System and method of determining standby time for mobile stations
View Patent ↗A method and system for determining standby time for a mobile station uses a battery simulator, a base station emulator, a computer to control the test equipment and MSUT for testing a mobile station. The computer includes a module for determining a radio off battery voltage, a module for deriving a battery capacity in dependence upon the radio off battery voltage, a module for measuring battery capacity usage in a predetermined time while the mobile station is in standby mode and a module for determining a standby time for the mobile station in dependence upon the battery capacity and the battery capacity usage, where the predetermined time is less than the standby time.
1. A method of determining a standby time of a mobile station, the method comprising:
measuring a first array of current measurement data points covering a transmit event of the mobile station in a standby mode, the standby mode comprising a transmit mode and a receive mode, the mobile station powered by a battery having an available battery capacity, the measuring being triggered by the transmit event; and
providing the standby time based on a transmit event number per time unit, a transmit capacity per time unit, a receive capacity per time unit, and the available battery capacity.
2. The method according to claim 1 , further comprising:
determining the transmit event number per time unit;
measuring a second array of current measurement data points covering a receive segment of the receive mode;
calculating a mean current value of the receive segment; and
calculating the receive capacity per time unit from the mean current value.
3. The method according to claim 2 , wherein the time unit is one hour.
4. The method according to claim 1 , further comprising determining a transmit duration, wherein the transmit duration is substantially shorter than the receive segment.
5. The method according to claim 4 , wherein the first array includes m measurement data points, each of the measurement data points has a sample interval Δt, and a transmit capacity for the transmit event is calculated by:
C
j
=
(
∑
k
=
0
m
(
i
k
)
)
*
Δ
t
,
and the transmit duration for the transmit event is calculated by:
t j =m*Δt.
6. The method according to claim 1 , wherein the first array of current measurement data points is extracted from a data array collected over a plurality of transmit events.
7. The method as claimed in claim 1 , wherein the transmit capacity per time unit is calculated by:
C
tx_per
_time
_uni
t
=
(
∑
j
=
1
N
(
C
j
)
)
*
(
M
/
N
)
,
wherein N is a total number of transmit events measured; and M is the transmit event number per time unit.
8. The method according to claim 7 , further comprising calculating a transmit time per time unit:
t
tx_per
_time
_uni
t
=
(
∑
j
=
1
N
(
t
j
)
)
*
(
M
/
N
)
.
9. The method according to claim 8 , further comprising calculating a mean receive current value over a plurality of mean current values from a plurality of receive segments.
10. The method according to claim 9 , wherein the mean receive current value is i rx , the receive capacity per time unit is calculated by:
C rx — per — time — unit =( i rx *(1− t tx — per — time — unit )).
11. The method according to claim 10 , wherein a capacity per time unit is determined by:
C per — time — unit =C tx — per — time — unit+ C rx — per — time — unit .
12. The method according to claim 10 , wherein the available battery capacity is C avail the standby time is determined by:
T standby =C avail /C per — time — unit .
13. The method according to claim 1 , wherein the available battery capacity is the difference between a new battery capacity and a cutoff battery capacity at a radio off battery voltage.
14. A test system for determining a standby time of a mobile station, the test system comprising:
a base station emulator provisioning the mobile station in a standby mode, the standby mode comprising a transmit mode and a receive mode, the mobile station powered by a battery having an available battery capacity;
a battery simulator measuring a first array of current measurement data points covering a transmit event of the transmit mode; the battery simulator being triggered by the transmit event; and
a computer providing the standby time based on a transmit event number per time unit, a transmit capacity per time unit, a receive capacity per time unit, and the available battery capacity.
15. The test system according to claim 14 , wherein the computer determines the transmit event number per time unit; and calculates a mean current value of the receive segment, and the receive capacity per time unit from the mean current value, and wherein the battery simulator measures a second array of receive current measurement data points covering a receive segment of the receive mode.
16. The test system according to claim 15 , wherein the first array of current measurement data points is extracted from a data array collected over a plurality of transmit events.
17. The test system according to claim 14 , wherein the computer determines a transmit duration used for the transmit event, and the transmit duration is substantially shorter than the receive segment.
18. The test system according to claim 14 , wherein the first array includes m measurement data points, each of the measurement data points has a sample interval Δt, and a transmit capacity for the transmit event is calculated by:
C
j
=
(
∑
k
=
0
m
(
i
k
)
)
*
Δ
t
,
and the transmit duration for the transmit event is calculated by:
t j =m*Δt.
19. The test system according to claim 14 , wherein the transmit capacity per time unit is calculated by:
C
tx_per
_time
_uni
t
=
(
∑
j
=
1
N
(
C
j
)
)
*
(
M
/
N
)
,
wherein N is a total number of transmit events measured; and M is the transmit event number per time unit.
20. A computer-readable memory storing instructions or statements for use in the execution in a computer of a method of determining a standby time of a mobile station, the method comprising:
measuring a first array of current measurement data points covering a transmit event of the mobile station in a standby mode, the standby mode comprising a transmit mode and a receive mode, the mobile station powered by a battery having an available battery capacity, the measuring being triggered by the transmit event; and
providing the standby time based on a transmit event number per time unit, a transmit capacity per time unit, a receive capacity per time unit, and the available battery capacity.