Subject: [manet] radio transmission levels

From: [email-masked]
Date: Thu, 10 Oct 2002 10:50:09 +0800

Hello everbody:
    In some papers related to power controlled MAC protocols in MANET, the power levels used are always different by different author.
    I want to know are there any real NICs with power control property which can be use in MANET? How many transmit power levels can be used and how much is the difference between maximum & minimum transmit power.
    Regards.
______________________________________

===================================================================
_______________________________________________
manet mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/manet

---

From: Guevara Noubir <[email-masked]>
Date: Thu, 10 Oct 2002 13:39:08 -0400 (EDT)

Hi,

Cisco Aironet 350 cards have 6 power levels
(http://www.cisco.com/warp/public/44/jump/wireless.shtml).

IEEE802.11 standard specifices 7 possible power levels.

Guevara

---

From: Guevara Noubir <[email-masked]>
Date: Thu, 10 Oct 2002 13:39:08 -0400 (EDT)

Hi,

Guevara

---

From: David Young <[email-masked]>
Date: Thu, 10 Oct 2002 13:37:56 -0500

The Cisco Aironet 350 cards are adjustable to 1, 5, 20, 30, 50, and 100
mW. I have heard that you have to do a reset between adjustments, however.

You can write a register on the baseband processor of the Prism 2.x
chipsets to adjust the power setting "goal." You read another register
to find out the actual level. I cannot find the units for the registers
in any document, however, the firmware may store some hints produced
when the manufacturer calibrated the radio. The firmware implements
an automatic TX level control, I think; you will have to disable that
before you make your own adjustments. I do not know the minimum TX level
for any Prism radio, but there are 100, 180, and 200mW Prism radios.

There may be a prohibitive time-cost to adjusting TX levels, if you want
to do it on a per-packet basis.  I do not know the expense of adjusting
power on the Prism 2.x chipsets, but it could be high. On Cisco's 350,
resets are probably very expensive.

If you limit yourself to queueing just one packet at a time on the NIC,
and if you accept more interrupts, then you can trade performance to
ensure per-packet TX power adjustments.

I think that it is desirable to be "sloppy" or "lazy" with TX power
adjustments, myself: guarantee that each packet is sent at LEAST as
"loudly" as its TX power label indicates. When you cannot afford a power
adjustment---because, for example, you would have to wait for the TX
queue to empty---send some packets more loudly than indicated.

Dave

-- 
David Young             OJC Technologies
[email-masked]      Engineering from the Right Brain
                        Urbana, IL * (217) 278-3933
_______________________________________________
manet mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/manet

---

From: David Young <[email-masked]>
Date: Thu, 10 Oct 2002 13:37:56 -0500

Dave

---

From: "Kaustubh S. Phanse" <[email-masked]>
Date: Thu, 10 Oct 2002 16:35:46 -0400

Linksys IEEE 802.11b cards (based on Intersil Prism chipset) also
support adjustable transmit power...I think it ranges from -44dBm to
20dBm.

regards
Kaustubh
-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
David Young
Sent: Thursday, October 10, 2002 2:38 PM
To: [email-masked]
Subject: Re: [manet] radio transmission levels

The Cisco Aironet 350 cards are adjustable to 1, 5, 20, 30, 50, and 100
mW. I have heard that you have to do a reset between adjustments,
however.

You can write a register on the baseband processor of the Prism 2.x
chipsets to adjust the power setting "goal." You read another register
to find out the actual level. I cannot find the units for the registers
in any document, however, the firmware may store some hints produced
when the manufacturer calibrated the radio. The firmware implements an
automatic TX level control, I think; you will have to disable that
before you make your own adjustments. I do not know the minimum TX level
for any Prism radio, but there are 100, 180, and 200mW Prism radios.

Dave

On Thu, Oct 10, 2002 at 10:50:09AM +0800, [email-masked] wrote:
> Hello everbody:
>     In some papers related to power controlled MAC protocols in MANET,
the power levels used are always different by different author.
>     I want to know are there any real NICs with power control property
which can be use in MANET? How many transmit power levels can be used
and how much is the difference between maximum & minimum transmit power.

---

From: "Kaustubh S. Phanse" <[email-masked]>
Date: Thu, 10 Oct 2002 16:35:46 -0400

regards
Kaustubh
-----Original Message-----

Dave