AU746292B2

AU746292B2 - Method of performing home zone service in mobile radio communication system

Info

Publication number: AU746292B2
Application number: AU66612/00A
Authority: AU
Inventors: Kyu-Sik Kim
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 1999-10-19
Filing date: 2000-10-19
Publication date: 2002-04-18
Anticipated expiration: 2020-10-19
Also published as: KR100617849B1; KR20010037735A; AU6661200A

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT

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V Applicant(s): SAMSUNG ELECTRONICS CO., LTD.

Invention Title: METHOD OF PERFORMING HOME ZONE SERVICE IN MOBILE RADIO COMMUNICATION SYSTEM The following statement is a full description of this invention, including the best method of performing it known to me/us: -1 METHOD OF PERFORMING HOME ZONE SERVICE IN MOBILE RADIO COMMUNICATION SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention 5 The present invention relates to a home zone service method in a mobile radio communication system, and more particularly to a method of updating home zone information for each mobile station.

2. Description of the Related Art At present, in order to secure more subscribers, the service providers of the mobile radio communication systems are developing various services such as different billing systems per time and location. Recently, a home zone service have been ooooo developed. According to the home zone service, if a subscriber designates a specified address desired by him/her (for example, his/her house or place of employment), a less expensive fee corresponding to a wired telephone call is charged with respect to a telephone call made within a corresponding distance centering around the address (Hereinafter, the region within the corresponding distance centering around the location designated by the respective subscriber is referred to as a "home zone").

In order to effect such a home zone service, a corresponding home zone is first assigned to the respective subscriber. The information on the corresponding home zone assigned at the time when the subscriber subscribes to the home zone service may be determined by a latitude, longitude, base station division information, round trip delay (RTD) information created during a cell planning process at the time point when the initial mobile radio communication network is designed. Here, the RTD information represents the time period during which a radio wave radiated from a base station reaches a mobile terminal and then returns to the base station. Generally, it can be considered as the distance between the base station and the mobile terminal. Also, if it is assumed that the area where the mobile radio communication service is performed is divided into a plurality of checks, the information created during the cell planning process may be the latitude, longitude, base station division information, sector 10 division information, minimum RTD value, maximum RTD value, etc. (hereinafter referred to as zone data) for each check.

However, since the information created during the cell planning process such as the zone data is calculated as a result of simulation, its accuracy is not high. Also, since the actual calling location of the respective subscriber is not estimated due to the characteristics of the mobile radio communication environment, the subscriber's dissatisfaction is expected when the home zone of the respective subscriber is determined and the home zone service is provided to the respective subscriber in accordance with the above information.

For instance, though a specified subscriber expects that a fee corresponding to a wired telephone call is charged for his/her telephone call if he/she makes the telephone call around his/her house or office, a fee corresponding to a radio telephone call may be actually charged. Also, even in the event that a plurality of subscribers designate the same home zone, the locations where the respective subscribers actually make telephone calls may be different from one another, and thus the information on the home zone created during the cell planning process may not be equally applied to all 3 the subscribers. In other words, the information on the home zone designated by the respective subscriber should be updated according to the location where the subscriber actually makes a telephone call. It is also necessary to update the home zone information of each mobile stations with respect to not only general telephone calls subject to billing, but also special telephone calls using specified dial keys such as 6, Here, the special telephone call service means a non-billing telephone call service used for the subscriber directly to update his/her home zone without payment of the telephone call fee.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an alternative method of performing a :home zone service in a mobile radio communication system.

According to the present invention, there is 20 provided a method of performing a home zone service in a mobile radio communication system comprising a first step of storing for each mobile station information on received home zone update requesting calls and general calls in a home zone, a second step of updating particular regions of the home zone allocated for each mobile station by analyzing stored call information, and a third step of storing in a home-location register the updated particular regions of the home zone for each mobile station.

