WO2000078018A1 - Method and apparatus for communicating via virtual office telephone extensions - Google Patents

Abstract

A system for (10) (and a method of) selectively establishing communication with at least one wireless device (70) associated with a single telephone number serving as a virtual office extension is provided. In a preferred embodiment, the system (10) includes a wireless connect unit (30) in communication with an enterprise private branch exchange (PBX) network (11). The wireless connect unit (30) preferably serves as a gateway between the PBX (14) and one or more remote communication devices, including at least one wireless device (70), associated with a virtual extension telephone number. The remote wireless device (70) can be used as a standard PBX office telephone for both inbound and outbound telephone calls. Thus, features of the PBX network (11) (e.g., voice mail, direct extension dialing, corporate calling plan, etc.) are available to the remote wireless device (70) even though it is not physically connected to the PBX (14).

Description

METHOD AND APPARATUS FOR COMMUNICATING VTA VIRTUAL OFFICE TELEPHONE EXTENSIONS

This application claims priority from provisional applications with Ser. Nos.

60/139, 498, filed June 14, 1999, and 60/185,070 filed February 25, 2000, which are

hereby incorporated by reference in their entireties.

BACKGROUND

The office telephone is the primary point of contact of most business people.

Typically, corporations invest significantly in their office telephone infrastructure,

including the considerable costs of constructing and maintaining a traditional hardwired

telephone infrastructure at each enterprise location. In addition, corporations typically

invest in a private branch exchange (PBX) network and its associated services, including

voice mail, paging and unified messaging systems. Further, most corporations have

negotiated contracts with their telephone carriers (e.g., local and long distance carriers)

to ensure they obtain the lowest possible rates for calls placed via their corporate

network. However, because the corporate workforce is becoming increasingly mobile,

more business people are using wireless telephones to conduct their business when they

are out of the office. This has resulted in corporations spending a larger portion of their

telecommunications budget on wireless communications, with far less favorable

negotiated rates than the rates of their corporate network. In addition, wireless

communication systems often lack the enhanced conveniences (e.g., interoffice voice

mail, direct extension dialing, etc.) that corporate users have come to expect in the office environment and for which most of the costs may have already been paid (e.g.,

the PBX network).

A solution to the aforementioned problems would be to assign to employees

wireless telephony devices (e.g., wireless telephones or pagers) able to access the office

telephone system as though they were conventional desktop telephones hardwired to

the company's PBX. It is desirable to incorporate wireless devices into the PBX

network so that users may place and receive telephone calls using the office PBX

telephone system whether they are at their desks or at a remote location (e.g., away

from their desks, out of the office, etc.). This would allow the enhanced conveniences

of today's PBX networks (e.g., interoffice voice mail, direct extension dialing, etc.) to

be available on wireless devices - a feature which is needed in today's society.

There have been recent attempts to incorporate wireless telephones into PBX

networks. One system provided by Ericsson, requires the creation of a mini-cellular

network within the confines of the enterprise. A cellular switching unit, unique wireless

telephones and an auxiliary server are required to route inbound telephone calls to a

wireless handset serving as a remote office telephone.

An in-building wireless system has been proposed by Nortel Networks. This

system requires the wiring of pico-cells throughout the enterprise's building. The

system routes inbound telephone calls to specialized wireless telephones serving as

additional office PBX telephones. The wireless telephones cannot be used as

conventional standard wireless telephones until they leave the premises. These systems allow use of a wireless telephone as an office telephone, but

they are not without their shortcomings. For example, each system requires specialized

cellular equipment and wireless handsets. Moreover, the systems only use the wireless

telephones for inbound telephone calls. In addition, these systems cannot use the

wireless telephone as a conventional wireless telephone (i.e., not part of the enteφrise's

PBX network) within the building.

SUMMARY

A system for (and a method of) selectively estabhshing communication with

one or more of a plurahty of wireless devices serving as a virtual office telephone is

provided. In a preferred embodiment, the system includes a wireless connect unit

preferably serving as (or in conjunction with) an enteφrise PBX. The wireless devices

can be used (on-site or off-site) as standard PBX office telephones for both inbound and

outbound telephone calls. Thus, features of the PBX network (e.g., voice mail, direct

extension dialing, corporate calling plan, etc.) may be made available to the wireless

device even though it is not physically connected to any enteφrise telecommunications

network (e.g., PBX). This system of virtual office telephones can be used to provide

wireless devices the same level of service traditionally provided to hardwired telephones

on a standard enteφrise PBX network. In accordance with an embodiment of the

invention, when the system receives an incoming call, it can route the call to a wireless

device associated with a virtual office telephone, as well as to a combination of devices

simultaneously, or as desired by the user. Outgoing calls can be placed from a wireless device associated with a virtual office telephone by dialing another extension telephone

number (e.g., using the office PBX system) or by conventional dialing (e.g., using the

PSTN).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary telecommunication system constructed in

accordance with an embodiment of the invention.

FIG 2. illustrates a wireless connect unit in accordance with an embodiment

of the invention.

FIG. 3 illustrates in flowchart form exemplary inbound station-to-station call

processing performed in accordance with an embodiment of the invention.

FIG. 4 illustrates in flowchart form exemplary inbound direct inward dialing

(DID) call processing performed in accordance with an embodiment of the invention.

FIG. 5 illustrates in flowchart form exemplary remote outbound call

processing performed in accordance with an embodiment of the invention.

FIG. 6 illustrates another exemplary telecommunication system constructed

in accordance with an embodiment of the invention

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Preferred embodiments and applications of the invention will now be

described. Other embodiments may be realized and structural or logical changes may

be made to the disclosed embodiments without departing from the spirit or scope of

the invention. Although the preferred embodiments disclosed herein have been

particularly described as applied to a business or office environment, it should be readily

apparent that the invention may be embodied for any use or application having the

same or similar problems.

The invention is more fully understood with reference to the preferred

embodiments depicted in FIGS. 1-6. An exemplary embodiment of the invention is

discussed and illustrated with reference to its implementation witiiin an office building

or other enterprise establishment. In an office, for example, personnel are assigned to

offices (or cubicles) with each office or person having an associated office telephone

extension and an office telephone. The office telephone extensions are typically

associated with a PBX, exchange, or other call processing infrastructure. The PBX

allows each office, or at least each user, to be assigned a telephone extension and a

direct inward dial (DID) telephone number. As known in the art, a telephone

extension is typically a three or four digit telephone number where station-to-station

(i.e., office-to-office) calls can be placed by dialing the three or four digit extension.

This is commonly referred to as direct extension dialing. As also known in the art, a

DID telephone number allows external calls (i.e., calls initiated outside of the office

PBX) to be placed directly to the user or office telephone. In contrast to traditional enteφrise communication networks, a preferred

embodiment of the invention employs one or more wireless devices as virtual office

telephones associated with one or more PBX extensions used in lieu of or in

conjunction with standard hardwired desktop telephone sets (e.g., shown as standard

telephone sets 89, 90). Referring to FIG. 1, wireless office telephones 82, 84, 86, 88

are not connected via hardwired lines to enteφrise communication systems (e.g., PBX

14), but instead may be accessed using conventional wireless equipment through PSTN

16, 54 to a commercial wireless carrier symbolically represented by a wireless switch 58

and an antenna 60. Because the need for hardwired lines is eliminated for these virtual

telephones, the considerable costs of constructing and mamtaining a traditional

hardwired telephone infrastructure at each enteφrise location can be saved. For

example, estimates of a large U.S. coφoration are that traditional handsets or desktop

telephones cost more than $100 per month per telephone due to the increasingly high

costs of estabhshing and mamtaining traditional hardwired telephone lines. For a large

enteφrise with personnel located in multiple geographic regions, the cost savings from

eliminating traditional handsets or desktop telephones may be significant.

The invention is not to be limited to any particular environment. The

invention may be implemented, for example, in a hotel, boarding house, dormitory,

apartment, or other commercial or residential establishment, where individuals are

assigned to a unique extension or DID telephone number. The term "office" as used

herein encompasses a singular room or space within a business or other enteφrise, or a

hotel room or similar facility. The term "user" as used herein encompasses office personnel, hotel guests or other individuals associated with a telephone extension and

DID telephone number.

FIG. 1 illustrates an exemplary telecommunication system 10 constructed in

accordance with an embodiment of the invention. As will be discussed below, the

system 10 provides for a full integration of communication devices, such as wireless

office telephones 82, 84, 86, 88, wired office telephones 89, 90, and a personal wireless

device 70, into an enteφrise communication network. In doing so, the system 10 can

selectively establish communications with one of a plurahty of telephony devices

associated with a particular telephone extension or DID telephone number. Moreover,

the system 10 will allow communication devices such as wireless office telephones 82,

84, 86, 88 to perform as fully functional standard office telephones for both inbound

and outbound communications. That is, wireless devices will be able to use features of

the office network (e.g., direct extension dialing, coφorate dialing plan, etc.) even

though the devices are not directly connected to the office PBX or even within the

confines of the office. The system also allows the wireless devices, including wireless

office telephones 82, 84, 86, 88 and personal wireless device 70, to operate as

independent wireless telephones capable of conventional interaction with a commercial

wireless carrier if so desired. That is, the wireless devices 82, 84, 86, 88, 70 may receive

calls placed to its (non-office) DID telephone number even though the system 10 also

routes PBX calls to the wireless devices 82, 84, 86, 88, 70.

The system 10, as particularly illustrated herein, includes an office PBX

network 11. The PBX network 11 may include a plurality of communication devices associated with PBX extensions at least logically connected by a conventional PBX 14.

The PBX 14, which may be any commercially available one such as a Meridian 1 PBX

produced by Nortel Networks, is connected to a calling network such as a public

switched telephone network (PSTN) 16 by a primary rate interface (PRI) connection

20 or other suitable communication line or medium. The PBX extensions can be

associated with wired or wireless telephones or other communication devices known in

the art. As illustrated in FIG. 1, four wireless telephones 82, 84, 86, 88, and two

standard wired telephones 89, 90 are each associated with a different PBX extension,

and are shown corresponding to six offices or users. For clarity puφoses only, six

telephones 82, 84, 86, 88, 89, and 90 are illustrated in FIG. 1, but it should be

appreciated that any number or combination of telephones or other communication

devices can be supported by the system 10. Moreover, although it is desirable to use

wireless telephones in lieu of (or in conjunction with) standard hardwired desktop

telephones, the invention is not to be Umited to the particular type of device used in the

system 10.

The PBX 14 is coupled to a wireless connect unit ( WC) 30. The WC 30 is

connected to the PBX 14 in this embodiment by a PRI connection 22 or other suitable

communication medium. The WC 30 is also connected to a PSTN 54 by a PRI

connection or other suitable digital communication medium. The illustrated PRI

connection between the WC 30 and the PSTN 54 includes a first PRI connection 32, a

channel service unit (CSU) 34, and a second PRI connection 36. As known in the art,

a CSU is a mechanism for connecting a computer (or other device) to a digital medium

that allows a customer to utilize their own equipment to retime and regenerate incoming signals. It should be appreciated that the illustrated connection between the

WC 30 and the PSTN 54 is one of many suitable connections. Accordingly, the

invention should not be limited to the illustrated connection. The WC 30 is one of the

mechanisms that allows the integration of virtual office telephones into the PBX

network 11 and its operation will be described below in more detail.

The WC 30 is preferably connected to a local area network (LAN) 40 by an

appropriate communication medium 38. Although a IAN 40 is illustrated, it should be

appreciated that any other network could be used. A plurahty of computers (e.g., 42a,

42b) may be respectively connected to the LAN 40 by any appropriate communication

lines 44a, 44b. The computers 42a, 42b can be used by network administrators or

others to maintain WC 30 and other portions of the system 10. The LAN 40 may also

be connected to the Internet 50 by a suitable communication medium 48. A firewall

46 may be used for security puφoses. In a preferred embodiment, Internet 50 can be

used to allow a remote administration device 52 (e.g., a personal computer) to perform

remote administration ofWC 30 by office personnel or other authorized users of the

system 10. Remote administration will allow office personnel to set user preferences for

particular telephone extensions. Thus, each telephone extension, particularly those

associated with a virtual office telephone, is individually configurable.

PSTN 54 is connected in this embodiment to a commercial wireless carrier

by the wireless switch 58 or other wireless carrier equipment by an appropriate

communication medium 56. The wireless switch 58 is connected to at least one

antenna 60 (by an appropriate communication medium 62) for transmitting signals 64 to wireless devices, such as wireless office telephones 82, 84, 86, 88 or personal wireless

device 70. The wireless device could also be a pager, personal digital assistant (PDA),

landline telephone, facsimile machine or other wired/wireless communication device.

It may desirable for the wireless device to be capable of handling both (or either) digital

and analog communication signals. It should be noted that any type of wireless

communication protocol (or a combination of different protocols), such as TDMA,

CDMA, GSM, AMPS, MSR, iDEN, WAP, etc., could be used.

It should be appreciated that the WC 30 is connected to a wireless carrier

through a PSTN 54 and not by unique hardware or an in-office cellular network. As a

result, WC 30 only has to interface with conventional components, such as the PBX 14

and PSTN 54. Thus, the system is substantially technology independent. Moreover,

special wireless devices are not required, which allows the wireless devices to function in

a conventional manner (e.g., as independent wireless telephones) and as part of the PBX

network 11 (if so desired) as if they were hardwired office telephones.

As noted above, the WC 30 allows for the full integration of wireless devices

into the PBX network 11 in lieu of (or in conjunction with) standard hardwired

telephones. In a preferred embodiment, WC 30 is a processor-based stand-alone unit

capable of hancUing communications directed to the PBX network 11. In a preferred

embodiment, WC 30 is composed of one or more processors genetically represented by

processor module 310 executing one or more computer programs stored in one or

more memory units genetically represented by memory module 320, which is coupled

to processor module 310 via bus 330, as shown in FIG. 2. Memory module 320 also contains one or more databases and other processing memory used during the overall

operation of system 10, as will be described below. Receiving and transmitting modules

340, 350, respectively, which are coupled to processor module 310 and memory

module 320 via bus 330, are employed to receive and transmit information to the PBX

and PSTN during call processing, as well as receiving and transmitting other

information such as administrative information.

The modules (310, 320, 330, 340, 350) making up WC 30 may be

implemented using any known hardware or software devices. For example, in one

embodiment, workload performed by receiving and transmitting modules 340, 350, as

well as some of the processing functions of processor module 310 of WC 30 are

implemented using one or more conventional processor-based programmable telephony

interface circuit cards used to interface WC 30 with PBX 14 and the PSTN. They are

programmed to perform the conventional telephony services required to place and

receive calls, as well as programmed to perform the unique call processing functions

described below. The WC 30 preferably contains a database of extension numbers (also

referred to herein as PBX extensions) and DID telephone numbers associated with each

existing PBX extension. The database will be stored on a computer readable storage

medium, which may be part of (e.g., in memory module 320) or connected to the WC

30. The database may also contain a wireless connect/PBX extension (hereinafter

referred to as a "WC-PBX extension") and one or more wireless device telephone

numbers associated with each PBX extension. In this embodiment, software mnning

on the telephony cards interfaces with the database to perform the various call

processing functions discussed below. In this embodiment, the PBX 14 contains a coordinated dialing plan (CDP)

steering table. The CDP steering table will be stored and retrieved from a computer

readable storage medium, which may be part of or connected to the PBX 14. The CDP

steering table directs the routing of PBX extensions to the WC 30 over the PRI 22

between the WC 30 and the PBX 14. In addition, the CDP steering table of the PBX

14 directs the routing of WC-PBX extensions received from the WC 30 to the

appropriate office extensions and associated office (or virtual office) telephones.

In accordance with a preferred embodiment of the invention, processor

module 310 executes one or more programs stored in memory module 320 to process

calls received through PBX 14 or PSTN. FIGS. 3-5 illustrate some of the basic call

processing events which WC 30 may be programmed to handle in accordance with

exemplary embodiments of the invention. As illustrated in Fig. 3, when an incoming

station-to-station call (i.e., a direct extension call from one PBX telephone device to

another PBX device) is received by the PBX 14 for an existing PBX extension (step

102), the PBX 14 looks up the PBX extension in the CDP steering table (step 104) to

determine where the call should be routed. Based on the CDP steering table the call to

the PBX extension is routed to the WC 30 (step 106).

As is known in the art, the incoming call will have automatic number

identification (ANI) and dialed number identification service (DNIS) information. The

ANI identifies the telephone number of the calling party and is traditionally used for

"caller ID." DNIS identifies the telephone number of the called party. The WC 30

reads the ANI/DNIS information from the incoming call to obtain the DNIS information (step 108). As noted above, the WC 30 has assigned a new WC-PBX

extension to each existing PBX extension. The WC-PBX extension, routing

information, and user preferences are obtained by using the DNIS information

(identifying the PBX extension) as an index into the WC 30 database (step 110).

Routing information will include any additional remote telephone numbers, voice mail

box numbers, or other identification numbers of communication devices associated with

the PBX extension.

At step 112, the WC 30 out-pulses the WC-PBX extension obtained in step

110 for any associated hardwired office telephone (e.g., 89, 90, etc.). Where the

associated office telephone is a virtual office telephone (e.g., telephone 82), however,

the call is routed through the PSTN 16, 54 and the commercial wireless carrier network

servicing the associated wireless device. In response, the commercial wireless carrier

relays its signal through its network (e.g., through the antenna 60) in a conventional

manner in an attempt to reach the user or wireless telephone associated with the PBX

extension dialed. In accordance with a preferred embodiment, at the same time (if

desired), the WC 30 attempts to contact one or more alternative communication

devices (e.g., out-dialing a remote telephone number via the PRI connection between

the WC 30 and the PSTN 54). In such an embodiment, the station-to-station call is

thus routed to both the virtual office telephone and also to at least one remote device

simultaneously or substantially simultaneously (or as determined by the user

preferences). It should be noted that the illustrated processing 100 is just one example

of how an incoming station-to-station call may be handled. Individual user preferences

may alter the way the call is processed. It should be noted that in a preferred embodiment, the WC 30 is out-pulsing the WC-PBX extension (for hardwired

telephones), dialing the virtual office telephone number, and contacting one or more

remote communication devices. This gives the WC 30 control over the connections to

the office telephones and any remote devices.

At step 114, it is determined if the current ring count (i.e., number of rings)

exceeds the maximum ring count denned by the user. Since the WC 30 is controlling

the call at this time it can track the number of rings. If the ring count exceeds the

maximum ring count, then the WC 30 (if desired) forwards the call to the enteφrise's

voice mail (step 120). If the ring count does not exceed the maximum ring count, the

WC 30 determines if the call is answered at the (virtual or standard) office telephone

associated with the PBX extension dialed (step 116). The PBX 14 will issue an off-

hook message to the WC 30 if the appropriate standard office telephone is answered. If

it is determined that the call is answered at the (virtual or standard) office telephone,

the WC 30 drops the call's path to any other remote devices (e.g., personal wireless

device 70) via the PSTN 54 and maintains the path to the office telephone (step 122).

In a preferred embodiment, it may be desired that the call to the virtual office

telephone or any remote devices be actually answered by a user and not by a service in

conjunction with the user's wireless carrier. In known systems, wireless carriers often

answer a call if there is a bad connection, the wireless channels are overloaded, or for

other reasons (such as initiating a wireless carrier's answering service). When the

wireless carrier answers the call in these situations, the call would appear to WC 30 as an

"answered call" even if the user did not actually answer the call. One way to distinguish a user answered call from a wireless service answered

call is to prompt the user to transmit an acknowledgement signal such as a dual tone

multi- frequency (DTMF) tone to the WC 30 via the keypad of the wireless device.

Upon detecting the answered call, WC 30 can send a voice message instructing the user

to "press the # button to complete the call." If the DTMF tone is not received, then

the WC 30 presumes that the call was answered by the wireless carrier, or that the user

does not want to answer the call which the WC 30 treats as an unanswered call. If at

step 118, for example, it is determined that the remote device (e.g., personal wireless

device 70) was answered by the user, the WC 30 drops the WC-PBX extension path

and initiates the connection between the calling party and the remote device (step 124).

If the call is not answered at the remote device in step 118, process flow returns to step

114 to check whether the ring count has exceeded the maximum ring count.

In accordance with a preferred embodiment of the invention, the database of

WC 30 may also contain numerous system-defined user access rights and user

modifiable preferences, which can alter the call processing of the invention. An office

administrator may use the network computers 42a, 42b or a remote administration

device 52 to set user access rights and priorities (example discussed below with respect

to outbound call processing 300 illustrated in FIG. 5). The user may use the remote

administration device 52 to set numerous user preferences. It is desirable that a Web-

based or graphical user interface be used so that the user can easily access and set user

preferences. The network computers 42a, 42b (or remote device 52) may also be used

by the user if so desired. User preferences may include how the user associated with a particular PBX

extension wants incoming calls to be routed. For example, the user can request that

incoming calls be routed to the (virtual or standard) office telephone and one or more

remote devices simultaneously. The user instead can request that an incoming call be

routed to the office telephone first, then after a user-defined number of rings, the

remote device(s) and eventually sent to the PBX voice mail. Alternatively, the user can

request that an incoming call be routed to one or more remote devices first, then the

office telephone, and subsequently to the PBX voice mail. The user can request that all

incoming calls be routed directly to the PBX voice mail. The user can request that a

menu of options be played to the caller so that the caller can decide how to complete

the call. The user can set separate ring counts for the office telephone and remote

devices. The user can set dial tone options, which allows the user to control how long a

dial tone is played before a dial tone time-out occurs. The user can adjust the time

between dials. These are just a few of the user preferences that can be stored and used

by the WC 30, which can alter incoming and out going call processing. If the user does

not change the user preferences, or only changes a few preferences, system defaults are

used.

When receiving an inbound DID call, call processing flow 200 (as illustrated

in FIG. 4) is performed in accordance with an embodiment of the invention. At step

202, a DID telephone call is dialed by an external telephone device and received by

system 10 through the PSTN. In a preferred embodiment, the PSTN has been

programmed in advance to route all DID telephone numbers used by the system 10 to

the WC 30. In addition, the PSTN has also been programmed to route calls incoming to the DID telephone number directly to the PBX 14 if the path to the WC 30 has

failed. That is, the embodiment incoφorates a failure path into the system 10 to ensure

that a failure of the WC 30 or the PRI connection between the WC 30 and the PSTN

does not interrupt the operation of the office PBX network 11. This is possible since

the steering table of the office PBX 14 contains the DID telephone numbers. The PBX

14 has the capability to resolve these DID numbers. Thus, the PBX 14 can be used if

needed to handle DID telephone calls. For puφoses of this discussion, it is presumed

that the WC 30 and the connection between the WC 30 and the PSTN 54 are fully

operational. Thus, at step 204, the PSTN routes the DID call to the WC 30.

The WC 30 reads the ANI/DNIS information from the incoming DID call

to obtain the DNIS information (step 206). The WC 30 resolves the call by

determining what WC-PBX extension is associated with the telephone number

identified by the DNIS. The WC-PBX extension, routing information and user

preferences are obtained by the WC 30 (step 208). At step 210, the WC 30 out-pulses

the PBX 14 through the PRI connection 22 between the WC 30 and PBX 14 with the

obtained WC-PBX extension for any hardwired office telephones (e.g., 89, 90). For

any virtual office telephones associated with the WC-PBX extension, WC 30 out dials

the commercial wireless carrier servicing the associated virtual office telephone in the

same manner described above. In accordance with an embodiment of the invention, at

the same time (if desired), the WC 30 attempts to contact one or more remote devices

(e.g., by out-dialing one or more user designated remote telephone numbers via the

PRI connections between the WC 30 and the PSTN 54). Therefore, the inbound DID

telephone call may be routed to the (virtual or standard) office telephone and one or more remote devices (e.g., personal wireless device 70) simultaneously (or as

determined by the user preferences). It should be noted that the illustrated processing

200 is just one example of how an incoming DID call may be handled.

At step 212, it is determined whether the current ring count exceeds the

maximum ring count defined by the user. If the ring count exceeds the maximum ring

count, then the WC 30 forwards the call to the enteφrise's voice mail (step 218). If

the ring count does not exceed the maximum ring count, the WC 30 determines

whether the call is answered at the PBX extension (step 214). If it is determined that

the call is answered at the PBX extension, the WC 30 drops the call's path to the

remote device via the PSTN and maintains the path to the PBX extension (i.e., virtual

or standard office telephone) (step 220). If at step 214 it is determined that the call is

not answered at the PBX extension, the WC 30 determines if the call is answered at the

remote device (e.g., 70 ) (step 216). In a preferred embodiment, it may be desired that

calls to virtual office telephones 82, 84, 86, 88 or remote devices are actually answered

by the user and not by a service of the wireless carrier. Therefore, to distinguish a user

answered call from a wireless service answered call, the WC 30 may require an

acknowledgment signal as in the previous embodiment described above. If at step 216

it is determined that the call was answered by the user using a remote device, the WC

30 drops the path to the PBX extension and maintains the connection to the answering

remote device (step 222). (As an alternative, control and responsibility for the

remainder of the call can be left with the PSTN in order to free up PRI channels

between WC 30 and PSTN 54.) If the call is not answered by any remote device in step 216, process returns to step 212 to check whether the ring count has exceeded the

maximum ring count.

Initially, the call processing reduces the processing load on the PBX 14, since

the WC 30 (and not PBX 14) is resolving the DID telephone numbers. This allows the

PBX 14 to handle call processing for more extensions if desired. Additionally, since the

WC 30 is resolving the DID calls, the WC 30 can out pulse the PBX 14 and out dial

the PSTN 54 simultaneously (if desired) without waiting for the PBX 14 to

process/resolve the call. Moreover, as noted above, redundancy is provided by allowing

the PBX network 11 to function as a standard PBX if the WC 30 or the link between

the WC 30 and the PSTN 54 fails.

In accordance with a preferred embodiment, WC 30 allows virtual office

telephones (e.g., wireless telephones 82, 84, 86, 88) or any remote device (e.g., remote

device 70) to act as standard office PBX telephones for outbound telephone calls

following call processing flow 300 illustrated in FIG. 5. That is, a user will be able to

use his virtual office telephone (or any remote device) to make station -to -station calls as

if he were using a hardwired standard office telephone directly connected to the office

PBX 14. From the virtual office telephone or remote device, the user will also be able

to perform other PBX functions as well. At step 302, a user places a call to the WC 30

from the device 82, 84, 86, 88, 70. One way the user may do this would be to define a

speed dial key (or sequence of keys) on the device handset. When the user activates the

appropriate speed dial key/keys, the device 82, 84, 86, 88, 70 dials into the WC 30.

Another way to dial into the WC 30 would be by fixed dialing. Fixed dialing is a feature provided by the wireless carrier to always connect the wireless telephone to a

particular number or service, and, in this case, it would connect the user to the WC 30.

Any number of other methods may be used to dial into the WC 30.

At step 304, the WC 30 reads the ANI/DNIS information received from the

device 82, 84, 86, 88, 70 to obtain the ANI information. The ANI identifies the

telephone number of the calling device. The WC 30 uses the ANI information to

obtain the user's access rights and user preferences (step 306). As noted above, a user is

provided with the ability to set various user preferences. The enteφrise also has the

ability to set access rights defining what type of calls the user can place from the remote

device (e.g., local, long distance, international, station-to-station, etc.). For example, if

using PRI connections between the PSTN 54 and the WC 30, the PBX 14 and the WC

30, and the PBX 14 and the PSTN 16, users can be assigned into particular access

groups by assigning each user to a particular channel or group of channels of the PRI.

The user assignments can be stored in a database memory within memory module 320

of WC 30 for access during a validation or authentication process performed by

processor module 310. In the alternative, the responsibility over the user assignments

can be incorporated into PBX 14 or some other (on-site/remote) equipment.

As is known in the art, in North America and Japan, for example, each PRI

contains 23 "B" channels that can be used for voice communications. Each B channel

can be programmed with different calling capabiUties by the PBX 14. That is, some

channels can be programmed for aU types of caUs (e.g., international, long distance,

local etc.), others for long distance and local caUs, wfiile others can be programmed solely for local or internal station-to-station caUs. The channels can also be restricted to

a Umited number of authorized telephone numbers as weU. The programming can be

determined by the enteφrise. Since the channels can be programmed with different

calling capabiUties, the enteφrise can implement different access groups, with each

group defining a user's device access.

This feature significantly Umits the enteφrise's device (e.g., wireless service)

costs because user access to services can be substantiaUy restricted. For example, die

enterprise may want delivery personnel to have a wireless telephone for internal dialing

purposes, but may be afraid of misuse by the personnel. Implementing the above

embodiment, the enteφrise can group all wireless telephones assigned to its deUvery

personnel to a channel(s) restricted solely to internal calls. Any grouping is possible.

Priorities may also be assigned. A user assigned to group 1 (programmed for all calling

capabUities) may be given priority to bump a user assigned to group 2 (having less

calUng capabilities) in the event that the channels assigned to group 1 are busy. Any

grouping or priority scheme can be implemented by the enteφrise and is application

specific.

At step 308, the WC 30 "spoofs" a dial tone to the virtual office telephone

82, 84, 86, 88 and remote device 70. That is, the WC 30 generates and transmits a dial

tone as if the user had picked up a conventional office telephone hardwired to the PBX

14. In a preferred embodiment, the spoofing of the dial tone is achieved by the WC

internaUy generating the appropriate tone (e.g., through software or hardware

modules). The dial tone is then played to the virtual office telephone 82, 84, 86, 88 or remote device 70 as a prompt while waiting to receive DTMF digits from the user

indicating the telephone number the user wishes to dial. At this point in the caU

process flow 300, the user is connected to the office PBX and may access any of its

standard features. For puφoses of this ulustrated embodiment, it is presumed that the

user wishes to place an outbound caU at this time. At step 310, the user attempts to

place a caU and the WC 30 receives the number dialed by the user. At step 312, the

WC 30 determines if the user is authorized to make the caU. For example, the WC 30

checks the user's access rights, and if the user is authorized to place the caU, the call is

routed to the correct channel by the WC 30 based on user preferences, access rights and

die channel definitions (step 314). If the user is not authorized to place the call (i.e.,

the call exceeds the user's access rights), the WC 30 performs unauthorized caU

processing (step 316). Unauthorized call processing may include playing a message to

the user stating that the user does not have authority to place the call, disconnecting the

call, or any other action desired by the enteφrise.

If the user decides to place a station-to-station caU, for example, the caU

would appear to be an internaUy dialed caU at the destination office telephone. For

example, if the PBX 14 uses a different ring for internal calls, then the internal ring

would be sent to the destination telephone even if the caU was made from a virtual

office telephone 82, 84, 86, 88 or remote device 70. If the PBX 14 normally displays

the PBX extension of the calling party on the caUed office phone, then the PBX

extension of the calling party would be displayed on the caUed office telephone even

though the caU was initiated from a virtual office telephone 82, 84, 86, 88 or remote

device 70. Many enteφrises have already provided wireless communication devices to

their personnel. These wireless devices already have existing telephone numbers and are

external to the enteφrise PBX. Since the devices are already in use by personnel and

their cUents, the enteφrise may not want to change their telephone numbers. There is

a need to integrate these telephone numbers into the enteφrise PBX. One way to

integrate these telephone numbers would be to forward their unanswered caUs to the

PBX voice mail. This can be accompUshed in accordance with an embodiment of the

invention whether the wireless device is associated with a PBX extension or not.

For example, the enterprise can purchase additional DID telephone numbers

from the telephone company (if necessary). These additional DID telephone numbers

are stored in the database of the WC 30 together with special routing instructions to

route all calls directly to a user's PBX voice mail box (or other destination as desired).

The user of a wireless telephone can program the wireless telephone to forward

unanswered calls to his associated DID telephone number. Alternatively, the user can

have the wireless carrier forward unanswered calls to the DID telephone number as

well. This way, any unanswered call to the wireless telephone wiU be forwarded to the

WC 30, which resolves the DID and forwards the caU to the appropriate PBX voice mail

box. Using this feature, the likelihood is increased that the user wiU retrieve his

messages since he can retrieve all of his messages through the PBX voice mail. This also

alleviates the need for the user to have a separate voice mail service from the wireless

carrier, which may reduce the cost of the wireless service. The invention can be embodied in any number of different appUcations.

One embodiment, for example, appUes the invention to a hotel having a large number

of rooms without routing telephone lines or other wiring to each room. Many if not aU

rooms would have a telephone extension that is associated with the enteφrise PBX, as

weU as a wireless telephone associated with the PBX extension (integrated using an

embodiment of the invention). In addition, one or more rooms could employ more

than one PBX extension if desired by hotel guests. If, for example, a guest of the hotel

were using a standard room telephone and associated PBX extension for network access

by his personal computer, he could stiU make and receive caUs through a virtual room

telephone using a wireless telephone or other device in a manner transparent to the

calling party. This embodiment allows an enteφrise to multiply the number of its

telephone lines without incurring the expense of conventional wiring previously

required to install additional lines for the hotel rooms.

In a preferred embodiment, WC 30 is co-located with the enterprises' PBX

14, but may also be centraUy located in a remote location or distributed among the

many locations, or any combination of these arrangements.

While the preferred embodiments have been described thus far with reference

to a PBX network 11 and hardwired standard office telephones, this structure is not

required and a system of virtual office telephones may be implemented using only the

wireless connect WC 30, as shown in FIG. 6. In this embodiment, the system 10' of

virtual office telephones could provide a central location for receiving caUs to an

enteφrise and placing caUs from an enteφrise, while affording system users the flexibiUty of wireless office telephones. Referring to FIG. 6, aU features of the

exemplary telecommunication system 10 ulustrated in FIG. 1 are included with the

exception of PBX network 11 including conventional PBX 14, PRIs 20, 22 and PSTN

16. Instead, the WC 30 directs all caUs to and from the wireless office telephones to the

PSTN 54 through the CSU 34 and PRIs 32, 36 for routing to wireless office devices

82, 84, 86, 88 or personal wireless device 70 using conventional wireless equipment as

described with reference to FIG. 1. Although the traditional features of a conventional

PBX, such as PBX voice maU, user access rights, multiple-location routing and channel

definitions, have been removed in this embodiment, many of these features may be

available from WC 30 or the wireless carrier for the wireless devices 82, 84, 86, 88, 70.

