Cordless modem system having multiple base and remote stations which are interusable and secure

• US 7,142,519 B2
• Filed: 06/29/2001
• Issued: 11/28/2006
• Est. Priority Date: 05/13/1994
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Fulton, Paul R., Saadeh, Said S.
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Jain, Raj
• Application Number:
  US09/896,428
• Publication Number:
  US 20020006812A1
• Time in Patent Office: 1,978 Days
• Field of Search: 370/310, 370/310.2, 370/328, 455/3.05, 455/403, 455/432.1, 455/421, 455/443, 4555561-561, 455/91, 455/92, 455/465, 455/447, 455/448, 710/64, 710/65, 710/72
• US Class Current: 370/310.2
• CPC Class Codes: H04M 1/725 Cordless telephones user interfaces specially adapted therefor H04M1/724
• 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 11/06 Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 12/08 Access security
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 74/00 Wireless channel access
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 92/00 Interfaces specially adapted for wireless communication networks

Abstract

A cordless modem system where a mobile station unit (MSU) is located in the computer and a base station unit (BSU) is connected to the telephone line. A radio frequency (RF) link is developed between the two units to allow a cordless connection. A series of commands are used between the two units to allow the MSU to request a channel, the BSU to grant a channel, the BSU to notify of a ring, and the MSU to request the BSU to go off hook. In addition, there is preferably a command sequence to allow authorization of a particular MSU or BSU. There are two full duplex channels in each MSU and BSU. This allows multiple BSUS and MSUS to be utilized in a small area. Communications between the two units are secure based on address values for each 15 unit contained in the various commands.

Claims

1. A system for transmitting modem data between a modem in a computer and a telephone line, the system comprising:

a mobile unit connected to the modem, said mobile unit having an identification value and including;

means for receiving modem data from and providing modem data to the modem;

a radio frequency transceiver connected to said mobile unit means for receiving and providing modem data for transmitting and receiving modem data over a radio frequency channel;

means connected to said mobile unit radio frequency transceiver for providing and receiving command information over said radio frequency channel; and

means connected to said mobile unit command information means for performing operations responsive to received command information; and

a base unit connected to the telephone line, said base unit having an identification value and including;

means for receiving modem data from and providing modem data to the telephone line;

a radio frequency transceiver connected to said base unit means for receiving and providing modem data for transmitting and receiving modem data over a radio frequency channel, said base unit radio frequency transceiver operating with said mobile unit radio frequency transceiver;

means connected to said base unit radio frequency transceiver for providing and receiving command information over said radio frequency channel; and

means connected to said base unit command information means for performing operations responsive to received command information,

wherein command information provided by said mobile unit command information means and said base unit command information means includes said mobile unit identification value and said base unit identification value and wherein said mobile unit means for performing operations operates only if said received command information includes the identification value of said mobile unit.

2. The system of claim 1, wherein said mobile unit command information means further provides an initial request command, wherein said initial request command including said mobile unit identification value but not said base unit identification value, and wherein said base unit means for performing operations is responsive to received command information containing said base unit identification value only if said received base unit identification value is the identification value of said base unit.

3. The system of claim 1, wherein said base unit command information means provides a ring indication command when a ring is received from the telephone line.

4. The system of claim 3, wherein said mobile station means for performing operations causes said mobile unit command information means to provide a ring acknowledge command in response to said ring indication command.

5. The system of claim 3, wherein said mobile station means for performing operations causes said mobile unit command information means to provide an off hook command in response to said ring indication command.

6. The system of claim 5, wherein said base unit means for performing operations causes said base unit to go off hook in response to said off hook command.

7. The system of claim 2, wherein said base unit means for performing operations causes said base unit command information means to provide an authorization grant command in response to an initial request command.

8. The system of claim 7, wherein said mobile station means for performing operations causes said mobile unit command information means to provide an off hook command in response to said authorization grant command.

9. The system of claim 8, wherein said base unit means for performing operations causes said base unit to go off hook in response to said off hook command.

10. The system of claim 1, wherein said mobile unit radio frequency transceiver uses a first frequency to transmit and a second frequency to receive and wherein said base unit radio frequency transceiver uses said second frequency to transmit and said first frequency to receive.

11. A system for transmitting modem data between a plurality of computers, each computer including a modem, and a plurality of telephone lines, the system comprising:

a plurality of mobile units, each connected to the modem in one of the plurality of computers, each said mobile unit having an identification value and including;

means for receiving modem data from and providing modem data to the modem;

a radio frequency transceiver connected to said mobile unit means for receiving and providing modem data for transmitting and receiving modem data over a radio frequency channel;

means connected to said mobile unit radio frequency transceiver for providing and receiving command information over said radio frequency channel; and

means connected to said mobile unit command information means for performing operations responsive to received command information; and

a plurality of base units, each connected to one of the plurality of telephone lines, each said base unit having an identification value and including;

means for receiving modem data from and providing modem data to the telephone line;

a radio frequency transceiver connected to said base unit means for receiving and providing modem data for transmitting and receiving modem data over a radio frequency channel, said base unit radio frequency transceiver operating with said mobile unit radio frequency transceiver;

means connected to said base unit radio frequency transceiver for providing and receiving command information over said radio frequency channel; and

means connected to said base unit command information means for performing operations responsive to received command information,

wherein command information provided by said mobile unit command information means and said base unit command information means includes said mobile unit identification value and said base unit identification value, wherein said mobile unit means for performing operations operates only if said received command information includes the identification value of said mobile unit and wherein said plurality of mobile units and said plurality of base units are all within effective radio frequency channel range of each other.

12. The system of claim 11, wherein said mobile unit command information means further provides an initial request command, wherein said initial request command including said mobile unit identification value but not said base unit identification value, and wherein said base unit means for performing operations is responsive to received command information containing said base unit identification value only if said received base unit identification value is the identification value of said base unit.

13. The system of claim 11, wherein said base unit command information means provides a ring indication command when a ring is received from the telephone line.

14. The system of claim 13, wherein said mobile station means for performing operations causes said mobile unit command information means to provide a ring acknowledge command in response to said ring indication command.

15. The system of claim 13, wherein said mobile station means for performing operations causes said mobile unit command information means to provide an off hook command in response to said ring indication command.

16. The system of claim 15, wherein said base unit means for performing operations causes said base unit to go off hook in response to said off hook command.

17. The system of claim 12, wherein said base unit means for performing operations causes said base unit command information means to provide an authorization grant command in response to an initial request command.

18. The system of claim 17, wherein said mobile station means for performing operations causes said mobile unit command information means to provide an off hook command in response to said authorization grant command.

19. The system of claim 18, wherein said base unit means for performing operations causes said base unit to go off hook in response to said off hook command.

20. The system of claim 11, wherein said mobile unit radio frequency transceiver uses a first frequency to transmit and a second frequency to receive and wherein said base unit radio frequency transceiver uses said second frequency to transmit and said first frequency to receive.

21. The system of claim 11, wherein each said mobile unit radio frequency transceiver and said base unit radio frequency transceiver provide and receive modem data and command information over one of two different channels, wherein said mobile unit command information means further provides an initial request command responsive to an off hook request from the modem, wherein said mobile unit command information means provides said initial request command after determining that one of said two radio frequency channels is vacant, wherein said base unit command information means further provides a ring indication command when a ring is received from the telephone line and wherein said base unit command information means provides said ring indication command after determining that one of said two radio frequency channels is vacant.