BRIEF DESCRIPTION OF THE DRAWINGS The above objects and advantages of the present invention will become more apparent by describing in detail preferred embodiment thereof with reference to the attached drawings in which: FIG. 1 is a block diagram illustrating the H:\amyo\Keep\Specifications\66612-00.doc 15/02/02 i. -4 construction for performing a home zone service in a mobile radio communication system according to an embodiment of the present invention; FIG. 2 is a flowchart illustrating a method of updating a home zone for each H:\amyo\Keep\Specificatjons\6661200doc 15/02/02 mobile station in a mobile radio communication system according to an embodiment of the present invention; and FIG. 3 is a view illustrating the state that particular regions of a new home zone are inserted in a home zone list managed for each mobile station according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT oo eo.

The preferred embodiment of the present invention will now be explained in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present .o invention rather unclear.

ooo.

The present invention discloses a method of updating information on a home zone designated for each mobile station according to a location where a subscriber 15 actually makes a telephone call in a mobile radio communication system. Also, the present invention discloses a method of updating a home zone for each subscriber by a special telephone call using a specified dial keys (hereinafter referred to as 'home zone update requesting call') as well as a certification process such as a general call subject to billing or location registration. The necessity of the home zone update for each mobile station through the home zone update requesting call will be described hereinafter.

FIG. 1 is a block diagram illustrating the construction for performing a home zone service in a mobile radio communication system according to an embodiment of ~I -6the present invention.

The construction of the mobile radio communication system can be divided into a base station and a mobile station. The base station may be divided into a base transmission system (BTS) 120 for performing a radio connection between mobile stations and a base station controller (BSC) 130 for controlling a plurality of base transmission systems and performing a call mobility management related to a call process. The mobile radio communication system also includes a mobile switching center 140 taking charge of transmitting/receiving path of data and control signals to oO..

another communication network such as a public switched telephone network 180.

Also, in the mobile radio communication system, a visitor location register (VLR) 160 is a register provided corresponding to the mobile switching center 140 in a one-to-one manner, and temporarily registers and stores therein subscriber information .of a mobile radio terminal. The VLR 160 may be constructed as a processor packaged in a mobile radio communication switching system, and in this case, it takes initiative in searching a subscriber number or requesting a location registration of a corresponding mobile station to a home location register (HLR) 170.

Meanwhile, an example of a general certification process for the mobile station will now be explained with reference to FIG. 1. When the mobile station 110 performs a location registration or a call termination/origination, the mobile switching center 140 inputs mobile station discrimination information such as a national switching number (NSN) of the mobile station 110, a mobile identification number (MIN), etc., and originating base station discrimination information such as a network identification (NID), a BTS ID, a sector ID, etc., through the BTS 120 and the BSC 130. The mobile switching center 140 searches a corresponding subscriber information 4. -7database such as the subscriber number currently registered in the VLR 160 using the above information as a search key. If the mobile station 110 is currently registered in the VLR 160 as a result of the search, the mobile switching center 140 confirms the certification of the mobile station 110, while if not, the mobile switching center 140 temporarily stores in the VLR 160 the corresponding NSN and so on, and makes inquiries about the mobile station 110 to the HLR 170. During this process, the mobile switching center 140 can provide the service in the same manner as the case that the certification of the mobile station 110 is performed.

•o If the certification of the mobile station 110 is requested by the mobile 10 switching center 140, the HLR 170 searches the provided subscriber database. Then, if the inherent number of the mobile station 110 is registered, the HLR 170 informs it to the mobile switching center 140. Also, the HLR 170 transmits the stored corresponding subscriber information, (for example, telephone number, ESN, information on the corresponding service such as the home zone service according to S 15 the present invention, etc.), to the mobile switching center 140. Accordingly, the mobile switching center 140 stores in the VLR 160 the inherent number of the mobile station 110 and data of the corresponding subscriber information, and then performs the certification of the mobile station 110 by searching the VLR 160.

When the general certification process as described above is performed, the mobile switching center 140 according to the embodiment of the present invention inputs the mobile station discrimination information generated by the mobile station 110 and the originating base station discrimination information through the BTS 120 and the BSC 130. Also, the mobile switching center 140 inputs RTD information provided for the tracking of the location of the mobile station 110 through the BTS 120 and the BSC 130. The process of creating the RTD information is not directly related :Zri7E 8to the present invention, and the explanation thereof will be omitted.. The mobile station discrimination information, the originating base station discrimination information, and the RTD information can be provided from the construction of the general mobile radio communication system, and are hereinafter referred to as "call information". The mobile switching center 140 outputs the call information of the mobile station 110 to a home zone updating device 150 to update the home zone for each mobile station.

