CENTRALIZED SYSTEM FOR THE REMOTE MONITORING OF
MULTIMEDIA SIGNALS
SUBJECT OF THE INVENTION
[0001] The present invention refers, in general, to a centralized system for monitoring and assessing the quality of telecommunications services and, more specifically, to a device whereby to assess and monitor the quality of the senaces offered over packet telecommunications networks, such as the distribution of television via Internet protocol based networks (IPTV)
STATE OF THE ART
[0002] In recent years access networks have been laid out fundamentally with xDSL (digital subscriber loop) technologies which permit the exploitation of the copper based subscriber loop infrastructure.
[0003] Up to how the xDSL access tecluiologies have covered the techmcal, management and capacity requirements imposed by the sei-vices which the market has demanded.
[0004] However, users are increasingly calling for more multimedia services based principally on quality video and voice over Internet, in addition to the existing Internet access services, known collectively as "triple play'\ and operators are thus having to progressively increase the capacity of their access networks.
[0005] Tlie aforementioned circumstances has allowed operators to offer a broad range of services of ail kinds via applications based on Internet protocols, such as IPTV and the streaming of multimedia content, voice and data over IP.

[0006] In order to provide multimedia services in real time on IP networks it is necessary to comply with a series of requirements which depend on the service or the combination of services offered. For example, a given bandwidth, which may be different in each transmission direction, is needed so that the incoming packets line may allow the maitimedia signals to be regenerated correctly. The operator must also guarantee that the quality of encoding is satisfactory a,nd that delays, network latency and tlie percentage of lost packets are not in excess of given limits depending on the type of service.
[0007] As a consequence of the foregoing, the provider of tPTV and other real¬time services needs to control the qual.it)' of the service (QoS) given to the end user and is therefore obliged to install, tliroughout the internet, the metropolitan network or the access network, quality of serxice monhorlng equipment.
[0008] In order to assess the quality of that senice, reference is inade to such parameters as the delay of the packets of data transmitted, the bandwidth used in the comiTiunication, the packet delay jitter or the loss probability of packets, or others of a similar nature which may permit the appraisal of the quality of the service of the stream of television data trammitted from the content provider to the subscribers as a whole. In the case of IPTV, multimedia signals are also supervised direct via TV monitor observation. A perception of the service similar to that of the end user mav thus be achieved.
[0009] The monitoring signals and the aforementioned assessment data are gathered at different points distributed throughout the telecommunications network.
[0010] It is known in the state of die art, shown in figure L that a digital subscriber line access multiplexer 21 represents one of the possible points of monitoring. It is to these items of equipment, wiiich are generally located in telephone exchanges, that the lines of the end users are connected. The connection is made via customer premises equipment 22. An example of customer premises equipment 22-1 is an ADSL rotiter to which the end user may connect a range of items such as multimedia decoders or set-top bo.Kes 27-1,

computers PC or IP telepliones. Figure I represents an example in which customer premises equipment 22->l, set-top boxes 27-1, computer PC and an IP telephone make up the home equipment of an end subscriber.
fOOll] The digital subscriber line access multiplexer 21 such as DSL AM may have a plurality of subscriber ports. In order to monitor the multimedia or data signals received by the digital subscriber Hne access multiplexer 21 it is cotiiraon practice to reserve one of those ports for the purpose.
[0012| It is known in the art that in order to obtain the parameters required for the monitoring and assessment of service qualit}' in a digital .subscriber line access multiplexer 21 the procedure is to connect to the subscriber port resen'ed for that purpose, in cascade and via a monitoring line 23 as shown, in fig. 1, a customer premises equipment 22-2, a multimedia decoding device or set-top box 27-2 and a computer 11. Ihese items of equipment are installed beside the digital subscriber line access multiplexer 21.
[0013] The computer 11 is in turn connected, likewise in cascade, to the DSLAM 21 or to some other item of telecommunications network access equipment via a return line 24. Tlie computer II receives the signal generated by the set-top boxes 27-2, for example, an analogue television signal, processes it and transmits it via the return line 24 to a central server 29 by means of a communications channel laid down tiirough the telecommunications network 30. The computer 11 similarly gathers and transmits to the centra} server 29 the signal service quality parameters.
[0014] At the central server 29 the monitoring and assessment of the multimedia signal received by ever>' DSI.AM 21 from the provider of content and'or services is performed by means of direct obsen'ation and the corresponding algorithms based on the parameters registered in each case.
[0015] The known system of monitoring and assessment has a number of disadvantages. The interconnection of various pieces of equipment and

