WO2007024139A9

WO2007024139A9 - Method and apparatus for displaying delivery status of video packets

Info

Publication number: WO2007024139A9
Application number: PCT/NO2006/000299
Authority: WO
Inventors: Simen K Frostad
Original assignee: Bridge Technologies Co As; Simen K Frostad
Priority date: 2005-08-23
Filing date: 2006-08-18
Publication date: 2007-08-16
Also published as: WO2007024139A3; WO2007024139B1; NO324261B1; NO20053942L; WO2007024139A2; NO20053942D0

Abstract

A user interface and a method to display delivery status is described for video packets that are transported over a packet switching data network that is characterised in that the user interface is set up to display a number of parameters for Media Delivery Index (MDI) simultaneously, with a scale which is set up to indicate parameters in real time in relation to a number of threshold values.

Description

METHOD AND APPARATUS FOR DISPLAYING DELIVERY STATUS OF VIDEO PACKETS

The present invention relates to a method and a user interface to display the delivery status for video data packets that are transported over a packet switching data network.

Known technology

Transport of video streams over packet switching networks is very common in today's data networks with fast data transfer. When video data is transferred via such networks, the video streams often go through time-distortion, i.e. that the time between the packets at a destination is different from the time between the packets at the transmitter. This concept is also known as jitter.

For a receiver to be able to display received video at its nominal rate, it is preferred that the receiver must adapt the varying times between the received data packets. This can be carried out by buffering the data early, and making sure that sufficient data is stored when the packets arrive late by collecting data in advance before one begins to display the video.

To be able to identify jitter and packet loss in a network is the key for maintaining a high quality of the delivery of data over a packet switching network. To be able to monitor and troubleshoot networks that are continuously transmitting data, a Media Delivery Index (MDI) has been developed. MDI can be applied to estimate how well a network can transport video and troubleshoot network problems where the performance has become poorer because of reconfiguration or changes in the traffic load.

MDI has two components, namely Delay Factor (DF) and Media Loss Rate (MLR), where

MDI = ^DF

MLR

Delay factor DF is the designation for the time it takes to empty a virtual buffer at the video rate, and is calculated at the time of arrival for each packet at the measuring point and is shown and/or registered at time intervals. A time interval is typically one second. DF is updated and displayed at the end of an interval. Given a virtual buffer level X, where DF is measured:

X = I Bytes received - Bytes lost\ DF = [max(X) - min(X)]/ media rate

where media rate is expressed in Bytes/sec and max(X) and min(X) are the maximum and minimum values measured in an interval.

Media Loss Rate

MLR is a designation for the number of media packets that are lost per second, and is calculated by subtracting the number of media packets that are received during one interval from the number of media packets that are expected to be received during the interval and the value is scaled to 1 second:

MLR = (Packets expected - packets received)/interval in seconds

A known method to apply MDI in installing, modifying and/or modification of a video network is: 1. To identify, localise and address problems in packet loss by applying MLR.

2. To identify, localise, measure and address time distortion margins by applying DF.

3. To display DF and MLR for transient drops that exceed certain thresholds which represent changes in network or server, faulty configuration, disruptions, etc. The thresholds can be determined based on type of network equipment, type of decoder, desired margin and quality, etc.

It is an object of the present invention to provide a graphic user interface (GUI) that can display status for both MDI parameters in real time simultaneously, and how near to the critical threshold values in a network one is.

It is also an object of the present invention to provide a method that displays parameters for MDI in an improved way. A further object of the present invention is to provide a user interface that shows desired data in desired time, for example, minutes, hours, days or months with the same scale reference.

The above mentioned objects and other objects are provided by a user interface and a method that are characterised by the independent claim 1 and claim 5, respectively.

Preferred embodiments of the invention are characterised by the characteristic. features in claims 2-5 and claims 7-10, respectively.

An advantage of the present invention is that the method according to the invention can display several MDI parameters at the same time which gives operators and other personnel a much faster identification of a problem, and also the possibility to be able to set their own threshold values for the scale changes manually/automatically.

