WIRELESS CONTROL OF A PBX

Abstract: A system and method for controlling a private branch exchange (PBX) from a remote user interface and a remote operator terminal is described. The requisite control over the processing unit of the PBX is established at a user interface which communicates to the processing unit using a wireless air interface. The requisite voice connection can either be co-located with the user interface or, alternatively, established at a cordless phone using a private wireless telephone system.

Description: WIRELESS CONTROL OF A PBX BACKGROUND OF THE INVENTION Technical Field of the Invention The present invention is related to Private Branch Exchanges and more particularly, to accessing the Private Branch Exchange over a wireless network. Description of Related Art A private branch exchange (PBX) is a circuit switch that serves a community of terminals, such as telephones, facsimile machines, and computers. By interconnecting the terminals, the PBX provides an inexpensive and convenient communication network among the community of terminals . The PBX is also connected to nodes in the public switched telephone network (PSTN) , thereby providing communication paths to terminals outside the network. Many PBXs also provide a number of special services . The PBX interconnects the terminals using voice and data lines which are connected to a digital switch via a voice or data interface card. The PBX is connected to the PSTN by a set of trunk line which are connected to the digital switch via a trunk interface card. The PBX also includes a line scanner for monitoring and detecting activity on the voice, data, and trunk lines. The PBX is controlled by a processing unit which responds to activity indications from the line scanner, allocates switching resources and service circuits as needed, maintains the connection for the duration of each call, returns the resources to idle state to await other calls, and supports numerous service features such as voice mail, call transfer, and conference calls. The processing unit also supports a user interface through which a user can control the operation of various features of the PBX. The user interface is usually similar to a user interface of a computer system. The processing unit receives inputs from the user through a keyboard or mouse and displays outputs on a visual display. By inputting various commands, the user can cause the PBX to route an incoming call to a particular terminal. Additionally, many PBXs include an integrated database which can store user name/extension pairs and other information. The processing unit allows the user to access the information in a quick and reliable manner. By allowing a user to route calls as well as access an integrated database, the user at the processing unit is well situated to act as an operator for the PBX. To further assist the operator of the PBX, the PBX includes a special terminal known as an operator terminal which allows the operator to communicate with users of the PBX, including parties making incoming calls to terminals interconnected to the PBX. The operator terminal is usually located in close proximity to the user interface. The processing unit, the user interface, and the operator terminal together provide the control over the PBX as well as the communications capability for an operator situated at the user interface and operator terminal to perform operator functions. However, because the operator terminal and the user interface are stationary, the mobility of the operator is confined to the proximate area of the operator terminal and the processing unit . The foregoing imposes a number of limitations which affect the operation of the PBX. For example, because the operator must remain in a confined area, the operator is unable to do other duties such as servicing terminals interconnected to the PBX. Additionally, certain maintenance operations on various portions of the PBX may require the user of operator functions for proper testing. Where the tested portion of the PBX is not situated in the proximate area of the operator terminal and the user interface, the restriction on the mobility of the operator becomes unduly inconvenient . Accordingly, it would be advantageous if the mobility of an operator in a PBX were unrestricted. SUMMARY OF THE INVENTION The present invention is directed to a system and method for controlling a private branch exchange (PBX) which includes a processing unit for controlling the PBX, a user interface for receiving input from an operator and receiving output from the processing unit, a transceiver for transmitting input from the user interface to the processing unit over a wireless air interface, a transceiver for transmitting output from the processing unit to the user interface over the wireless air inter ace . BRIEF DESCRIPTION OF THE DRAWINGS The disclosed inventions will be described with reference to the accompanying drawings, which show important sample embodiments of the invention and which are incorporated in the specification hereof by reference, wherein: FIGURE 1 is an exemplary Private Branch Exchange (PBX) system; FIGURE 2 is an exemplary embodiment of a PBX system integrated with a wireless Local Area Network (LAN) in accordance with the principals of the present invention; FIGURE 3 is an alternative embodiment of the present invention wherein a private wireless telephone system is used to support the operator terminal; and FIGURE 4 is a flow diagram illustrating the operation of the client, the PBX system, and the cordless phone in accordance with the principals of the present invention. DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS The numerous innovative teachings of the present application will be described with particular reference to the presently preferred exemplary embodiments. However, it should be understood that this class