Multi-mode communication network with handset-selected channel assignments

• US 5,774,805 A
• Filed: 06/06/1996
• Issued: 06/30/1998
• Est. Priority Date: 02/24/1994
• Status: Expired due to Term

• Current Assignee: GTE Wireless Incorporated (Verizon Communications Inc.)
• Original Assignee: GTE Mobile Communications Service Corporation (Verizon Communications Inc.)
• Inventors: Zicker, Robert G.
• Primary Examiner(s): Bost, Dwayne D.
• Assistant Examiner(s): WYCHE, MYRON
• Application Number:
  US08/660,031
• Time in Patent Office: 754 Days
• Field of Search: 455/450, 455/451, 455/452, 455/454, 455/455, 455/553, 455/462, 455/463, 455/465, 455/552, 455/418, 455/410, 455/426
• US Class Current: 455/426.1
• CPC Class Codes: H04M 1/2745 using static electronic memories, e.g. chips
• CPC Class Codes: H04M 1/57 Arrangements for indicating or recording the number of the calling subscriber at the called subscriber's set at the operator set in a manual exchange H04M5/20
• CPC Class Codes: H04M 1/724 User interfaces specially adapted for cordless or mobile telephones
• CPC Class Codes: H04M 1/725 Cordless telephones user interfaces specially adapted therefor H04M1/724
• CPC Class Codes: H04M 1/72511 Searching for available channels
• CPC Class Codes: H04Q 2213/13098 Mobile subscriber
• CPC Class Codes: H04Q 2213/13213 Counting, timing circuits
• CPC Class Codes: H04W 16/16 for PBS [Private Base Station] arrangements
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 48/14 using user query or user detection
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 84/105 PBS [Private Base Station] network H04W84/12 - H04W84/16 take precedence
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A multi-mode communication network (12) accommodates piloted cellular operation and pilotless cordless operation using a multi-mode handset (18). A common pool of channels (28) serves cellular and cordless operations. At least some channels from a cordless subset (32) of the pool of channels (28) are unused in cellular operations regardless of location. The handset (18) monitors forward portions of all cordless subset channels when the handset (18) is within the coverage area (16) of its cordless base station (22). Unused channels are indicated on a dormant channel list (70), which is passed to the handset'"'"'s cordless base station (22) when the handset (18) registers for cordless operation. The cordless base station (22) makes an active channel list (62) based upon the dormant channel list (70). Cordless operation messages transmitted from either a handset (18) or cordless base station (22) use a channel selected from the active channel list (62).

Claims

1. In a multi-mode communication network in which a common pool of channels is used for both cellular mode communications and cordless mode communications and in which radio coverage areas of a cellular land station and a cordless base station overlap, a method of operating a portable radiotelephone handset comprising the steps of:

determining a location for said handset;

identifying, after said determining step, a plurality of radio communication channels which are unused by said cellular land station, said identifying step being performed when said location determining step indicates that said handset is located proximate said cellular base station;

passing identities of said channels to said cordless base station; and

engaging in user communications with said cordless base station using one of said channels.

2. A method as claimed in claim 1 wherein:

said method additionally comprises the step of receiving, after said passing step, a list of available channels from said cordless base station; and

said engaging step is configured to utilize a channel identified by said available channel list while engaging in said user communications.

8. A method as claimed in claim 1 wherein:

said location determining step determines when said handset is within said radio coverage area of said cordless base station; and

said identifying step is performed when said handset is within said radio coverage area of said cordless base station.

9. A method as claimed in claim 1 wherein said identifying step comprises the steps of:

sequentially tuning a receiver to a predetermined plurality of radio communication channels;

for each of said plurality of channels, detecting signal strength of RF energy received over said channel; and

for each of said plurality of channels, determining whether said signal strength for said channel is less than a predetermined threshold.

10. A method as claimed in claim 9 wherein:

additional cordless base stations may be located near said cordless base station; and

said identifying step additionally comprises the step of defining, for any of said plurality of channels, a channel conveying a communication originating at any of said cordless base stations as being unused by said land station.

