Method for changing over to different frequency at cellular phone system and cellular phone system using the method and base station controlling apparatus in the system

A method for changing over to a different frequency at a cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and a base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure first reception quality in said first frequency and second reception quality in said second frequency during the communication with said first base station by setting a channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station when the difference between said second reception quality and said first reception quality exceeded a third threshold value, wherein:
• said method for changing over to a different frequency, comprising the steps of:
• measuring the traffic in said first frequency by said base station controlling apparatus;
• and
• changing said third threshold value corresponding to said measured traffic by said base station controlling apparatus.

A method for changing over to a different frequency at a cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and a base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure second reception quality in said second frequency during the communication with said first base station by setting a channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station when said second reception quality exceeded a fourth threshold value, wherein:
• said method for changing over to a different frequency, comprising the steps of:
• measuring the traffic in said first frequency by said base station controlling apparatus;
• and
• changing said fourth threshold value corresponding to said measured traffic by said base station controlling apparatus.

A method for changing over to a different frequency at a cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and a base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure first reception quality in said first frequency during the communication with said first base station by setting a channel, and also
• said mobile communication terminal is controlled to measure second reception quality in said second frequency corresponding to said first reception quality during the communication with said first base station by setting the channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station corresponding to said first and second reception quality, wherein:
• said method for changing over to a different frequency, comprising the step of:
• changing the condition of measuring said second reception quality corresponding to the transmission rate in said mobile communication terminal by said base station controlling apparatus.

A method for changing over to a different frequency at a cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and a base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure first reception quality in said first frequency and second reception quality in said second frequency during the communication with said first base station by setting a channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station when the difference between said second reception quality and said first reception quality exceeded a third threshold value, wherein:
• said method for changing over to a different frequency, comprising the step of:
• changing said third threshold value corresponding to said transmission rate in said mobile communication terminal by said base station controlling apparatus.

A method for changing over to a different frequency at a cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and a base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure second reception quality in said second frequency during the communication with said first base station by setting a channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station when said second reception quality exceeded a fourth threshold value, wherein
• said method for changing over to a different frequency, comprising the step of:
• changing said fourth threshold value corresponding to said transmission rate in said mobile communication terminal by said base station controlling apparatus.

A cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and a base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure first reception quality in said first frequency during the communication with said first base station by setting a channel, and also said mobile communication terminal is controlled to measure second reception quality in said second frequency corresponding to said first reception quality during the communication with said first base station by setting the channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station corresponding to said first and second reception quality, wherein:
• said base station controlling apparatus, comprising:
• a condition changing means for changing the condition of measuring said second reception quality corresponding to the traffic in said first frequency.

A cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and a base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure first reception quality in said first frequency and second reception quality in said second frequency during the communication with said first base station by setting a channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station when the difference between said second reception quality and said first reception quality exceeded a third threshold value, wherein:
• said base station controlling apparatus, comprising:
• a traffic measuring means for measuring the traffic in said first frequency;
• and
• a second threshold value changing means for changing said third threshold value corresponding to said measured traffic.

A cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and a base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure second reception quality in said second frequency during the communication with said first base station by setting a channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station when said second reception quality exceeded a fourth threshold value, wherein:
• said base station controlling apparatus, comprising:
• a traffic measuring means for measuring the traffic in said first frequency;
• and
• a third threshold value changing means for changing said fourth threshold value corresponding to said measured traffic.

A cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and a base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure first reception quality in said first frequency during the communication with said first base station by setting a channel, and also
• said mobile communication terminal is controlled to measure second reception quality in said second frequency corresponding to said first reception quality during the communication with said first base station by setting the channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station corresponding to said first and second reception quality, wherein:
• said base station controlling apparatus, comprising:
• a condition changing means for changing the condition of measuring said second reception quality corresponding to the transmission rate in said mobile communication terminal.

A cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and a base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure first reception quality in said first frequency and second reception quality in said second frequency during the communication with said first base station by setting a channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station when the difference between said second reception quality and said first reception quality exceeded a third threshold value, wherein:
• said base station controlling apparatus, comprising:
• a second threshold value changing means for changing said third threshold value corresponding to said transmission rate in said mobile communication terminal.

A cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and a base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure second reception quality in said second frequency during the communication with said first base station by setting a channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station when said second reception quality exceeded a fourth threshold value, wherein:
• said base station controlling apparatus, comprising:
• a third threshold value changing means for changing said fourth threshold value corresponding to said transmission rate in said mobile communication terminal.

A base station controlling apparatus in a cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and said base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure first reception quality in said first frequency during the communication with said first base station by setting a channel, and also
• said mobile communication terminal is controlled to measure second reception quality in said second frequency corresponding to said first reception quality during the communication with said first base station by setting the channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station corresponding to said first and second reception quality, wherein:
• said base station controlling apparatus, comprising:
• a condition changing means for changing the condition of measuring said second reception quality corresponding to the traffic in said first frequency.

A base station controlling apparatus in a cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and said base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure first reception quality in said first frequency and second reception quality in said second frequency during the communication with said first base station by setting a channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station when the difference between said second reception quality and said first reception quality exceeded a third threshold value, wherein:
• said base station controlling apparatus, comprising:
• a traffic measuring means for measuring the traffic in said first frequency;
• and
• a second threshold value changing means for changing said third threshold value corresponding to said measured traffic.

A base station controlling apparatus in a cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and said base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure second reception quality in said second frequency during the communication with said first base station by setting a channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station when said second reception quality exceeded a fourth threshold value, wherein:
• said base station controlling apparatus, comprising:
• a traffic measuring means for measuring the traffic in said first frequency;
• and
• a third threshold value changing means for changing said fourth threshold value corresponding to said measured traffic.

A base station controlling apparatus in a cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and said base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure first reception quality in said first frequency during the communication with said first base station by setting a channel, and also
• said mobile communication terminal is controlled to measure second reception quality in said second frequency corresponding to said first reception quality during the communication with said first base station by setting the channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station corresponding to said first and second reception quality, wherein:
• said base station controlling apparatus, comprising:
• a condition changing means for changing the condition of measuring said second reception quality corresponding to the transmission rate in said mobile communication terminal.

A base station controlling apparatus in a cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and said base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure first reception quality in said first frequency and second reception quality in said second frequency during the communication with said first base station by setting a channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station when the difference between said second reception quality and said first reception quality exceeded a third threshold value, wherein:
• said base station controlling apparatus, comprising:
• a second threshold value changing means for changing said third threshold value corresponding to said transmission rate in said mobile communication terminal.

A base station controlling apparatus in a cellular phone system, in which a mobile communication terminal, a first base station and a second base station, and said base station controlling apparatus are provided, wherein:

• said first base station communicates with said mobile communication terminal by setting a channel using a first frequency, and
• said second base station communicates with said mobile communication terminal by setting a channel using a second frequency, and
• said mobile communication terminal is controlled to measure second reception quality in said second frequency during the communication with said first base station by setting a channel, and
• said mobile communication terminal is controlled to communicate with said second base station by changing over the channel from said first base station to said second base station when said second reception quality exceeded a fourth threshold value, wherein:
• said base station controlling apparatus, comprising:
• a third threshold value changing means for changing said fourth threshold value corresponding to said transmission rate in said mobile communication terminal.