Wireless private branch exchange (WPBX) and communicating between mobile units and base stations

• US 20020132630A1
• Filed: 02/20/2002
• Published: 09/19/2002
• Est. Priority Date: 04/07/2000
• Status: Abandoned Application

• Current Assignee: Commil USA LLC (Commil)
• Original Assignee: Commil, Ltd.
• Inventors: Barak, Haim, Arazi, Nitzan, Soffer, Yaron
• Application Number:
  US10/078,008
• Publication Number:
  US 20020132630A1
• Time in Patent Office: Days
• US Class Current: 455/502
• 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 1/733 with a plurality of base stations connected to a plurality of lines for selection in cordless PBX H04W84/16
• CPC Class Codes: H04M 2250/02 including a Bluetooth interface
• CPC Class Codes: H04W 36/0033 with transfer of context information
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 76/00 Connection management
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 84/105 PBS [Private Base Station] network H04W84/12 - H04W84/16 take precedence
• CPC Class Codes: H04W 84/16 WPBX [Wireless Private Branch Exchange]
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

Methods to create a cellular-like communication system, such as a Wireless Private Branch Exchange (WPBX), which includes mobile devices such as standard cordless phones (handsets), particularly, mobile devices utilizing the Bluetooth short-range wireless communication protocol. The methods provide seamless and reliable handoff of sessions between Base Stations while the mobile device is moving between picocells, by implementing a high-level of synchronization between the Base Stations and the Switch. Base Stations of picocells having small coverage areas communicate with the handsets. The communication protocol is divided into a low-level protocol performed by the Base Stations and a high-level protocol performed by the Switch connected to all the Base Stations. The methods support mobile computing or telephony devices and communication protocols, which are not specified to handle handoffs of sessions while moving between Base Stations coverage areas in a data, voice or telephony wireless network.

Claims

1. In a wireless communication system comprising a plurality of Base Stations and at least one Switch in communication with the Base Stations, a method of synchronizing at least one neighboring Base Station to a Base Station connected with a mobile unit comprising:

from the Base Station connected with the mobile unit, periodically transmitting during a selected time interval with higher transmission power than during normal transmission; and

receiving the transmission with higher transmission power at the least one neighboring Base Station.

2. Method, according to claim 1, wherein:

the selected time interval is a synchronization hop in a series of periodic hops; and

the increased transmission power during the synchronization hop is at least twice as great as the normal transmission power.

3. Method, according to claim 1, wherein:

the selected time interval is a synchronization hop in a series of periodic hops; and

the synchronization hop is transmitted at a different frequency than the remaining periodic hops.

4. Method, according to claim 1, wherein:

the mobile unit is equipped with a short-range wireless communication transmitter/receiver.

5. Method, according to claim 1, wherein the mobile unit is a device selected from the group consisting of:

telephone handset, standard cordless telephone handset, cellular telephone handset, personal data device, personal digital assistant (PDA), computer, laptop computer, e-mail server, a device utilizing point-to-point protocol (PPP) to the Internet via a central remote access server a headset, a personal server, a wearable computer, a wireless camera, and a mobile music player.

6. Method, according to claim 1, further comprising:

providing communication links between the Base Stations, wherein the communication links between the Base Stations are selected from the group consisting of RF links and land lines; and

transferring connection status information and rough synchronization information between the Base Stations over the communications links.

7. Method, according to claim 1, wherein:

the Base Stations and the Switch are connected via a wired or wireless local area network (LAN).

8. Method, according to claim 1, wherein:

a first plurality of Base Stations are connected to a first Switch;

a second plurality of Base Stations are connected to a second Switch;

the Switches maintain status tables for calls and connections that they are handling, and maintain copies of each other'"'"'s status tables; and

when a Switch updates one of its status tables, it sends the updated status table to the other Switches.

9. Method, according to claim 1, wherein:

the wireless communication system comprises a wireless private branch exchange (WPBX) handling calls from mobile units comprising handsets.

10. Method, according to claim 9, further comprising:

in the Switch, maintaining a table of calls being handled by the WPBX, comprising information selected from the group consisting of a unique Call Identification number for each active call being handles by the WPBX, the origin of the call, the destination of the call, Calling Number Identification (CNID), Destination Number (DN), Originating Base Station Identification, Destination Base Station Identification, Status of call, information for billing, and information for performance analysis.

11. Method, according to claim 9, further comprising:

in the Switch, for each call, maintaining a table of connections comprising information selected from the group consisting of Handset ID, Current Base Station ID, handle of high-level protocols, handle of low-level protocols, Number of candidate Base Stations for handoff, List of candidate Base Stations for handoff, and List of handoff status for each candidate Base Station.