3. In a multi-mode communication network in which a common pool of channels is used for both cellular mode communications and cordless mode communications and in which radio coverage areas of a cellular land station and a cordless base station overlap, wherein said cellular land station communicates using a first subset of said pool of channels and said cordless base station communicates using channels selected from a second subset of said pool of channels, a method of operating a portable radiotelephone handset configured to communicate with said land station and said cordless base station over any channel included in said common pool of channels, said method comprising the steps of:

identifying a plurality of radio communication channels which are unused by said cellular land station, by monitoring each channel included in said second subset to determine which of said second subset of channels also belongs to said first subset;

passing identities of said channels to said cordless base station; and

engaging in user communications with said cordless base station using one of said channels.

4. A method as claimed in claim 3 wherein said second subset of channels is configured as a contiguous block of channels.

5. A method as claimed in claim 3 additionally comprising the steps of:

monitoring a forward portion of a pilot channel continuously transmitted by said land station when operating in said cellular mode; and

monitoring forward portions of all channels included in said second subset of channels when operating in said cordless mode.

6. A method as claimed in claim 3 wherein said identifying step comprises the step of selecting a third subset of channels wherein each channel in said third subset of channels is included in said second subset of channels and said third subset of channels has fewer channels than said second subset of channels.

7. A method as claimed in claim 6 wherein:

said selecting step comprises the step of limiting said third subset to include a maximum number of channels, said maximum number of channels being less than 75% of the number of channels included in said second subset of channels; and

said passing step passes said third subset of channels to said cordless base station.

11. In a multi-mode communication network in which a common pool of channels is used for both cellular mode communications and cordless mode communications and in which radio coverage areas of a cellular land station and a cordless base station overlap, a method of operating a cordless radiotelephone communication system comprising the steps of:

identifying, in a portable radiotelephone handset configured to provide said cellular and said cordless modes of communications and to move within said radio coverage area of said cordless base station, a plurality of radio communication channels which are unused by said cellular land station;

passing identities of said plurality of channels from said handset to said cordless base station; and

engaging in user communications between said handset and said cordless base station using one of said channels.

12. In a multi-mode communication network in which a common pool of channels is used for both cellular mode communications and cordless mode communications and in which radio coverage areas of a cellular land station and a cordless base station overlap, a method of operating a cordless radiotelephone communication system comprising the steps of:

identifying, in a handset configured to operate in said cordless mode, a plurality of radio communication channels which are unused by said cellular land station;

passing identities of said plurality of channels from said handset to said cordless base station;

composing, in said cordless base station after said passing step, a list of available channels, said list of available channels being responsive to said plurality of channels;

transmitting said list of available channels from said cordless base station to said handset; and

engaging in user communications between said handset and said cordless base station using one of said channels by selecting a channel from said available channel list on which to conduct said user communications.

13. A method as claimed in claim 12 additionally comprising the step of monitoring, at said cordless base station, all channels included on said available channel list to detect an incoming message from said handset, said incoming message being transmitted on any of said channels included on said available channel list.

14. In a multi-mode communication network in which a common pool of channels is used for both cellular mode communications and cordless mode communications and in which radio coverage areas of a cellular land station and a cordless base station overlap, wherein said cellular land station communicates using a first subset of said pool of channels and said cordless base station communicates using channels selected from a second subset of said pool of channels, a method of operating a cordless radiotelephone communication system comprising the steps of:

identifying, in a handset configured to operate in said cordless mode, a plurality of radio communication channels which are unused by said cellular land station, said identifying step comprising the step of monitoring each channel included in said second subset to determine which of said second subset of channels also belongs to said first subset;

passing identities of said plurality of channels from said handset to said cordless base station; and

engaging in user communications between said handset and said cordless base station using one of said channels.

15. A method as claimed in claim 14 wherein:

said handset is configured to engage in cellular mode communications with said cellular land station and to engage in cordless mode communications with said cordless base station;

said method additionally comprises the step of monitoring, at said handset, a pilot channel continuously transmitted by said cellular land station when said handset operates in said cellular mode; and

said method additionally comprises the step of monitoring, at said handset, all channels included in said second subset of channels when said handset operates in said cordless mode.