The home zone updating device 150 manages the home zone list for the 10 respective mobile station. Specifically, the home zone updating device 150 stores the call information for the respective mobile station, and updates the home zone list by analyzing the information if the number of the call information for each mobile station exceeds a predetermined number, or a predetermined time elapses. The home zone information list may be composed of a plurality of particular region inform-ation. The home zone updating device 150 stores in the HLR 170 the home zone information list 15 for the respective mobile station through the mobile switching center 140.

If the mobile station 110 requests a telephone call, the mobile switching center 140 compares the information for the call with the home zone information list stored in the HLR 170. If the call corresponds to the call request in the home zone, the mobile switching center 140 performs the home zone service.

Meanwhile, Table 1 as shown below represents a home zone list for each mobile station according. to the embodiment of the present invention.

[Table 1] Home zone information list for .each subscriber NSN National Switching Number Hz unm(1) Nid #1 Network Identifier Bts #1 (N=

I

)BTS_ID(0) Sector #1 (N=)SECTOR_ID(123) Rtdmin #1 (N=1)RTDMIN(2) a a.

a a Rtd max #1 (N=1)RTDMAX Nid #8 (N=8)BTS_ID Bts #8 (N=8)BTS_ID Hz_unm(l) Sector #8 (N=8)SECTOR_ID Rtdmin #8 (N=8)RTD_MIN Rtdmax #8 (N=8)RTD_MAX As shown in Table 1, the home zone list of the respective mobile according to the embodiment of the present invention has 8 particular information for each subscriber.

station region Table 2 as shown below is a table for storing and analyzing call information to update the home zone list.for each mobile station according to the embodiment of the present invention.

[Table 2] Callinfo table: Table for analyzing call record information per mobile station Nsn Calling Subscriber Number Nid Network Identification Btsid BTS ID Sector id SECTORID Rtd RTD Value that call Created Number of terminating /originating calls Cnt location registration calls Priority number of home zone Hz num particular regions

S.

a S S a a a In Table 2, the term "cnt" means the accumulated value of the number of received calls having the same values ofNSN, NID, BTS_ID, SECTOR_ID, and RTD.

Here, the call may be the originating/terminating call, the location registration call, or the home zone update request call. The term "hz_num" may be the priority number of the particular regions shown in Table 1.

Table 3 as shown below represents the process of storing call information for each mobile station according to the embodiment of the present invention.

-11- [Table 3] NSN NID BTS ID SECTOR ID RTD 1234567 0 123 2 42 1234567 0 123 2 41 1234567 0 123 2 41 1234567 0 123 2 1234567 0 123 2 42 1234567 0 125 1 1234567 0 123 2 42 1234567 0 125 1 1234567 0 123 2 42 2345678 0 125 1 43

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Table 4 as shown below is a table for mobile station created by Table 3 according invention.

analyzing call information for each to the embodiment of the present [Table 4] Chip_num table Range of home zone matching with characteristics of respective BTS is determined.

Bts id BTS ID Chip_no update reduced to RTD_MIN Chipno2 update increased to RTD MAX I 12- Table 5 as shown below is a table for storing the predetermined maximum RTD value and minimum RTD value for the home zone range matching with the characteristics of the respective BTS in case of updating the corresponding maximum RTD value and minimum RTD value of the home zone list by analyzing the call information for each mobile station according to the embodiment of the present invention.

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0 [Table NSN NID BTS ID SECTOR ID. RTD CNT HZ NUM 1234567 0 123 2 42 4 1 1234567 0 123 2 41 2 1 1234567 0 123 2 40 1 1 1234567 0 125 1 45 2 9 2345678 0 125 1 43 1 2 FIG. 2 is a flowchart illustrating the home zone updating method for each mobile station in a mobile radio communication system according to the embodiment of the present invention.

Referring to FIG. 2, the home zone updating method may be divided into a process for the general calls generated inside the home zone, a process for the general calls generated outside the home zone, and a process for the home zone update requesting calls. First, the general call process will be explained with reference to FIG.

