PSDN CORDLESS TELEPHONE SYSTEM
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a cordless telephone system, and more particularly to a cordless telephone system with a base unit capable of communicating directly to a packet switched data network (PSDN), such as an Internet Protocol (IP) network.
2. Discussion of the Related Art
The rapid expansion of the Internet has quickly made it the most widely used means for data communication throughout the world. Using the Internet, the cost of data communications has dropped to an insignificant amount, with the largest cost factor being the local telephone line access charges to the nearest Internet server location.
In 1995, a method was introduced for making telephone-like calls on the Tntemet, using a sound card in a computer. The caller's voice is digitized via the sound card, and then sent as packet data using a standard modem over the Internet. The call is received on the other end as E-mail using a modem, and it is reorganized by software as it is received, and used to reproduce the voice. Since its introduction, this concept of low cost international calls via the Internet has captured market attention, and several competitors have entered the field, each using a proprietary encoding scheme which makes them incompatible. Without the appropriate software, it is impossible to reconstruct a voice message from the stream of packet data received by the computer from the Internet.
A conventional telephone network, such as the Public Switched Telephone Network (PSTN), and a packet switched data network (PSDN) like the Internet are generally separate and distinct. Generally speaking, a normal telephone call is placed utilizing circuit switching technology via the PSTN, whereas an Internet phone call is a coded stream of packet data transmitted over a packet switched data network (PSDN), such as the Internet. Although both are forms of communication, currently there is limited integration of these systems, with telephones that connect directly to a PSDN, often referred to as IP phones, only recently slowly beginning to emerge.
However, these emerging IP telephones lack many of the conveniences currently enjoyed by users of telephones communicating via the PSTN. For instance, one such convenience is the added mobility afforded by cordless telephones. Cordless telephone systems generally include a base unit and a handset which communicates using Radio Frequency (RF) signals. The base unit is connected to a telephone network, such as the PSTN, while the handset may be removed from the base unit and used within a predetermined range, limited only by the RF signal strength.
Additionally, current IP telephones arc not fully incorporating all the features that could be available, such as voice mail applications, call forwarding, speed dialing, calendar events, etc., when the telephone is connected directly to a data network that also included computers.
Therefore, a need exists for a cordless telephone system having a base unit which connects to a PSDN and optionally interfaces to a computer.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a cordless telephone system having a base unit which connects to a PSDN.
It is another object of the present invention to provide a cordless telephone system having a base unit which connects to a PSDN and interfaces to a computer and corresponding software applications for receiving, placing, and forwarding calls.
It is still another object of the present invention to provide a PSDN cordless telephone system having a base unit which also functions as a local paging system.
It is another object of the present invention to enable users to have access to information on computers in the data network such as contact databases and calendars through their cordless handset.
It is yet another object of the present invention to provide a PSDN cordless telephone system having a cordless handset which also functions as a cellular telephone.
To achieve the above objects, a PSDN cordless telephone system in accordance with the present invention includes a base unit connecting directly to a packet switched data network (PSDN) with means to initiate and receive telephone calls on the PSDN and a cordless handset with a transceiver for transmitting and receiving radio frequency (RF) signals to and from the base unit to remotely initiate and receive the telephone calls on the PSDN.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features, and advantages of the present invention will become more apparent in light of the following detailed description of an exemplary embodiment thereof taken in conjunction with the attached drawings in which:
Figure 1 illustrates a cordless PSDN telephone system with a base unit connected directly to a PSDN in accordance with an embodiment of the current invention;
Figure 2 illustrates the cordless PSDN telephone system with a base unit connected directly to a PSDN, where the base unit further includes an auxiliary PSDN port for connecting another device to the PSDN in accordance with another embodiment of the current invention;
Figure 3 illustrates a cordless PSDN telephone card for use in a computer system and a cordless handset, the cordless PSDN telephone card and the computer together providing the PSDN base unit and connection to the PSDN network in accordance with still another embodiment of the current invention;
Figure 4 illustrates the cordless PSDN telephone system with the base unit computer card of Figure 3 interfaced to a computer which is connected to a PSDN, in accordance with the embodiment of Figure 3 of the current invention;
Figure 5 illustrates a cordless PSDN telephone system with the base unit connected to a switch or hub of a local area network which is part of a PSDN network in accordance with yet another embodiment of the current invention; and
Figure 6 illustrates a cordless PSDN telephone system with the base unit cormectcd to a PSDN and a handset having cellular telephone capabilities in accordance with yet another embodiment of the current invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, in which like reference numerals identify similar or identical elements throughout the several views, Figure 1 illustrates a cordless PSDN telephone system with a base unit 20 connected directly to a PSDN 5 through network interface port 27 in accordance with an embodiment of the current invention. Referring to Figure 1, a cordless PSDN telephone system comprises a base unit 20 connected directly to a PSDN 5 through network interface port 27 and a cordless handset 10. The cordless handset 10 communicates with the base unit 20 using radio frequency (RF)
signals, similar to a conventional cordless phone system. Through the network interface port 27, the base unit 20 connects directly to a PSDN 5, such as the Internet, and communicates data using a data communications protocol, for instance the Internet Protocol (IP).