16. A multi-mode portable radiotelephone which communicates in a cellular mode with a cellular land station having a first radio coverage area and in a cordless mode with a cordless base station having a second radio coverage area, said first and second areas overlapping each other, said portable radiotelephone comprising:

a controller;

an RF transmitter coupled to said controller; and

an RF receiver coupled to said controller;

wherein,

said portable radiotelephone moves within said second radio coverage area; and

said controller is configured to control said portable radiotelephone receiver to identify a plurality of radio communication channels which are unused by said cellular land station, to cause said portable radiotelephone transmitter to pass identities of said channels to said cordless base station, and to cause said portable radiotelephone transmitter and receiver to engage in user communications with said cordless base station using one of said channels.

17. A multi-mode portable radiotelephone configured to communicate in a cellular mode with a cellular land station having a first radio coverage area and in a cordless mode with a cordless base station having a second radio coverage area, said first and second areas overlapping each other, over any channel included in a pool of channels, wherein said cellular land station communicates using a first subset of said pool of channels, said cordless base station communicates using channels selected from a second subset of said pool of channels, said portable radiotelephone comprising:

a controller;

a transmitter coupled to said controller; and

a receiver coupled to said controller;

wherein,

said controller is configured to control said receiver to monitor each channel included in said second subset to determine which of said second subset of channels also belongs to said first subset, to identify a plurality of radio communication channels which are unused by said cellular land station, to cause said transmitter to pass identities of said channels to said cordless base station, and to cause said transmitter and receiver to engage in user communications with said cordless base station using one of said channels.

18. A portable radiotelephone as claimed in claim 17 wherein said second subset of channels is configured as a contiguous block of channels.

19. A multi-mode portable radiotelephone which communicates in a cellular mode with a cellular land station having a first radio coverage area and in a cordless mode with a cordless base station having a second radio coverage area, said first and second areas overlapping each other, said portable radiotelephone comprising:

a controller;

a transmitter coupled to said controller; and

a receiver coupled to said controller;

wherein,

said controller is configured to verify that said handset is located in said second radio coverage area prior to identifying a plurality of radio communication channels which are unused by said cellular land station, to cause said transmitter to pass identities of said channels to said cordless base station, and to cause said transmitter and receiver to engage in user communications with said cordless base station using one of said channels.

20. In a multi-mode communication network in which a common pool of channels is used for both cellular mode communications and cordless mode communications and in which a radio coverage area of a cellular land station overlies radio coverage areas for a plurality of cordless base stations, a method of operating a portable radiotelephone handset comprising the steps of:

identifying a used channel at said handset from said common pool of channels;

determining, in said handset, whether said used channel is conveying a cordless communication originating from one of said cordless base stations;

defining said used channel as being an available channel if said user-channel is conveying said cordless communication; and

passing an identity of said available channel from said handset to a home one of said cordless base stations to assign said available channel to said home cordless base station.

21. A method as claimed in claim 20 additionally comprising, after said passing step, the steps of:

deciding whether said available channel is in use;

refraining from using said available channel to communicate with said home cordless base station when said deciding step decides that said available channel is in use; and

engaging in user communications with said home cordless base station using said available channel when said deciding step decides that said available channel is not in use.

22. A method as claimed in claim 20 wherein said identifying step comprises the steps of:

sequentially tuning a receiver to a predetermined plurality of radio communication channels;

for each of said plurality of channels, detecting signal strength of RF energy received over said channel; and

for each of said plurality of channels, determining whether said signal strength for said channel is greater than a predetermined threshold.

23. A method as claimed in claim 20 wherein:

said handset is configured to communicate with said land station and said home cordless base station over any channel included in said pool of channels;

said cellular land station communicates using a first subset of said pool of channels;

said cordless base stations communicate using channels selected from a second subset of said pool of channels; and

said identifying step comprises the step of monitoring each channel included in said second subset of channels.

24. A method as claimed in claim 23 additionally comprising the steps of:

monitoring a forward portion of a pilot channel continuously transmitted by said land station when operating in said cellular mode; and

monitoring forward portions of all channels included in said second subset of channels when operating in said cordless mode.

25. A method as claimed in claim 20 additionally comprising the steps of:

determining a location for said handset prior to said identifying step; and

performing said identifying step when said location determining step indicates that said handset is located proximate said cellular base station.

26. A method as claimed in claim 25 wherein:

said location determining step determines when said handset is within said radio coverage area of said home cordless base station; and

said identifying step is performed when said handset is within said radio coverage area of said home cordless base station.