Mobile communication system enabling efficient use of small-zone base stations

Abstract

A mobile communication system includes a plurality of radio base stations forming respective radio zones and a mobile station selecting a wait zone and a base station to which a request for a message channel is to be issued. Each of the plurality of radio base stations is assigned an order of priority. Information relating to the order of priority is used by the mobile station to select a wait zone and a base station to which a request for a message channel is to be issued.

1. A mobile communication system comprising:
 a plurality of radio base stations forming respective radio zones and effecting a radio channel setting control in accordance with a predetermined procedure; and  
 a mobile station selecting, as a wait zone, one of the radio zones that satisfies a criteria demanded by the predetermined procedure, and receiving communication service via the selected wait zone,  
 each of the radio base stations comprising: 
 traffic control means for setting a traffic distribution for the plurality of radio zones; and  
 announcing means for generating announcement information including the order of priority assigned to the plurality of radio zones, the order of priority being assigned in accordance with a probability density given to each of the plurality of radio zones under the distribution set by the traffic control means, and for transmitting announcement information to the radio zone formed by the radio station to which the announcing means belongs,  
 
 the mobile station comprising: 
 announcement information receiving means for receiving the announcement information transmitted by the announcing means in accordance with the predetermined procedure; and  
 wait control means for selecting one of the radio zones as a wait zone, the radio zone to which a highest priority is assigned being a first candidate for selection by the wait control means.  
 
 
     
     
       2. A mobile communication system comprising:
 a plurality of radio base stations forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping radio zones,  and effecting a radio channel setting control in accordance with a predetermined procedure; and  
 a mobile station accessing one of the radio zones formed by the respective one of the plurality of radio base stations, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone,  
 each of the plurality of radio base stations comprising: 
 announcing means for transmitting announcement information which includes identification information for identifying radio channels assigned to respective radio zones and small-scale radio zones,  via the  a radio channel assigned to the radio zone formed by the radio base station to which the announcing means belongs, the identification information being arranged in the announcement information so as to correspond to the hierarchy of overlapping radio zones  announcement information including a priority of the respective radio zones,  
 
 the mobile station comprising: 
 announcement information receiving means for receiving the announcement information transmitted by the announcing means, in accordance with the procedure for radio channel setting control;  
 measuring means for measuring an electric field intensity for the  a characteristic of a radio channel corresponding to the identification information included in the announcement information received by the announcement information receiving means  a respective radio zone; and  
 wait control means for comparing an electric field intensity  the measured by the measuring means  characteristic with a preset  threshold level, and designating a radio zone to which the radio channel lowest in the hierarchy is assigned as a wait zone in which to receive the communication service, on the condition that the electric field intensity measured by the measuring means exceeds the preset threshold level  based upon the priority of the respective radio zones received from the announcement information and the comparison of the measured characteristic with the threshold level.  
 
 
     
     
       3. The mobile communication system as claimed in  claim 2 , wherein
 said announcing means comprises  includes means for adding, in the announcement information, preset  threshold values individually provided for the radio zone formed by the radio base station to which the announcing means belongs and the overlapping radio zones and small-scale radio zones, resulting in a hierarchy that corresponds to the hierarchy of overlapping zones , and  
 said wait control means employs the threshold values added to the announcement information by the announcing means in making comparisons with the electric field intensity  characteristic.  
 
     
     
       4. The mobile communication system as claimed in  claim 2  wherein
 said announcing means comprisesincludes means for adding a relative value indicating the preset  threshold value for the zone formed by the radio base station to which the announcing means belongs, in the form of a difference with respect to a reference value for the threshold value, and  
 said announcement information receiving means includes means for determining the relative value added to the announcement information, in relation to the radio zone in which the announcement information is received, and  
 said wait control means compares the electric field intensity  measured characteristic by the measuring means with a sum of the reference value and the relative value determined by the announcement information receiving means in relation to the radio zone in which the electric field intensity  characteristic is measured.  
 
     
     
       5. The mobile communication system as claimed in  claim 2 , wherein
 said announcing means comprises  includes means for adding relative values indicating the preset  threshold values for the radio zone formed by the radio base station to which the announcing means belongs and the overlapping radio zones and small-scale radio zones,  in the form of differences with respect to a reference value common to the threshold values, resulting in a hierarchy  priority that corresponds to the hierarchy of overlapping  priority radio zones, and  
 said wait control means compares the electric field intensity  characteristic with a sum of the relative value and the reference value.  
 
