Radio communication system

• US 20040224719A1
• Filed: 05/17/2004
• Published: 11/11/2004
• Est. Priority Date: 01/18/1996
• Status: Active Grant

• Current Assignee: Eiji Kamagata, Katsuya Nounin, Kiyoshi Toshimitsu, Mutsumu Serizawa, Nobuyasu Nakajima, Takafumi Sakamoto
• Original Assignee: Eiji Kamagata, Katsuya Nounin, Kiyoshi Toshimitsu, Mutsumu Serizawa, Nobuyasu Nakajima, Takafumi Sakamoto
• Inventors: Toshimitsu, Kiyoshi, Sakamoto, Takafumi, Kamagata, Eiji, Serizawa, Mutsumu, Nakajima, Nobuyasu, Nounin, Katsuya
• Granted Patent: US 6,999,438 B2
• Time in Patent Office: Days
• US Class Current: 455/553.1
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 36/00837 Determination of triggering parameters for hand-off
• CPC Class Codes: H04W 36/00838 Resource reservation for handover
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/12 Reselecting a serving backbone network switching or routing node
• CPC Class Codes: H04W 36/302 due to low signal strength

Abstract

In a radio communication system having narrow-band up- and down-link radio channels and a wide-band down-link radio channel, when a radio terminal is to receive data through the wide-band down-link radio channel, the narrow-band up- and down-link radio channels are assigned to the radio terminal in advance. With this operation, communication an be performed by using the wide-band down-link radio channel. In addition, the narrow-band up- and down-link radio channels can be used as radio channels for performing control to efficiently transmit data by using the wide-band down-link radio channel.

Claims

1. A radio communication system comprising:

a narrow-band radio base station having narrow-band transmission/reception means for data transmission;

a wide-band radio base station having wide-band transmission means for data transmission; and

a radio terminal having narrow-band transmission/reception means for transmitting/receiving data to/from said narrow-band radio base station and wide-band reception means for receiving data from said wide-band radio base station,

wherein said radio terminal measures a received signal strength indicator of a signal transmitted from said narrow-band radio base station, and performs handover processing for said narrow-band radio base station when the measurement result is lower than a predetermined handover threshold level, and

said radio terminal includes means for changing the handover threshold level when data is received from said wide-band radio base station.

2. A radio communication system comprising:

a narrow-band radio base station having narrow-band transmission/reception means for data transmission;

a wide-band radio base station having wide-band transmission means for data transmission; and

a radio terminal having narrow-band transmission/reception means for transmitting/receiving data to/from said narrow-band radio bane station and wide band reception means far receiving data from said wide-band radio base station,

wherein said radio terminal measures a received signal strength indicator of a signal transmitted from said narrow-band radio base station, performs handover processing for said narrow-band radio base station when the measurement result is lower than a predetermined handover threshold level, and performs the handover processing when no data is received from said wide-band radio base station.

3. A radio communication system comprising:

a narrow-band radio base station having narrow-band transmission/reception means for data transmission;

a wide-band radio base station having wide-band transmission means for data transmission;

a server for providing a predetermined service through said radio base stations; and

a radio terminal having narrow-band transmission reception means for transmitting/receiving data to/from said narrow-band radio base station and wide-band reception means for receiving data from said wide-band radio base station,

wherein said radio terminal includes means for measuring a received signal strength indicator of a signal transmitted from said narrow-band radio base station, and means for transmitting a signal for stopping data transmission from said server to said wide-band radio base station when the measurement result is lower than a predetermined threshold level.

4. A system according to claim 3, wherein the threshold level in said radio terminal is set to be not less than the handover threshold.