middleware is required to obtain the return signal for monitoring and the quality of service assessment parameters. Further, the multimedia signal received by the centi-al server 29 is not the digital signal received by the DSLAM 21 but, instead, a signal processed by the set-top box 27-2 and tlie computer 11 connected to the monitoring line 24 as shown in fig. 1.
[0016] As a result, the assessment of the television signal received by the DSLAM 21 is perfbnned in an indirect manner and calls for the use of a complex system including various items of equipments The overall cost of the quality of service assessment system is therefore high, while the monitored signal is not that received by the DSLAM 21.
CHARACTERISTICS OF THE INVENTION
[0017] The present invention seeks to resolve or to minimize one or more of the disadvantages mentioned above by means of a centralized system for monitoring remote multimedia signals as described in claim 1. "fhe embodiments of the invention are as established in the dependent claims.
[0018] One object of the invention is that of providing a system for the monitoring and assessment of tiie quality of the services rendered by a provider of content and''or services within a packet teleconununications network which genuinely gauges the quality of the triple play services, comprising voice, data and television over IP, delivered by that provider to the end subscriber.
[0019] The packet network quality of seivice assessment data takes in both QoS parameters perceptible to the customer and those pertahiing to the operation of the network.
[0020] Another object of the invention is that of providing a simple system requiring a minimum amount of devices. The number of such items of equipment is consequently reduced.

[0021] A fuiUier object of tlie invention is that of avoiding the increase of restrictions on the topology of the communications network and on the increase in the number of access gateways such as access multiplexers DSLAMs.
[0022] A further object of the invention is that of providing a monitoring and assessment system requiring a minimum consumptiori of electricity fer its operations and thtis helping the parties to the Kyoto protocol to meet their obligations thereunder.
[0023] A further object of the invention is that of providing an Internet QoS monitoring and assessment system at an affordable overall cost for the Internet content provider, so that the system may adapt easily to market lieeds at any time and that tliere may be scalability in the investment in network infrastructure and the assessment of Internet sen'ices.
BRIEF DESCRrPTION OF THE FIGURES
[0024] A more detailed explanation of the invention is provided in the following description of the attached tlgures.
[0025] Figure 1 shows a packet telecommunications network monitoring system accordine to the state of the art, and
[0026] Figure 2 shows an IP monitoring system according to the invention.
DESCRIPTION OF THE INVENTION
[0027] There follow^s a description, with reference to figure 2, of a system for the monilonng of the IP multimedia services rendered by a provider of IP content and/or services.

[0028] The assessment system includes an item of subscriber access equipment 22-2 such as customer premises equipment CPE, an ADSL modem, connected ro an access gateway 21 such as a digital subscriber line access multiplexer DSLAM via a line reserved 23 for that purpose.
[0029] The access multiplexer 21 may be located on the premises of the provider's customer, which may for example be a company, alihough it is more commonly located in a telephone exchange.
[0030] When the access multiplexer 21 receive.s from the Internet content provider Internet services such as triple play sei-vices it relays the stream of multimedia content, which includes IPTV, to subscriber ports connected thereto,
[0031] One of the items of subscriber access equipment receiving that How of television over Internet is subscriber access equipment 22-2 which forms pan of the monitoring system. The transmission of the IPTV stream fi*om the access m\dtiplexer 21 takes pi ace via a monitoring line 23.
[0032] Upon receiving the IPTV stream, subscriber access equipment 22-2 returns it to the access multiplexer DSLAM 21 from which it came via the return line 24.