     
     
       6. The mobile communication system as claimed in  claim 2 , wherein said mobile station comprises zone determination means for performing a cyclic measurement of the electric field intensity of the radio zones in which the mobile station can be located, comparing a measured electric field intensity with a lower acceptance value by which an entry into the radio zone is enabled, stopping processes of measurement and comparison when it is found that the former exceeds the latter, and selecting the associated radio zone as a candidate in which the announcement information receiving means is to receive the announcement information. 
     
     
       7. The mobile communication system as claimed in  claim 2 , wherein said wait control means compares the electric field intensity measured by the measuring means with the threshold value in the descending order in the hierarchy of the radio zones subject to the measurement, and designates the radio zone for which it is found that the former exceeds the latter as a wait zone. 
     
     
       8. The mobile communication system as claimed in  claim 6 , wherein said measuring means comprises means which omits a measurement of the radio zone selected by the zone determination means and substitutes therefor the electric field intensity measured by the zone determination means. 
     
     
       9. A mobile communication system comprising:
 a plurality of radio base stations forming one or  a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping  the radio zones having respective priorities, and effecting a radio channel setting control in accordance with a predetermined procedure; and  
 a mobile station accessing one of the radio zones formed by the respective one of the plurality of radio base stations, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone,  
 each of the plurality of radio base stations comprising: 
 announcing means for transmitting announcement information which includes identification information for identifying the one or the plurality of radio zones and the one or the plurality of small-scale radio zones, via the radio channel assigned to the radio zone formed by the radio base station to which the announcing means belongs, the identification information being arranged in the announcement information according to respective positions in the hierarchy of overlapping  the priorities of the radio zones,  
 
 the mobile station comprising: 
 announcement information receiving means for receiving the announcement information transmitted by the announcing means, in accordance with the procedure for radio channel setting control;  
 measuring means for measuring an electric field intensity for the radio zone corresponding to the identification information included in the announcement information received by the announcement information receiving means  a characteristic of respective radio zones; and  
 wait control means for comparing an electric field intensity  the measured by the measuring means  characteristic of the respective radio zones with a preset  threshold level, and designating, as a wait zone in which to receive the communication service, a radio zone lowest in the hierarchy of overlapping zones on the condition that the electric field intensity measured by the measuring means exceeds the threshold level  based upon the priority of the respective radio zones received from the announcement information and the comparison of the measured characteristic with the threshold level.  
 
 
     
     
       10. A mobile communication system comprising:
 a plurality of radio base stations forming one or  a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones , and effecting a radio channel setting control in accordance with a predetermined procedure; and  
 a mobile station accessing one of the radio zones formed by the respective one of the plurality of radio base stations, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone,  
 each of the plurality of radio base stations comprising: 
 announcing means for transmitting announcement information which includes identification information for identifying radio channels for the  one or the plurality of radio zones and the one or the plurality of small-scale radio zones,  via the  a radio channel assigned to the radio zone formed by the radio base station to which the announcing means belongs, the identification information being arranged in the announcement information according to respective positions in the hierarchy of overlapping zones  announcement information also including priority information of the plurality of radio zones,  
 
 the mobile station comprising: 
 announcement information receiving means for receiving the announcement information transmitted by the announcing means, in accordance with the procedure for radio channel setting control;  
 measuring means for measuring an electric field intensity for the  a characteristic of respective radio channel corresponding to the identification information included in the announcement information received by the announcement information receiving means  channels; and  
 wait control means for comparing an electric field intensity  the measured by the measuring means  characteristic with a preset  threshold level, and based upon the comparison designating one of the radio channels, which is assigned to the radio zone lowest in the hierarchy and for which the control means has determined that the electric field intensity measured by the measuring means exceeds the preset threshold level, as a radio channel  radio zones with the highest priority as first candidates via which to receive the communication service.  
 