1, and Table 1 to Table If a call is received at step 210, the mobile switching center 140 checks whether tvx:rtwz2Itytz:- 13 the received call is the home zone update requesting call at step 220. If the received call is not the home zone update requesting call at step 220, the mobile switching center 140 checks whether the received call is the call generated inside the home zone by searching the HLR 170 at step 230. If the received call is the call generated outside the home zone as a result of checking, the mobile switching center 140 performs the radio telephone call service at step 240. The radio telephone call service is identical to the general call service of the mobile switching center 140. Meanwhile, if the received call is the call generated inside the home zone at step 230, the mobile switching-1 center 140 performs the wired telephone call service at step 250. The wired telephone call 10 service is performed as the general telephone call service, but the fee corresponding to the wired telephone call is charged.

The mobile switching center 140 transmits the information of the received call to the home zone updating device 150 at step 260. Specifically, if the received call is the general call, it can be recognized that the mobile switching center 140 transmits only the call information generated inside the home zone to the home zone updating V. device 150. This is because the home zone should not be updated by the information of the call that does not relate to the home zone, the call that is possibly generated in a place far apart from the place designated by the subscriber. Also, if the mobile switching center 140 transmits to the home zone updating device the information of all the calls received form the mobile terminal 110, a lot of data will be unnecessarily transmitted, and this is not efficient and economical.

The home zone updating device 150 stores and analyzes the call information for each mobile station at step 270. At this time, the home zone updating device 150 can use the table for storing and analyzing the call information as shown in Table 2.

Thereafter, the home zone updating device 150 updates the home zone list managed by A 14each mobile station according to a result of analysis at step 280. At this time, the list as shown in Table 1 may be used as the home zone list. At step 290, the home zone updating device 150 stores the new updated home zone list for each mobile station in the HLR 170 through the mobile switching center 140. Accordingly, if a new call is receiyed thereafter, the mobile switching center 140 can determine whether to perform the home zone service with respect to the received call according to the updated home zone list for each mobile station. Specifically, during the general call process, the method according to the embodiment of the present invention updates the home zone list for each mobile station according to the received call information, and thus it can .0.0 ooo:: 10 be recognized that the home zone is updated according to the location where the subscriber actually makes a telephone call.

0 0 Meanwhile, during the general call process, if the received call is the general call, it can be recognized that the mobile switching center 140 transmits only the call 0000 information generated inside the home zone to the home zone updating device 150 (step 260). According to the above general call process, updating is possible only for the particular regions allocated by the cell planning when the respective subscriber initially subscribes to the home zone service. According to the characteristics of the mobile radio communication environment, however, management of the home zone list should be performed with respect to not only the allocated particular regions, but also other adjacent particular regions according to the actual calling location of the user.

Hereinafter, the home zone update requesting call process according to the embodiment of the present invention will be explained with reference to FIG. 2.

If a call is received at step 210, the mobile switching center 140 checks whether the received call is the home zone update requesting call at step 220. The home zone update requesting call does not relate to the general call or location registration call, but is a call for updating the home zone particularly managed for each mobile station.

The subscriber can directly update the particular home zone information by performing the home zone update requesting call in a desired location. Also, according to the subscriber's request, the home zone service provider can perform the home zone update requesting call in a location desired by the subscriber.

If the received call is the home zone update request call, the mobile switching center 140 does not perform steps 230 to 250, but performs the operation of step 260.

10 Specifically, the mobile switching center 140 transmits the information of the home zone update requesting call to the -home zone updating device 150. Thus, the information of the home zone update requesting call may be the information inside or outside the home zone.

That is, the subscriber can make the special telephone call inside the home zone, .15 (currently determined and managed), or outside the home zone, (at this time, around 9.9.99 the home zone).

At step 270, the home zone updating device 150 stores and analyzes the call information for each mobilestation. At this time, the call information is composed of the information of the general call inside the home zone for each mobile station and the information of the home zone update requesting call.

