US20020118676A1 - Access network over a shared medium - Google Patents

Abstract

A method for providing access to sources of at least one telephone network and at least one IP based network over a TV distribution network. The method uses the IP protocols as an internal multiplexing technique and transport mechanism. The IP handling takes places between a TV IP network terminal, connected to a user end of the TV distribution network, via an IP access server, connected to a TV transmitter end of the TV distribution network, to a telephony server and a router, respectively. The method and system allows for simultaneous datacom and telephone traffic within one network terminal, within the TV distribution network, or access to connected service providers of telephone and IP based networks.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• This application is a continuation fo application Ser. No. 08/868,653, filed on Jun. 4, 1997, the entire disclosure of which is hereby incorporated by reference.[0001]
TECHNICAL FIELD
• The present invention relates to telecommunication in general and to voice and data communication. In particular the invention relates to access to telephony networks and Internet protocol (IP) based networks over a shared physical medium, such as a TV distribution network.[0002]
BACKGROUND
• Traditional cable TV (CATV) networks are analogue and unidirectional networks for distribution of TV programs to many users. This is performed via a branched distribution network comprising cascaded amplifiers. The cable will constitute a shared physical medium, where the headend provides the analogue signals and the user end terminals tap the signals. A single cable TV headend may serve over 100000 users within a distance of up to 15 km via one single trunk.[0003]
• Upgraded CATV networks support bi-directional communication, and thus the amplifiers also have to support bi-directional communication. The cable will then behave like a closed ether, the frequency spectrum of which is available for communication between the head end and the users. The network is normally asymmetric in transfer capabilities, a few Mb/s available in the upstream channels and 10-50 Mb/s in the downstream channels, beside a number of TV channels. The number of users is so large that non-compressed voice may only be provided to a small fraction of users.[0004]
• Hybrid-fibre coax network, where parts of the coax network are replaced by networks with optical fibre, have fewer users, normally a couple of thousand. The available bandwidth is shared by much fewer users and is sufficient to provide two-way communication for all users. An even more upgraded type of network solution is according to the Regional Hub/Passive Coaxial Network Architecture. The fibre node in such a configuration typically serves 200-500 users.[0005]
• Recently, a rapid development has taken place in order to extend the range of services which can be supported by cable TV network. The main issue is related to support of IP access and telephone access by using two-way channels over a cable TV network. An IEEE group 802.14 is developing a standard for the physical layer and a MAC (Medium Access Control) protocol for CATV networks. It will support both connectionless and connection-oriented services. Stream services, such as constant bit rate (CBR), variable bit rate (VBR) and available bit rate (ABR) will be handled. The network should be used to support unicast, multicast and broadcast services. It will also support ATM (Asynchronous Transfer Mode). Generally, the upstream bandwidth is much lower than the downstream bandwidth.[0006]
• One example of a possible protocol stack is one using the IEEE protocols, which uses Medium Access Control (MAC) layers, according to IEEE 802.3 and 802.14 (in particular the Draft Supplement to IEEE Std 802.14, 802.14MACN 1.1, Dec. 31, 1996), above which there is a Logical Link Control (LLC) layer, according to IEEE 802, which at the end user and the IP access server supports the Internet Protocol (IP). The IEEE protocols can be part of a solution to provide access to telephony networks, e.g. PSTN (Public Switched Telephone Network). A control protocol, as well as the user data are carried on top of the link layer.[0007]
• Other telephony access approaches over a CATV network allocate a channel, allowing for a two-way, e.g. 64 kb/s, stream for each call. Also such solutions are dependent on the development of control signalling handling solutions.[0008]
• An interaction channel is provided to digital video broadcasting (DVB) systems based on digital enhanced cordless telecommunications (DECT). A European draft specification of such a system is known in the art, e.g. through “Draft specification of DVB Interaction Channel based on DECT”, DVB-RC-165[0009]rev 7, version 4.0, Mar. 27, 1997. In this specification a packet distributing service point-to-point is available together with the DVB. The DECT specification also provides 32 kb/s channels for telephony. In this specification a protocol stack model is presented, which in the bottom has protocols for modulation, channel coding, frequency range, filtering, equalisation and power. On top of this, protocols for the access mechanism and packet structure is provided, all connected to the actual network. The network independent protocols are then placed on top of this.
• A new technique that for simultaneously an Internet session and a telephony session over the same telephone access line includes a telephone doubler arrangementphone doubler described in FIG. 10 below and in Swedish Patent Application No. 9602212-4.[0010]
• The telephone doubler arrangement permits a user which is connected to an analogue telephone network to access an IP-based communication service and still be able to receive and answer incoming calls, and to place outgoing calls, while simultaneously surfing the Internet.[0011]
• In FIG. 10 the[0012]telephone doubler arrangement101 is shown to be connected to PSTN102 and to Internet103. At the user side amodem104 is connected to PSTN102, to a standardanalogue telephone105 and to a PC106. Thetelephone doubler arrangement101 comprises amodem pool107 connected to PSTN102, to Internet103 and to atelephony server109. Thetelephony server109 is connected to PSTN102.
• When a user A is connected to Internet[0013]103 via a dialed up PSTN connection to themodem pool107 thetelephone105 cannot be used. On his/her PC the user can still communicate with other PSTN users by using the connectivity and multiplexing capabilities of IP. The dialed up line can carry a multiplexed stream of IP packages of: (a) an Internet session and (b) a telephony call. Speech carrying IP packages are routed to/from thetelephony server109 to PSTN. Telephony control signals are exchanged between thetelephony server109 and atelephony application110 which runs on the PC. If the PC has audio capabilities, symbolized by aheadset111 comprising earphones and a microphone, a user A can be engaged in speech conversations with other users connected to the PSTN or ISDN. The user has got a new, soft phone on the PC106.
• Another new technique that allows for simultaneously an Internet session and a telephony session over the same telephone access line includes makes use of the telephone doubler principle described above complemented, at the user end, with an[0014]IP modem112 as shown in FIG. 11 and in Swedish Patent Application No. 9604409-4. IP functionality, such as provided by the PC106 in FIG. 10, has been integrated in themodem112 and therefore the modem is referred to as an IP modem.
• This arrangement makes possible a dialed up connection, using a standard analog telephone, or a telephony application on a PC, while simultaneously an Internet user is engaged in an Internet session over a PC connected to the same IP modem.[0015]
• The arrangement shown in FIG. 11 is similar to that of FIG. 10. A[0016]telephone doubler arrangement101 is connected to PSTN and Internet and comprises the same units as in FIG. 10.
• Over a[0017]first IP link113 between the IP modem and Internet103 IP packets containing information relating to an Internet session are transported. Part of this link comprises asubscriber line114 extending between the IP modem and PSTN. Over asecond IP link115 IP packets carrying digitized, compressed speech are transported to/from the telephony server and the modem pool. The telephony server creates a dynamic relation between the IP address of the IP modem and the telephone number of user A. Using the call forwarding service in PSTN incoming calls to user A are redirected to the telephony server.
