Cordless cellular system

• US 6,611,692 B2
• Filed: 09/04/2002
• Issued: 08/26/2003
• Est. Priority Date: 09/08/1995
• Status: Expired due to Fees

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Wireless Services Incorporated (AT&T, Inc.)
• Inventors: Jarett, Keith, Williams, Roland E., Raffel, Michael A., Leuca, Ileana A., Winship, Peter L., Bamburak, Michael D., Kibria, Masud, Lawrence, Christopher G., Nelson, Roderick, Marx, Joseph P., Glass, David R., Lee, Tony S., OʼNeill, Paul B.
• Primary Examiner(s): Cumming, William
• Application Number:
  US10/235,039
• Publication Number:
  US 20030050090A1
• Time in Patent Office: 356 Days
• Field of Search: 455/406, 455/462, 455/450, 455/556, 455/552, 455/553, 455/465, 455/416, 455/168.1, 455/445, 455/433, 455/432, 370/331, 370/330, 320/115, 375/220
• US Class Current: 455/552.1
• CPC Class Codes: H04W 16/16 for PBS [Private Base Station] arrangements
• CPC Class Codes: H04W 16/20 for indoor coverage or short range network deployment
• CPC Class Codes: H04W 40/248 Connectivity information update
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 60/04 using triggered events
• CPC Class Codes: H04W 60/06 De-registration or detaching
• CPC Class Codes: H04W 72/54 based on quality criteria
• 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

Abstract

A mobile station communicates with both a cellular network, by which it is assigned a mobile identification number, and to a cordless cellular base station utilizing the same cellular frequency range and communications protocol. The cordless cellular base station is preferably connected to a public switched telephone network and is assigned a landline number. The cordless cellular base station acts as a conduit between the mobile station and the public switched telephone network. When the mobile station comes within range of a cordless cellular base station, it deregisters automatically from the cellular network and register with the cordless cellular base station. Once the mobile station is communicating with the cordless cellular base station, the cordless cellular base station communicates with the cellular network to instruct the cellular network to route all calls for mobile identification number to the cordless cellular base station'"'"'s landline number. In addition, all calls placed on the mobile station are sent through the cordless cellular base station to the public switched telephone network. When the mobile station severs contact with the cordless cellular base station, the mobile station registers with the regional cellular base station of the regional cellular network. The cordless cellular base station then sends a network forwarding cancellation message to the cellular network to cancel the forwarding of calls for the mobile station'"'"'s identification number. Once the mobile station is registered with the regional cell, calls to the mobile stations identification number are directly routed by the cellular network to the mobile station.

Claims

1. A method of controlling a base station, the base station coupled to a cellular network and a public switched telephone network (PSTN) to support a dual mode mobile telephone to provide both cellular service and cordless landline service, wherein the method of controlling the base station comprises the steps of:

initially registering with the cellular network to receive operational information including base station operating frequencies and base station operating power levels that support user-selected service levels;

registering the mobile telephone to receive telephone service through the base station upon being detected by the mobile telephone, wherein the mobile telephone, while operating in a cellular mode and communicating via the cellular network, detects the base station using the base station operating power levels to recognize locations that are in proximity to the base station and searches for the base station using stored base station identification information when in proximity to the base station, wherein the mobile telephone automatically de-registers with the cellular network upon detecting the base station;

receiving confirmation that the mobile telephone has automatically switched from providing cellular service to providing cordless landline service;

providing a call forwarding update message to the cellular network upon receiving the confirmation, the message requesting re-routing of calls addressed to the mobile telephone from the cellular network to the PSTN telephone number;

receiving a forwarded call addressed to the mobile telephone;

determining a status of the mobile telephone in response to the received call;

selecting a call information message in response to the status;

sending the call information message to the mobile telephone; and

transferring the forwarded call to the mobile telephone via a wireless link in response to receipt of a user response to the call information message.

2. The method of controlling a base station of claim 1, wherein registering the mobile telephone further comprises the steps of:

receiving a mobile station identification number from the mobile telephone which is received by the base station upon detection of the base station by the mobile telephone;

comparing the received mobile station identification number with a list of mobile station identification numbers stored in the base station, wherein the mobile station identification numbers of the list each correspond to mobile stations registered with the base station; and

processing communications from the mobile telephone in response to a match between the received mobile station identification number and an entry of the list of mobile station identification numbers resulting from the comparison.

3. The method of controlling a base station of claim 1, wherein the base station further performs an initial registration of the mobile telephone, comprising the steps of:

receiving a registration request message from the mobile telephone;

transmitting a registration receipt message to the mobile telephone in response to the registration request message, wherein the registration receipt message requests user confirmation of a desire to register with the base station;

receiving a registration acknowledge message from the mobile telephone in response to the registration receipt message, wherein the registration acknowledge message is an acceptance of the registration with the base station;

transmitting a registration accept message to the mobile telephone in response to the registration acknowledge message; and

storing a mobile station identification number of the mobile telephone.

4. The method of controlling a base station of claim 1, wherein the base station further updates the operational information, comprising the steps of:

sending a status update message from the base station to the cellular network;

receiving a confirmation message from the cellular network when no update of the operational information is required;

receiving an authorization message from the cellular network when an update of the operational information is required.

5. The method of controlling a base station of claim 1, wherein the base station further collects and uses radio frequency (RF) interference data in selecting a communication frequency for use by the steps of:

storing a list comprising the base station operating frequencies and corresponding interference scores;

periodically measuring interference on each of the operating frequencies;

updating the interference scores of the list of frequencies in response to the periodic measurements of interference, wherein updating includes increasing an interference score by a first value if a corresponding interference measurement is above a first interference threshold and is below a second interference threshold, increasing the interference score by a second value that is greater than the first value if the corresponding interference measurement is above the second interference threshold, and decreasing the interference score by a third value that is less than the first value if the interference measurement is below the first interference threshold; and

selecting a communication frequency for use from the list of frequencies, wherein said selected frequency has an interference score below a pre-specified threshold.

6. The method of controlling a base station of claim 1, wherein the base station communicates using time division multiplexed cellular communication channels including receive channels comprising the steps of:

receiving digital control channel information in a first time slot;

receiving data regarding a first digital traffic channel in a second time slot;

receives data regarding a second digital traffic channel in a third time slot; and

receiving interference information regarding potential interference on the cellular communications channel in a fourth time slot.

7. The method of controlling a base station of claim 1, wherein the base station communicates using time division multiplexed cellular communication channels including transmit channels comprising the steps of:

transmitting digital control channel information in a first time slot;

transmitting data regarding a first digital traffic channel in a second time slot; and

transmitting data regarding a second digital traffic channel in a third time slot.

8. The method of controlling a base station of claim 1, wherein the call information message includes digital control channel information and calling number information when up to two mobile telephones are registered with the base station in a standby mode, wherein the call information message includes an alert message that rings the mobile telephones when more than two mobile telephones are registered with the base station in a standby mode.