Method and system for mobile communications

• US 7,664,507 B2
• Filed: 04/06/2006
• Issued: 02/16/2010
• Est. Priority Date: 04/24/1997
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Watanabe, Yasuyuki, Sato, Takaaki, Hata, Masafumi, Tamura, Motoshi, Uchiyama, Nobuhide, Igarashi, Daisuke, Uchikoshi, Akihiro, Okamoto, Akiko, Ishikawa, Nobutaka, Hagiwara, Junichiro, Miki, Mutsumaru, Hamajima, Takuya, Yunoki, Kazufumi, Yasuda, Yoshiyuki, Kusunose, Kenya, Yamagata, Katsuhiko
• Primary Examiner(s): Ly; Nghi H
• Application Number:
  US11/399,674
• Publication Number:
  US 20060251038A1
• Time in Patent Office: 1,412 Days
• Field of Search: 455/450, 455/452.1, 455/422.1, 370/329, 370/335, 370/342
• US Class Current: 455/450
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04W 12/03 Protecting confidentiality, e.g. by encryption
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/302 due to low signal strength
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 52/12 Outer and inner loops
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/12 Access point controller devices

Abstract

When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover. Additionally, when a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, the mobile station uses the same branch structure and the same communication frequency band for all of calls. Additionally, when a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, a branch structure and a communication frequency band, which can continue all of the calls, are selected and used. Therefore, the mobile communications system is suitable for transmission of various sorts of data in accordance with the development of multimedia.

Claims

1. A radio mobile communication system wherein a plurality of channels can be established on a single carrier frequency by code division multiple access, characterized in that the system comprises a plurality of assignable code resources, each of code resources corresponding to a certain bandwidth and being independent of the other code resources;

and reassigning means for reassigning a part of an assignable code resource to one of the channels to which a part of another assignable code resource is already assigned if there is not an unused code resource corresponding to a bandwidth suitable for a necessary transmission rate when assigning an unused assignable code resource to one of the channels in accordance with the necessary transmission rate,

wherein at least one standard code resource corresponding to a predetermined bandwidth is preselected and the system comprises assignment-possibility-determining means for determining at predetermined moments if there is at least one unused standard code resource or not, the reassigning means reassigning a part of an assignable code resource to one of the channels to which a part of another assignable code resource is already assigned until an unused standard code resource is reserved if the determination result by the assignment possibility determining means has been negative.

2. A radio mobile communication system, comprising:

a plurality of channels, each of which has a transmission rate, the plurality of channels being able to be established on a single carrier frequency by code division multiplex access;

a plurality of code resources, each of which is categorized in a level from among a plurality of levels, the plurality of code resources having a tree structure in which a code resource in a level is divided into lower level code resources, each of the plurality of code resources having a parameter relating to a predetermined transmission rate;

a code resource assigning unit configured to assign at least a part of unused code resources of the plurality of code resources to each of the plurality of channels, in response to a necessary transmission rate of each channel;

a storage unit configured to store usage status of the plurality of code resources;

an unused code resources determining unit configured to determine whether one or a plurality of successive unused code resources having the parameter corresponding to the necessary transmission rate of a specified channel of the plurality of channels exist, on the basis of the usage status stored in the storage unit;

a code resource releasing unit configured to perform a releasing operation, the releasing operation including newly assigning at least a part of the unused code resources to another code resource and releasing a code resource previously assigned to the other code resource, in a case that the unused code resources determining unit determines that one or a plurality of successive unused code resources having the parameter corresponding to the necessary transmission rate of a specified channel of the plurality of channels does not exist;

an assignment-possibility-determining unit configured to determine at a predetermined timing whether one or a plurality of successive unused code resources having a standard parameter exist, on the basis of the usage status stored in the storage unit, the standard parameter being the parameter corresponding to a predetermined standard code resource,

wherein in a case that the assignment-possibility-determining unit determines that one or a plurality of successive unused code resources having the standard parameter does not exist, the code resource releasing unit is configured to perform the releasing operation until one or a plurality of successive unused code resources having a standard parameter exists.