• The arrangement will allow user A to take and to place telephone calls using the ordinary telephone while there is an ongoing Internet session on the personal computer. Also a “soft phone” like the one in Appl. No. 9602212-4 cited above is provided. Since the modem has IP capabilities it will be possible to communicate with other devices, such as additional equipment can be connected to it, such as a private LAN, an electricity consumption meter and similar devices, over a home network.[0018]
• The IP modem is shown in FIG. 12 and comprises a[0019]subscriber line interface116, one ormore telephone interfaces117,118, at least onePC interface119 and, optionally, aLAN interface120. There is also an IP multiplexor/demultiplexor121 and acontroller122. Anoptional application123 can run in the IP modem, such as for example an e-mail poller for polling electronic mail-boxes of user A. The IP multiplexor/demultiplexor routes IP packets from the subscriber line interface to their destinations; the PC, the telephone or the LAN. The controller provides control over the functionalities of the IP modem.
• The Swedish applications cited above both provide telephony access and IP traffic can be superimposed the telephony access. However, both solutions are limited to one service provider of telephone networks or IP based networks. The solutions are also limited to a PSTN network as access network.[0020]
SUMMARY
• One object of the present invention is to provide access to services of at least one telephony network and at least one IP based network over a TV distribution network, a shared medium, which is enhanced to provide logical two-way links.[0021]
• Another object of the present invention is to provide simultaneous telephony and IP access and to provide more than one simultaneous telephony connection to one particular customer.[0022]
• Still another object of the present invention is to allow different users of the same network or a single user to relate to different service providers of the same service, e.g. telephony or Internet.[0023]
• Internal calls between different telephony devices of the same network terminal or connected to the same TV distribution network are also to be supported.[0024]
• The above objects are provided by a method and devices according to the present invention as it is defined in the enclosed claims.[0025]
• According to the invention a method is provided, which provides access to at least one telephony network, using a TV distribution network with an interaction channel, supporting bi-directional communication, as a transmission medium simultaneously to TV broadcasting. The method uses IP as an internal multiplexing technique.[0026]
• Moreover, according to the invention a TV Internet Protocol Network Terminal, hereafter called “NT”, which functions as an end user network terminal, i.e. a receiver end, of the TV distribution network, is provided with interfaces for different terminal units, e.g. telephony interfaces and computer or LAN interfaces. The LAN/PC interface supports exchange of IP packets and the telephony interfaces are enhanced with capabilities to detect control signals from the phone and to generate control signals to the phone as well as to digitise speech and decode digital information into speech. The NT also contains functionality to support services, e.g. telephony. It also provides communication with external applications.[0027]
• The invention also provides a telephony server, which has connections to at least one telephony network and which comprises means for associating a certain telephone number with a certain NT and means assisting in using IP as a multiplexing technique. The telephony server also provides functionality to support telephony, and comprises means to interface one or more telephony networks.[0028]
• Similarly, the invention also provides a router, which has access to at least one IP based network and which comprises means for associating a certain external IP address with a certain NT and means assisting in using IP as a multiplexing technique.[0029]
BRIEF DESCRIPTION OF THE DRAWINGS
• The invention and its merits will be described in connection with the accompanying drawings, in which[0030]
• FIG. 1 is a block diagram of entities involved in the access handling via a TV distribution network in accordance with the invention,[0031]
• FIG. 2 is a functional block diagram of the network terminal in accordance with the invention,[0032]
• FIG. 3[0033]ais a block diagram of an example of a part of a protocol stack, which may be used for the external port in the NT in accordance with the invention,
• FIG. 3[0034]bis a block diagram illustrating how the access network handles the telephony application,
• FIG. 3[0035]cis a block diagram illustrating how the access network handles the IP application,
• FIG. 4 is a block diagram of entities involved in the access handling via a TV distribution network in accordance with the invention, with two telephones connected to the same NT.[0036]
• FIG. 5 is a block diagram of entities involved in the telephony access handling via a TV distribution network in accordance with the invention, illustrating telephone communication between a telephony application at a computer and a normal telephone.[0037]
• FIG. 6 is a block diagram of entities involved in the telephony access handling via a TV distribution network in accordance with the invention, illustrating telephone communication between a telephone and a telephony application at a computer via Internet.[0038]
• FIG. 7 is a block diagram of entities involved in the access handling via a TV distribution network in accordance with the invention, where several service providers are present,[0039]
• FIG. 8 is a block diagram of entities involved in the telephony access handling via a TV distribution network in accordance with the invention, illustrating internal communication between two telephones or between a telephone and a telephony application on a computer, connected to the same NT,[0040]
• FIG. 9 is a block diagram of entities involved in the telephony access handling via a TV distribution network in accordance with the invention, illustrating internal communication between two telephones connected to the same TV distribution network,[0041]
• FIG. 10 shows a block diagram of a related art “phone doubler” technique, as presented in reference [1],[0042]
• FIG. 11 shows a block diagram of a related art “IP modem” technique, as presented in reference [2], and[0043]
• FIG. 12 shows the functional blocks of the IP modem, shown in FIG. 11.[0044]
DETAILED DESCRIPTION
• In FIG. 1 a user A has a[0045]telephone1, apersonal computer2 and atelevision set3. Thetelevision set3 is connected via a set top box (STB)4 to aNT5 in accordance with the invention. TheNT5 includes atelephony interface6 and acomputer interface7, by which thetelephone1 and thepersonal computer2, respectively, are connected. TheNT5 constitutes the user end terminal, i.e. a TV receiver end, of aTV distribution network8. It communicates with aTV transmitter end9 via theTV distribution network8.
• The[0046]TV transmitter end9 is conventionally supplied with TV programs from various sources, one of which is shown at10. TheTV programs10 are distributed from theTV transmitter end9 to the different end users via theTV distribution network8 according to conventional methods. TheNT5 is transparent regarding the frequency channels used for the TV broadcasting and these frequencies are passed unaltered to theSTB4, which carries out the conventional procedures for supplying the TV programs to theTV set3. The information flow for the TV broadcasting is indicated by thedashdot line11 in FIG. 1.
• The distribution of TV programs is not affected by the use of the present invention, and this will therefore not be discussed in full detail. The only feature request of the[0047]TV distribution network8 is that it supplies a link service, which receives IP-packets and delivers them safely to the intended destination point. For example, in a conventional CATV network, theTV transmitter end9 is e.g. constituted by a CATV headend. TheTV transmitter end9 is thus only characterised by being a point in the network which is common for a suitable set of users. In more sophisticated CATV network configurations, see e.g. Draft Supplement to IEEE 802.14, “Physical layer Specification for HFC CATV Networks”, 802.14PHYN.1.0, Feb. 7, 1997, fibre hubs, regional hubs etc. may thus be theTV transmitter end9 of the present invention.
