发明名称 |
Cordless key telephone system for covering multiple service areas having exclusively assigned control channels |
摘要 |
In a cordless key telephone system for covering multiple service areas, access units are divided into groups corresponding respectively to the service areas, the access units of each group being located in the corresponding service area for broadcasting a recurrent sequence of address signals on a two-way radio control channel and carrying speech signals on an assigned two-way telephone channel. The access units of each group has a uniquely assigned control channel different in frequency from the control channel of the other group. Cordless stations are switchable to the control channel of a first group of the access units for detecting an address signal and subsequently switchable to the control channel of the access units of a second group if the address signal is not detected in a first sequence for detecting the addressed signal in a second sequence. A main controller is coupled to a switched telephone network for causing the access units to broadcast the address signals in response to an incoming call from the network and for establishing a connection between the network and one of the cordless stations.
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申请公布号 |
US5283817(A) |
申请公布日期 |
1994.02.01 |
申请号 |
US19910686469 |
申请日期 |
1991.04.17 |
申请人 |
NEC CORPORATION;NIPPON TELEGRAPH & TELEPHONE |
发明人 |
HARA, TOSHIHIRO;SHIMURA, YUKIHIRO;KUMATAKA, SHINJI;HASHIMOTO, KOSUKE |
分类号 |
H04W84/16;(IPC1-7):H04M11/00 |
主分类号 |
H04W84/16 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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