of embodiments provides only a few examples of the many advantageous uses of the innovative teachings herein. In general, statements made in the specification of the present application do not necessarily delimit any of the various claimed inventions. Moreover, some statements may apply to some inventive features but not to others. Referring now to FIGURE 1, a Private Branch Exchange (PBX) system 100 is illustrated. The PBX system includes a PBX 105 serving any number of terminals 110, such as telephones 110a, facsimile machines 110b, and computers 110c. By interconnecting the terminals 110, the PBX 105 provides an inexpensive and convenient communication network among the community of terminals. The PBX 105 is also connected to nodes in the public switched telephone network (PSTN) 115, thereby providing communication paths to terminals outside the PBX system 100 (not shown) . The PBX interconnects the terminals 105 using voice and data lines 120a, 120b which are connected to a digital switch 125 via a voice or data interface card 130a, 130b. The PBX 105 is connected to the PSTN by a set of trunk lines 120c which are connected to the digital switch 125 via a trunk interface card 140. The PBX also includes a line scanner 145 for monitoring and detecting activity on the voice, data, and trunk lines 120a, 120b, 120c. The PBX system 100 is controlled by a processing unit 142 which responds to activity indications from the line scanner 145, allocates switching resources and service circuits as needed, maintains the connection for the duration of each call, returns the resources to idle state to await other calls, and supports numerous service features such as voice mail, call transfer, and conference calls. The processing unit 142 also supports a user interface 150 connected to the processing unit via a set of cords 152a through which a user can control the operation of various features of the PBX. The user interface 150 is usually similar to a user interface of a computer system. The processing unit 142 receives inputs from the user through input means such as a keyboard 150a or mouse 150b and displays outputs on output means such as a visual display 150c. By inputting various commands, the user can cause the PBX 105 to route an incoming call to a particular terminal 110. Additionally, many PBXs systems include an integrated database 155 which can store user name/extension pairs and other information. The processing unit 142 allows the user to access the information in a quick and reliable manner. In some PBX systems 100, the processing unit 142, the user interface 150 and the integrated database 155 form a computer system 160 connectable to the PBX 105. In other PBX systems 100, the processing unit 142, the user interface 150, and the integrated database 155 are completely integrated and physically form a portion of the PBX 105. By allowing a user to route calls as well as access an integrated database 155, the user at the user interface 142 is well situated to act as an operator for the PBX. To further assist the operator of the PBX, the PBX includes a special terminal known as an operator terminal 165 which allows the operator to communicate with users of the PBX, including parties making incoming calls to terminals interconnected to the PBX. The operator terminal 165 is usually located in close proximity to the user interface . The processing unit 142, the user interface 150, and the operator terminal 165, together provide the control over the PBX system 100 as well as the communications capability for an operator situated at the user interface 150 and operator terminal 165 to perform operator functions. However, because the operator terminal 165 and the processing unit 142 attached to the user interface 150 are stationary, the mobility of the operator is confined to the proximate area of the operator terminal 165 and the processing unit 142. The foregoing imposes a number of limitations which affect the operation of the PBX system 100. For example, because the operator must remain in a confined area, the operator is unable to do other duties such as servicing terminals interconnected 110 by the PBX system 100. Additionally, certain maintenance operations on various portions of the PBX system 100 may require the user of operator functions for proper testing. Where the tested portion of the PBX system 100 is not situated in the proximate area of the user interface 150 and the operator terminal 165, the restriction on the mobility of the operator becomes unduly inconvenient . The restriction on the mobility of the operator can be removed by using a wireless air interface through which the user interface and the processing unit communicate, as well as the operator terminal and the PBX. The operator can input data for the processing unit using a portable user interface which transmits the inputs over a wireless air interface to the processing unit. The processing unit can output data to the portable user interface by transmitting the output over the wireless air interface to the portable user interface . The operator terminal and the PBX can similarly use the wireless air interface. The foregoing is realized by integrating the PBX system with a wireless Local Area Network (LAN) Referring now to FIGURE 2, an exemplary PBX system 100 integrated with a wireless LAN 200 is described. The processing unit 142 and the user interface 150 are incorporated into a computer network wherein the processing unit 142 forms a portion of a server 242. A server 242 is a class of computers used to handle file, print, and application services which are common to all the networked computers, known as clients 250. Because the server 242 comprises the processing unit 142 of the PBX system 100, the server is able to provide the operator function capabilities supported by the processing unit 142. Providing the operator functionality