Cellular communications system employing wireless optical links
First Claim
1. A cellular communication system based on a plurality of radio-based communication units, said communication system comprising:
- a central main communication unit;
a primary-cell radio-based communication unit interconnected to said central main unit;
a number of secondary-cell radio-based communication units, each of which is connected to said primary-cell radio-based communication unit via a respective wireless optical link and provided as a remote radio unit forming a distributed radio base station together with said central main unit, said distributed radio base station having radio transceiver functionality divided between said remote secondary-cell radio unit and said central main unit;
means for measuring the quality of at least one of said wireless optical links;
means for re-directing radio traffic, if the measured wireless optical link quality associated with a secondary-cell communication unit is insufficient, from the secondary-cell communication unit to another one of said communication units within said cellular communication system; and
means for making a determination if radio coverage of the another one of said communication units covers an area where the wireless optical link quality associated with the secondary-cell communication unit is insufficient, and if the determination is negative for increasing the radio coverage of the another one of said communication units.
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Accused Products
Abstract
The invention relates to a cellular communication system based on a central main unit, a primary-cell communication unit connected to the central main unit, and a number of secondary-cell communication units. Each secondary-cell unit is connected to the primary-cell unit via a respective wireless optical link. The secondary-cell communication units are preferably remote radio units in a distributed radio base system, where each remote radio unit forms a distributed radio base station together with the central main unit. The wireless optical link quality is measured to detect reduced link availability. The invention compensates for insufficient link availability by providing adequate radio coverage from another communication unit within the cellular system and re-directing the radio traffic to that communication unit. Adequate radio coverage from another communication unit within the cellular system and re-directing the radio traffic to that communication unit. Adequate radio coverage is accomplished either by dynamically increasing the radio coverage or using a micro-macro cell architecture.
106 Citations
24 Claims
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1. A cellular communication system based on a plurality of radio-based communication units, said communication system comprising:
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a central main communication unit; a primary-cell radio-based communication unit interconnected to said central main unit; a number of secondary-cell radio-based communication units, each of which is connected to said primary-cell radio-based communication unit via a respective wireless optical link and provided as a remote radio unit forming a distributed radio base station together with said central main unit, said distributed radio base station having radio transceiver functionality divided between said remote secondary-cell radio unit and said central main unit; means for measuring the quality of at least one of said wireless optical links; means for re-directing radio traffic, if the measured wireless optical link quality associated with a secondary-cell communication unit is insufficient, from the secondary-cell communication unit to another one of said communication units within said cellular communication system; and means for making a determination if radio coverage of the another one of said communication units covers an area where the wireless optical link quality associated with the secondary-cell communication unit is insufficient, and if the determination is negative for increasing the radio coverage of the another one of said communication units. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 12, 13)
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10. A cellular communication system based on a plurality of radio-based communication units, said communication system comprising:
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a central main communication unit; a primary-cell radio-based communication unit interconnected to said central main unit; a number of secondary-cell radio-based communication units, each of which is connected to said primary-cell radio-based communication unit via a respective wireless optical link and provided as a remote radio unit forming a distributed radio base station together with said central main unit, said distributed radio base station having radio transceiver functionality divided between said remote secondary-cell radio unit and said central main unit; means for measuring the quality of at least one of said wireless optical links; and means for re-directing radio traffic, if the measured wireless optical link quality associated with a secondary-cell communication unit is insufficient, from the secondary-cell communication unit to another one of said communication units within said cellular communication system; wherein said secondary-cell communication unit with insufficient wireless optical link quality is a micro-cell communication unit and said other communication unit is a macro-cell communication unit; means for causing said secondary-cell communication unit with insufficient wireless optical link quality to enter radio stand-by mode, and wherein in stand-by mode the secondary-cell communication unit is operable for locally initiating handover by reducing the RF output power. - View Dependent Claims (11, 14, 15, 16, 17)
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18. A cellular communication system based on a plurality of radio-based communication units, said communication system comprising:
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a central main communication unit; a primary-cell radio-based communication unit interconnected to said central main unit; a number of secondary-cell radio-based communication units, each of which is connected to said primary-cell radio-based communication unit via a respective wireless optical link and provided as a remote radio unit forming a distributed radio base station together with said central main unit, said distributed radio base station having radio transceiver functionality divided between said remote secondary-cell radio unit and said central main unit; a link quality analysis unit for measuring the quality of at least one of said wireless optical links; means for re-directing radio traffic, if the measured wireless optical link quality associated with a secondary-cell communication unit is insufficient, from the secondary-cell communication unit to another one of said communication units within said cellular communication system and means for making a determination if radio coverage of the another one of said communication units covers an area where the wireless optical link quality associated with the secondary-cell communication unit is insufficient, and if the determination is negative for increasing the radio coverage of the another one of said communication units.
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19. A method of operating a cellular communication system based on a plurality of radio-based communication units, said communication system comprising a central main communication unit, a primary-cell radio-based communication unit interconnected to said central main unit, and a number of secondary-cell radio-based communication units, each of which is connected to said primary-cell radio-based communication unit via a respective wireless optical link and provided as a remote radio unit forming a distributed radio base station together with said central main unit, said distributed radio base station having radio transceiver functionality divided between said remote secondary-cell radio unit and said central main unit;
- the method comprising;
measuring quality of at least one of said wireless optical links; re-directing radio traffic, if the measured wireless optical link quality associated with a secondary-cell communication unit is insufficient, from the secondary-cell communication unit to another one of said communication units within said cellular communication system; making a determination if radio coverage of the another one of said communication units covers an area where the wireless optical link quality associated with the secondary-cell communication unit is insufficient; and if the determination is negative, increasing the radio coverage of the another one of said communication units. - View Dependent Claims (20, 21, 22, 23, 24)
- the method comprising;
Specification