 
     
     
       11. A mobile communication system comprising:
 a plurality of radio base stations forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones, and effecting a radio channel setting control in accordance with a predetermined procedure; and    a mobile station accessing one of the radio zones formed by the respective one of the plurality of radio base stations, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone,    each of the plurality of radio base stations comprising: 
 announcing means for transmitting announcement information which includes identification information for identifying the one or the plurality of radio zones and the one or the plurality of small-scale radio zones, via the radio channel assigned to the radio zone formed by the radio base station to which the announcing means belongs, the identification information being arranged in the announcement information according to respective positions in the hierarchy of overlapping zones,  
   the mobile station comprising: 
 announcement information receiving means for receiving the announcement information transmitted by the announcing means, in accordance with the procedure for radio channel setting control;  
 measuring means for measuring an electric field intensity for the radio zone corresponding to the identification information included in the announcement information received by the announcement information receiving means; and  
 wait control means for comparing an electric field intensity measured by the measuring means with a preset threshold level, and designating, as a wait zone in which to receive the communication service, a radio zone identified by the identification information to be lowest in the hierarchy of overlapping zones, on the condition that the electric field intensity measured by the measuring means exceeds the threshold level.  
   
     
     
       12. A mobile communication system comprising:
 a plurality of radio base stations forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones, and effecting a radio channel setting control in accordance with a predetermined procedure; and    a mobile station accessing one of the radio zones formed by the respective one of the plurality of radio base stations, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone,    each of the plurality of radio base stations comprising: 
 announcing means for transmitting announcement information which includes first identification information for identifying a radio channel assigned to the radio zone formed by the radio base station to which the announcing means belongs, as well as including second identification information identifying the radio zones and the small-scale radio zones which overlap the radio zone formed by the radio base station to which the announcing means belongs, via the radio channel assigned to the radio zone formed by the radio base station to which the announcing means belongs, the second identification information being arranged in the announcement information according to respective positions in the hierarchy of overlapping zones,  
   the mobile station comprising: 
 announcement information receiving means for receiving the announcement information transmitted by the announcing means, in accordance with the procedure for radio channel setting control;  
 measuring means for measuring an electric field intensity for the radio channel corresponding to the identification information included in the announcement information received by the announcement information receiving means; and  
 wait control means for comparing an electric field intensity measured by the measuring means with a preset threshold level, determining the radio channel which is identified by the associated second identification information, if available, to have a lowest hierarchical order, and designating, as a wait zone in which to receive the communication service, the radio zone to which the determined radio channel is assigned, on the condition that the electric field intensity measured by the measuring means exceeds the threshold level.  
   
     
     
       13. A mobile communication system comprising:
 a plurality of radio base stations forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones, and effecting a radio channel setting control in accordance with a predetermined procedure; and    a mobile station accessing one of the radio zones formed by the respective one of the plurality of radio base stations, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone,    each of the plurality of radio base stations comprising: 
 announcing means for transmitting announcement information which includes first identification information for identifying a radio channel assigned to a radio zone formed by the radio base station to which the announcing means belongs, as well as including second identification information identifying the radio zones and the small-scale radio zones which overlap the radio zone formed by the radio base station to which the announcing means belongs, over the radio zone formed by the radio base station to which the announcing means belongs, the second identification information being arranged in the announcement information according to respective positions in the hierarchy of overlapping zones,  
   the mobile station comprising: 
 announcement information receiving means for receiving the announcement information transmitted by the announcing means, in accordance with the procedure for radio channel setting control;  
 measuring means for measuring an electric field intensity for the radio zone corresponding to the identification information included in the announcement information received by the announcement information receiving means; and  
 wait control means for comparing an electric field intensity measured by the measuring means with a preset threshold level, determining the radio zone corresponding to the radio channel which is identified by the associated second identification information, if available, to have a lowest hierarchical order, and designating the determined radio zone as a wait zone in which to receive the communication service on the condition that the electric field intensity measured by the measuring means exceeds the threshold level.  
   