Another advantage of the present invention is that the user interface according to the invention can present statistical data in a much less complex way, in reality very simply.

The invention shall now be described in more detail with reference to the enclosed figures, in which:

Figure 1 shows a typical interface according to the invention for two different MDI parameters.

Figure 2 shows the interface in figure 1 in a typical case according to the invention.

Figure 3 shows an interface over measurements taken over time according to the invention.

Figure 1 shows a graphic user interface that is divided into two parts, namely the two MDI parameters DF and MLR. The two modes for this real time interface are continuous or trigged. The continuous mode can always provide relevant status for the MDI measurement, while the trigger mode freezes all cases with critical errors until they are released by an operator. This gives a typical main control centre (MCC) a time stamp and assurance that the problem level is known immediately. The prevailing status is typically divided into three zones, namely, "ok", "critical" and "error". According to figure 1 , the zone "ok" is shown in green, the zone "critical" in orange and the zone "error" in red.

Figure 2 shows the interface in figure 1 according to the present invention in a typical measuring case. The interface in figure 2 provides a complete, temporary status and exact representation with a simple indication of how near the system is to the threshold values for critical errors. Information about the threshold values is important for simple detection of possible error points. Also provided is a graphic correlation tool for multiple measuring points for the operator.

The individual threshold values that are determined by the operating personnel are dependent on the different user areas, and it can be mentioned, for example, that a FTTH net (Fibre to the Home) can have very low values of DF, for example between 1.3 to 2.8 and xDSL based networks can have normal values from 2.4 to 4.8. It is important to use a scale that one can set threshold values on differentially.

Based on the above mentioned, it shall be noted that the threshold value for the different MDI parameters can vary and the invention is therefore not restricted to value examples that are mentioned here.

Figure 3 shows a continuous display of measuring cases over a given time. A preferably continuous display provides an operator with the same graphic indicators in a historical perspective as in a real time perspective. The two can be presented at the same time. A water-flow function is implemented in figure 3 to provide a visual buffer of the last minutes with MDI measurements at a network point up to several days recording. In the interface, it is preferred that the time line moves steadily and all data floats from left to right, i.e. from real time to historical time. The time scale or the resolution on the water-flow time line can be anything from a representation of the last minutes to the last months, dependent on the storage capacity of the correlation device or on the measuring device. The amount of sampling that is provided is also dependent on the capacity of the device. Typically, samples every second are sufficient to give historical overviews that are reliable. If a critical event or a fault happens, the device will be able to switch to high resolution recording and display the incident in full detail for later use.

Claims

CLAIMS.

1. User interface to display delivery status for video packets that are transported over a packet switching data network, characterised in that the user interface is arranged to provide a number of parameters for Media Delivery Index (MDI) simultaneously, by a scale that is set up to indicate parameters in relation to a number of critical threshold levels.

2. User interface according to claim ^characterised in that the parameters are displayed in real time.

3. User interface according to claims 1-2, characterised in that a parameter for MDI is a delay factor (DF) and one parameter is a loss rate for media (media loss rate, MLR).

4. User interface according to claims 1-3, characterised in that the packet switching data network is an IP network, such as the internet.

5. User interface according to one of the preceding claims, characterised in that DF parameters and MLR parameters are displayed in a continuous or trigged mode.

6. Method to display delivery status of video packets that are transported over a packet switching data network, characterised in displaying a number of parameters for Media Delivery Index (MDI) simultaneously, by a scale that indicates the values of the parameters in real time in relation to a number of critical threshold values.

7. Method according to claim 6, characterised in displaying parameters in real time.

8. Method according to claims 6-7, characterised in displaying one parameter for MDI which is a delay factor (DF) and one parameter that is a rate of loss of media (media loss rate, MLR).

9. Method according to one of the preceding claims 6-8, characterised in displaying DF parameters and MLR parameters in a continuous and/or trigged mode.

10. Method according to one of the preceding claims 4-6, characterised in displaying DF parameters and MLR parameters running over time, such as the last minutes to the last months.