• An attractive scheme for providing an interaction channel in a[0048]TV distribution network8 is presented by “Draft specification of DVB Interaction Channel based on DECT”, DVB-RC-165rev 7, vers. 4.0, Mar. 27, 1997. In this scheme two channels are established between the service provider and the user. A unidirectional broadband broadcast channel including video, audio and data corresponds to the conventional cable TV service. A bi-directional interaction channel is also established between the service provider and the user for interaction purposes and is formed by a forward interaction path and a return interaction path.
• The[0049]TV transmitter end9 Is also permanently connected to anIP access server12 via e.g. aLAN13 with a link protocol. TheIP access server12 is connected to arouter24 and atelephony server15. Therouter24 has in a conventional manner access toInternet14. Thetelephony server15 is in turn connected toPSTN16 and provides the telephony service to users of theTV distribution network8. Anotheruser B17 has a telephone connected to thePSTN16 via asubscriber line18.
• The IEEE set of LAN related protocols gives an opportunity to extend the link service between the NT:s[0050]5 and theIP access server12. By the means of a bridging protocol42 (FIG. 3a) according to IEEE 802.1, the link protocol, e.g. LLC41 (FIG. 3a) can operate over different domains with different physical and MAC protocols, e.g. the cable TV MAC protocol according to IEEE 802.14 between anNT5 and aTV transmitter end9 and Ethernet (IEEE 802.3) between theTV transmitter end9 and theIP access server12. This means that the bridging protocol42 (FIG. 3a) takes care of the task of changing medium during the transmission of packets from/to theIP access server12 to/from theright NT5.
• FIG. 3[0051]ashows an example of a part of a possible protocol stack of the external port in theNT5. The external coaxial port stack has theAnalogue bearer45 as the lowest protocol layer. On top of this, aPhysical layer44 and above that a MediumAccess Control layer43, and abridging protocol42. On top of the bridging layer is aLLC layer41, and on top of that anIP layer40 which transmits packets between theNT5 and theIP access server12 ports. The service of theLLC41 is to transfer packets point to point between NT's5 and theIP access server12.
• The[0052]telephony server15 comprises atelephony application50a(FIG. 3b). Thistelephony application50ais intended to communicate with atelephony application50c(FIG. 3b) in theNT5 and create a relation (call) between instances in both entities, i.e. thetelephony applications50a,50chandle the relations between telephone numbers or equivalent and local addresses and port numbers for the telephony applications. Thetelephony applications50a,50calso handle the telephony signalling, i.e. handle the service specific protocols, e.g. control protocols for telephony.
• More in detail, FIG. 3[0053]billustrates how the access network handles the telephony application. The basic principle is that the internal communication, to/from thetelephony server15 from/to theNT5, is performed by IP. Accordingly, the system provides anIP domain40, in which several units communicate by IP. It may also be noted that the entire communication takes place on a level above theTV transmitter end9.
• A[0054]telephony application50ain thetelephony server15 communicates with a telephony service network (not shown). This is preferably done using conventional protocols for control signalling53a(e.g. V5.2) and speech transferring52a. Thetelephony application50ain thetelephony server15 also communicates with atelephony application50cin theNT:s5 by an internal application specific protocol, which e.g. can be V5.2 or another protocol for telephony. In this communication, speech is controlled by aspeech handling protocol52b,52cand a UDP (User Datagram Protocol)54b,54cin both thetelephony server15 and the NT:s5 and the resulting packages are communicated by theIP domain40. In parallel, control signalling is handled by acontrol protocol53b,53cand a TDP (Transmission Control Protocol)55b,55cabove theIP communication layer40.
• The[0055]telephony application50cin theNT5 is in its turn communicating with aconnected telephone1 and users using them, using an analogue traditional protocol fortelephony51, via e.g. an analogue telephone interface. Also here speech and control signalling are separated, the speech using aUDP54dand aCODEC56, while the control signalling is using aTCP55dandcontrol protocol53d. There are also possibilities to handle the communication between thetelephone application50cand the respective interfaces in NT:s5 in other ways than withIP40, butIP40 is presently considered as the most preferable solution.
• The IP router[0056]24 (FIG. 1) comprises an IP application. This IP application is intended to handle the relations between external IP addresses or equivalent and local addresses and port numbers for the IP applications.
• FIG. 3[0057]cillustrates how the access network works with theIP application60a,60b. In this example, the address mapping between external and internal addresses (described further below) in the case of IP communication can be solved by e.g. using tunnelling, which by itself is known in the art. There are several knowntunnelling protocols61a,61b, and the procedure to establish a tunnel between therouter24 and thePC2 and will therefore not be further described in detail. In this case, however, a tunnel is a mechanism to convey IP packets between two points by means of IP as atransport protocol40. IP packets are thus conveyed as data in other IP packets. The address spaces are different between the two layers of IP. Generally, thelower IP layer40 is associated with internal IP addresses, while theupper IP layer60a,60bis associated with external IP addresses. In cases where the communication is to be terminated in theNT5, there are also (not shown) corresponding tunnelling protocols and IP available. This may be useful, for instance, when a user via an analogue telephone wants to have access to the Internet phone capabilities.
• Address Mapping and Routing[0058]
• Address mapping plays an important role in the present invention. The arrangement with several different service providers of each type of service network give rise to several address spaces, which therefore are not possible to use as internal addresses.[0059]
• An IP address is a reference to an interface and a port behind that interface.[0060]
• Usually, a port designates an application.[0061]
• A[0062]network terminal5 has an internal IP address (internal refers to the access network, i.e. the IP address is not known outside of the access network). Further, a number of ports, each one attached to an application (residing in the NT), which can be reached over IP, are defined for anNT5. E.g., thetelephony application50cis addressed by the IP address of theNT5, and a unique port number. The different accesses, which supports a single device (e.g. a serial port or an analogue telephone access) are seen as applications, and are thus addressed by port numbers. Devices connected to a LAN have their own internal IP address. If they want to communicate over anexternal IP network14, they have to have an external IP address as well.
• A telephony number, which is associated to a subscription of a telephony service, is associated to one or more devices (attached to an NT[0063]5) with capabilities to handle telephony. Such devices can be e.g. analogue or digital telephones.
• Within the access network, e.g. in case of an incoming call to this destination, it is sufficient to be able to address the[0064]NT5 and thetelephone application50c. This is done by mapping the external telephone number (or a representation of it) on the internal address of theNT5, and the port number of thetelephony application50c. By information carried over the application protocol, thetelephony application50cknows the destination of the call. Thetelephony application50cholds information of which telephone interfaces are involved in the destination.
• The[0065]telephony application50cin anNT5 communicates with thetelephony application50ain thetelephony server15, which has a similar address (IP address of thetelephony server15 including a port address. Thetelephony application50ain the telephony server can in its turn address the proper interface of a wantedtelephony network16.
