Multiplex communications – Fault recovery
Reexamination Certificate
1998-12-15
2002-04-09
Olms, Douglas (Department: 2661)
Multiplex communications
Fault recovery
C370S331000, C370S468000, C455S343200, C455S574000, C375S295000
Reexamination Certificate
active
06370111
ABSTRACT:
TECHNICAL FIELD
This invention relates to a method for controlling mobile equipment in which communication is performed between a base station and a mobile station, and to a mobile equipment per se, and more particularly to a method for controlling mobile equipment in which in the event that a control signal transmitted from the base station cannot be continuously received during asynchronous reception to establish synchronization with the base station, the duration of reception suspending time elapsed until the mobile station resumes asynchronous reception, thereby reducing power consumption, and to a mobile equipment effecting the method.
BACKGROUND ART
In general, as regards this kind of mobile communication system, the base station sends control signals at fixed intervals. When the power is turned on or when synchronization with the base station has been lost, the mobile station (mobile equipment) performs continuous reception (asynchronous reception) of given duration to establish synchronization with the base station.
When a control signal is received from the base station during this asynchronous reception, the mobile station reproduces the transmission clock of the base station from this control signal, thereby to establish the synchronization.
Thereafter, reception is performed only with timing and slots instructed by the control channel; otherwise, no reception is performed or only transmission is performed.
FIG. 9
is shows operations of a mobile station of the above-described conventional mobile communication system in the form of a state transition diagram.
In
FIG. 9
, when the power of the mobile station is turned “ON” (state
701
), this mobile station is not yet in synchronization with the base station. Therefore, it first performs asynchronous reception (state
702
). When reception of a control signal from a base station not depicted in the drawing has been successful, the mobile station reproduces the transmission clock of the base station from the control signal sent over the control channel so as to establish the synchronization. After that, the mobile station performs reception only with a timing and slots instructed by the control signal, and otherwise it becomes in an intermittent reception state for power saving (state
703
).
In this state, when there is an originating call from the mobile station or an incoming call from the base station, the mobile station becomes in a communication state (state
704
). When this call ends, the mobile station returns to the intermittent reception state of state
703
.
Also, in the intermittent reception state of state
703
or the talking state of state
704
, if reception of the control signal from the base station becomes impossible and synchronization is lost, the mobile station returns to the asynchronous reception state for establishing synchronization of state
702
.
Further, in the asynchronous reception state of state
702
, if reception of a control signal from the base station fails, this asynchronous reception is suspended (state
705
). Then, after standing by for a given time (state
706
) the mobile station again returns to state
702
, performs asynchronous reception for establishing synchronization, and repeats this operation until a control signal is successfully received from the base station in state
702
and synchronization is established.
FIG. 10
is a graph showing standby time indicated in state
706
in the conventional mobile station shown in
FIG. 9
, that is to say, the reception suspending time until resuming the asynchronous reception in the event that reception of a control signal sent from the base station has failed by asynchronous reception of the mobile station.
As described above, in the conventional mobile station, as shown in
FIG. 10
, the reception suspending time is a fixed value that is not dependent on the number of consecutive reception failures of a control signal. For example, in the event that the mobile station is outside the communication range of the base station or in a place where radio wave propagation is poor such as in a place between buildings so that reception from the base station for a long time is not possible, asynchronous reception is repeated according to this fixed number, and this creates the problem of useless power consumption.
Also, conventionally, there is known a mobile communication system in which a mobile station is capable of simultaneously establishing synchronization with two different base stations (double waiting). In this system, the mobile station has two synchronization generating units and has two independent control channel timings. Priority level is set in advance for these base stations, and asynchronous reception is first performed with the base station having high priority, and asynchronous reception is next performed with the base station having lower priority.
FIG. 11
depicts a specific example of a receiving operation of a double waiting mobile station capable of simultaneous establishing of synchronization with two different base stations. In this system, the mobile station
901
is designed, for example, to be able to perform double waiting for establishing synchronization with two different base stations, i.e., a public base station
902
located on a utility pole or the like and a household base station
903
located in a household. It is assumed that the household base station
903
is the high priority base station and the public base station
902
is the lower priority base station.
In this system, it is sometimes the case that these two different base stations are not synchronized with each other so that the transmission timing of control signals of the two bases may overlap. Accordingly, in the case that the transmission timing of control signals overlaps, the mobile station performs a receiving operation for the control signal of the base station of higher priority.
FIG. 12
shows a relationship of respective transmission timing of control signals of a higher priority base station A and a lower priority base station B to a reception control signal at the double waiting mobile station.
In
FIG. 12
, if the transmission timing of a control signal of the higher priority base station A and the transmission timing of a control signal of the lower priority base station B overlap, the double waiting mobile station receives a control signal of the higher priority base station A and does not receive a control signal from the lower priority base station B, so the number of failures in receiving the control signal from the lower priority base station B is greater than with the higher priority base station A.
Incidentally, with this conventional double waiting mobile station, where there has been a failure to receive a control signal, the reception suspending time elapsed until asynchronous reception resumes is a fixed value for each of the two, so that even if one of the base stations establishes synchronization, reception of a control signal from the other base station fails repeatedly, creating a problem of increased power consumption.
As stated above, in mobile communication equipment, the reception suspending time of asynchronous receiving operations is a fixed value, and therefore asynchronous reception is repeated by the fixed value even when it is outside of the communication range of the base station for a long time, creating the problem of useless power consumption.
In double waiting mobile stations, where synchronization with one of the base stations has been established while reception of a control signal for the other base station fails repeatedly, the problem of increased power consumption is created.
DISCLOSURE OF THE INVENTION
Accordingly, an object of the present invention is to provide a method for controlling communication of mobile equipment and mobile equipment designed to reduce power consumption caused by the repetition of useless asynchronous reception for establishing synchronization.
To achieve the abovementioned object, the invention of claim
1
is a method for controlling communication of a mobile
Kushige Naohide
Takeda Yasuhide
Hom Shick
Kabushiki Kaisha Toshiba
Olms Douglas
LandOfFree
Method for controlling communication of mobile equipment and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for controlling communication of mobile equipment and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for controlling communication of mobile equipment and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2930694