at the server 242 is advantageous because the operator functionality can be accessed from any of the clients 150 which can be sparsely located about a geographic area. The user interface 150 and the operator terminal 165 are integrated into the client 250. Those skilled in the art will recognize that the client 250 is easily adapted to incorporate the user interface 150 and the operator terminal 165. For example, the keyboard 250a, mouse 250b, and visual display 250c indigenous to the client 250 can be used as the user interface 150. The operator terminal 165 can be supported by a suitably connected microphone 265a to receive voice from the operator, and suitably connected speakers 265b to send audible signals to the operator. Supporting the operator terminal 165 in the foregoing manner is known in the art as Computer/Telephony Integration. The client 250 accesses the server 242 through a wireless air interface 268. Input signals received at the client 250 from the operator via either the keyboard 250a, mouse 250b, or the microphone 265b are forwarded to a wireless modem 271. The wireless modem 271 can either be integrated into the client 250 or connected thereto. The wireless modem 271 includes a transceiver 274 which transforms the inputs into a radio signal that is transmitted over the wireless air interface 268. The radio signal is received by a transceiver known as an access point 277 which forwards the signal to the server 242. Outputs from the server 242, as well as voice signals directed to the operator, are sent to the client 250 in a similar manner. The outputs and voice signals are transmitted as a radio signal by the access points 277 to the client 250 over the wireless air interface 268. The radio signals is received by the transceiver 274 of the wireless modem 271 which sends the outputs and voice signals to the client 250. The client 250 displays the outputs on the visual display 250c and sends the voice signals to the speaker 265b. Although the server 242 is shown directly connected to the access point 277 receiving the signal from the client 250, those skilled in the art will recognize that numerous other access point configurations are possible. For example, the signal can be received by an access point 277 known as a repeater which retransmits the radio signal from the client 250 to another access point 277 which is in closer proximity to the server 242. The process is repeated until an access point 277 connected to the server 242 via a wireline receives the signal and sends the signal to the server 242. By integrating the PBX system 100 with the wireless LAN 200, the expands geographic confines for the operator to the range of the wireless air interface 268. By using a portable personal computer as a client 250, the operator's mobility is further expanded. Accordingly, the operator can do numerous other tasks such as testing a terminal of the PBX system 100. Although the wireless LAN 200 is suitable for transmitting the voice signals to and from the operator terminal 165, use of an alternative transmission means may be preferable. For example, the protocols and communication standards for the wireless LAN 200 are often optimized for data transmission and may be disadvantageous for voice signal transmission. Additionally, the additional traffic of the voice signals may create bottlenecks where the wireless LAN 200 is used by clients 250 for computer functions besides the controlling the PBX system 100. Furthermore, many PBX systems 100 support a private wireless telephone system. Accordingly, in an alternative embodiment, the operator terminal 165 can use the private wireless telephone system. Referring now to FIGURE 3, an alternative embodiment of the invention is described, wherein the PBX system 100 uses a wireless LAN 200 to communicate to the user interface 150, and a private wireless telephone system 300 to communicate to the operator terminal 165. The operator terminal 165 is realized using a cordless phone 305. The cordless phone 305 receives voice input from the operator and transmits radio signals representing the voice input to a base station 310 over a wireless air interface 315. The base station 310 forms a portion of network of base stations known as a base station system (BSS) 320. The BSS 320 can include base stations 310 either connected to the PBX system 100 or physically separate from the PBX system. The base stations 310 which are connected to the PBX system 100 forward the received signal to the PBX system 100 using a wireline connection. The base stations 310 that are separated from the PBX system 100 act as repeaters and retransmit the received signal to another base station 310 that is in closer proximity to the PBX system 100. The process is repeated until the signal is received at a base station 310 that is connected to the PBX system 100 via a wireline connection. Voice signals at the PBX system 100 that are to be directed to the operator are transmitted to the cordless phone 305 in a similar manner. The voice signal is transmitted by the BSS 320 as a radio signal across the wireless air interface 315 to the cordless phone 305. The cordless phone 305 receives the radio signals and converts the radio signals into an audible voice signal for the operator. The private wireless telephone network 300 represents an alternative communication channel for the operator terminal 165. Because the wireless LAN 200 is not used for voice transmission, the cordless phone 305 can be completely separated from the client 250. This is especially advantageous in an office with both a wireless LAN 200 and a private wireless telephone system 300 because the modifications to preexisting clients 250 and cordless phones 305. It is noted that the private wireless telephone network may include any number of cordless phones 305 and clients 250. Because the client 250 and the cordless