The data communications protocol, IP, is responsible for relaying packets of data, protocol data units (PDU), from node to node. IP 's specific function is to route blocks of data over each of the networks between users wishing to communicate. IP protocols are supported over a variety of underlying media, such as asynchronous transfer mode (ATM), frame relay, dedicated lines, integrated services digital network (ISDN),
Ethernet, Token Ring, and so forth. An IP protocol data unit is a sequence of bytes containing a header and a payload. The header information identifies the source, destination, length, and characteristics of the payload contents. The payload is the actual data transported, which is preferably voice data in the present invention.
The base unit 20 includes the capabilities to communicate with other devices on the PSDN 5 through the network interface port 27. For example, the base unit 20 may use an Internet Protocol and communicate with other devices on the network to perform call setup initiation and teπninatioii functions using an H.323 protocol or a session initiation protocol (SIP), as is known in the art. Additionally, the base unit 20 may include capabilities to communicate with a network manager, as an agent, using simple network management protocol (SNMP), as is commonly known in the art. The base unit 20 also includes typical features available in cordless telephones, and may optionally include speakerphone capabilities and communicate with not only the cordless handset 10, but a number of different communication devices including a cordless microphone, multiple cordless speakers, a sound system interface unit, and/or a cordless headset, all using RF signals. The base unit 20 may also further include capabilities to automatically forward calls to an alternate telephone number or network address when the cordless handset 10 is out of range or busy. The cordless handset 10 may include all the features commonly known in the art for a handset in a conventional cordless telephone system.
Figure 2 illustrates the cordless PSDN telephone system with a base unit connected directly to a PSDN 5 through the network interface port 27, where the base unit further includes an auxiliary PSDN port 29 for connecting another device to the PSDN 5 in accordance with another embodiment of the current invention. The base unit 20, in essence, acts as a networic hub to which other devices, such as a computer 30, may connect and communicate with the PSDN 5 or the base unit 20 directly.
Figure 3 and Figure 4 illustrates a cordless PSDN telephone system wherein the base unit 20 is embodied in a base unit computer card 21 for connection to a computer in accordance with still another embodiment of the current invention. The base unit computer card 21 includes a transceiver and antenna for communicating to the cordless handset 10 using RF signals. The base unit computer card 21 is configured to be plugged into an expansion slot of a standard computer 40, as an option card. The computer 40 further includes a network interface card (NIC) 35 to provide the network interface port 27 to communicate with the PSDN 5. In this embodiment the PSDN telephone supporting electronics includes the base unit computer card 21, the central processing unit (CPU) and memory of the computer 40, and the NIC 35, in addition to the cordless handset 10. This configuration results in lower cost PSDN telephone electronics, but requires sharing a computer 40, which must be powered on to place and receive phone calls.
Figure 5 illustrates a cordless PSDN telephone system with the base unit 20 wherein the base unit 20 has a connection to a PSDN 5 by means of a Local Area Network (LAM). The PSDN cordless telephone system therefore gains access to the PSDN 5 and to other computers 30 on the PSDN 5, utilizing the computers for performing the computer application related functions described herein below. Alternatively, the base unit 20 can access the computer 30 located on a remote LAN via the PSDN 5.
Figure 6 illustrates a cordless PSDN telephone system with the base unit 20 connected to a PSDN 5 and a cordless handset 10 having cellular telephone capabilities in
accordance with yet another embodiment of the current invention. The cordless handset 10, in addition to performing standard cordless handset functions like communicating to the base unit 20, also provides all the features of a cellular telephone. When outside the range of the base unit 20, the cordless handset 10 switches to a cellular telephone mode and communicates with the base unit 20, first via a cellular telephone network having a radio tower 55 and communicating with the PSTN 50. The PSTN 50 then communicates the corresponding signals to the PSDN 5 via a gateway 60. The base unit 20 finally receives the communications from the cordless handset 10 via the PSDN 5 in one of the connection configurations described above allowing the handset 10 to continue to access the value added functions provided by the base unit 20 even when the handset 10 is out of direct RF signal range of the base unit 20. Here, the cordless handset 10 monitors the base unit 20 to determine when the cordless handset 10 is out of range of the base unit 20 using monitoring methods commonly known in the art. The base unit 20 also gains access to other computers 30 on the PSDN 5, utilizing the computers for performing some of the computer application related functions described below.
The configurations of Figures 2-6 advantageously include access to at least one computer 30, 40 by the base unit 20, either directly or through a network. In this way the base unit 20 may interact with a computer and a corresponding computer software application. The computer 30, 40 may be used to configure the PSDN telephone, allowing easy programming of the PSDN telephone. Features such as voice mail forwarding, call forwarding, speed dialing, emergency phone numbers and the like may be configured within the base unit 20 via the computer 30, 40.
The base unit 20, having H.323, SIP, and/or SNMP capabilities, as discussed above, can communicate via the PSDN 5 to automatically perform voice mail forwarding and call forwarding operations when the cordless handset 10 is out of range of the base unit 20, when the base unit 20/cordless handset 10 is busy with another call, or unconditionally when selected by the PSDN cordless telephone user.
Additionally, the computer 30, 40 may be accessed for such computer applications as calendar functions, allowing individuals to access their calendar information to receive reminders of calendar events, such as meetings or appointments, via the cordless handset 10. An individual's contact database may likewise be accessible via the cordless handset 10. The contact database may be used for caller ID, for identifying known calling parties. Upon receiving a call the base unit 20 queries the computer 30, 0 to determine, based on the phone number, whether the caller is listed in the contact database. Upon finding a listing in the database the caller's name and number, and other optional information, is sent to the cordless handset 10 for viewing. Tf no listing is located, only the phone number is forwarded to the cordless handset 10.
When placing calls, a user may enter a function key on the cordless handset 10, allowing the user to browse the list of names in the contact list. The user selects a name from the contact list and a call is placed to the corresponding number. Where the computer 30, 0 includes voice recognition capabilities, the user may also select the name from the contact list using voice commands. Here, it is important to note that all the above applications need not be located on a single computer for access by the Base unit 20, For instance, the contact information may be located on an individual's personal computer for retrieval and processing by the base unit 20 and the calendar functions may be located on a server on a company's LAN or elsewhere in the PSDN 5. An individual skilled in the art of client/server programming and calendar and contact databases applications would be able to implement these functions.
Also, where the base unit 20 includes voice recognition capabilities, voice commands can be used to initiate calls using the base unit's speed dialing function. A user may say the name of a party corresponding to a stored speed dial number, at which time the base unit 20 automatically dials the party's telephone number, without the aid of the computer 30, 40. Voice commands can also be used to dial a phone number one digit at a time. Similarly, voice commands can also be used to initiate a call and perform the subsequent related commands as required to retrieve a stored voice mail message from a voice mail messaging system.
In another embodiment, the PSDN telephone system is further configured as a local paging system. The paging application sends a page to the base unit 20 via the PSDN 5. The base unit 20 determines if the cordless handset 10 is within range using monitoring methods commonly known in the art. If the cordless handset 10 is within range, the page is relayed to the cordless handset 10. However, when the cordless handset 10 is out of the range of the base unit 20, the base unit 20 notifies the paging application accordingly, and the paging application then delivers the page using a pre- established alternative method. A copy of the page may also be forwarded to the individual's e-mail address by the base unit 20.
In yet another embodiment, the cordless handset 10 may be used to remotely initiate command on the computer 30, 40 via the base unit 20. The cordless handset 10 communicates to the base unit either locally, using RF signals, or in cellular telephone mode as described above. A list of commands is previously set up in the computer 30, 40. A user may enter a function key on the cordless handset 10, allowing the user to browse the list of commands. A command is selected from the command list by the user and subsequently relayed to the computer 30, 40 from the base unit 20 via the PSDN 5 or directly using the communication methods described above. The computer 30, 40 then carries out the command and optionaJly returns the result to the cordless handset 10. Where the computer 30, 40 includes voice recognition capabilities, the user may also select the command from the command list using voice commands. Security code features commonly known in the art may be incorporated to prevent unauthorized access to the computer 30, 40.
While the present invention has been described in detail with reference to the preferred embodiments, these represent mere exemplary applications. Thus, it is to be clearly understood that many variations may be made by anyone of ordinary skill in the art while staying within the scope and spirit of the present invention as defined by the appended claims.