Compared to the cost of a traditional PBX system, for smaller enteφrises, obtaining

these features from the wireless carrier may be a more cost effective option.

While preferred embodiments have been specificaUy described and Ulustrated

herein, it should be apparent that many modifications to the embodiments and

implementations of the invention can be made without departing from the spirit or

scope of the invention. For example, wh e the preferred embodiments lustrated

herein have been Umited to the processing of voice (packet or circuit switched) caUs, it

should be readily apparent that any form of caU (e.g., audio, video, data) may be

processed through WC 30 to any communication device (e.g., cellular phone, pager,

office/residential landline telephone, computer terminal, personal digital assistant

(PDA), etc.). The individual method steps of the exemplary operational flows

Ulustrated in FIGS. 3-5 may be interchanged in order, combined, replaced or even added to without departing from the scope of the invention. Any number of different

operations not ulustrated herein may be performed utiUzing the invention.

In addition, whUe the ulustrated embodiments have demonstrated

implementations of the invention using PBX-based communication systems, it should

be readUy apparent that the WC module may be connected (directly or indirectly) with

any other network switching device or communication system used to process caUs such

as a central switching office, Centrex system, or Internet server for telephone caUs made

over the public switched telephone network, private telephone networks, or even

Internet Protocol (IP) telephony networks made over the Internet.

It should be apparent that, whUe only PRI lines (e.g., between PBX 14 and

WC 30, between PBX 14 and PSTN 16) have been Ulustrated in discussing preferred

embodiments of the invention, these communication Unes (as weU as any other

communication lines or media discussed herein) may be of any form, format, or

medium (e.g., PRI, Tl, OC3, electrical, optical, wired, wireless, digital, analog, etc.).

Moreover, although PSTN 16, 54 are depicted as separate networks for illustration

puφoses, it should be readUy apparent that a single PSTN network alone may be used

in reducing the invention to practice. The use of a commercial wireless carrier network

(represented by the wireless switch 58 and the antenna 60) as described herein may be

implemented using one or more commercial carriers using the same or different

signaling protocols (e.g., Sprint PCS and Nextel, etc.) depending on the

communication devices registered with the system. The modules described herein such as the modules making up WC 30, as

weU as WC 30 and PBX 14 themselves, may be one or more hardware, software, or

hybrid components residing in (or distributed among) one or more local or remote

systems. It should be readUy apparent that the modules may be combined (e.g., WC 30

and PBX 14) or further separated into a variety of different components, sharing

different resources (including processing units, memory, clock devices, software

routines, etc.) as required for the particular implementation of the embodiments

disclosed herein. Indeed, even a single general puφose computer executing a computer

program stored on a recording medium to produce the functionaUty and any other

memory devices referred to herein may be utiUzed to implement the illustrated

embodiments. User interface devices utilized by in or in conjunction with WC 30 may

be any device used to input and/or ouφut information. The interface devices may be

implemented as a graphical user interface (GUI) containing a display or the Uke, or may

be a link to other user input/output devices known in the art.

Furthermore, memory units employed by the system may be any one or more

of the known storage devices (e.g., Random Access Memory (RAM), Read Only

Memory (ROM), hard disk drive (HDD), floppy drive, zip drive, compact disk-ROM,

DVD, bubble memory, etc.), and may also be one or more memory devices embedded

within a CPU, or shared with one or more of the other components. Accordingly, the

invention is not to be seen as limited by the foregoing description, but is only limited

by the scope of the appended claims. What is claimed as new and desired to be protected by Letters Patent of the

United States is:

Claims

1. A telecommunication device comprising:

a telephony interface, said telephony interface for receiving a telephone caU

and identifying a dialed telephone number associated with the caU, said telephony

interface using the dialed telephone number to retrieve at least a wireless telephone

number and at least one user preference from a storage medium, and said telephony

interface using said at least one retrieved user preference to route the call to at least one

destination telephone number, wherein said at least one destination telephone number

is selected from the group consisting of said retrieved wireless telephone number and a

voice maUbox telephone number.

2. The device of claim 1, wherein said telephony interface routes the caU to

two destination telephone numbers simultaneously, a first destination telephone

number corresponding to said retrieved wireless telephone number and a second

destination telephone number corresponding to a retrieved second telephone number.

3. The device of claim 2, wherein said telephony interface routes the caU to a

third destination number corresponding to said voice maUbox telephone number after a

predetermined time as defined by said at least one retrieved user preference.

4. The device of claim 3, wherein said predetermined time corresponds to a

number of telephone rings defined by said at least one retrieved user preference.

5. The device of claim 1, wherein said telephony interface routes the caU to a

first destination telephone number corresponding to said retrieved wireless telephone

number and to a second destination telephone number corresponding to a retrieved

second telephone number in a sequential manner and as defined by said at least one

retrieved user preference.

6. The device of claim 5, wherein said at least one retrieved user preference

defines a first ring count for the caU to said first destination telephone number and a

second different ring count for the call to said second destination telephone number.

7. The device of claim 6, wherein said telephony interface routes the call to a

third destination telephone number corresponding to said voice maUbox telephone

number after said telephony interface rings said first destination number more than said

first ring count.

8. The device of claim 1, wherem said telephony interface routes the caU to a

single destination telephone number corresponding to said voice maUbox telephone

number.

9. The device of claim 1, wherein said telephony interface prompts a caUer of

the telephone caU with a menu of caU destination options and said telephony interface

places the caU to at least one destination telephone number in accordance with an

option selected by the caUer.

