Cable modem apparatus and frequency setting method applied thereto
AssigneeKabushiki Kaisha Toshiba
InventorTsutomu Rokuhara
Life of this patent
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Abstract
A CPU selects frequency data from a flash memory at power-on and performs processing of tuning in to a data transmission frequency in a downlink in an RF interface. The flash memory includes a cache area for storing previously used frequency data in addition to a frequency table. The CPU selects frequency data with priority from the cache area.
Claims8
A cable modem apparatus connected to a network system through a cable, comprising:
- an interface configured to transmit and receive a data signal transported through said cable based on set frequency data;
- a memory configured to store a frequency table for selecting a frequency matching the frequency of said data signal transmitted through said cable and having a cache area for saving frequency data which has been selected previously from said frequency table;
- setting means configured to select matching frequency data from said cache area or said frequency table in said memory at start of communication to set said selected frequency data in said interface;
- and
- saving means configured to save information indicative of frequency data in said cache area when said frequency data selected from said frequency table is matching.
A method of setting a frequency applied to a cable modem apparatus connected to a network system through a cable, said cable modem apparatus comprising an interface configured to transmit and receive a data signal based on set frequency data, and a memory configured to store a frequency table for selecting a frequency matching the frequency of said data signal transmitted through said cable and having a cache area for saving frequency data which has been selected previously from said frequency table, said method comprising the steps of:
- selecting frequency data with priority from said cache area of said memory at start of communication;
- sequentially selecting frequency data from said frequency table to find matching frequency data when said frequency data selected from said cache area is not matching;
- and
- selecting matching frequency data from said cache area or said frequency table to set said selected data in said interface.
A method of setting a frequency applied to a cable modem apparatus connected to a network system through a cable, said cable modem apparatus comprising an interface configured to transmit and receive a data signal based on set frequency data, and a memory configured to store a frequency table for selecting a frequency matching the frequency of said data signal transmitted through said cable and having a cache area for saving frequency data which has been selected previously from said frequency table, said method comprising the steps of:
- searching said cache area of said memory at start of communication, and when frequency data is stored in said cache area, setting said frequency data stored in said cache area in said interface, and when no frequency data is stored in said cache area, setting matching frequency data from said frequency table in said interface;
- and
- when a data signal is successfully captured in said interface, saving said frequency data in said cache area.
Dependencies are inferred from the claim text.