• In case of communication with an[0066]external IP network14, a tunnelling technique can be used. There are several ways to handle this. We assume that the tunnel extends between thePC2 and therouter24, which handles the interfaces to theexternal networks14. All packets travelling a tunnel towards therouter24 are destinated to the sameexternal IP network14. APC2 has an internal IP address and an external IP address.
• In that case, an IP packet, which arrives to the[0067]router24 from anexternal IP network14, and which is addressed to an application on the PC2 (by an external IP address with a port number), is handled in the following way. The external IP address is mapped on the internal IP address of thePC2, including a port number referring to an application which handles the tunnelling protocol. The IP packet is then put in a new IP envelope with the internal IP address, and routed over the access network to to thedestination PC2.
• An IP packet, which is sent from a[0068]PC2 to an external address, is tunnelled in the same way by an internal IP address, which points out an application handling the tunnelling protocols. The tunnel identity points out which interface the packet is aimed for.
• Before the[0069]NT5 is used for traffic purposes it has to be configured, e.g. in order to support the address mapping. The NT is supplied with an internal address of therouter24 and/ortelephony server15 and with data related to the requested use of the access possibilities, i.e. the NT configuration, Such configuration possibilities are discussed further below. When theNT5 subsequently is installed in theTV distribution network8, therouter24 and thetelephony server15 has to be informed. Accordingly, thetelephony server15 is informed about its existence and associated internal IP addresses, the port number of the telephony application of theNT5 and the corresponding telephone number or numbers or equivalent, e.g. port number in the telephony server. Similarly, therouter24 is informed about the internal IP address and the port number of the IP application of theNT5 and the corresponding external IP address or addresses. In cases where tunnelling protocols are used, the internal address of the PC has to be known. TheNT5 has to be configured accordingly. E.g., a telephone number is related to a number of interfaces.
• IP-Session[0070]
• Data communication with an IP network is always possible through the[0071]TV distribution network8. TheNT5 sends IP formatted data in the upstream channel of theTV distribution network8 to theIP access server12, which directs the data to therouter24, which in turn distributes the data towards the intended IP network, in this embodiment atInternet14. Therouter24 andIP access server12 also direct data addressed to the IP address of theNT5 in the downstream channel of theTV distribution network8 to theNT5 and from there to the intended terminal. Thus, the Internet traffic follows the path indicated by a dashedline19 in FIG. 1.
• Incoming Call[0072]
• An incoming call will be handled as follows.[0073]User B17 wants to speak withuser A1 over the telephone and dials the telephone number to user A. The telephony application of thetelephony server15 receives the incoming call. The telephony application in thetelephony server15 creates a message about the incoming call. This message is supplied with the internal IP address of theNT5, using the previously created relation between the destination telephone number of the incoming call and the internal IP address, and distributed to theIP access server12. TheIP access server12 uses the link protocol in order to deliver it to theproper NT5. TheNT5 receives the data packets and deliver it to the telephony application of theNT5, which associates the information about the intended receiver telephone number with a certain interface6 (or several). The message about the incoming call is interpreted and user A is finally noticed about the incoming call by a conventional ring signal on a phone initiated from theNT5.
• If user A does not answer the call, the[0074]telephony server15 signals this to thePSTN16 and the call is rejected, if the caller has not given up before, and the PSTN has not already rejected the call.
• If user A answers the call by lifting the receiver at the telephone unit, the[0075]NT5 detects the off hook operation and sends back a message to thetelephony server15, via theTV distribution network8 and theIP access server12, for establishing the connection towards the calling user B. In this case, the upstream communication channels in theTV distribution network8 are used. Thetelephony server15 forwards the answer message toPSTN16. When the call is completed, thetelephony server15 digitises, compresses and packetizes B's speech and sends it over theTV distribution network8 using the IP protocol. TheNT5 depacketizes the packages, decompresses the information and transforms the digital information into speech again, which is sent to thetelephone1 via thetelephony interface6 and anordinary telephone line21. This information flow is described in detail below. Speech originating from the user A is in a similar way digitised, compressed and packetized in theNT5 and is sent over theTV distribution network8 to thetelephony server15. Thetelephony server15 recovers the speech and sends it touser B17 over theordinary PSTN network16. This is also described in detail below.
• The information flow from user B to user A is as follows: From user B, the speech is sent via the[0076]PSTN network16, using any of the conventional transmission techniques, to thetelephony server15. This is indicated byfull lines18,20 in FIG. 1. Here the speech is digitised and packetized. Thetelephony server15 formats the data packages according to the IP protocol and provides the packets with an address to the NT internal IP address using the previously stored relation between A's telephone number and A's IP address. The information here passes as data packets on alink13, indicated as heavy lines in FIG. 1. TheTV transmitter end9 sends the data packages over its downstream information channels to the requested TV receiver end, i.e. the requestedNT5. Here, the information travels over theTV distribution network8, in this example comprising DECT, indicated by ashadow line22 in FIG. 1. TheNT5 receives the data packages, unpacks them and sends them to theappropriate telephony interface6. Here the digital information is decoded into speech information and sent to the telephone as normal speech on a line, indicated by afull line21 in FIG. 1. The information flow from user B to user A is indicated by the dottedline23 in FIG. 1.
• The information flow from user A to user B is as follows. From user A, the speech is sent via a[0077]line21 to thetelephony interface6 on theNT5, indicated by a full line in FIG. 1. Here the speech is digitised and packetized. TheNT5 formats the data packages according to the IP protocol, providing the data packets with an address corresponding to thetelephony server12 internal IP address. The data packages are sent via the upstream information channels of theTV distribution network8 to theTV transmitter end9, c.f. the shadowedline22 in FIG. 1. Here, the content in the upstream information channels is forwarded to theIP access server12, where the IP address of thetelephony server15 is detected and subsequently, the data packages are forwarded to thetelephony server15, c.f. theheavy lines13 in FIG. 1 . Thetelephony server15 receives the data packages, unpacks them, decodes the data into speech, which is sent to the appropriate telephony port and via thePSTN network16 touser B17.
• When the conversation between user A and user B is finished and A puts the receiver on hook, the[0078]NT5 detects the on hook condition of the telephone of user A. This on hook condition is forwarded via theTV distribution network8 to thetelephony server15, which terminates the connection to user B. Also, if user B terminates the call, thetelephony server15 forwards the on hook condition over theTV distribution network8 to theNT5, and the call is terminated.
• Outgoing Call[0079]
• An outgoing call will be handled in a similar way. User A wants to speak with user B over the telephone and lifts the receiver. The[0080]NT5 detects the off hook condition and gives a dialling tone to the user A telephone. User A dials the telephone number to user B. TheNT5 detects the number sequence dialled by user A and sends it to thetelephony server15 via theTV distribution network8 and theIP access server12. Thetelephony server15 places an outgoing call to the requested number on thePSTN network16, and sends back a confirmation message to theNT5, which, in turn, supplies a ring tone to the telephone of user A.