     
     
       14. A mobile communication system comprising:
 a plurality of radio base stations forming one or  a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones, and effecting a radio channel setting control in accordance with a predetermined procedure ; and  
 a mobile station accessing one of the radio zones formed by the respective one of the  plurality of radio base stations, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone,  
 each of the plurality of radio base stations comprising: 
 announcing means for transmitting announcement information which includes a hierarchical (equal or subordinate) order  priority of the radio zone formed by  the plurality of radio base station to which the announcing means belongs with respect to the overlapping radio zones and small-scale radio zones,  stations and which also includes identification information for identifying radio channels assigned to the radio zone formed by the radio base station to which the announcing means belongs, and the overlapping radio zones and small-scale radio zones,  via the radio channel assigned to the radio zone formed by the radio base station to which the announcing means belongs,  
 
 the mobile station comprising: 
 announcement information receiving means for receiving the announcement information transmitted by the announcing means, in accordance with the procedure for radio channel setting control, for extracting the identification information from the announcement information, and for determining the hierarchy priority of the radio zones to which the radio channels identified by the identification information are assigned  of the plurality of radio base stations;  
 measuring means for measuring an electric field intensity for the radio channel corresponding to the identification information obtained by the announcement information receiving means  a characteristic a received signal from respective radio base stations of the plurality of radio base stations; and  
 wait control means for comparing an electric field intensity  the measured by the measuring means  characteristic with a preset  threshold level, and designating a radio zone to which the radio channel lowest in the hierarchy is assigned  as a wait zone in which to receive the communication service, on the condition that the electric field intensity measured by the measuring means for the radio channel lowest in the hierarchy exceeds the preset threshold level  based upon the comparison and the hierarchy priority.  
 
 
     
     
       15. A mobile communication system comprising:
 a plurality of radio base stations forming one or a plurality of radio zones and one or a plurality of small-scale radio zones, resulting in a hierarchy of overlapping zones, and effecting a radio channel setting control in accordance with a predetermined procedure; and    a mobile station accessing one of the radio zones formed by the respective one of the plurality of radio base stations, in accordance with a predetermined procedure, and receiving communication service via the accessed radio zone, each of the plurality of radio base stations comprising: 
 announcing means for transmitting announcement information which includes a hierarchical (equal or subordinate) order of the radio zone formed by the radio base station to which the announcing means belongs with respect to the overlapping radio zones and small-scale radio zones, and which also includes identification information for identifying the radio zone formed by the radio base station to which the announcing means belongs and the overlapping radio zones and small-scale radio zones, over the radio zone formed by the radio base station to which the announcing means belongs,  
   the mobile station comprising: 
 announcement information receiving means for receiving the announcement information transmitted by the announcing means, in accordance with the procedure for radio channel setting control, for extracting the identification information from the announcement information, and for determining the hierarchy of the radio zones corresponding to the identification information;  
 measuring means for measuring an electric field intensity for the radio zone corresponding to the identification information extracted by the announcement information receiving means  14 g; and  
 wait control means for comparing an electric field intensity measured by the measuring means with a preset threshold level, and designating a radio zone lowest in the hierarchy determined by the announcement information receiving means as a wait zone in which to receive the communication service, on the condition that the electric field intensity measured by the measuring means for the radio zone lowest in the hierarchy exceeds the preset threshold level.  
   
     
     
       16. A mobile station comprising:
 announcement information receiving means for receiving announcement information including orders of  priority information assigned to radio zones formed by a plurality of radio base stations, the reception by the announcement information receiving means being conducted according to a descending order of preset traffic distribution and in accordance with a radio channel setting control procedure ;  
 wait means for determining whether the radio zone  zones associated with the highest order of priority included in the announcement information received by the announcement information receiving means satisfies a criteria adapted for the radio channel setting control procedure, and for designating the  a radio zone from among radio zones for which an affirmative answer is given as a wait zone; and  
 communication control means which receives communication service from the radio base station forming the radio zone designated by the wait means.  
 
     
     
       17. A mobile communication system comprising:
 a plurality of base stations forming respective radio zones that overlap each other ;  
 a mobile station transportable between said radio zones; wherein  
 each of said plurality of base stations having: 
 announcing means for sending announcement information including an order of  priority information of respective base stations of said plurality of base stations to the mobile station located in one of said radio zones, and  
 
 said mobile station having:  
 a control means for selecting a base station from among said plurality of base stations, to which a request for a message channel is to be issued,  based on the order of  priority information of said plurality of base stations included in the announcement information transmitted from said plurality of base stations,  rather than based on an order of respective received electric field intensities provided by the plurality of base stations and having a received signal characteristic being equal to or greater than a predetermined received electric field intensity  threshold value.  
 
     
     
       18. The mobile communication system as claimed in  claim 17 , wherein said mobile station further comprises:
 announcement information receiving means for receiving the announcement information including the order of  priority of said plurality of base stations and transmitted from said plurality of base stations; and  
 transmission means for issuing a request for a message channel to the base station selected by said control means.  
 