At step 280, the home zone updating device 150 updates the home zone information for each mobile station as a result of analysis. At this time, the home zone updating device 150 analyzes the information of the home zone update requesting -16call generated outside the home zone, and if the analyzed information satisfies a specified condition, the home zone updating device 150 can insert at least one new corresponding particular region into the home zone list. Then, the home zone updating device 150 can replace at least one particular region pre-allocated in the home zone list with new other particular regions. At step 290, the home zone updating device 150 stores the updated home zone list for each mobile station in the HLR 170 through the mobile switching center 140.

Meanwhile, it may be considered that the subscriber makes a home zone update requesting call in a location having no relation to the home zone designated by 10 himself/herself by mistake or on purpose. This is called a bad call. The embodiment of FIG. 2 omits such a call process. In this case, the mobile switching center 140 compares the information of the received home zone update requesting call with all the zone data, (for example, NID information, BTS discrimination information, sector discrimination information, etc.), for the corresponding home zone during the cell oeeo° planning, and if the information of the received home zone update requesting call is not included in the zone data, the mobile switching center 140 performs an error .oeo•i Sprocessing.

In the embodiment of FIG. 2, the home zone update requesting call process is explained only for the telephone call, but it can be performed with respect to all the calls generated from the mobile station 110 during the general certification process such as the location tracking.

FIG. 3 is a view illustrating the state that particular regions of a new home zone are inserted in a home zone list managed for each mobile station according to an embodiment of the present invention.

17- Referring to FIG. 3, reference numerals '3 10' to '330' mean particular regions which the home zone updating device 150 currently manages for the mob ile station 1 10. As illustrated, the home zone updating device 150 analyzes the information of the home zone update requesting call generated outside the home zone,'and inserts the corresponding particular region 340, which satisfies a specified condition, in the home zone l ist managed for the mobile station 110. Also, in the embodiment of FIG. 3, the particular region 330 is deleted from the home zone list. The reference numeral '350' indicates the location where the subscriber performs an actual telephone call under the satisfactory condition.

Now, the process of updating the home zone list by analyzing the call information for each* mobile station according to an embodiment of the present invention will be explained with reference to Table 1 to Table In Table 2, the term "cnit" means the accumulated value of the number of received telephone calls, location registration calls, or home zone update requesting calls having the same values of NSN, NID, BTS_ID, SECTORID, and RTD. The term "hz-numn" is the priority number of the particular regions included in the home zone list of the respective mobile station in Table 1, and has the value in the range of to The term "hz-num" has the value of For instance, if the values of NID, BTSID, and SECTORID of the call information of a certain mobile station are included in the home zone list of the mobile station in Table 2, the corresponding "hz-num" becomes one among the values of 1 to 8. If the values of NID, BTSID, and SECTORID of the call information of a certain mobile station are not included in the home zone list of the mobile station in Table 2, the corresponding "hz num" becomes 9. The priority number of the home zone list can be determined by the signal strength.

2JZiiIi2JLIJ.:..J 18- Table 4 is a table for analyzing the call information for each mobile station created by Table 3 according to an embodiment of the present invention, and it may be the table including values obtained by the NSN's counting of the number of the received calls for the same NID, BTS_ID, SECTOR_ID, RTD with respect to the call information generated by the mobile station of '1234567'.

Hereinafter, the process of updating the home zone list for each mobile station by analyzing the call information for each mobile station according to an embodiment of the present invention will be explained in detail with reference to Table 1 to Table as described above.

10 The home zone updating device 150 analyzes the call information for the respective mobile station, and updates the corresponding maximum RTD value and minimum RTD value of the home zone list for each mobile station as below.

First, with respect to the call information whose value of "hz-num" is in the range of 1 to 8 in Table 4, the home zone updating device 150 obtains the maximum value of "cnt" MAX(cnt) and the number of MAX(cnt) among respective rows of the table for analyzing the call record information for each mobile station in Table 4. The MAX(cnt) in Table 4 is "cnt(4)" corresponding to the first row. Since only one cnt value of exists, the number of MAX(cnt) becomes 1. If the number of MAX(cnt) is the home zone updating device 150 obtains the RTD value, '42' accordingly.