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[0033] In the implementation as shown in figure 2, subscriber access equipment 22-2 receives the muUlmedia stream from access multiplexer DSLAM. 21 via a downstream line 23 as an ADSL line and returns it via an Ethernet line 24 in turn linking subscriber access 22 to the access multiplexer DSLAM 21.
[0034] The access multiplexer 21 is in turn linked to switch such as a first Etheniet switch 25-1 and thus, via a teleconmiunications network 30 which includes nn IP network, it is connected to the monitoring sers'er 29 which is in turn Unked to the network 30 Ihroudi a second Ethernet switch 25-2.

[0035] The IPTV stream returned to the access muUiplexer 21 from the subscriber access equipment 22-2 is relayed to the monitoring server 29 through a communicfition channel 31 laid down between the first and second Etlieniet switches 25-1.25-2.
[0036] The commnnication chjmnel 31 thus laid down across the telecommunications network 30 conveys packets of data relating to the returned IPTV stream obtained tlirough the application of a tunnelling protocol such as the virtual leased line (VLL) protocol. By means of this procedure the packets of multimedia flow originally received by subscriber access equipment 22 from access mtdtiplexer 21 may be transmitted to the moiiitoring server 29 without alteration.
[0037] The second Ethernet switch 25-2 is connected to at least one multimedia decoder 27-3 such as a set-top box. The number of set-top boxes 27-3 connected to that second switch 25-2 will depend on the number of access multiplexer DSLAM 21 to be monitored simultaneously.
[0038] By means of a computer application the operator of the central monitoring sender 29 may relay to a given set-top box 27-3 the signal coming from a given access multiplexer 21 DSLAM. "ITie set-top box 27-3 generates a television signal which may be seen on a monitor 26. Similarly, the operator of the central monitoring server 29 may perform on the set-top box 27-3 all or part of the actions that the end user may carry out with his remote control. The operator thus obtains a perception of the service similar to that of the end user.
[0039] Tlie tunnel 31 hetv.'een both switches 25-1, 25-2 also allows communications to be conveyed imaliered from the set-top box 27-3 controlled by the monitoring 29 server to the remote subscriber access equipment 22 used to send the monitoring signal of the access multiplexer DSLAMs 21.

[0040] Upon receipt of the packets of data relating to the monitoring signals from the access multiplexer DSLAMs 21, the centra] monitoring server 29 executes an assessment algorithm using the parameters obtained from the analysis of the packets received from each access multiplexer DSLAM 21.
[0041] The monitoring system of multimedia traffic 28 enables the remote connection of any subscriber access equipment 22-2 of a plurality of items of subscriber access eqttipment 22, with any set-top box 27-3 of a plurality of set-top box 27-3.
[0042] Also the monitoring system 28 permits the capture by the monitoring server 29 of the remote return signal coming from any of the subscriber access equipment 22-2. Furthermore, the monitoring server 29 may be connected to a set-top box 27-3 by means of infrared transmitters controlled by the monitoring server 29.
[0043] The embodimentis and examples contained in this specification are put forward by way of explanation of the significance of the present invention and of the practical appHcation thereof, so that experts in the art may put into practice and use the invention. The experts in the art will appreciate, however, tliat the preceding description and examples only constitute an outline. The description is not intended to be all encompassing, nor is the scope of the invention restricted thereto. Many modifications and variations may therefore be made without parting company with the spirit and scope of the following claims.

