Wireless communication system
First Claim
1. A wireless communication system, comprising:
- a control apparatus;
at least one relay apparatus connected with said control apparatus via an optical transmission path; and
a plurality of wireless communication terminals communicating wirelessly with said at least one relay apparatus, wherein;
said control apparatus comprises;
a first optical transmitting section for converting a downstream electric signal into a downstream optical signal and transmitting the downstream optical signal to said at least one relay apparatus via the optical transmission path; and
a first optical receiving section for converting an upstream optical signal transmitted from said at least one relay apparatus via the optical transmission path into an upstream electric signal,said at least one relay apparatus comprises;
a second optical receiving section for converting the downstream optical signal transmitted from said control apparatus via the optical transmission path into the downstream electric signal;
a level control section for attenuating a level of the downstream electric signal so as to narrow a communicable area of said at least one relay apparatus and to allow a level of a wireless signal transmitted by one of said wireless communication terminals existing in the communicable area to be within a predetermined range;
wherein when said wireless communication terminals use a respective channel, the predetermined range is smaller than a difference between (a) a leakage ratio which is a ratio of a level of a wireless signal using the respective channel with respect to a level of a frequency component leaking to another channel different from the respective channel, and (b) a signal to noise ratio which is a ratio of a level of a leakage signal from a wireless communication terminal using another channel different from the respective channel with respect to the level of the wireless signal using the respective channel;
a transmitting/receiving antenna section for transmitting the downstream electric signal converted by said second optical receiving section to said one wireless communication terminal as a wireless signal, and receiving a wireless signal transmitted from said one wireless communication terminal as the upstream electric signal; and
a second optical transmitting section for converting the upstream electric signal received by said transmitting/receiving antenna section into the upstream optical signal and transmitting the upstream optical signal to said control apparatus via the optical transmission path.
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Accused Products
Abstract
A wireless communication system capable of keeping a level of a wireless signal received by a relay apparatus within a predetermined dynamic range. In a control apparatus, a transmitting section converts a downstream electric signal into a downstream optical signal and transmits the downstream optical signal to the relay apparatus via an optical transmission path. The relay apparatus converts the received downstream optical signal into a downstream electric signal and transmits the downstream electric signal as a wireless signal to a wireless communication terminal from a transmitting/receiving antenna section. In the relay apparatus, a level adjustment section adjusts the level of the wireless signal transmitted by the relay apparatus such that the receiving level of the wireless signal received by the relay apparatus is kept within a predetermined range.
95 Citations
28 Claims
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1. A wireless communication system, comprising:
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a control apparatus; at least one relay apparatus connected with said control apparatus via an optical transmission path; and a plurality of wireless communication terminals communicating wirelessly with said at least one relay apparatus, wherein; said control apparatus comprises; a first optical transmitting section for converting a downstream electric signal into a downstream optical signal and transmitting the downstream optical signal to said at least one relay apparatus via the optical transmission path; and a first optical receiving section for converting an upstream optical signal transmitted from said at least one relay apparatus via the optical transmission path into an upstream electric signal, said at least one relay apparatus comprises; a second optical receiving section for converting the downstream optical signal transmitted from said control apparatus via the optical transmission path into the downstream electric signal; a level control section for attenuating a level of the downstream electric signal so as to narrow a communicable area of said at least one relay apparatus and to allow a level of a wireless signal transmitted by one of said wireless communication terminals existing in the communicable area to be within a predetermined range;
wherein when said wireless communication terminals use a respective channel, the predetermined range is smaller than a difference between (a) a leakage ratio which is a ratio of a level of a wireless signal using the respective channel with respect to a level of a frequency component leaking to another channel different from the respective channel, and (b) a signal to noise ratio which is a ratio of a level of a leakage signal from a wireless communication terminal using another channel different from the respective channel with respect to the level of the wireless signal using the respective channel;a transmitting/receiving antenna section for transmitting the downstream electric signal converted by said second optical receiving section to said one wireless communication terminal as a wireless signal, and receiving a wireless signal transmitted from said one wireless communication terminal as the upstream electric signal; and a second optical transmitting section for converting the upstream electric signal received by said transmitting/receiving antenna section into the upstream optical signal and transmitting the upstream optical signal to said control apparatus via the optical transmission path. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A wireless communication system, comprising:
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a control apparatus; at least one relay apparatus connected with said control apparatus via an optical transmission path; and a plurality of wireless communication terminals communicating wirelessly with said at least one relay apparatus, wherein; said control apparatus comprises; a first optical transmitter operable to convert a downstream electric signal into a downstream optical signal and transmit the downstream optical signal to said at least one relay apparatus via the optical transmission path; and a first optical receiver operable to convert an upstream optical signal transmitted from said at least one relay apparatus via the optical transmission path into an upstream electric signal, said at least one relay apparatus comprises; a second optical receiver operable to convert the downstream optical signal transmitted from said control apparatus via the optical transmission path into the downstream electric signal; a level controller operable to attenuate a level of the downstream electric signal so as to narrow a communicable area of said at least one relay apparatus and to allow a level of a wireless signal transmitted by one of said wireless communication terminals existing in the communicable area to be within a predetermined range;
wherein when said wireless communication terminals use a respective channel, the predetermined range is smaller than a difference between (a) a leakage ratio which is a ratio of a level of a wireless signal using the respective channel with respect to a level of a frequency component leaking to another channel different from the respective channel, and (b) a signal to noise ratio which is a ratio of a level of a leakage signal from a wireless communication terminal using another channel different from the respective channel with respect to the level of the wireless signal using the respective channel;a transmitting/receiving antenna section operable to transmit the downstream electric signal converted by said second optical receiver to said one wireless communication terminal as a wireless signal, and receive a wireless signal transmitted from said one wireless communication terminal as the upstream electric signal; and a second optical transmitter operable to convert the upstream electric signal received by said transmitting/receiving antenna section into the upstream optical signal and transmit the upstream optical signal to said control apparatus via the optical transmission path. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification