WO2006072777A2

WO2006072777A2 - Apparatus, system and method of voice over ip technology

Info

Publication number: WO2006072777A2
Application number: PCT/GB2006/000009
Authority: WO
Inventors: Andreas Tapakoudes
Original assignee: Volptech Ltd
Priority date: 2005-01-04
Filing date: 2006-01-04
Publication date: 2006-07-13
Also published as: GB2421876A; WO2006072777A3; GB0500021D0

Abstract

A VoIP wireless PBX comprises at least a first base station. Said base station itself comprises means to facilitate connection to the internet, as well as wireless communications hardware, and software suitable for managing the base station's role in the VoIP wireless PBX. The VoIP wireless PBX also comprises at least one of either; a mobile handset, operable to communicate with a base station in the wireless VoIP PBX, either directly of via a VoIP repeater, or a mobile terminal, operable to link a peripheral telecommunications device to the VoIP wireless PBX.

Description

Apparatus, System and Method of Voice over IP Technology

The present application is related to voice over internet protocol telephony, and in particular, but not exclusively, with voice over internet protocol telephony devices.

In a standard public switched telephone network (PSTN), when one phone dials another phone's number, a pair of dedicated links are formed. Originally, this was performed by operators physically wiring phone lines together- to form continuous physical wire links, but for the last few decades the switching function has been provided by mechanical, and later, digital exchanges. The resulting links, or circuits, remain in place for the duration of the call.

In consequence, network resources are allocated to a call regardless of the amount of speech data actually being transmitted. Given that in a typical conversation any one party may only be talking for less than 50% of the time, this is clearly wasteful.

In contrast, cellular phone network providers, facing pressure on limited bandwidth, developed packet-switched phone networks (PSNs). In a PSN, speech data on one phone is divided into individually labelled packets, which are routed to another phone where their contents are reassembled in order to deliver the speech. In this form of network, links are formed in different parts of the overall network only for as long as is necessary to send a packet on each leg of its journey. In this way, routing systems in the network can pick less congested routes for packets, and individual routes can service multiple users, as packets can be sent faster than real-time.

Moreover, because packets are discontinuous, optionally they need only be sent when there is speech to convey, further reducing the load on the network. Recently, it has been proposed that instead of using a dedicated packet switched network to make phone calls,, one could use the packet-based Internet as a backbone for such calls.

This approach is known as voice over internet protocol, or VoBP. The principle behind VoIP is that a computer can take speech signals and packetise them according to internet protocols. It can then send them like any email or web page data to another computer, which could reassemble the speech, again much like it would reassemble an email or web page. Software packages exist that provide VoIP functions for computers, such as Skype (see www.skype.com) and Vonage (see www.vonage.com).

In addition to using a computer terminal equipped with a microphone and speakers, more recently there have been attempts to integrate a telephone form factor with VoIP functionality.

This integration has taken two main forms:

Firstly, analogue telephone adapters (ATAs) allow a user to connect their phone to their computer. The ATA acts as an analogue to digital converter, enabling the user to use their phone handset in lieu of a microphone and speaker on the computer. These typically connect either to the computer's sound card (e.g. see http://www.1wacomm.com/Mo/PhoneBridgeIP.htm) or universal serial bus (e.g. see http://www.ame-group.com/ipo 11.htm).

Secondly, IP phones are specifically designed to plug into an Ethernet network rather than the telephone network, and incorporate all the hardware and software necessary to conduct VoIP calls.

However, there is considerable scope for improvement in this new telecommunications system.

Accordingly, aspects of the present invention seek to provide additional functionality to a VoIP system. According to one aspect of the present invention, a voice over internet protocol (VoIP) base station comprises connectors suitable for connection to the internet via at least one intermediary device, as well as wireless communications hardware, and software suitable for managing the base station's role in a VoIP private branch exchange (PBX).

In one configuration of the present aspect, the VoIP base station comprises connectors suitable for connection to a VoIP gateway.

In an alternative configuration of the present aspect, the VoIP base station comprises connectors suitable for connection to a VoIP box operably coupled to a PC.

According to another aspect of the present invention, a voice over internet protocol (VoIP) base station comprises internet connection means, as well as wireless communications hardware, and software suitable for managing the base station's role in a VoIP private branch exchange (PBX).

Lti a configuration of either of the above two aspects, the VoIP base station can coordinate operation of a wireless VoIP PBX with other similar VoIP base stations, each base station associated with a VoIP line into and out of the VoIP PBX

In a configuration of either of the above two aspects, a two-number extension code provides for up to nine base stations, and ninety mobile devices. These may be on extensions 01 to 09 and extensions 10 to 99 respectively.

According to another aspect of the present invention, a VoIP repeater comprising wireless communications hardware is dedicated to wirelessly relaying calls between a specific VoIP base station and one or more mobile devices involved in a current call.

According to a further aspect of the present invention, a mobile device takes the form of a mobile handset, operable to communicate with any one of the plurality of base stations in a wireless VoIP PBX, either directly or via a VoIP repeater. In one configuration of the present aspect, the mobile handset comprises a PBX identification number stored in a memory, a user interface and audio input and output, wherein the mobile handset is operable to compare its PBX ID number with call notifications broadcast from a base station, in order to determine if it is the intended recipient of an incoming call.

According to another aspect of the present invention, a mobile device takes the form of a mobile terminal, the mobile terminal comprising a PBX ID stored in a memory, wireless communications hardware, and a means to connect a peripheral telecommunications device to the terminal to allow that device to access the VoIP PBX.

In one configuration of the present aspect, the connections means is a Registered Jack 11 (RJI l) port.

In one configuration of the present aspect, the mobile terminal also comprises a user interface, itself comprising an alert buzzer and a control button operable to adjust call volume.

In one configuration of the present aspect, the mobile terminal is mountable in a car and operable to draw electrical power from a car supply.

According to yet another aspect of the present invention, a VoIP wireless PBX comprises at least a first base station, the base station itself comprising connectors suitable for connection to the internet via at least one intermediary device, as well as wireless communications hardware, and software suitable for managing the base station's role in the VoIP wireless PBX, the VoIP wireless PBX further comprising at least one of either; a mobile handset, operable to communicate with a base station in the wireless VoIP PBX, either directly or via a VoIP repeater, or a mobile terminal, operable to link a peripheral telecommunications device to the VoIP wireless PBX.

In one configuration of the present aspect, the base stations of the VoIP wireless PBX connect to the internet via either a VoIP gateway operably coupled to a broadband modem, or a VoIP box operably coupled to a computer, itself operably coupled to a broadband modem.

In another configuration of the present aspect, one, some or all of the base stations connect to the Internet by one of the following means; i. a PSN link; ii. a satellite link, and; iii. a mobile phone link

In another aspect of the present invention, around five mobile devices are dedicated to one base station and are not differentiated by PBX identification number, the VoIP wireless PBX thus allowing any of said mobile devices to make or answer a call on the VoIP line serviced by said base station.

In one configuration of the present aspect, any or all of the mobile devices may pass a call to any other, or share a call between them.

According to an aspect of the present invention, a handset comprises means for connection to a computer via a USB port, and means to draw power from this connection, the handset further comprising echo cancelling means and a liquid crystal display.

In one configuration of the present invention, the display is arranged in operation to inform the user of the number they are dialling, the number or associated name of an incoming caller, and the status of the VoIP call.

According to an aspect of the present invention, a method of placing a call over a VoIP connection involves initially connecting a peripheral telecommunications device to a mobile terminal, and then either using the mobile terminal to scan for an available base station, or nominating a base station via a user interface of the peripheral telecommunications device, before the selected base station initiates a VoIP session, enabling a VoIP call to be conducted via a wireless link between the base station and mobile station. According to another aspect of the present invention, a method of receiving a call over a VoIP connection involves initially connecting a peripheral telecommunications device to the mobile terminal of a target user; subsequently, when the PBX ID of the target user is obtained from an incoming caller, the mobile terminal is alerted by the base station, and upon acceptance of the call by the user, a VoIP call is conducted via a wireless link between the base station and mobile station.

In one configuration of the present aspect, the mobile terminal alerts the user to the presence of an incoming call using an integral audio device.

In another configuration of the present aspect, the mobile terminal alerts the user to the presence of an incoming call by causing the peripheral telecommunications device to alert a call in its normal manner.

In an aspect of the present invention, a computer program product comprises a computer readable storage medium on which is stored information which, when loaded into a computer, causes the computer to perform either a method of placing or receiving a VoIP call.

In a similar aspect of the present invention, a computer receivable signal comprises information which, when loaded into a computer, causes the computer to perform either a method of placing or receiving a VoIP call.

In another aspect of the present invention, a computer program product comprises a computer readable storage medium on which is stored information which, when loaded into a computer equipped with suitable hardware, causes the computer to operate as a VoIP base station.

In another aspect of the present invention, a computer program product comprises a computer readable storage medium on which is stored information which, when loaded into a computer equipped with suitable hardware, causes the computer to operate as a VoEP mobile terminal. Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a schematic diagram of a voice over IP (VoIP) private branch exchange in accordance with an embodiment of the present invention.

Figure 2 is a schematic diagram of a VoIP base station in accordance with an embodiment of the present invention.

Figure 3 is a flow diagram of a method of call placement in accordance with an embodiment of the present invention.

Figure 4 is a flow diagram of a method of call reception in accordance with an embodiment of the present invention.

Figure 5 is a schematic diagram of a VoIP mobile terminal in accordance with an embodiment of the present invention.

Figure 6 is a schematic diagram of a VoIP USB phone unit, in accordance with an embodiment of the present invention.

Referring to Figure 1, in an embodiment of the present invention a broadband modem 110 is connected to the Internet 101. Two voice over internet protocol (VoIP) gateways 121 and 122 are connected to the broadband modem, as are three PCs 112, 114, 116. Each PC 112, 114, 116 is further connected to a VoIP box 123, 124, 125 providing a connection between the PC 112, 114, 116 and further VoIP equipment.

Connected to each of the gateways 121, 122 and VoIP boxes 123, 124 and 125 are VoIP base stations 131-135. These VoIP base stations 131-135 are operable to communicate wirelessly with mobile handsets 171, 172 and mobile terminals 151, 155 (collectively referred to hereinafter as mobile devices) identified as belonging to a private branch exchange (PBX) served by the base stations. Optionally, at least a first repeater 141 rebroadcasts communications between a specific base station 131-135 and a mobile device 171, 172, 151, 155 as necessary. The repeater 141 is pre-set to serve a specific base station 131-135 by retransmitting an amplified signal at the base stations' frequency. In addition, base stations 131-135 and mobile devices 171, 172, 151, 155 employ automatically adjustable signal gain to mitigate channel conditions.

It will be appreciated that further repeaters may be provided as desired.

In operation, for incoming data, VoIP gateways 121 and 122 and PCs 112, 114, 116 unpack VoIP data for the IP network, and, in the case of gateways 121, 122, output an analog signal. In the case of PCs 112, 114, 116, the VoIP box 123, 124, 125 interfaces with the PC to generate the analog signal. This signal is then passed to a base station 131-135 which digitises the signal for wireless communication to the mobile devices 171, 172, 151, 155 and/or repeater 141. For outgoing data, the process is reversed, with base station 131-135 converting the wireless digital signal to analog, which is then packetised at the gateway 121, 122 or PCl 12, 114, 116.

Referring to Figure 2, in an embodiment of the present invention the base stations 131- 135 each comprise a broadband communication unit 210 suitable for connecting the base station 131-135 with a VoIP gateway 121, 122 or VoIP box 123-125. Each base station 131-135 further comprises a wireless communication unit 220 and aerial 230, suitable for wirelessly communicating with a mobile device 171, 172, 151, 155 or a repeater 141. In addition, user interface 270 comprises a microphone and speaker (not shown). The broadband communication unit 210, user interface 270 and wireless communication unit 220 are operable to communicate with a processor 240 via bus 201. In working memory 250, a PBX management application 260 comprises software instructions executable by the processor 240 to provide wireless PBX communications facilities suitable for the base station 131-135.

Each base station is associated with a VoIP line to the broadband connection 110. A dynamic host configuration protocol (DHCP) router assigns each VoIP line with an IP address, and this address is associated with a telephone number. Consequently each line, in addition to its own PBX number, will have its own telephone number by which it can be called by parties external to the PBX. This telephone number is programmed into the relevant gateway 121, 122 or PC 112 to 116.

The telephone number is associated with a service provider account. Authentication details (typically user ID and password) for the account are programmed into the PBX management application 260 of the base station 131-135. The line number (for example, 01 to 09) that the base station 131-135 will serve is also programmed into the PBX management application 260. Thus each additional base station can be assigned the next available line number. There is no requirement for each VoIP line to be with the same service provider.

The IP address, telephone number and account identification together serve to distinguish each base station 131-135 and VoIP line.

Up to 9 base stations are connected to a typical ADSL broadband connection. Each VoIP line, using CELP codec G.729, requires 15kbps bandwidth, with 8kbps for speech and 7kbps for IP address and overhead. Thus for 9 base stations, 135kbps is required on both the up and down links. On a typical 256/512 kbps broadband connection this therefore provides remaining bandwidth for other applications. Additionally, a voice activity detector (VAD) reduces the overall bandwidth use, typically by 50 to 60 percent, by only sending packets over a VoIP line if speech is detected.

In operation, the base stations 131-135 act to manage a private branched network consisting of themselves, any repeater 141 and the mobile devices 151, 155, 171, 172:

Referring now to the method illustrated in Figure 3, when a user wishes to make a call they may initiate connection in one of two ways; firstly, the mobile device 171, 172, 151, 155 may scan for the first available base station 131-135 in step s3-l. Secondly, they may explicitly nominate which base station 131-135 they wish to connect to, if available, by keying in the relevant line number (for example, 01 to 09) in step s3-2. The ability to explicitly nominate a base station allows for the option to have different service providers for different VoIP lines. Thus for example in a nine VoIP base station system, lines 1 to 4 may connect to a low cost IP to PSTN service, whilst lines 5 to 7 are connected to a provider of free IP to IP calls only, and lines 8 and 9 connect to a premium service. In the event that two callers nominate the same base station at exactly the same time, contention procedures will select one of these callers, for example based on PBX number, or on user priority if such information is stored.

Independent of the method of selection, the selected base station 131-135 subsequently establishes its VoIP link to the IP network using the session initiation protocol (SIP) in step s3-3, and wirelessly provides a dial tone to the handset in step s3-4. The user may then call someone in the normal manner in step s3-5, and will appear to have the IP address and phone number of the serving base station 131-135. When the call is finished, the VoIP session is terminated at the serving base station in step s3-6 and the wireless link is ended in step s3-7.

Communication between base stations 131-135, repeaters 141 and mobile devices 171, 172, 151, 155 use digital signals transmitted at radio frequencies. Typically, the connection uses channels near 900MHz as this frequency range is commonly used by mobile phones; for example, the GSM standard uses channels in the 880 to 960MHz range, and so electrical devices are generally designed not to interfere in this part of the spectrum.

Note that a call can be to another mobile device 171, 172, 151, 155 within the PBX if only the PBX number of the other mobile device 171, 172, 151, 155 is used, in a similar manner to dialling just an extension within an ordinary PBX. This effectively provides full duplex communication between the mobile devices 171, 172, 151, 155 of the PBX.

Referring now to Figure 4, in step s4-l incoming calls are distributed by the service provider in a manner similar to a PSTN exchange, wherein if one line is busy, the incoming call may be assigned to the next. Where several service providers are used, then they assign within the subset of lines they serve. If no line is currently available, the service provider may provide a voice mail service.

When a call has been assigned to a line, in step s4-2 a direct inward system access (DISA) automated operator requests the PBX number (for example, a number from 10 to 99) of the desired mobile device 171, 172, 151, 155. The base station sends a signal comprising the PBX number, and any mobile devices 171, 172, 151, 155 within the PBX determine if their own PBX ID number corresponds. The corresponding mobile device, for example mobile handset 171, is then connected in step s4-3 and rings to alert its user. If the user accepts the call in step s4-4, the VoIP session begins in step 4-5 and the user joins the call. Where the DISA requests the PBX number using a voice prompt, then the VoIP session begins at step s4-2 and is routed to the desired mobile device 171, 172, 151, 155 upon acceptance of the call by the user. If a user does not respond to a call, optionally the session is routed to a voicemail or answer phone service hosted on the base station 131-135, in step s4-6.

Note that voicemail facilities may therefore be provided both centrally by the service provider if a line is unavailable, and locally within the PBX if a specific mobile device is unavailable or not answered.

Each handset 171, 172 comprises a PBX identity number (for example, a number between 10 and 99), allowing confirmation of whether a communication is intended for that specific handset. This PBX identity number may be pre-set, or programmed in via the keypad while the handset is in a programming mode. Typically a handset is assigned the next available number in the PBX upon joining.

Referring now to Figure 5, in an embodiment of the present invention the mobile terminals 151, 155 each comprise a wireless communication unit 320 and aerial 330, suitable for wirelessly communicating with a base station 131-135 or a repeater 141, and a user interface 370, the user interface 370 itself comprising a control button (not shown) and paging buzzer (not shown). The mobile terminal 151, 155 further comprises a registered jack 11 (RJl 1) telephone port 310. The RJl 1 port 310, wireless communication unit 320 and user interface 370 are operable to communicate with a processor 340 via bus 301. In working memory 350 a PBX identity number is stored, allowing processor 340 to confirm whether a communication is intended for the specific mobile terminal.

In operation, a mobile terminal 151, 155, can accept a telephone, fax or computer with telephone modem connection that is plugged into the RJl 1 port of the mobile terminal 151, 155. The mobile terminal then-acts as a wireless VoIP RJl 1 port within the PBX.

Advantageously, if one were for example to deploy a PBX comprising such VoIP mobile terminals within an office building, then that office can connect standard PSTN telephone equipment for use with VoIP calls without the need to install a physical wire- based network in the office, or to purchase dedicated VoIP phones. This enable the setting up of a cost effective office communications solution.

Also advantageously, the PBX need not be limited to one building, as a communication range of 10 km (or more with repeaters 141) is possible, so enabling communication for a number of buildings on one or more local sites. It is noteable that this range is considerably greater than that which can be provided by a Wi-Fi hotspot, and avoids the need to purchase expensive Wi-Fi enabled EP phones that may not have all the desired features and formats available from a range of standard PSTN phones, faxes and modems.

The mobile terminal 151, 155 comprises a buzzer operable to alert the user to an incoming call, for example if there is no phone device currently connected to it, or to alert the user if the terminal is paged from a base station, either automatically or by an operator. The mobile terminal 151, 155 also comprises a control button, operable during a call to control the volume at the RJl 1 port.

A mobile terminal's 151, 155 PBX identity number and any other device parameters can be transmitted to the base stations 131-135 when the mobile terminal 151, 155 is added to the PBX, by pressing the control button when the mobile terminal is not in a call. The PBX identity number (for example, a number between 10 and 99) may be preset, or programmed by connecting the mobile terminal 151, 155 to a programming tool. The programming tool is operable to set mobile terminal parameters via a keypad, and inform the user of the parameter status via a display. Typically a mobile terminal is assigned the next available number in the PBX upon joining.

Where a laptop computer 161 is attached to a mobile terminal 151 via a 'phone modem (not shown), then optionally a VoIP unit with a phone form factor may in turn be attached to the laptop for the convenience of the user.

Referring now to Figure 6, in an embodiment of the present invention a USB VoIP phone unit 162 comprises a USB connector 410, an audio interface 472, the audio interface 472 itself comprising a loud speaker and a microphone in typical phone handset arrangement, a keypad 474, a liquid crystal display 476 and an echo canceller 478. The USB connector 410, audio interface 472, keypad 474, display 476 and echo canceller 478 are operable to communicate with a processor 440 via bus 401. In working memory 450 a display driver is stored, allowing processor 440 to display user feedback on display 476.

In use, the USB phone 162 plugs into a USB port of laptop 161, and draws power from this USB port. The USB connection allows the USB phone 162 to co-operate with software hosted on the laptop, in order to communicate with the VoIP PBX via the laptop. The software hosted on the laptop is operable to, inter alia, cause the USB phone 162 to ring in order to alert a user to an incoming call.

The display drivers 466 allow processor 440 to present feedback on the display 476, that feedback comprising the number being dialled on the keypad, the number or name of an incoming call if available, and the status of the VoIP call session, as applicable.

Echo is a common problem in VoIP , typically due to the connection to a computer of a loudspeaker and microphone arranged in such a way that the microphone picks up the output of the loudspeaker, resulting in a feedback loop. A phone form factor such as USB phone 162 mitigates this problem by placing the speaker and microphone close to the user's ear and mouth respectively, allowing lower speaker volumes and microphone sensitivities, thereby reducing feedback levels. To enhance this effect, the USB phone 162 also adapts the microphone sensitivity to further reduce feedback.

However, other sources of echo exist, for example due to impedance mismatches in the circuit, delays in digitising the speech, and the transmission distance. Consequently, the echo canceller 478 employs G.168 line echo cancellation to reduce transmission echo, and the USB phone 162 also employs a processor capable of fast speech digitising to reduce digitisation echo. These features thus further mitigate sources of echo in the system.

The VoIP PBX system is further arranged in operation to provide; i. call transfers between mobile devices 171, 172, 151, 155 for incoming or outgoing calls; ii. the addition of new parties to form a conference call; iii. an answering machine or voice mail service, wherein base stations are operable to cause a VoIP message for a mobile device 171, 172, 151, 155 in the PBX to be recorded if the relevant device is unavailable.

A number of the above features (for example, voice mail) are currently only provided by service providers for a monthly fee. By providing the above facilities locally, advantageously this service cost is reduced.

A number of configurations of the above embodiments are envisaged. For example, the base stations and mobile devices may be arranged to transmit at different power levels, so conferring different effective ranges. Table 1 below provides a selection of possible configurations:

Table 1 — Power levels In addition, with sufficient repeaters 141 placed appropriately within the PBX, ranges in the order of 1000km may be achieved. Over such a wide range, it may be desirable to incorporate security measures to prevent eavesdropping. Such measures may include;

1. Secure IDs at each base station 131-135 and mobile device 171, 172, 151, 155;

2. Voice scrambling or encryption within the PBX, and;

3. Attachment of an external voice scrambling or encryption device between mobile terminal 151, 155 and a telephone.

In another configuration, call transfer is envisaged, wherein a user in the PBX currently on a call nominates another mobile device 171, 172, 151, 155 using its PBX number, and the other device is then connected to the call

In yet another configuration, conference calling is envisaged, wherein a user in the PBX currently on a call nominates another mobile device 171, 172, 151, 155 using its PBX number, and the other mobile device 171, 172, 151, 155 is then connected to the call in addition to the original user. Outgoing speech signals are combined prior to encoding by the base station 131-135.

Other configurations include the provision of any or all of the following additional features:

Caller ID on mobile handsets 171, 172;

Caller ID on devices connected to mobile terminals 151, 155;

Voice scramble between base stations 131-135 and mobile devices 171, 172, 151, 155;

Multi-channel auto scan of 40 or 80 channels by mobile devices 171, 172, 151, 155;

Free channel scanning while talking by mobile devices 171, 172, 151, 155;

Two-way paging between a base 131-135 and a mobile device 171, 172, 151, 155, and;

Call blocking by mobile device 171, 172, 151, 155.

In addition, handsets 171, 172 and USB phone 162 may incorporate known phone functions such as; ringer and/or vibration on call, keypad lock/unlock, battery alert, received signal strength indication, phonebook, redial, microphone mute and a connector for hands-free equipment.

In another configuration, one or more mobile terminals 151, 155 are located in a car and powered by a car battery. In this configuration, the one or more mobile terminals provide in-car VoIP connectivity within the wireless PBX range. In similar configuration, an in-car base station is connected to the internet via a mobile phone or satellite link, allowing the formation of a wireless VoIP PBX local to the car.

In a yet further configuration, a limited number of mobile devices 171, 172, 151, 155, for example five, are assigned to a VoIP box 123, 124, 125, the VoIP box being additionally capable of wireless communication. In this configuration, the mobile devices 171, 172, 151, 155 are not differentiated by number and so any may be used to make or answer a call through the VoIP box. If several mobile devices 171, 172, 151, 155, are used, then calls may be shared or transferred between them.

In another configuration, a mobile terminal 151, 155 may be configured for use with other types of wireless base station, for example domestic cordless phone base stations, enabling use of standard PSTN phones within a cordless system.

It will be clear to a person skilled in the art that the PBX shown in Figure 1 is by way of illustration only, and that it is envisaged that any suitable number of VoIP connections, base stations, repeaters, mobile handsets and mobile terminals may be deployed in such a PBX, and the base stations connected to the internet by any suitable means.

It will be clear to a person skilled in the art that one or more VoIP lines in a VoIP PBX may be supplied via one or more PSTN connections in addition to or instead of a broadband connection, where such PSTN connections provide sufficient bandwidth.

It will be clear to a person skilled in the art that in a VoIP PBX, addressing up to nine base stations with numbers 01 to 09, and up to ninety handsets or mobile terminals with numbers 10 to 99, provides a simple two-digit PBX extension number, but that for a larger PBX, a different three or more digit numbering scheme and modified software to accommodate the scheme could be employed.

It will also be clear to a person skilled in the art that the base stations 131-135 need not be co-located and may, for example, occupy different buildings in order to provide wider wireless coverage.

It will be clear to a person skilled in the art that one or more base stations 131-135 may comprise a VoIP gateway 121-122, and further may comprise a broadband modem 110, so enabling direct connection to the Internet.

It will also be clear to a person skilled in the art that the step of converting from a digital signal to analog between the gateway 121 , 122 or PC 112, 114, 116 and the base station 131-135 may be avoided if a suitable digital transfer means is provided, or if the gateway 121, 122 is integral to the base station 131, 135.

It will also be clear to a person skilled in the art that as an alternative to 900MHz, any appropriate set of radio channels may be used within the PBX; for example, the commonly used wireless operating frequency near 1800MHz.

It will similarly be clear to a person skilled in the art that a codec other than G.729 may be employed, such as G.729A, G.728 or GSM 06.10, and that for a PBX with more than 9 base stations, one or more broadband links may be shared with as many base stations as the link bandwidth reasonably allows, given the bandwidth used by the selected codec and overheads.

It will be clear to a person skilled in the art that the broadband connection may be DSL, ADSL₅ satellite broadband or any suitable broadband connection means.

It will be clear to a person skilled in the art that a DISA may parse the PBX extension number without interacting with the incoming caller, if that number is provided in a timely fashion or as part of a telephone number sequence upon dialling. It will be clear to a person skilled in the art that the VoIP wireless PBX system and devices described herein may be adapted to meet the local or current prevailing IP and VoIP protocols and session procedures.

It will be clear to a person skilled in the art that the facility to scan for an available base station and the ability to specify a base station for the purpose of using a particular service type may be amalgamated. In this amalgamated form a mobile device 171, 172, 151, 155 may scan for an available base station that provides a particular service type. Thus in the example used previously, it may scan amongst lines 1 to 4 for an available IP to PSTN line.

It will be clear to a person skilled in the art that the mobile terminal 151, 155 may be equipped with a telephone port other than RJI l that is suitable for a local or proprietary telephone standard.

It will also be clear to a person skilled in the art that the mobile terminal 151, 155, may comprise a speaker instead of a buzzer, facilitating voice paging from the microphone of a base station 131-135, or synthetic speech from said base station.

It will be further clear to a person skilled in the art that certain functionality of a mobile terminal when acting as a mobile device may only be possible if a suitable phone unit is attached; for example, explicitly nominating a base station with which to make a call (step s3-2 of Figure 3) requires the use of a connected phone's keypad.

It will be clear to a person skilled in the art that the USB phone 162 may be connected to a computer that has its own VoD? access independent of any VoDP PBX. It will also be clear to a person skilled in the art that the USB connector 410 may comprise either a USB port or a USB cable.

It will also be clear to a person skilled in the art that the USB phone 162 may employ any suitable echo canceller 478, display means 476 or processor 440. It will similarly be clear that processing tasks may be assigned between a general processor 440 and a dedicated digital signal processor.

It will similarly be clear to a person skilled in the art that in the USB phone 162, the displayed feedback may comprise any or all of the following; i. the number being dialled by the user; ii. the status of the call; iii. the number of the person calling the user; iv. the name of the person calling the user, and; v. VoIP line availability.

The present invention may be implemented in any suitable manner to provide suitable apparatus or operation. In particular, a VoIP mobile terminal or VoIP base station may consist of a single discrete entity, a single discrete entity such as a PCMCIA card added to a conventional host device such as a laptop, multiple entities added to a conventional host device, or may be formed by adapting existing parts of a conventional host device. Alternatively, a combination of additional and adapted entities may be envisaged. For example, call processing may be shared between the processor of the gateway and that of the base station. Thus adapting existing parts of a conventional host device may comprise for example reprogramming of one or more processors therein. As such the required adaptation may be implemented in the form of a computer program product comprising processor-implementable instructions stored on a storage medium, such as a floppy disk, hard disk, PROM, RAM or any combination of these or other storage media or signals.

It will be understood that the wireless VoIP PBX system and apparatus described above provide at least one or more of the following advantages:

i. Easy deployment of a VoIP PBX; ii. Wireless connection of standard telephony equipment to a VoIP service; iii. Long range wireless PBX; iv. Local voicemail in the wireless VoIP PBX; v. Wireless connection to a base station for multiple handsets, and; vi. A phone style form factor for VoIP computer users.

Claims

CLAIMS:

1. A voice over internet protocol (VoIP) base station comprising means to connect to an IP network, wireless transceiver means and private branch network (PBX) management means, the VoIP base station being arranged in operation to wirelessly link a VoIP call between an IP network and one or more specified devices of a wireless PBX.

2. A VoIP base station according to claim 1, operable to co-ordinate a wireless PBX in conjunction with at least a first other of said VoIP base stations whilst sharing a single broadband link to an IP network.

3. A VoIP base station according to claim 2, wherein up to nine of said VoIP base stations are operable to co-ordinate a wireless PBX.

4. A VoEP base station according to any preceding claim, operable to address up to 90 mobile devices.

5. A VoE? base station according to any preceding claim wherein the VoIP base station further comprises a VoIP gateway.

6. A voice over internet protocol (VoIP) repeater comprising a wireless transceiver and PBX routing means, the VoE? repeater being arranged in operation to wirelessly relay a VoEP call link between an assigned VoIP base station and one or more selected terminals of a wireless PBX.

7. A voice over internet protocol (VoEP) wireless handset, comprising PBX identification means, wireless transceiver means, keypad, microphone and loudspeaker.

8. A wireless terminal, comprising wireless transceiver means, and at least a first connection port for connecting to a communications device.

9. A voice over internet protocol (VoEP) wireless terminal, comprising PBX identification means, wireless transceiver means, and at least a first connection port for connecting to a communications device.

10. A terminal according to any one of claims 8 and 9, wherein the at least first connection port is a registered jack 11 (RJl 1) telephone socket.

11. A terminal according to any one of claims 8 to 10 wherein the terminal further comprises a user interface, the user interface comprising an alert means and a control button operable to control volume during a call.

12. A terminal according to any one of claims 9 to 11 wherein the terminal is situated in a car, and in use is powered by the car battery.

13. A terminal according to any one of claims 9 to 12 wherein the terminal comprises a PBX identification number, and is arranged in operation to compare that number with a number transmitted by a VoIP base station, in order to determine if it is the intended recipient of an incoming call.

14. A VoIP terminal according to any one of claims 9 to 13 wherein the VoIP terminal is operable to cause a connected communications device to alert a user to the presence of an incoming call.

15. A VoIP terminal according to any one of claims 9 to 14 further comprising a scrambling or encryption means operable to connect between the VoIP terminal transmission means and a phone.

16. A voice over internet protocol (VoIP) wireless private branch network (PBX), comprising at least a first VoIP base station in accordance with one of claims 1 to 4, and any or all of the following; i. at least a first VoIP handset in accordance with claim7, and; ii. at least a first VoIP terminal in accordance with one of claims 9 to 15.

17. A VoIP wireless PBX in accordance claim 16 further comprising at least a first VoIP repeater in accordance with claim 6.

18. A VoIP wireless PBX in accordance with one of claims 16 and 17 wherein the or all VoIP base stations each connect to a broadband link via any one of the following means respectively; i. A VoIP gateway operably coupled to a broadband modem, and; ii. A VoIP box operably coupled to computer, in turn operably coupled to a broadband modem.

19. A VoIP wireless PBX in accordance with one of claims 16 and 17 wherein the, any or all VoIP base stations each connect to an internet service provider via one of the following; i. a public switched telephone link; ii. a satellite link, and; iii. a mobile phone link.

20. A VoIP wireless PBX in accordance with one of claims 16 to 17 wherein the or all base stations are situated in-car, powered in use by the car battery and connect to an internet service provider via any or all of; i. satellite link, and; ii. mobile phone link.

21. VoIP wireless system comprising a VoIP box comprising wireless transceiver means, and a plurality of mobile devices operable to wirelessly communicate with the VoE? box, the VoIP wireless system being arranged in operation to allow any of the said mobile devices make or answer a VoD? call via the VoD? box.

22. A VoD? wireless system according to any one of claims 16 to 21 further comprising means operable to transfer VoIP calls between mobile devices.

23. VoD? wireless system according to any one of claims 16 to 21 further comprising means operable to share calls between mobile devices.

24. A vehicle comprising any or all of; i. a base sationin accordance with any one of claims 1 to 5, wherein the base station is arranged in operation to draw electrical power from the car, and; ii. a mobile terminal in accordance with any one of claims 9 to 15, wherein the mobile station is arranged in operation to draw electrical power from the car.

25. A VoIP USB handset comprising USB connection means, echo cancellation means and an LCD display, arranged in operation to connect to the USB port of a computer and draw power through said port, and provide feedback to the user via the display means.

26. A VoIP USB handset according to claim 25 and wherein the feedback may comprise any or all of the following; i. the number being dialled by the user; ii. the status of the call; iii. the number of the person calling the user; iv. the name of the person calling the user, and; v. VoIP line availability.

27. A method of placing a VoIP call comprising the steps of; connecting a communications device to a mobile terminal; selecting from among one or more VoIP base stations; initiating a VoIP call session, and; conducting a call via a wireless link between the selected VoIP base station and the mobile terminal.

28. A method of receiving a VoIP call comprising the steps of; connecting a communications device to a mobile terminal; obtaining the PBX identity of a target user's mobile terminal; alerting the identified mobile terminal to the presence of an incoming call; upon acceptance of the call by the user, conducting a call via a wireless link between the selected VoIP base station and the mobile terminal.

29. A method according to any one of claims 27 and 28 wherein the communications device is any one of the following; i. a PSTN standard phone with RJl 1 connector; ii. a PSTN standard fax machine with RJl 1 connector; iii. a PSTN standard modem with RJl 1 connector, and; iv. a scrambling or encryption device arranged in operation to further connect to a phone.

30. A computer program product comprising a computer readable storage medium on which is stored information which, when loaded into a computer, causes the computer to operate as a base station according to any one of claims 1 to 5.

31. A computer program product comprising a computer readable storage medium on which is stored information which, when loaded into a computer, causes the computer to operate as a VoIP mobile terminal according to any one of claims 9 to 15.

32. A computer program product comprising a computer readable storage medium on which is stored information which, when loaded into a computer, causes the computer to co-operate with a VoIP USB handset according to any one of claims 25 and 26.

33. A computer program product comprising a computer readable storage medium on which is stored information which, when loaded into a computer, causes the computer to perform a method of placing a VoIP call according to claim 27.

34. A computer program product comprising a computer readable storage medium on which is stored information which, when loaded into a computer, causes the computer to perform a method of recieving a VoIP call according to claim 28.

35. A computer receivable signal bearing information which, when loaded into a computer, causes the computer to operate as a base station according to any of claims 1 to 5.

36. A computer receivable signal bearing information which, when loaded into a computer, causes the computer to operate as a mobile station according to any of claims 9 tol5.

37. A computer receivable signal bearing information which, when loaded into a computer, causes the computer to co-operate with a VoIP USB handset according to any one of claims 25 and 26.

38. A computer receivable signal bearing information which, when loaded into a computer, causes the computer to perform a method of placing a VoIP call according to claim 27.

39. A computer receivable signal bearing information which, when loaded into a computer, causes the computer to perform a method of recieving a VoIP call according to claim 28.

40. A VoIP base station substantially according to any of the illustrated embodiments of the invention, with reference to the accompanying drawings.

41. A VoIP repeater substantially according to any of the illustrated embodiments of the invention, with reference to the accompanying drawings.

42. A VoIP wireless handset substantially according to any of the illustrated embodiments of the invention, with reference to the accompanying drawings.

43. A VoIP wireless terminal substantially according to any of the illustrated embodiments of the invention, with reference to the accompanying drawings.

44. A VoEP wireless PBX substantially according to any of the illustrated embodiments of the invention, with reference to the accompanying drawings.

45. A voice over internet protocol (VoIP) wireless system substantially according to any of the illustrated embodiments of the invention, with reference to the accompanying drawings.

46. A voice over internet protocol (VoIP ) USB handset substantially according to any of the illustrated embodiments of the invention, with reference to the accompanying drawings.

47. A method of placing a VoIP call substantially according to any of the illustrated embodiments of the invention, with reference to the accompanying drawings.

48. A method of placing a VoIP call substantially according to any of the illustrated embodiments of the invention, with reference to the accompanying drawings.