     
     
       19. The mobile communication system as claimed in  claim 18 , wherein said transmission means includes first transmission means for issuing a request for a message channel to the base station selected by the control means when a call is originated. 
     
     
       20. The mobile communication system as claimed in  claim 18 , wherein said transmission means includes second transmission means for issuing a request for a message channel to the base station selected by the control means when a call is incoming. 
     
     
       21. The mobile communication system as claimed in  claim 18 , wherein said transmission means includes third transmission means for transmitting a request for a communication to the base station selected by the control means when a message channel is switched from one to another in the event of a handover of a call. 
     
     
       22. The mobile communication system as claimed in  claim 17 , wherein said mobile station further comprises:
 storage means for storing the announcement information;  
 measuring means for measuring a reception level in  of reception-level determining channels in a descending order of priority  of said plurality of base stations, based on the announcement information stored in said storage means and including the order of priority and based on information relating to the reception-level determining channels  as the received signal characteristic.  
 
     
     
       23. The mobile communication system as claimed in  claim 22 , wherein said control means includes determining means for determining whether the reception level in a reception-level determining channel is equal to or exceeds a predetermined level that enables a request for a message channel . 
     
     
       24. The mobile communication system as claimed in  claim 17 , wherein said announcing means includes first arranging means for ordering the announcement information so as to arrange information relating to reception-level determining channels in a descending order of priority. 
     
     
       25. The mobile communication system as claimed in  claim 17 , wherein said announcing means includes second arranging means for ordering the announcement information so as to couple information relating to each reception-level determining channel to an order of priority associated therewith. 
     
     
       26. A mobile station for use in a mobile communication system, comprising:
 control means for selecting a base station from among a plurality of base stations, to which a request for a message channel is to be issued,  based on an order of  a priority of said plurality of base stations, said priority information included in announcement information received from said plurality of base stations, rather than based on an order of respective received electric field intensities provided by the plurality of base stations and said selected base station having a signal characteristic being equal to or greater than a predetermined received electric field intensity  value.  
 
     
     
       27. The mobile station as claimed in  claim 26 , further comprising:
 announcement information receiving means for receiving, from said plurality of base stations, the announcement information including the order of  priority information of said plurality of base stations; and  
 transmission means for transmitting a request for a message channel to the base station selected by said control means.  
 
     
     
       28. The mobile station as claimed in  claim 27 , wherein said transmission means includes first transmission means for issuing a request for a message channel to the base station selected by the control means when a call is originated. 
     
     
       29. The mobile station as claimed in  claim 27 , wherein said transmission means includes second transmission means for issuing a request for a message channel to the base station selected by the control means when a call is incoming. 
     
     
       30. The mobile station as claimed in  claim 27 , wherein said transmission means includes third transmission means for transmitting a request for a communication to the base station selected by the control means when a message channel is switched from one to another in the event of a handover of a call. 
     
     
       31. The mobile station as claimed in  claim 26 , further comprising:
 storage means for storing the announcement information;  
 measuring means for measuring a reception level in reception-level determining channels in a descending order of priority of said plurality of base stations, based on the announcement information stored in said storage means and including the order of priority and based on information relating to the reception-level determining channels  as the received signal characteristic.  
 
     
     
       32. The mobile station as claimed in  claim 31 , wherein said control means includes determining means for determining whether the reception level in a reception-level determining channel  is equal to or exceeds a predetermined level that enables a request for a message channel. 
     
     
       33. A base station forming a radio zone that overlaps radio zones formed by other base stations of a plurality of base stations  in a mobile communication system having a plurality of base stations; comprising:
 announcing means for sending announcement information including an order of  a priority of respective base stations of said plurality of base stations constituting the mobile communication system  to a mobile station located in one of the radio zones, a sending  candidate base station being selected by a mobile station from among the plurality of base stations, to which a request for a message channel is to be issued,  based on the order of priority of the plurality of base stations included in the announcement information, rather than based on an order of respective received electric field intensities provided by the plurality of base stations and  base stations having a received signal criteria being equal to or greater than a predetermined received electric field intensity  value.  
 