• If user B answers the call, a connection between the[0081]telephony server15 and user B is established over thePSTN network16 in a conventional manner. A message about the connection is sent by thetelephony server15 to theNT5, the ring tone is interrupted and the full connection is established.
• If user B does not answer, user A will place the receiver on hook. The[0082]NT5 detects the on hook condition and sends a message to thetelephony server15 to interrupt the call over thePSTN network16.
• The Network Terminal[0083]
• In the following the[0084]NT5 functionality will be described in connection with FIG. 2. First of all, there is anoverall control functionality30 for controlling the operation of the various functionalities of theNT5. TheNT5 further comprises at least one LAN/PC interface31, an IP MUX/DEMUX section32, at least onedevice feature section33, at least onetelephone interface34, adigital stream service35 and aTV interface36.
• The Digital Stream Service (DSS)[0085]35 uses the transmission capabilities of the TV distribution network8 (FIG. 1) to provide a two-way digital transport capability. It uses a link protocol, including a medium access protocol, which takes care of the segmentation of information and delivery to the intended destination point.Such DSS35 may e.g. work according to the DVB interaction channel based on DECT (“Draft specification of DVB Interaction Channel based on DECT”, DVB-RC-165rev 7, vers. 4.0, Mar. 27, 1997) or the specification of the IEEE 802.2 logical link over IEEE 802.14 MAC protocol for HFC CATV networks.
• The LAN/[0086]PC interface31 supports exchange of IP packets. It comprises a LAN or PC interface providing a serial interface supporting IP and PPP protocol layers.
• Other interfaces supporting IP is also possible, such as LAN interfaces or the universal serial bus (“Universal Serial Bus Specification Revision 1.0”, available at http://teleport.com/˜USB).[0087]
• The[0088]telephone interface34 can be an ordinary analogue interface, with capabilities to detect control signals from the telephone, such as off hook, on hook, hook flash, DTMF (Dual Tone Multi Frequency) signals etc. It may also be a digital interface, wired or wireless, supporting corresponding signals. Thetelephone interface34 also generates ringing and acoustic signals, e.g. dial tone. Furthermore, it also converts the analogue speech stream into a digital stream (which may be compressed, e.g. by GSM (General System for Mobile communication) standard or DECT), and puts it in IP packets of proper size. Incoming IP packets, which carries speech, are processed the reverse way, i.e. are decoded from a digital stream into analogue speech.
• The IP MUX/[0089]DEMUX32 takes packets from the digital stream service and delivers them to their respective interfaces (demultiplexing). It also multiplex together the IP packets from the different interfaces and sends them mUltiplexed to theDigital Stream Service35.
• The[0090]TV interface36 is a conventional interface for the TV distribution network8 (FIG. 1) and is not further discussed. It is assumed that the TV channels passes theNT5 but that it may insert or extract TV channels.
• Other Important Features[0091]
• Above, the invention is discussed only regarding ordinary phone calls. However, there are other useful features of the invention. One such useful feature is the possibility of simultaneous IP sessions and telephone calls over the[0092]same NT5. A communication capability is always available between theIP access server12 and thePC2. The telephony procedure uses the same communication medium as the IP session, the telephony data packages are certainly mixed with the datacom traffic, but the telephone call will not influence the session. In other words, a user of Internet does not have to interrupt his session to make a phone call or to receive a call from outside.
• Another advantage of the telephony access according to the present invention is illustrated by FIG. 4. In this figure, user A has two telephones connected to the[0093]NT5. The two phones, designated1aand1b, are connected to arespective telephone interface6, as shown in FIG. 1. The two phones may be associated with different phone numbers, but also with the same number. When theNT5 is configured it has to be decided which relations should be available within theNT5.
• If the phones are associated with different numbers, the procedure is very similar to the above described incoming call. A call to the first telephone number will be directed to the[0094]phone1aand a call to the second telephone number will be directed to thephone1b. TheNT5 thus enables a multi-access possibility. Although only two telephones of user A is shown in the figure it will be understood that any number of telephones may be connected in this manner.
• If the different telephones are associated with the same telephone number, the following situation is one of the possible solutions. When a first call is initiated from an external user, such as user B, a ringing may be initiated on both telephones. When someone answers the call at one of the phones, the call is connected to that particular phone, and the ringing on the other phone is stopped. If a second call to the same phone number is initiated from another external user, one phone is occupied but the other one is free and the new call is alerted at the non-occupied telephone. The[0095]NT5 may therefore direct the new call to the second, non-occupied phone, using a second,non-occupied telephone interface6.
• By configuring the[0096]NT5 in a slightly different way other situations are possible. It is for instance possible to configure theNT5 in such a way that theNT5 detects from which number the call origins and dependent on this, call signals are sent to either or both of thetelephones1a,1b.
• In the same way, it is possible to make an outgoing call even if another telephone conversation is going on on one of the phones. The second, non-occupied telephony interface will assist in establishing the contact to the[0097]PSTN network16.
• Although only two telephones of user A is shown in the figure it will be understood that any number of telephones may be connected in this manner.[0098]
• Similarly, one telephone connected to the[0099]NT5 may be associated with more than one external telephone number. This means that e.g. if one telephone number is requested the first telephone is addressed, if another telephone number is requested both telephones may be addressed. It is in this way possible to configure the functionality of theNT5 with any combination of addresses.
• In the description of the telephony access, analogue telephones have been assumed. Digital phones will of course work equally well. The[0100]NT5 will then have aninterface6 for a digital telephone. TheNT5 then supports control signals, ringing signals and acoustic signals, but is transferring both these signals and the speech in digital form to the telephone.
• The[0101]PC2 may also have atelephony application25, as indicated in FIG. 5. ThePC2 is then normally equipped with sound capabilities with associated audio devices. Thetelephony application25 comprises software running on thePC2 which allows bi-directional speech communication over the sound capability and the audio devices. The sound capability converts the speech to digitised and compressed audio signals, which are packetized into IP packets. These packets are handled in the same manner as the IP packets from the telephony interfaces, although in this case thePC interface7 is used. In this manner thetelephony application25 offers the same alternatives as an ordinary telephone. For outgoing Internet calls, the telephony application of theNT5 is not involved at all. For incoming calls, the configuration of theNT5 may decide whether alerting of the telephones and atelephony application25 on aPC2 should be provided or not as in the previously described cases.
• In known art Internet connections, the Internet Phone service offered to the users normally requires that both the caller and the receiver are connected to Internet and furthermore that they both have a[0102]telephony application25 running in their computers. Since the speech information according to the present invention is packetized in IP packages during the transmission on theTV distribution network8 andInternet14 lines, there is also a possibility for a communication between an ordinary telephone and the Internet Phone service. One possibility is described above, where theInternet14 user is connected to theTV distribution network8.
