JPS62101136A - Method of registering position of mobile station - Google Patents

Abstract

PURPOSE:To reduce the retrieval time of a control channel by providing a common control channel in a position registration zone and its adjacent radio zone and providing a time zone respectively. CONSTITUTION:In sending the signal of the same frequency fsd from radio base stations 4d, 4e... in a position registration zone 2d, the radio base station 4f of a radio zone 3f in a position registration zone 2e in contact with the position registration zone 2d sends the signal of the same frequency fsd as that of the stations 4d, 4e... at the same time. Similarly, the signal is sent in the same radio frequency fsd as that used in the radio zone in the position registration area 2e also from a radio zone 3e in contact with the position registration zone 2e. The mobile station always compares the reception level of a radio wave sent at a time band informing the information specific to each base station in the control channel and when the band having the highest reception level is a time zone informing the information specific to each base station adjacent to the position registration zone, the control channel is switched to a radio frequency included in a signal informed at the time zone to apply position registration.

Description

Detailed Description of the Invention (Industrial Application Field) This invention provides a mobile communication system in which a service area consists of a plurality of location registration zones, and a location registration station having a registration memory lJ' manages at least one location registration zone. The present invention relates to a location registration method of a mobile station with respect to a location registration station.

(Prior Art) This type of mobile communication system is currently in practical use as a car phone system. In other words, in the car telephone system, as shown in Fig. 3, a service area 1 has multiple location registration zones 2.
a, 2b, 2c, etc., and each location registration zone, for example 2a, is divided into multiple wireless zones 3a.
, 3b, 3c..., and each wireless zone 3
a, 3 b r 3. Base station 4 for each person
a, 4 b p 4 c... are provided. In the case of a mobile station terminating call, it is difficult to determine the terminating exchange where the mobile station 6 is located using only the selection number (mobile station number) dialed by the calling subscriber. Therefore, one or more wireless zones are grouped together as a location registration zone, and each time a mobile station makes a complete transition between location registration zones, the mobile station detects which location registration zone it is in. Location registration station 5
has been reported. The location registration station stores this information in its registration memory, and uses this information to manage which location registration zone each mobile station is in. When a mobile station receives a call, it registers a location where no mobile station is present. This prevents invalid incoming call processing (such as calling a mobile station) into the zone.

Location registration at a mobile station has conventionally been performed as follows. For example, when the mobile station 6 is moving within the wireless zone 3a, when the reception level of the signal from the base station falls below a predetermined value, the control channel specific to the location registration zone transmitted from each base station sequentially, determines that the mobile station exists in the location registration zone corresponding to the control channel with the highest reception level, and notifies the location registration station of the determination result along with the mobile station number via the control channel. I was registering my location.

(Means for Solving the Problems) As shown in the configuration of FIG. 1, the present invention transmits signals at the same frequency fad from each radio base station 4d, 4e, etc. Location registration zone 2
The wireless base station 4f of the wireless zone 3f in the location registration zone 2e adjacent to d also has the same frequency fs as 4d, 4e...
Send a signal at d. In other words, the same frequency fs is used within the sea 77d including the location registration zone 2d and the adjacent wireless zone.
A signal is sent out at d.

The radio waves of frequency fsd are used during the time period when a common signal is transmitted throughout the location registration zone 2d, during the time period during which unique information is broadcast for each wireless zone within the location registration zone 2d, and during the time period when the radio waves are transmitted in a location registration zone such as the wireless zone 3f. The most important feature is that it has a time slot for broadcasting information specific to the wireless zone adjacent to 2d. Carefully, measures are taken to prevent interference by matching the phases of these radio frequencies and modulation signals.

Furthermore, depending on the state of radio wave propagation, even if the user is moving in a wireless zone other than the wireless zone at the boundary of the location registration zone, the reception level of the control channel will fall below a predetermined value and the location registration zone search will be performed.

(Problems to be Solved by the Invention) In the past, location registration zone searches were conducted in vain even when there was no possibility of immediate movement to an adjacent location registration zone. While the mobile station is searching for a location registration zone, it becomes impossible to receive calls to the mobile station, and it is particularly undesirable as a communication method that calls cannot be received because of the useless location registration zone search.

In addition, in the past, location registration zone searches were performed sequentially for control channels of all location registration zones.
When there are many location registration zones, it takes a long time to search for location registration zones. Conventionally, control channels of location registration zones other than the location registration zone adjacent to the location registration zone in which the mobile station is moving are also searched.
I was searching in vain.

SUMMARY OF THE INVENTION An object of the present invention is to provide a mobile station location registration method that eliminates unnecessary searches for location registration zones and shortens the search time.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of the present invention.
e is a location registration zone, 3d, 3e, and 3f.

3g is a wireless zone, 4d p 4 e -4f t
4 g is a wireless base station, and f3d and f88 are radio frequencies. Further, 7d is a zone including the location registration zone 2d and an adjacent wireless zone, and 7e is a zone including the location registration zone 2e and an adjacent wireless zone.

