Method and apparatus for synchronizing synchronous information of each base station in cordless telephone system

• US 6,119,015 A
• Filed: 09/25/1997
• Issued: 09/12/2000
• Est. Priority Date: 09/25/1996
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Eun, Jin-Puo
• Primary Examiner(s): Bost, Dwayne D.
• Assistant Examiner(s): Persino, Raymond B.
• Application Number:
  US08/937,458
• Time in Patent Office: 1,083 Days
• Field of Search: 455/502, 455/422, 455/465, 455/403, 455/436, 455/438, 455/524, 455/561, 455/70, 455/88, 455/421, 455/67.1, 455/560, 370/504, 370/331, 370/510, 370/503, 370/506, 370/347, 370/509, 370/350, 370/520, 370/366, 370/363, 375/356, 375/354, 375/366, 375/363
• US Class Current: 455/502
• CPC Class Codes: H04M 1/733 with a plurality of base stations connected to a plurality of lines for selection in cordless PBX H04W84/16
• CPC Class Codes: H04M 2250/08 home cordless telephone systems using the DECT standard
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 92/12 between access points and access point controllers

Abstract

A cordless telephone system synchronizes a frame number, a multi-frame number, and a primary scan carrier number (PSCN) of every base stations, to provide an inter-cell handover between the base station. The cordless telephone system includes a plurality of slave base station connectors each having a plurality of base stations connected thereto, a master base station connector having a plurality of the base stations connected thereto, and a plurality of DECT terminals connected to the base stations, wherein the cordless telephone system provides a radio communication service to a DECT terminal subscriber accommodated by a PABX or key system. The cordless telephone system initializes the slave base station connectors, requests a multi-frame transmission to the master base station connector when an interrupt for synchronization is generated, and transfers a multiframe number to the slave base station connector when a next interrupt is generated from the master base station connector. Therefore, a frame number and the multiframe number and a PSCN of all base stations are synchronized.

Claims

1. A method for synchronizing synchronous information in a cordless telephone system, comprising the steps of:

providing a main system and a plurality of primary base stations and a plurality of secondary base stations in a cordless telephone system;

initializing each slave base station connector contained in said main system, each slave base station connector respectively serving a corresponding said plurality of secondary base stations;

requesting a multi-frame transmission to a master base station connector contained in said main system serving said plurality of primary base stations, when an interrupt for synchronization is generated; and

when a next interrupt is generated from the master base station connector, transferring a multi-frame number to each said slave base station connector for synchronizing a frame number and the multi-frame number and a primary scan carrier number of all base stations for radio communication services.

2. The method of claim 1, further comprised of generating said interrupt for synchronization at a period of 800 msec.

3. The method of claim 1, further comprised of said main system corresponding to one of a private automatic branch exchange system and a key system.

4. The method of claim 1, further comprised of each base station comprising:

a connecting unit for exchanging signal information with one of the master base station connector and a corresponding slave base station connector of said main system;

a radio-frequency signal processor for allowing communication between the base station with mobile units assigned to the base station;

a digital European Cordless Telecommunications (DECT) protocol processor connected to the radio-frequency signal processor, for processing a physical layer and a medium access control layer of the digital European Cordless Telecommunications (DECT) protocol;

a voice processor disposed between the connecting unit and the digital European Cordless Telecommunications (DECT) protocol processor, for processing voice signal information from the connecting unit for transfer to the digital European Cordless Telecommunications (DECT) protocol processor, and for processing voice signal information from the digital European Cordless Telecommunications (DECT) protocol processor for transfer to the connecting unit; and

a controller for controlling operation of the connecting unit, the voice processor, and the digital European Cordless Telecommunications (DECT) protocol processor.