• It is also possible for a user of a[0103]TV distribution network8 to use an ordinary telephone to reach anotherInternet14 user over the Internet Phone service. When placing the call, the caller informs theNT5 about the requested IP address instead of thePSTN16 telephone number, e.g. by selecting an address from a list. Such a situation is sketched in FIG. 6. Note that thePC2aof user A may not even be turned on.
• The above described multi-addressing possibilities are in a similar way present also for the pure datacom access. One[0104]PC2 may be assigned to one IP address, while anotherPC2 may have another IP address, which may belong to anotherInternet14 service provider.
• Today, several service providers of the same service are often available, e.g. different telephone companies. The present invention offers a possibility for the user to select among different service providers. One way to provide this possibility is to have the telephony server connected to each service provider, as shown in FIG. 7.[0105]
• Above, the service supplier selection was made at the configuration of the[0106]NT5 and is valid for all calls from a certain user. A change of supplier would involve a reconfiguration of theNT5. However, it is also possible to make the selection for each separate call. The user will then have to provide the information representing the desired service provider, e.g. a code or prefix. Such information is easily integrated, for instance in the requested telephone number. Other possibilities for selecting service suppliers are to include at least a part of the selection procedure in theNT5. The selection may then be performed automatically and the service provider can be selected based on e.g. the time of the day, the day in the week, etc. Besides the access to the public telephone network there are other possibilities of voice communication. An internal voice communication channel between thePC2, using atelephony application25 or similar software, and anordinary telephone1, connected to thesame NT5. If a call is requested from an ordinary telephone, where the receiver is thetelephony application25 of thePC2, theNT5 may connect the phone and thetelephony application25 of thePC2. This use of the NT is illustrated in FIG. 8, where a broken line designate the connection between thecomputer2 and thephone1a.
• A generalisation of this, connecting two[0107]analogue phones1a,1bconnected to twotelephony interfaces6 on thesame NT5, is also possible, as is shown in FIG. 8 as a dotted line. This opens the possibility to use theNT5 as a service node for a local internal phone network, e.g. between different rooms in the same building.
• The above described internal network configuration is also possible using datacom.[0108]Different computers2 connected to thesame NT5 may communicate directly without using theTV distribution network8. TheNT5 will in such a case serve as an intranet server.
• FIG. 9 shows another possibility of communication within the same[0109]TV distribution network8. A user A wants to make a request for a call to user B within the sameTV distribution network8. The destination of the call is the ordinary telephone number of user B. When the request of establishing a connection with user B reaches thetelephony server15, thetelephony server15 recognises the telephone number as one of the users in theTV distribution network8. The call is then forwarded direct to the right end user without passing thepublic PSTN network16. Such services may therefore supply a regional telephone network with the same extent as theTV distribution network8.
• Also in this context, the above ideas of intra-rietwork communication apply to datacom. In such a case, the[0110]router24 will recognise the external IP address as one that is connected to the sameTV distribution network8 and thus forward the datacom traffic directly to the receiver without passing any regular IP basednetwork14.
• The[0111]TV distribution network8 is used as a distribution medium, without influencing the TV broadcasting. However, there are some advantageous possibilities to use the TV programs themselves as well the available hardware. A TV channel that is broadcasted over theTV distribution network8 passes normally right through theNT5 to be presented at theTV set3. However, as mentioned briefly earlier, it would be possible to tap a TV channel and send the information e.g. to thePC2 or other device with capabilities for visual presentation.
• In a similar way information from e.g. the[0112]PC2 may be presented at theTV set3 as visual information, either in a separate free TV channel or overlaid any other TV channel.
• All of the above described possibilities are possible to achieve by configuring the[0113]NT5 in a proper way. It is thus convenient if theNT5 is equipped with a WWW server, making it possible to manage theNT5 configuration.
• The above descriptions are examples of embodiments of the present invention. Someone skilled in the art will easily be able to make modifications and alternatives, which also should be considered to fall within the claims of the present invention. As an example, in the description above it is stated that the data representing the voice is compressed before it Is sent over the[0114]TV distribution network8. It is obviously also possible to exclude this step in cases where the transmission capability is enough for sending non-compressed calls. Similarly, the protocol stacks presented are only examples of possible solutions and do not belong to the scope of the invention.
• Different variations are possible, depending on the particular transmission medium used, e.g. analogue vs. digital TV distribution networks. It is also possible to use different shared media, i.e. the above described TV distribution network. In the above description a DECT solution is used. In this case a DVB is used as TV distribution network. Since the data communication channels are independent of the broadcasting channels, the DECT solution may also be used in connection with analogue TV networks.[0115]
• According to the specification “Draft specification of DVB Interaction Channel based on DECT”, DVB-RC-165[0116]rev 7, vers. 4.0, Mar. 27, 1997 it can be applied to various TV broadcasting systems, such as satellite. cable, SMATV (Satellite Master Antenna Television) terrestial, DVB-MC (Microwave as cable), DVB-MS (Microwave as Satellite) or any future DVB broadcasting system.
• DVB is also developing for including MPEG (Motion Picture Expert Group) coded video. This implies that the downstream information streams becomes bursty, why space for multiplexing other types of streams becomes available. In such systems, the interactive downstream channels are provided by the broadcasting protocols, while DECT is used only for the upstream channels.[0117]
• The DECT scheme for interaction channels is one possible example. Other solutions are also available in the state of the art. The IEEE 802.14 standard discloses a standard for the physical layer and a MAC protocol for CATV networks.[0118]
• The[0119]NT5 has above been described without stating anything about the physical realisation. It is obvious for anyone skilled in the art that theNT5 may be integrated into one single unit as well as be separated into two or more units.
• In the description above, only the case, where one[0120]router24 andtelephony server15, respectively are connected to one singleIP access server12, is discussed. It is of course possible for thetelephony server15 androuter24 to be a part of any kind of network system, including severalIP access servers12 or not, eventually leading to aservice provider network14,16. Above nothing has been described about the physical realisation of these units. It is obvious for anyone skilled in the art that theIP access server12. thetelephony server15 and therouter24 may be integrated into one single unit. forming a network node, as well as be separated into two or more units.
• The interfaces of the[0121]NT5 may also be assigned to other applications than PC:s2 ortelephones1, parallel to what was discussed in the Swedish patent applications cited above. Such other interface possibilities are e.g. interfaces for DECT systems, LAN's, digital telephones, or phones connected through LAN's. It is thus obvious that also such applications have the same type of communication possibilities, both internal and external as described above.

