cnet's Application Programming Interface
- NAME
- CNET_set_wlaninfo - set the transmission and reception characteristics of a WLAN link
- SYNOPSIS
#include <cnet.h>
typedef struct {
double frequency_GHz;
double tx_power_dBm;
double tx_cable_loss_dBm;
double tx_antenna_gain_dBi;
double rx_antenna_gain_dBi;
double rx_cable_loss_dBm;
double rx_sensitivity_dBm;
double rx_signal_to_noise_dBm;
double sleep_current_mA;
double idle_current_mA;
double tx_current_mA;
double rx_current_mA;
} WLANINFO;
int CNET_set_wlaninfo(int link, WLANINFO *wlaninfo);
- DESCRIPTION
-
CNET_set_wlaninfo sets the transmission and reception
characteristics of a link of type LT_WLAN.
CNET_set_wlaninfo assumes that its second argument is a pointer
to a WLANINFO structure, whose definition is provided
in <cnet.h> .
The fields defining the transmitting "half" of each LT_WLAN link
are prefixed by tx_,
and the fields defining the receiving "half"
are prefixed by rx_ .
The units of transmission and reception power are decibel-meters (dBm),
with values near 15.0dBm being typical for a PCMCIA-type wireless card.
An equivalent power measured in Watts (typically 30mW for a PCMCIA card)
is related to power measured in decibel-meters using the formula:
dBm = 10*log10(Watts / 0.001)
A WLAN link may be in one of four states.
In sleep state, a link cannot transmit nor receive signals,
and consumes very little energy.
From idle state, the link may be asked to temporarily
enter transmit state to transmit a signal,
and will temporarily enter receive state to receive each signal
within range.
Idle, transmit, and receive states all consume considerably more energy
than idle state.
The battery energy consumed by these four states depends on how long the link
is in each state.
- NOTE
- No sanity checks are performed on the value of each field.
- RETURN VALUE
-
-
The value 0 is returned on success.
On failure, the value -1 is returned,
and the global variable cnet_errno is set to one of the
following values to describe the error:
- ER_BADLINK
- The value of link is not a valid link number.
- ER_NOTSUPPORTED
- The indicated link is not of type LT_WLAN.
- SEE ALSO
-
CNET_get_wlaninfo.
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cnet v3.3.4, written by Chris.McDonald@uwa.edu.au
Last modified: Tue Mar 1 7:43AM 2016