     
     
       34. The base station as claimed in  claim 33 , wherein said announcing means includes first arranging means for ordering the announcement information so as to arrange information relating to reception-level determining channels in a descending order of priority. 
     
     
       35. The base station as claimed in  claim 33 , wherein said announcing means includes second arranging means for ordering the announcement information so as to couple information relating to each reception-level determining channel to an order of priority associated therewith. 
     
     
       36. A mobile station for use in a mobile communication system including a plurality of base stations which respectively transmit announcement information including an order of priority of said plurality of base stations, said mobile station comprising:
 control means for selecting a base station from among the plurality of base stations, to which a request for a message channel is to be issued, based on said order of priority of said plurality of base stations included in said announcement information from said plurality of base stations, rather than based on an order of respective received electric field intensities provided by the plurality of base stations and being equal to or greater than a predetermined received electric field intensity.  
 
     
     
       37. A radio communication unit in a mobile communication system including a plurality of base stations, the radio communication unit comprising:
   a receiver receiving system information from one or more base stations, the system information including a respective priority of the one or more base stations;        a measuring unit measuring a characteristic of received signals from one or more base stations; and        a controller determining one or more base stations where the measured characteristic meets a predetermined criteria and selecting a base station with the highest priority from among the base stations meeting the predetermined criteria.     
     
     
       38. The radio communication unit of  claim 37 , wherein the base station transmitting the system information includes it's own priority and priorities of adjacent base stations. 
     
     
       39. The radio communication unit of  claim 37 , wherein the predetermined criteria includes being equal to or greater than a predetermined value. 
     
     
       40. A method in a mobile radio communication unit of a mobile communication system including a plurality of base stations, which transmit announcement information including a priority of said plurality of base stations, the method comprising:
   measuring a characteristic of received signals from one or more base stations;        determining if the measured characteristic meets a predetermined criteria;        receiving priority information from one or more base stations, the priority information including a respective priority of the one or more base stations; and        selecting a base station with the highest priority from among the base stations meeting the predetermined criteria.     
     
     
       41. The method of  claim 40 , wherein the measured characteristic includes the receive level to a signal and the priority information is received from a base station transmitting the system information including it's own priority and priorities of adjacent base stations. 
     
     
       42. A mobile communication system having a plurality of radio base stations forming respective radio zones and a mobile station accessing a radio base station and receiving communication service via the accessed base station, the system comprising:
   transmission/reception unit transmitting announcement information which includes identification information for identifying radio channels assigned to respective radio zones and priority information of respective radio base stations;        a receiver receiving the announcement information from one or more base stations and the priority information of respective radio base stations;        a measuring unit measuring a characteristic of received signals from one or more base stations; and        a controller determining one or more base stations where the measured characteristic meets a predetermined criteria and selecting a base station with the highest priority from among the base stations meeting the predetermined criteria.     
     
     
       43. A mobile station for use in a mobile communication system including a plurality of base stations which respectively transmit announcement information including a priority of said plurality of base stations, said mobile station comprising:
   a controller selecting a base station from among the plurality of base stations based on said priority of base stations having a received signal criteria being equal to or greater than a value.     
     
     
       44. A mobile station for use in a mobile communication system including a plurality of radio zones, said mobile station comprising:
   a receiver receiving priority information about said radio zones from a base station forming any one of said radio zones,        a controller selecting a radio zone from among the radio zones based on said priority information.     
     
     
       45. A base station for use in a mobile communication system, comprising:
   a transmitter transmitting a broadcast signal including priority information relating to said base station and an adjacent base station for zone selection in a mobile station.     
     
     
       46. A mobile communication system comprising:
   a plurality of radio base stations forming respective radio zones and effecting a radio channel setting control in accordance with a predetermined procedure; and        a mobile station selecting, as a wait zone, one of the radio zones that satisfies a criteria demanded by the predetermined procedure, and receiving communication service via the selected wait zone,        each of the radio base stations comprising:      announcing means for generating announcement information including the order of priority assigned to the plurality of radio zones, and for transmitting announcement information to the radio zone formed by the radio station to which the announcing means belongs,          the mobile station comprising:      announcement information receiving means for receiving the announcement information transmitted by the announcing means in accordance with the predetermined procedure; and        wait control means for selecting one of the radio zones as a wait zone, the radio zones to which a highest priority is assigned being first candidates for selection by the wait control means.