10. The device of claim 1, wherein said telephony interface communicates

with a private branch exchange, and wherein at least one of said at least one destination

telephone numbers is associated with the private branch exchange.

11. The device of claim 10, wherem said at least one destination telephone

number associated with the private branch exchange is associated with a ceUular

telephone.

12. The device of claim 11, wherem the ceUular telephone can operate

independently from said device.

13. The device of claim 10, wherein another of said at least one destination

telephone number is associated with a pager.

14. The device of claim 10, wherem another of said at least one destination

telephone number is associated with a personal digital assistant.

15. The device of claim 1, wherem said telephony interface receives the caU

from a public switched telephone network, and wherein at least one of said at least one

destination telephone number is associated with a private branch exchange.

16. The device of claim 15, wherein said at least one destination telephone

number associated with the private branch exchange is associated with a ceUular

telephone.

17. The device of claim 1, wherein said telephony interface is connected to a

local area network and said at least one user preference is input via the local area

network.

18. The device of claim 1, wherem said telephony interface is connected to

the Internet and said at least one user preference is input via the Internet.

19. A telecommunication device comprising:

a telephony interface coupled to an enteφrise telecommunication network,

said telephony interface receiving a telephone call from a wireless telephone and

identifying a wireless telephone number of the wireless telephone, said telephony

interface using the wireless telephone number to retrieve a first enteφrise telephone

number associated with the enteφrise telecommunication network and with the wireless

telephone and to retrieve at least one user preference from a storage medium, said

telephony interface generating and sending a simulated dial tone to the wireless

telephone to provide access to the enteφrise telecommunication network based on said

at least one user preference and at least one enteφrise preference associated with said

first enteφrise telephone number.

20. The device of claim 19, wherein said at least one enteφrise preference

comprises a security group defining authorized outbound caU access of a user of the

wireless telephone.

21. The device of claim 19, wherein said at least one user preference

comprises a dial tone timeout period, wherem a user of the wireless telephone is

prevented from placing a caU after the dial tone timeout period expires.

22. The device of claim 19, wherein said telephony interface further

comprises:

means for receiving a second telephone caU, said second telephone caU being

placed to said first enteφrise telephone number associated with the enteφrise telephone

network;

means for identifying the first enteφrise number;

means for using the first enteφrise telephone number to retrieve at least the

wireless telephone number; and

means for using said at least one user preference to route the second call to at

least one destination telephone number, wherein said at least one destination telephone

number is selected from the group consisting of the wireless telephone number and a

voice maUbox telephone number.

23. The device of claim 22, wherein said telephony interface routes the

second caU to two destination telephone numbers simultaneously, a first destination

telephone number corresponding to the wireless telephone and a second destination

telephone number corresponding to a retrieved second telephone number.

24. The device of claim 23, wherein said telephony interface routes the

second caU to a third destination number corresponding to said voice mailbox

telephone number after a predetermined time as defined by at least one retrieved user

preference.

25. The device of claim 22, wherem said telephony interface routes the

second call to a first destination telephone number corresponding to the wireless

telephone number and to a second destination telephone number corresponding to a

retrieved second telephone number in a sequential manner and as defined by at least

one retrieved user preference.

26. A method of operating a wireless connect unit to implement a virtual

dual fine telephone interface into an enteφrise telecommunication network location

havmg a single line telephone interface, said method comprises: connecting the enteφrise telecommunication network to a wireless connect

unit;

providing at least one wireless telephone to the location;

routing a telephone caU made to an extension of the enteφrise network to

the wireless connect unit;

identifying the extension from the routed telephone caU;

using the identified extension to retrieve a first telephone number associated

with the wireless telephone and a second telephone number associated with a

telecommunications device;

routing the telephone caU to at least one destination telephone number,

wherein said at least one destination telephone number is selected from the group

consisting of the first and second telephone numbers, and

wherein the wireless telephone can receive the caU if the device associated

with the second telephone number is unable to receive a caU and the device associated

with the second telephone number can receive the caU if the wireless telephone is

unable to receive the caU.

27. A method of providing telecommunications between users of first and

second enteφrise telecommunication networks, said method comprising: connecting each enteφrise telecommunication network to a respective

wireless connect unit;

providing at least one wireless telephone to the users of the first and second

telecommunications networks;

routing a telephone caU made from a first user of the first enteφrise network

to the wireless connect unit connected to the second enteφrise network, the telephone

call being for an extension of the second enteφrise network;

identifying the extension from the routed telephone caU;

using the identified extension to retrieve a first telephone number associated

with a wireless telephone and a user preference; and

routing the telephone caU in accordance with the user preference to at least

one destination telephone number, wherein said at least one destination telephone

number is selected from the group consisting of the first telephone number and a voice

maUbox telephone number.

28. A method of providing telecommunications to a user of an enteφrise

telecommunication network, said method comprises:

connecting the enteφrise telecommunication network to a wireless connect

unit; providing an extension of the enteφrise network associated with the user;

providing a wireless device to the user;

routing a telephone caU made to the extension to the wireless connect unit;

identifying the extension from the routed telephone caU;

using the identified extension to retrieve a first telephone number associated

with the wireless device and at least one user preference; and

routing the telephone caU in accordance with the user preference to at least

one destination telephone number, wherem said at least one destination telephone

number is selected from the group consisting of the first telephone number and a voice

maUbox telephone number.

29. A method of providing access to an enteφrise telecommunication

network from a wireless telephone, said method comprises:

receiving a telephone caU from the wireless telephone;

identifying a wireless telephone number of the wireless telephone;

using the wireless telephone number to retrieve an enteφrise telephone

number associated with the enteφrise telecommunication network; generating a simulated dial tone;

sending the simulated dial tone to the wireless telephone;

providing telecommunication access to the enteφrise telecommunication

network based on at least one user preference and at least one enteφrise preference

associated with the retrieved enteφrise telephone number.