Claims (47)

1. A method to provide access to services of a multitude of different communication service networks over a TV distribution network, comprising the step of using Internet Protocols (IP) as a common internal multiplexing and transport mechanism in an interaction channel of the TV distribution network, the interaction channel supporting bi-directional communication via the TV distribution network with the multitude of different communication service networks simultaneously with TV broadcasting in the TV distribution network.

2. The method ofclaim 1, wherein the multitude of communication service networks comprises at least one telephony service network.

3. The method ofclaim 1, wherein the multitude of communication service networks comprises at least one IP based network.

4. The method ofclaim 2, further comprising the step of providing IP protocol handling in a network terminal connected to a user end of the TV distribution network.

5. The method ofclaim 4, further comprising the step of carrying out access to the telephony service network via a telephony server connected to an IP access server, which in turn is connected to a TV transmitter end of the TV distribution network, which is common for a suitable set of users.

6. The method ofclaim 4, further comprising the step of carrying out access to the IP based network via a router connected to an IP access server, which in turn is connected to a TV transmitter end of the TV distribution network, which is common for a suitable set of users.

7. The method ofclaim 5, further comprising the step of associating in at least one of the telephony server and the router, an external address with an IP address in the TV distribution network.

8. The method ofclaim 4, further comprising the step of allowing simultaneous telephony and data communication sessions on the same network terminal.

9. The method ofclaim 4, further comprising the step of providing access simultaneously for more than one telephony session on the same network terminal.

10. The method ofclaim 9, wherein the simultaneous telephony sessions on the same network terminal use different telephony service networks.

11. The method ofclaim 4, further comprising the step of providing access simultaneously for more than one datacom session on the same network terminal.

12. The method ofclaim 11, wherein the simultaneous datacom sessions on the same network terminal are given access to different IP based networks.

13. The method ofclaim 4, wherein at least one addressable unit related to one network terminal is associated with more than one external address.

14. The method ofclaim 4, wherein at least one external address is associated with more than one addressable unit related to the same network terminal.

15. The method ofclaim 4, further comprising the step of supporting internal telephone calls between different telephony devices connected to the same network terminal.

16. The method ofclaim 4, further comprising the step of supporting internal datacom sessions between different computer devices connected to the same network terminal.

17. The method ofclaim 4, further comprising the step of providing users of the same network terminal with access to several different telephony service networks.

18. The method ofclaim 17, further comprising the step of selecting required telephony service network on a per call basis.

19. The method ofclaim 4, further comprising the step of providing users of the same network terminal with access to several different IP based networks.