Then, the home zone updating device 150 updates the first minimum RTD value and the first maximum RTD value of"hz_num(l)" in Table 1 according to the values of the corresponding BTS_ID, values of"chip_nol" and "chip_no2" of '123' stored in table 5. For example, if the values of "chip_nol' and "chip_no2" stored in Table 5 are 19- '-4'and respectively, the updated first minimum RTD value and first maximum RTD value become '38(42-4)' and respectively. Then, the home zone updating device 150 updates the first minimum RTD value and first maximum RTD value of "hz-num(l)" in Table 1 to the obtained '38' and If the number of MAX(cnt) is equal to or greater than the home zone updating device 150 obtains the mean value of the RTD values accordingly. Then, the home zone updating device 150 obtains the RTD value corresponding to the mean value, and updates the minimum RTD values and maximum RTD values of the respective home zone particular regions which correspond to MAX(cnt) according to the values of"chip_nol" and "chip_no2" S 10 of the respective corresponding BTS_ID.

Meanwhile, if the value of"hznum" in Table 4 is the home zone updating device 150 classifies the "cnt" values in the order of their size with respect to NID, BTS_ID, SECTOR_ID, and RTD of the call information whose value of "hznum" is from the table for storing and analyzing the call information for each mobile station in Table 2. For example, if 5 home zone particular regions for each mobile station presently managed exist, and the "cnt" value of at least one information among the call information ofNID, BTS_ID, SECTOR_ID, and RTD whose value of"hz_num" is '9' satisfies the specified condition, the home zone updating device 150 inserts new particular regions corresponding to the call information of NID, BTS_ID, SECTOR_ID, and RTD which satisfy the specified condition in. the home zone list for each mobile station. Then, the home zone updating device 150 obtains the corresponding minimum RTD value and maximum RTD value in the same manner as the case that the value of "hz_num" is in the range of 1 to 8, and updates the home zone list for each mobile station accordingly.

For example, if the "cnt" value of at least one information, among the call ,v-*Z$-tt

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information of NID, BTS_ID, SECTORID, and RTD whose value of"hz num" is '9' becomes more than a specified percent of the sum of the whole "cnt" values in Table 2, the home zone updating device 150 may judge that the specified condition is satisfied.

As described above, the present invention provides the advantages that it can provide an improved home zone service and thus reduce the subscriber's dissatisfaction by updating the initial home zone for the respective subscriber according to the location where the subscriber actually makes a telephone call. Further, according to the present invention, the subscriber can conveniently update the home 10 zone for the respective mobile station by a home zone update requesting call without the necessity of an actual telephone call. Furthermore, the method using the home zone update requesting call according to the present invention enables the updating of the S. home zone list for each mobile station with respect to not only the corresponding particular regions pre-allocated by the cell planning, and so on, but also other adjacent 15 particular regions according to the location where the user actually makes a telephone call, thereby preventing the cause of the user's dissatisfaction.

While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that other modifications thereof may be made without departing from the scope of the invention. Thus, the invention should not be limited to the disclosed embodiment, but should be defined by the scope of the appended claims and their equivalents.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

For the purposes of this specification it will be clearly understood that the word "comprising" means "including but not limited to", and that the word "comprises" has a corresponding meaning.

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Claims

2. The home zone service performing method as claimed in claim 1, further comprising a fourth step of determining whether to perform the home zone service by comparing the call information with information on the home zone particular regions for each mobile station stored in the home-location register if a call is received.
3. The home zone service performing method as claimed in claim 1, wherein r•eeo the second step inserts a new corresponding home zone particular region in the home zone managed for each mobile station if the call information generated outside the home zone satisfies a specified condition.
4. The home zone service performing method as claimed in claim 1, wherein the second step replaces a certain particular region among the pre-allocated particular regions for each mobile station by a new corresponding home zone particular region if the call information generated outside the home zone satisfies a specified condition. The home zone service performing method as claimed in claim 1, wherein 22 the first step comprises the steps of: a mobile switching center outputting the information on the received home zone update requesting calls and the general calls inside the home zone to a home zone updating device; and the home zone updating device storing the respective received call information.
6. A method of performing a home zone service in a mobile radio communication system, substantially as herein described with reference to the accompanying figures. Dated this 15th day of February 2002 SAMSUNG ELECTRONICS CO., LTD. By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia 0 *eeo H:\ayo\Keep\Specifications\66612-OO.doc 15/02/02 i;i; II