CLAIMS
1. A system for monitoririg and assessing the quality of services distributed over
a packet telecommunications network, such as the Internet, comprising at least
one piece of subscriber access equipment (22-2) and an access gateway (21);
characterized in that the subscriber access equipment (22-2) is connectable to
the access gateway (21) via a line (23) susceptible of receiving multimedia
content such as data, voice and video, the said content being returned to the
coinmunicatiotis network (30) via a return line (24).
2. Systetn according to claim 1, characterized in that the retum line (24) providing a link of predetermined capacity to retuni the multimedia strean). saici return Ime (24) may be of a technology such as an Ethernet line.
3. System according to claim 2, characterized in that a line susceptible of conveying the multimedia stream from the access gateway (21.) to the subscriber access equipment (22-2) is connectable to a subscriber port of the access gateway (21) and tlierefore uses a type of access technology such as x,DSL or the like.
4. System according to claim 3, characterized in that the access equipment (22-2) is capable of communicating through return line (24) with a remote multimedia traffic monitoring (29) server via a packet telccounuunications network (30).
5. System according to claim 4, characterized in that the packet
telecommunications network (30) comprises a first interface (25-1) connectable
to the access gateway (21) and a second interface (25-2) connectable to the traffic
monitoring (29) server, so that the return signal is conveyed unaltered between
the first and second interface (25-1, 25-2), and vice versa, via a tunnel
communication protocol for packets such as a virtual leased line (VLL).

6. System according to claim 5, characterized in tliat the first and second interfaces (25-1, 25-2) may he Ethernet switches, ATM switches, routers, access multiplexers or the like.
7. System according to claim 5, characterized in that the second interlace (25-2) is connectable to at least a multimedia decoder (27-3).
8. System according to claim 7, characterized in that between the subscriber access equipment (22-2) and the multimedia decoder (27-3) there is a direct tunnelled communication chatmel (31), without there being a need for a specific configuration of the subscriber access equipment (22-2) or of the multimedia decoder (27-3).
9. System according to preceding claijns, characterized in that the subscriber access equipment (22-2) is a customer premises equipment such as ^m ADSL modem, a residential router or the like.
10. System according to preceding claims, characterized in that the access gateway (21) is a digital subscriber line access multiplexer, access media gateway or the like.
U. An access gateway connectable to subscriber access equipment (22-2) characterized in that the access gateway (21) is connectable to the remote monitoring server in accordance with any of the preceding claims.
12. Access gateway according to claim il, characterized in that the access gateway (21) is connectable to the subscriber access equipment (22-2) via a h'ne susceptible of conveying a stream of multimedia content dov-'nward from access gateway (21) to subscriber access equipment (22-2), the said stream of multimedia content then returning uplink via a return line (24).

13. Access gateway according to claim 12, characterized in thar the subscriber access equipment (22-2) may establish bi-directiona! contact wiLh a remote multimedia decoder (27-3).
14. A multimedia decoder: ctiaraeterized in that the multimedia decoder (27-3) is connectable to the remote quality of seivice monitoring server (29) via a second interface (25-2) according to claim 6.
15. A procedure for monitoring and assessing the quality of services provided over a packet telecommunications network (30), comprising the broadcasting of television over IP networks; characterized In that it comprises the step of direct transmission of a stream of muftimedia content, including television over packet networks, from an access gateway (21) to subscriber access equipment (22-2) and retiu-ns to the communications network (30) via a return line (24).
16. Procedure according to claim 15 characterized in that it also comprises the step of transmission using a tunnel communication protocol from the access gateway (21) to the remote monitoring seiver (29) in accordance with claims 1 to 8.
17. A monitoring system of multimedia traffic according to the preceding claims,
characterized in that it enables the remote connection of at least one piece of
subscriber access equipment (22-2) with any multimedia decoder (27-3) of a
plurality of multimedia decoders (27-3).
18. Monitoring system of muhimedia traffic according to claim 17,
characterized in that it permits the capture by the monitoring server (29) of the
remote return signal coming from any item of the subscriber access equipment
(22-2).

19. Monitoring system of multimedia traffic according to claim 18, characterized in that the monitoring server (29) is coanectable to a multimedia decoder (27-3) by means of inirared transmitters controlkd by the monitoring server (29).