20. The method ofclaim 19, further comprising the step of selecting a required IP based network on a per session basis.

21. The method ofclaim 1, further comprising the step of supporting internal telephone calls between different telephony devices connected to the same TV distribution network.

22. The method ofclaim 1, further comprising the step of supporting internal datacom sessions between different computer devices connected to the same TV distribution network.

23. A network terminal for providing access to services of a multitude of different communication service networks over a TV distribution network, wherein the network terminal is located at a user end of the TV distribution network and comprises means for using Internet Protocols (IP) as a common internal multiplexing and transport mechanism in an interaction channel of the TV distribution network, and at least one interface for communicating with a respective one of the multitude of different communication service networks, wherein the interaction channel supports bi-directional communication via the TV distribution network between the network terminal and the multitude of different communication service networks simultaneously with TV broadcasting in the TV distribution network.

24. The network terminal ofclaim 23, wherein the multitude of communication service networks includes at least one telephony service network.

25. The network terminal ofclaim 23, wherein the multitude of communication service networks includes at least one IP based network.

26. The network terminal ofclaim 25, wherein the network terminal comprises at least one interface to a terminal unit.

27. The network terminal ofclaim 26, further comprising at least one telephony interface supporting communication for access to the telephony network.

28. The network terminal ofclaim 26, further comprising at least one PC/LAN interface supporting communication for access to the IP based network.

29. The network terminal ofclaim 25, further comprising applications for telephony, IP traffic and management of the network terminal configuration.

30. The network terminal ofclaim 29, further comprising means for communication with the management application of the network terminal, for enabling modification of a configuration of the network terminal.

31. A telephony server for providing access to services of at least one telephony network over a TV distribution network, comprising means for connecting the telephony server to an Internet Protocol (IP) access server, which in turn is connected to a TV transmitter end of the TV distribution network, and means for using the IP protocols as a common internal multiplexing and transport mechanism in an interaction channel of the TV distribution network, and means for associating a telephone number with a terminal at a user end of the TV distribution network, wherein the interaction channel supports bi-directional communication via the TV distribution network between the terminal and the at least one telephony network simultaneously with TV broadcasting in the TV distribution network.

32. The telephony server ofclaim 31, wherein the telephony server has access to more than one telephony network.

33. The telephony server ofclaim 31, wherein the telephony server comprises a telephony application.

34. The telephony server ofclaim 31, further comprising means for associating an external telephony address with an internal IP address.

35. The telephony server ofclaim 31, further comprising an application for management of the telephony server and means for communication with the management application, for enabling modification of a configuration of the telephony server.

36. A router for providing access to services of at least one Internet Protocol (IP) based network over a TV distribution network, comprising means for connecting the router to an IP access server, which in turn is connected to a TV transmitter end of the TV distribution network, and means for using the IP protocols as a common internal multiplexing and transport mechanism in an interaction channel of the TV distribution network, wherein the interaction channel supports bi-directional communication via the TV distribution network between a terminal at a user end of the TV distribution network and the at least one IP based network simultaneously with TV broadcasting in the TV distribution network.

37. The router ofclaim 36, wherein the router has access to more than IP based network.

38. The router ofclaim 37, wherein the router has an IP application which communicates with the IP based networks.

39. The router ofclaim 36, further comprising means for associating an external IP address with an internal IP address.

40. The router ofclaim 36, further comprising an application for management of the router and means for communication with the management application, for enabling modification of the configuration of router.

41. A network node for providing access to services of at least one Internet Protocol (IP) based network and of at least one telephony service network, comprising an IP access server, a router connected to the IP access server and with IP interfaces for connection to a respective one of the IP based networks, a telephony server connected to the IP access server and with a number of telephony interfaces for connection to respective ones of the telephony service networks, the IP protocol being used as a common internal multiplexing and transport mechanism, whereby a user terminal in communication with the network node is able to communicate using IP with the at least one IP based network and with the at least one telephony service network.

42. An arrangement for providing access to services of an Internet Protocol (IP) based network over a TV distribution network, comprising a network terminal located at a user end of the TV distribution network, a telephony server connected to an IP access server, which in turn is connected to a TV transmitter end of the TV distribution network, and a router connected to the IP access server, using the IP protocols as a common internal multiplexing and transport mechanism in an interaction channel of the TV distribution network, wherein the interaction channel supports bi-directional communication via the TV distribution network between the network terminal and the IP based network simultaneously with TV broadcasting in the TV distribution network.

43. An access network comprising a number of network terminals and a network node, the network node having a telephony network interface and an Internet Protocol (IP) access server, a router connected to the IP access server and having an IP network interface, a telephony server connected to the IP access server and to the telephony network interface, the number of network terminals being connected to the IP access server at TV distribution network interfaces provided in the IP access server networks, wherein the TV distribution network interfaces support bi-directional IP based communication between the network terminals and at least one IP based network and at least one telephony service network simultaneously with TV broadcasting in a TV distribution network to which the TV distribution network interfaces are connected, the IP protocol being used as a common internal multiplexing and transport mechanism in an interaction channel of the TV distribution network, whereby the network terminals are able to communicate using IP with the at least one IP based network and telephony service network via the TV distribution network interfaces.

44. The access network ofclaim 43, wherein the router has several IP network interfaces, each one of which is connected to a respective one of several IP networks.

45. The access network ofclaim 43, wherein the telephony server has several telephony network interfaces, each one of which is connected to a respective one of several telephony service networks.

46. A network terminal comprising:

at least one local area network (LAN) interface;

a plurality of telephone interfaces;

a TV interface compatible with a TV distribution network;

a digital stream service (DSS), wherein the DSS provides a bi-directional interaction channel over the TV distribution network through which Internet protocol (IP) is used as the common internal multiplexing and transport mechanism and IP packets are transmitted and received; and

an IP multiplexer/demultiplexer, which transfers IP packets between the DSS and one of the at least one LAN interface and the plurality of telephone interfaces, wherein IP packets corresponding to a telephone call are routed to one of the plurality of telephone interfaces depending on the origin of the telephone call.

47. The network terminal of claim91, wherein the at least a portion of the plurality of telephone interfaces are associated with a same telephone number.

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