phones 305 are separated, any client/cordless phone pair can be used by an operator. Although the client 250 and the cordless phone 305 can be physically separated, proper performance of operator functions from a particular client 250 and a particular cordless phone 305 require a logical association from the standpoint of the PBX system 100. Referring now to FIGURE 4, a flowchart illustrating the operation of the client 250, the PBX system 100, and the cordless phone 305 is described. At step 405, an operator at a client 250 establishes a client/server session with the processing unit 142 of the PBX system 100, known in the art as "logging on." As a security measure, the PBX system 100 may require a predetermined password from the operator to log on. Logging on permits the operator at the client 250 establishes an interface with the processing unit 142 of the PBX system 100. However, because the cordless phone 305 is separated from the client 250, an operator terminal session must be established between the cordless phone 305 and the PBX system 100. Accordingly, the particular cordless phone 305 must be identified to the PBX system 100. At step 410, the operator enters an identification number associated with the cordless phone 305 at the client 250. Those skilled in the art will recognize that the identification number can comprise, for example, a serial number, an extension number, or a directory phone number. At step 415, the PBX system 100 establishes the cordless phone 305 as the operator terminal and the operator can then proceed to use the cordless phone 305 and the client 250 for operator functions. Although the invention has been described with a certain degree of particularity, it should be recognized that elements thereof may be altered by persons skilled in the art without departing from the spirit and scope of the invention. For example, although the illustrated embodiments disclose the use of a wireless LAN, the invention is not limited to a wireless LAN and, in fact, can use any communication network comprising a wireless air interface. Therefore, the invention is limited only by the following claims and their equivalents.

Claims: WHAT IS CLAIMED IS: 1. A communications system for supporting telephonic communication at at least one of a plurality of terminals, said communication system comprising: a private branch exchange (PBX) for interconnecting said plurality of terminals; a processing unit for controlling said PBX; input means for receiving input from an operator; output means for receiving output from said processing unit; means for transmitting said input from said input means to said processing unit over a first wireless air interface; and means for transmitting said output from said processing unit to said output means over said first wireless air interface. 2. The communications system of claim 1, further comprising: an operator terminal for establishing a voice connection between an operator and said PBX; wherein said means for transmitting said input transmits voice signals from said operator terminal to said PBX over said first wireless air interface; and wherein said means for transmitting said output transmits voice signals from said PBX to said operator terminal over said wireless air interface. 3. The communications system of claim 1, wherein said input means comprises a keyboard, and wherein said output means comprises a visual display. 4. The communications system of claim 3 , further comprising a wireless Local Area Network (LAN) , said wireless LAN comprising: a client, wherein said keyboard and said visual display form a portion of said client; and a server, wherein said processing unit forms a portion of said server. 5. The communications system of claim 4, wherein said client comprises a portable computer system. 6. The communications system of claim 4, wherein said means for transmitting said input comprises a wireless modem. 7. The communications system of claim 4, wherein said means for transmitting said output comprises an access point . 8. The communications system of claim 1, further comprising a cordless phone for establishing a voice connection between an operator and said PBX, and for transmitting voice signals from said cordless phone over a second wireless air interface to said PBX. 9. The communications system of claim 8, further comprising a base station for transmitting voice signals from said PBX to said cordless phone over said second wireless air interface . 10. A method for controlling a Private Branch Exchange, said method comprising the steps of: receiving inputs from a keyboard at a client; transmitting said inputs over a first wireless air interface; receiving said inputs at a PBX; generating outputs at said PBX, responsive to said inputs; transmitting said outputs from said PBX to said client over said first wireless air interface; and displaying said outputs on a visual display forming a portion of said client. 11. The method of claim 10, further comprising the steps of : transmitting voice signals from said client to said PBX over said first wireless air interface; and transmitting voice signals from said PBX to said client over said first wireless air interface. 12. The method of claim 10, further comprising the steps of : transmitting voice signals from a cordless phone to said PBX over a second wireless air interface; and transmitting voice signals from said PBX to said cordless phone over said second wireless air interface. 13. The method of claim 12, further comprising the step of inputting an identification number, said identification number identifying said cordless phone, at said client.

Inventors: CHEN TED, KUFTEDJIAN OHANESS, LAM COREY, MCCALL DANIEL, CHEN, TED, KUFTEDJIAN, OHANESS, LAM, COREY, MCCALL, DANIEL
Applicants: ERICSSON INC, ERICSSON INC.
Application year: 1999
Main classification: H04Q7
IPC codes: H04M1, H04W84