3. The radio mobile communication system according to claim 2, further comprising:

a mobile station having a transmission rate capability; and

a channel assigning unit configured to assign a channel of the plurality of channels, the assigned channel corresponding to the transmission rate capability of the mobile station.

4. The radio mobile communication system according to claim 2, further comprising:

a reassigning unit configured to reassign to the channel a part of the code resources released by the code resource releasing unit.

5. A radio base station, comprising:

a plurality of channels, each of which has a transmission rate, the plurality of channels being able to be established on a single carrier frequency by code division multiplex access;

a plurality of code resources, each of which is categorized in a level from among a plurality of levels, the plurality of code resources having a tree structure in which a code resource in a level is divided into lower level code resources, each of the plurality of code resources having a parameter relating to a predetermined transmission rate;

a code resource assigning unit configured to assign at least a part of unused code resources of the plurality of code resources to each of the plurality of channels, in response to a necessary transmission rate of each channel;

a storage unit configured to store usage status of the plurality of code resources;

an unused code resources determining unit configured to determine whether one or a plurality of successive unused code resources having the parameter corresponding to the necessary transmission rate of a specified channel of the plurality of channels exist, on the basis of the usage status stored in the storage unit;

a code resource releasing unit configured to perform a releasing operation, the releasing operation including newly assigning at least a part of the unused code resources to another code resource and releasing a code resource previously assigned to the other code resource, in a case that the unused code resources determining unit determines that one or a plurality of successive unused code resources having the parameter corresponding to the necessary transmission rate of a specified channel of the plurality of channels does not exist;

an assignment-possibility-determining unit configured to determine at a predetermined timing whether one or a plurality of successive unused code resources having a standard parameter exist, on the basis of the usage status stored in the storage unit, the standard parameter being the parameter corresponding to a predetermined standard code resource,

wherein in a case that the assignment-possibility-determining unit determines that one or a plurality of successive unused code resources having the standard parameter does not exist, the code resource releasing unit is configured to perform the releasing operation until one or a plurality of successive unused code resources having a standard parameter exists.

6. A base station controller, comprising:

a communication unit configured to communicate with the radio base station of claim 5; and

a channel assigning unit configured to assign to the mobile station a channel of the plurality of channels, to which the code resources corresponding to the transmission rate capability of the mobile station is assigned.

7. A communication control method, comprising:

assigning at least a part of unused code resources of a plurality of code resources to each of a plurality of channels, in response to a necessary transmission rate of each channel, each of the plurality of channels having a transmission rate, the plurality of channels being able to be established on a single carrier frequency by code division multiplex access, each of the plurality of code resources being categorized in a level form among a plurality of levels, the plurality of code resources having a tree structure in which a code resource in a level is divided into lower level code resources, each of the plurality of code resources having a parameter relating to a predetermined transmission rate;

storing usage status of the plurality of code resources

determining whether one or a plurality of successive unused code resources having the parameter corresponding to the necessary transmission rate of a specified channel of the plurality of channels exist, on the basis of the stored usage status;

performing a releasing operation, the releasing operation including newly assigning at least a part of the unused code resources to another code resource and releasing a code resource previously assigned to the other code resource, in a case that it is determined that one or a plurality of successive unused code resources having the parameter corresponding to the necessary transmission rate of a specified channel of the plurality of channels does not exist;

determining at a predetermined timing whether one or a plurality of successive unused code resources having a standard parameter exist, on the basis of the stored usage status, the standard parameter being the parameter corresponding to a predetermined standard code resource,

wherein in a case that it is determined that one or a plurality of successive unused code resources having the standard parameter does not exist, the releasing operation is performed until one or a plurality of successive unused code resources having a standard parameter exists.