WWAN_SIGNAL_STATE structure (wwan.h)
The WWAN_SIGNAL_STATE structure represents the signal state of the MB device.
Syntax
typedef struct _WWAN_SIGNAL_STATE {
ULONG Rssi;
ULONG ErrorRate;
ULONG RssiInterval;
ULONG RssiThreshold;
WWAN_LIST_HEADER SignalStateListHeader;
} WWAN_SIGNAL_STATE, *PWWAN_SIGNAL_STATE;
Members
Rssi
A value that represents the strength of the wireless signal. Miniport drivers that report their WWAN_CELLULAR_CLASS to be WwanCellularClassGSM or WwanCellularClassCDMA must report Rssi in decibels above the device's sensitivity noise floor.
| Signal Strength (in dBm) | Coded Value (Minimum=0, Maximum=31) |
|---|---|
| -113 or less | 0 |
| -111 | 1 |
| -109 | 2 |
| ... | ... |
| -51 or greater | 31 |
| Unknown or undetectable | WWAN_RSSI_UNKNOWN |
CDMA-based devices must report signal strength based on compensated RSSI (accounts for noise) and not based on raw RSSI.
ErrorRate
A coded value that represents a percentage range of error rates. For GSM-based devices, use the values from the Channel bit error rate column in the following table. For CDMA-based devices, use the values from the Frame error rate column. For both cases, use WWAN_ERROR_RATE_UNKNOWN to denote an unknown error rate.
| Channel bit error rate (in %) | Frame error rate (in %) | Coded value (Min=0, Max=7) |
|---|---|---|
| < 0.2 | < 0.01 | 0 |
| 0.2-0.4 | 0.01-0.1 | 1 |
| 0.4-0.8 | 0.1-0.5 | 2 |
| 0.8-1.6 | 0.5-1.0 | 3 |
| - 3.2 | 1.0 - -2.0 | 4 |
| - 6.4 | 2.0-4.0 | 5 |
| 6.4-12.8 | 4.0-8.0 | 6 |
| > 12.8 | > 8.0 | 7 |
| Unknown or undetectable | WWAN_ERROR_RATE_UNKNOWN | |
RssiInterval
The current interval, in seconds, at which the miniport driver has been set to (or the default interval, if one has not been set), that the miniport driver will provide updates about the signal state. Specify WWAN_RSSI_DISABLE to indicate that the miniport driver does not implement interval-based reporting. Miniport drivers should populate this member with the interval in response to an earlier request from the MB Service for WWAN_RSSI_DEFAULT.
RssiThreshold
The current threshold, in threshold units, at which the miniport driver has been set to (or the default interval, if one has not been set), that the miniport driver will provide updates about the signal state. Specify WWAN_RSSI_DISABLE to indicate that the miniport driver does not implement threshold-based reporting. Miniport drivers should populate this member with the threshold units in response to an earlier request from the MB Service for WWAN_RSSI_DEFAULT.
SignalStateListHeader
A formatted WWAN_LIST_HEADER structure that represents a list of signal state extensions per data class and the number of data classes. The miniport driver must return a list of all supported data classes.
This member points to a list of WWAN_SIGNAL_STATE_EXT structures that use the WWAN_LIST_HEADER structure. The rest of the members of the WWAN_SIGNAL_STATE_EX structures are filled based on the highest available data class.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Available in Windows 7 and later versions of Windows. |
| Header | wwan.h (include Wwan.h) |