5. A method for synchronizing synchronous information in a cordless telephone system, comprising the steps of:

providing each slave base station connector, each slave base station connector having connected thereto a plurality of base stations;

providing a master base station connector having connected thereto a plurality of base stations;

providing a plurality of subscriber terminals respectively connected to the base stations, wherein the cordless telephone system provides a radio communication service to a terminal subscriber accommodated by one of a private automatic branch exchange system and a key system;

allowing the master base station connector to generate a first interrupt to each slave base station connector, upon initialization of each slave base station connector;

indicating that a synchronization process is started, upon generation of the first interrupt;

when each slave base station connector is designated, allowing a designated slave base station connector to request a multi-frame transmission to the master base station connector; and

when a next interrupt is generated from the master base station connector, transferring a multi-frame number to said designated slave base station connector, wherein a frame number and the multi-frame number and a primary scan carrier number of all base stations are synchronized.

6. A cordless telephone system, comprising:

a plurality of primary base stations at a first plurality of different remote locations;

a plurality of secondary base stations at a second plurality of different remote locations;

a private automatic branch exchange system connected to a telephone network for serving a plurality of individual telephones, said private automatic branch exchange system including a master base station connector serving, via wireless transmission, said plurality of primary base stations located at different remote locations, and a plurality of slave base station connectors each serving different secondary base stations of said plurality of secondary base stations at different remote locations, said private automatic branch exchange system synchronizing synchronous information of each base station by;

initializing said plurality of slave base station connectors;

receiving, via said master base station connector, a multi-frame transmission requested from any one of said plurality of primary base stations upon occurrence of an interrupt for synchronization from said master base station connector; and

when a subsequent interrupt for synchronization is generated from the master base station connector, transferring a multi-frame number to said plurality of slave base station connectors to synchronize a frame number, a multi-frame number, and a primary scan carrier number of all primary base stations and secondary base stations for radio communication services.

7. The cordless telephone system of claim 6, further comprised of said interrupt for synchronization being generated at a period of 800 msec.

8. The cordless telephone system of claim 6, further comprised of each base station comprising:

a connecting unit exchanging signal information with one of the master base station connector and a corresponding slave base station connector of said private automatic branch exchange system;

a radio-frequency signal processor allowing communication between the base station with mobile units assigned to communicate with the base station;

a digital European Cordless Telecommunications protocol processor connected to the radio-frequency signal processor, for processing a physical layer and a medium access control layer of a protocol; and

a voice processor disposed between said connecting unit and said digital European Cordless Telecommunications protocol processor, for processing voice signal information from the connecting unit for transfer to said digital European Cordless Telecommunications protocol processor, and for processing voice signal information from said digital European Cordless Telecommunications protocol processor for transfer to the connecting unit.

9. A cordless telephone system, comprising:

a plurality of primary base stations at a first plurality of different remote locations;

a plurality of secondary base stations at a second plurality of different remote locations;

a private automatic branch exchange system connected to a telephone network for serving a plurality of individual telephones, said private automatic branch exchange system including a master base station connector serving, via wireless transmission, said plurality of primary base stations located at different remote locations, and a plurality of slave base station connectors each serving different secondary base stations of said plurality of secondary base stations at different remote locations, said private automatic branch exchange system synchronizing synchronous information of each base station by;

initializing said plurality of slave base station connectors;

receiving, via said master base station connector, a multi-frame transmission requested from any one of said plurality of primary base stations upon occurrence of an interrupt for synchronization from said master base station connector; and

when a subsequent interrupt for synchronization is generated from the master base station connector, transferring a multi-frame number to said plurality of slave base station connectors to synchronize a frame number, a multi-frame number, and a primary scan carrier number of all primary base stations and secondary base stations for radio communication services, further comprised of each base station comprising;

a connecting unit exchanging signal information with one of the master base station connector and a corresponding slave base station connector of said private automatic branch exchange system;

a radio-frequency signal processor allowing communication between the base station with mobile units assigned to communicate with the base station;

a digital European Cordless Telecommunications protocol processor connected to the radio-frequency signal processor, for processing a physical layer and a medium access control layer of a protocol; and

a voice processor disposed between said connecting unit and said digital European Cordless Telecommunications protocol processor, for processing voice signal information from the connecting unit for transfer to said digital European Cordless Telecommunications protocol processor, and for processing voice signal information from said digital European Cordless Telecommunications protocol processor for transfer to the connecting unit, and further comprised of said radio-frequency signal processor comprising;

a modulator which is realized by a Gaussian filter for modulating signal information from said digital European Cordless Telecommunications protocol processor;

