On Oct 15, 2009, at 12:32 PM, Alexandru Petrescu wrote:
JP Vasseur a écrit :
On Oct 14, 2009, at 9:30 PM, Philip Levis wrote:
On Oct 12, 2009, at 3:09 PM, Maxence Dalmais wrote:
I am saying that when using wireless links, a node should be aware
that his communication could interfere with other communication.
Less powered is the transmission signal, less noise is seen by
neighbours.
It also means that it's more greatly affected by interference from
neighbors: there is no free lunch.
A low powered node will also need less energy to communicate in a
less noisy environnement.
In low-power wireless chipsets, CMOS dominates power costs. E.g., a
chip that draws 60mW transmits at 1mW. Reducing transmit power
typically does not conserve much energy.
I have the same data.
What is the device you commonly talk about?
From just one (leading) manufacturer:
CC1000 (868MHz): @5mW, draws 75mW; @ 0.01mW draws 25mW
CC1100 (868MHz): @10mW, draws 90mW; @0.1mW draws 42mW
CC2420 (2.4GHz): @1mW, draws 50mW: @0.003mW draws 25mW
CC2520 (2.4GHz): @3mW, draws 75mW: @1mW draws 60mW
This 1/6 computing/transmitting fraction seems illogical to me, when
considering other similar chipsets.
Please read some data sheets.