As shown in the figure, each wireless base station 4d * 4e, . Base station 4f or 4d,
All signals are sent out at the same frequency fsd as 4e... That is, within zone 7d, signals are transmitted at the same frequency fsd. Similarly, wireless zone 3e adjacent to location registration zone 2e
Also, a signal is transmitted at the same radio frequency fBe as used in the radio zone within the location registration area 2e. That is, the base stations 4e and 4f are equipped with two transmitters that transmit waves of frequencies fsd and fs8. More generally, base stations at the boundaries of location zones are equipped with transceivers equal to the number of adjacent location zones.

FIG. 2 shows an example of the configuration of the control channel. Reference numeral 7 denotes a synchronization signal that is commonly and simultaneously transmitted by base stations that transmit signals at the same frequency fsd, and serves as a time reference. 8 is information common within the location registration zone, and is not transmitted by base stations 4f belonging to other location registration zones. 9d, 9e, and 10f are information unique to the wireless base stations 4d, 4e, and 4f, respectively. The synchronization signal 7 and the information 8 common to the location registration zone are the second
As shown in the figure, the signals are transmitted in synchronization between the base stations. Furthermore, the information 9d, 9e, and 10f unique to each base station are sequentially transmitted at staggered transmission times so as not to interfere with each other.

For example, the base station 4d transmits 9d and stops radio waves during times corresponding to 9e and 10f. When the mobile station 6 stays in the zone of frequency fsd and receives all the signals in the format shown in FIG. 2, when the mobile station 6 is near the center of the location registration zone 2d, the signal 1Of in FIG. Unable to receive.

If the mobile station 6 is located near the boundary of the location registration zone 2d, for example, near the boundary between wireless zones 3e and 3f, it will also receive the signal of 10f. In this case, if there is a radio wave in the time slot 10f, it is known that the mobile station 6 is at the boundary of the location registration zone, so it searches for a control channel and performs a location registration operation.

Also, by broadcasting the frequency of the control channel to be searched or information equivalent to it in the information 10f specific to the base station 4f, the mobile station 6 searches for the control channel according to the broadcasted contents and registers the location. perform an action. This makes it possible to shorten control channel search time.

In another embodiment, if the mobile station is 9dr9e in FIG.
By comparing the reception levels of rlOf, a location registration operation is performed according to the broadcast information from the base station with the highest reception level. As a result, when a mobile device located at the boundary of a location registration zone searches for a control channel, the process of switching control channels, sequentially measuring the reception level, and capturing the control channel with the highest reception level has been changed to the frequency fad. Since this can be done simply by receiving radio waves, the control channel search time for location registration can be significantly reduced. Furthermore, since radio waves of the same frequency fsd can be received at all times, the accuracy of measuring the reception level for determining the location registration zone is improved, so the accuracy of determining the location registration zone is improved.

As another example, the time slot for broadcasting information unique to each base station included in zone 7d in FIG. The ratio of time slots for broadcasting information can be reduced.

(Effects of the Invention) As explained above, a common control channel is provided within the location registration zone and the wireless zone adjacent to the location registration zone, and the time period during which unique information is broadcast for each base station within the location registration zone is provided. By setting a time period in which all information unique to each adjacent wireless zone is broadcast, the mobile station can control location registration according to the information broadcast during the time period in which all information unique to each adjacent wireless zone is broadcast. Since channel search is performed, search time can be shortened.

In addition, since the reception level of the signal transmitted from each wireless base station within the location registration zone and the reception level of the signal transmitted from the wireless base station adjacent to the location registration zone can be constantly compared, when searching for a control channel associated with location registration This has the advantage that the comparison of reception levels can be omitted and the accuracy of determining the location registration zone can be improved.

[Brief explanation of drawings]

FIG. 1 is a configuration example showing an embodiment of the present invention, FIG. 2 is a configuration example of a control channel, and FIG. 3 is a configuration diagram of a conventional car telephone system. 2 d p 2 e are location registration zones, 3 d, 3 e. 3f and 3g are wireless zones, 4d+4e+4f. 4g is a wireless base station, fsd, fse is a radio frequency, 7
d is a zone including the location registration zone 2d and an adjacent wireless zone, and 7e is a zone including the location registration zone 2e and an adjacent wireless zone. Patent applicant Nippon Telegraph and Telephone Corporation Patent application agent Patent attorney Megumi Yamamoto - Figure 3

Claims (1)

[Claims] A service area consists of a plurality of location registration zones, each location registration area consists of at least one wireless zone, a base station is installed in each wireless zone, and communication is performed on a channel other than the communication channel. In a mobile communication system that has a control channel dedicated for connection to a location registration zone, a common control channel is created for a base station within a location registration zone and its neighboring base stations, and within that control channel, each base station uses the same frequency. Each base station simultaneously transmits a synchronization signal that serves as a time reference through a control channel, and following the synchronization signal, base stations within the location registration zone transmit a common signal within the location registration zone. Neighboring base stations stop radio waves, each base station transmits unique information at a unique time period after the synchronization signal or the aforementioned common signal, and the mobile station transmits unique information for each base station within the control channel. The reception level of the radio waves being transmitted during the time period for broadcasting information is constantly compared, and if the time period with the highest reception level is the time period for broadcasting unique information for each base station adjacent to the location registration zone, A mobile station location registration method characterized by switching a control channel to a radio frequency included in a signal broadcast during that time period and performing location registration.