an up-converter for doubling a frequency of modulation data from the modulator;

a first band-pass filter for filtering a signal output from the up-converter within a frequency band of approximately 1.88 GHz to 1.9 GHz;

a first amplifier for amplifying a power of a signal output from the first band-pass filter;

a switch for enabling one of transmission and reception of a radio-frequency signal via an antenna under control of said digital European Cordless Telecommunications protocol processor;

a second band-pass filter for filtering a signal output received via the antenna within a frequency band of approximately 1.88 GHz to 1.9 GHz;

a second amplifier for amplifying a signal output from the second band-pass filter;

a third band-pass filter for filtering a signal output from the second amplifier within a frequency band of approximately 1.88 GHz to 1.9 GHz;

a down-converter for converting a frequency of a signal output from the third band-pass filter into a signal exhibiting a frequency of 110.592 MHz;

a third amplifier for amplifying a signal output from the down-converter; and

a demodulator for demodulating a signal output from the third amplifier for application to said digital European Cordless Telecommunications protocol processor.

10. The cordless telephone system of claim 9, further comprised of said interrupt for synchronization being generated at a period of 800 msec.

11. A method for synchronizing synchronous information in a cordless telephone system, comprising the steps of:

providing a main system and a plurality of primary base stations and a plurality of secondary base stations in a cordless telephone system;

initializing each slave base station connector contained in said main system, each slave base station connector respectively serving a corresponding said plurality of secondary base stations;

requesting a multi-frame transmission to a master base station connector contained in said main system serving said plurality of primary base stations, when an interrupt for synchronization is generated, further comprised of each base station comprising;

a connecting unit for exchanging signal information with one of the master base station connector and a corresponding slave base station connector of said main system;

a radio-frequency signal processor for allowing communication between the base station with mobile units assigned to the base station;

a digital European Cordless Telecommunications (DECT) protocol processor connected to the radio-frequency signal processor, for processing a physical layer and a medium access control layer of the digital European Cordless Telecommunications (DECT) protocol;

a voice processor disposed between the connecting unit and the digital European Cordless Telecommunications (DECT) protocol processor, for processing voice signal information from the connecting unit for transfer to the digital European Cordless Telecommunications (DECT) protocol processor, and for processing voice signal information from the digital European Cordless Telecommunications (DECT) protocol processor for transfer to the connecting unit; and

a controller for controlling operation of the connecting unit, the voice processor, and the digital European Cordless Telecommunications (DECT) protocol processor, further comprised of said radio-frequency signal processor comprising;

a modulator which is realized by a Gaussian filter for modulating signal information from the digital European Cordless Telecommunications (DECT) protocol processor;

an up-converter for doubling a frequency of modulation data from the modulator;

a first band-pass filter for filtering a signal output from the up-converter within a frequency band of approximately 1.88 GHz to 1.9 GHz;

a first amplifier for amplifying a power of a signal output from the first band-pass filter;

a switch for enabling one of transmission and reception of a radio-frequency signal via an antenna under control of the digital European Cordless Telecommunications (DECT) protocol processor;

a second band-pass filter for filtering a signal output received via the antenna within a frequency band of approximately 1.88 GHz to 1.9 GHz;

a second amplifier for amplifying a signal output from the second band-pass filter;

a third band-pass filter for filtering a signal output from the second amplifier within a frequency band of approximately 1.88 GHz to 1.9 GHz;

a down-converter for down converting a frequency of a signal output from the third band-pass filter into a signal exhibiting a frequency of 110.592 MHz;

a third amplifier for amplifying a signal output of the down-converter; and

a demodulator for demodulating a modulated signal received from the third amplifier for application to the digital European Cordless Telecommunications (DECT) protocol processor; and

when a next interrupt is generated from the master base station connector, transferring a multi-frame number to each said slave base station connector for synchronizing a frame number and the multi-frame number and a primary scan carrier number of all base stations for radio communication services.

12. The method of claim 11, further comprised of generating said interrupt for synchronization at a period of 800 msec.

13. The method of claim 11, further comprised of said main system corresponding to one of a private automatic branch exchange system and a key system.