      			Secretary: 217-333-0282
CSL					Fax: 217-244-1653
1308 West Main St			WWW: http://black.csl.uiuc.edu/~prkumar
Urbana, IL 61801			Email: [email-masked]

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From: Phani Syam Yadavalli <[email-masked]>
Date: Sun, 6 May 2001 13:48:41 -0700 (PDT)

Can some one guide me to articles on MANET
applications in the military?

Also Can you please guide me to articles on CARNET?

Thank you in advance.

Phani Yadavalli

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From: Javier Gomez-Castellanos <[email-masked]>
Date: Tue, 8 May 2001 11:14:43 -0400 (EDT)

Hi Felix,

we are developing a power-aware routing optimization protocol for ad hoc 
networks at Columbia University. Description of the protocol was presented
a the last IETF meeting. 

http://www.comet.columbia.edu/~javierg/paro/draft-gomez-paro-manet-00.txt

cheers
--Javier
-----------------------------------------
COMET Group
Columbia University, New York. 	
http://www.comet.columbia.edu/~javierg