Modem and network search method of modem
View Patent ↗The present application provides a modem and a network search method of the modem. The method includes: sampling a signal level value and a signal quality value of a serving cell; obtaining a signal power condition according to the signal level value, and obtaining a signal stability condition according to the signal quality value; and when both the signal power condition and the signal stability condition are higher than set conditions, determining a network search state as an off state. In embodiments of the present application, power consumption and a workload may be reduced.
1. A network search method performed by a modem, comprising:
periodically sampling signals of a serving cell so as to obtain at least two signal level values and at least two signal quality values of the serving cell;
determining a signal power condition according to the signal level values, and determining a signal stability condition according to the signal quality values;
when both the signal power condition and the signal stability condition are better than their respective preset condition thresholds, setting a network search state of the modem as an off state, wherein the network search state of the modem includes an off state and a start state, when the modem is in the off state, a network search operation is not performed by the modem;
determining a signal level change condition according to the signal level values;
determining, according to the signal level change condition, whether signal strength of the serving cell decreases monotonically; and
when it is determined that the signal strength of the serving cell decreases monotonically, setting the network search state of the modem as the start state, wherein when the modem is in the start state, the network search operation is performed for reselecting another serving cell.
2. The method according to claim 1 , wherein determining a signal power condition according to the signal level values comprises:
calculating the signal power condition according to the following formula:
R
avg
=
∑
n
=
1
N
rx
n
N
wherein R avg is a value of the signal power condition, rx n is the n th signal level value, n=1, . . . , N, and N is the number of signal level values.
3. The method according to claim 1 , wherein determining the signal stability condition according to the signal quality values comprises:
calculating the signal stability condition according to the following formula:
Q
var
=
∑
n
=
1
N
q
n
-
Q
avg
N
wherein
Q
avg
=
∑
n
=
1
N
q
n
N
,
Q var is a value of the signal stability condition, q n is the n th signal quality value, n=1, . . . , N, and N is the number of signal quality values.
4. The method according to claim 1 , wherein the signal level change condition is calculated according to the following formula:
Rx
n
′
=
rx
n
+
1
-
rx
n
Δ
t
wherein Rx′ n is the n th value of the signal level change condition, rx n and rx n+1 are n th and (n+1) th signal level values obtained through the periodic sampling, and Δt is a sampling time interval.
5. The method according to claim 4 , wherein the determining, according to the signal level change condition, whether the signal strength of the serving cell decreases monotonically comprises:
if the calculated value of the signal level change condition is repeatedly smaller than 0 for a number greater than a set threshold, determining that the signal strength of the serving cell decreases monotonically.
6. A modem capable of being served by a cellular communication network, comprising:
a signal sampling unit, configured to periodically sample signals of a serving cell periodically so as to obtain at least two signal level values and at least two signal quality values of the serving cell;
a determining unit, configured to determine a signal power condition according to the signal level values, and a signal stability condition according to the signal quality values; and
a state setting unit, configured to, when both the signal power condition and the signal stability condition are better than their respective preset condition thresholds, set a network search state of the modem as an off state, wherein the network search state of the modem includes an off state and a start state, when the modem is in the off state, a network search operation is not performed by the modem,
wherein the determining unit is further configured to determine a signal level change condition according to the signal level values; and, according to the signal level change condition, determine whether signal strength of the serving cell decreases monotonically; and
the state setting unit is further configured to, when it is determined that the signal strength of the serving cell decreases monotonically, set the network search state of the modem as the start state, wherein when the modem is in the start state, the network search operation is performed by the modem for reselecting another serving cell.
7. The modem according to claim 6 , wherein the determining unit is configured to:
determine the signal power condition according to the following formula:
R
avg
=
∑
n
=
1
N
rx
n
N
wherein R avg is a value of the signal power condition, rx n is the n th signal level value, n=1, . . . , N, and N is the number of signal level values.
8. The modem according to claim 6 , wherein the determining unit is configured to:
determine the signal stability condition according to the following formula:
Q
var
=
∑
n
=
1
N
q
n
-
Q
avg
N
wherein
Q
avg
=
∑
n
=
1
N
q
n
N
,
Q var is a value of the signal stability condition, q n is the n th signal quality value, n=1, . . . , N, and N is the number of signal quality values.
9. The modem according to claim 6 , wherein the determining unit is configured to:
calculate the signal level change condition according to the following formula:
Rx
n
′
=
rx
n
+
1
-
rx
n
Δ
t
wherein Rx′ n is the n th value of the signal level change condition, rx n and rx n+1 are n th and (n+1) th signal level values obtained through the periodic sampling, and Δt is a sampling time interval.
10. The modem according to claim 9 , wherein the determining unit is configured to, when the calculated value of the signal level change condition is repeatedly smaller than 0 for a number greater than a set threshold, determine that the signal strength of the serving cell decreases monotonically.