TLA700 Series Upgrade Guide

Features & Benefits

• Create Transport Streams to Evaluate Your Decoder
• Generator and Analyzer in One Package
• Six Different I/O's Available
• Bit Rates Up to 45 Mbps
• DVB Information
• Up to 20 Programs Per Transport Stream
• Up to 10 Elements Per Program
• Suite of Elementary Streams Provided
• Channel Coding and Decoding
• Change Any PID
• 8 GB for Transport Stream Storage
• Graphical Interface
• Error-Checking Within the Packet Header
• In-Range and Out-of-Range Parameter Adjustment

Applications

Analyzer Features

• Search for Syntax or Semantic Errors
• Timing Errors in the PCRs
• View Multiplex Allocation Tables
• Check Table CRCs
• Multiplex Rates
• Table Extraction (DVB Tables)
• Allows You to Search For Timing Errors in the PTS/DTS Time Stamps
• Verify PID Values
• Extract Elementary Streams, Transport, and PES Packets

Create Transport Streams for Decoder Evaluation

• Time-Shifted PCRs (Jittered)
• DVB Channel Coded
• DVB Channel Decoded
• High or Low Multiplex Rates
• Delay Offset Control of Elementary Streams
• User-Definable PID Values
• User-Defined Multiplex Data Rate
• Add DVB Tables with Coherence Checking
• User-Defined PCR Period and Program Start Delays

Tektronix leads the market in developing products for new and emerging audio, video, and cable technologies. This time in the field of MPEG-2 transport streams. The MTS100 is an innovative solution to the problem of testing equipment used in a MPEG-2 network.

Perform creation, generation acquisition, and analysis of MPEG-2 transport streams quickly using the intuitive icon-driven user interface. The MTS100 can create, generate, acquire, and analyze MPEG-2 transport streams. From a transport stream as basic as a single program to a more complex transport stream with multiple programs and many elements in each program, the MTS100 can handle it.

All applications are preloaded, making the MTS100 fully configured and ready to use immediately. Each of the six specific software applications performs their own function to aid in evaluating your system.

The MTS100 gives you the ability to create transport streams with complete control over many of the various MPEG-2 parameters. A few examples are: placement of time stamps, timing offsets, data rates, PES packet size, jitter, channel coding, and DVB-SI information.

An included CD-ROM contains several audio and video elementary streams. The video elementary streams contain both motion sequences and traditional television test patterns. Use these elementary streams for creating your own MPEG-2 transport streams.

Analyze acquired transport streams using a simple graphical interface. The hierarchical view gives an outline of the transport stream's structure, while the interpreted view lets you examine syntax and the data values for each field in the packet headers. It will even allow you to examine the actual hex and binary values. It searches for errors in the transport stream, PES packet, and Table Headers, highlighting any it finds.

The Analyzer application has easily accessible, clear explanations of the fields and parameters. You could even use the Analyzer to train people on the composition of the MPEG-2 transport stream.

Data rates from 1 Mbps to 45 Mbps are available. With the 8 GB of storage capacity, this allows a minimum of 20 minutes of acquisition or generation time (four files, 5 minutes in length at 45 Mbps). The acquisition or generation can be made nearly continuous by using the end-to-start looping feature.

The MTS100 operates on a Windows NT™ platform. This makes interconnecting to any existing network relatively simple.

Analyzer Features

• Multiple document windows
• Hierarchical transport-stream view
• Packet header displays
• Syntax and semantic information
• Timing analysis (PCR and PTS/DTS)
• Error analysis of the Packet Header
• Extract elements for use in other transport streams

Multiplexer Features

• Interactive configuration definition
• Hierarchical and dynamic views
• Configuration stored as ASCII file
• Many variable parameters

PSI and SI Table Editor Features

• Edits nearly all ETS 300 468 October 1995 parameters
• Checks both inter- and intra-table coherence
• Global view displays table interrelationships

Channel Coding/Decoding Features

• Meets DVB baseline system requirements for satellite broadcasting

Packet Jitter Features

• Jitter all or only selected program PIDs
• Four jitter types available
• Jitter amplitude and frequency are user definable

Data Store Features

• Controls the I/O
• Manages the Data Store Disks for maximum efficiency

Interfaces

The MTS100 provides several interfaces for transmitting and receiving the transport streams. (SMB to BNC adapter cables are also provided.)

G703 Ports

This serial interface complies with the electrical characteristics of ITU-T rec. G703 (HDB3 code) for 8.448 and 34.368 Mbps. These are the only G703 frequencies available. The mechanical connectors are SMBs.

ECL Serial and Parallel Ports

The ECL Serial and ECL Parallel ports share the same 25-pin subminiature D connector. The parallel version provides eight balanced data pairs while the serial version provides one. Additionally, CLOCK, DATA_VALID, and header-sync (PSYNC) values are available. The voltages are at ECL levels. The maximum operating bit rate is 45 Mbps and the minimum is 1 Mbps.

A control port is available to regulate the flow of data in this port. The control port is a subminiature 9-pin D connector, and adds flexibility to the ECL Parallel and Serial port by adding three control signals that provide two more operating modes.

TTL 50 Ohm

The TTL 50 ohm serial interface takes the form of a clock and data signal. The signals operate at TTL levels, with a maximum data rate of 45 Mbps. The connectors are male SMBs (one data and one clock). This port can be synchronized to an external clock using the Clock Port.

10 Mb Serial Port and Clock (RS-422 Levels)

This serial interface provides a differential signal at RS-422 levels. It provides both input and output ports. The mechanical connector is a 9-pin subminiature D connector.

Clock Port

This input provides timing for the TTL 50 ohm and 10-Mb Serial ports. It expects inputs at TTL levels. The maximum operating frequency is 45 MHz. The mechanical connector is an SMB male.

Analyzer

There is a tremendous amount of information in a transport stream. The Analyzer displays this information in a logical and convenient manner. Figure 1 gives the hierarchical tree display shown when first performing an analysis. From here, you can quickly see an overview of the transport stream.

The hierarchical view contains:

• The transport stream (TS)
• The PSI tables (PAT, NIT, and PMT)
• The PES packets
• The elementary streams (video, audio, or data)

You can shift to a more detailed view, the interpreted view shown in Figure 2. This view gives the details of all Packet Headers, including PAT, PMT, NIT, PES, transport, and DVB-specific tables.

There are two parts to each parameter in this display: syntax and semantic. The syntax defines each field, while the semantic gives the current value (in decimal or hexadecimal). Obtain more information on either field by double-clicking on it. (Figure 2 shows the additional information available when the syntax portion of the PID is double-clicked.) If the syntax information is not required, a binary- or hex-dump view is also available.

Scrolling through the packets is easy. Use the Next or Previous arrow button at the bottom of the application window. You can also specify a packet by the number.

Each packet and table have a defined structure and the Analyzer allows you to view each of these to check structure and search for errors. Parameters in red, flag errors.

The Analyzer performs error analysis. The application calculates the table CRCs and compares them to the CRC value in the table data. The semantic values are compared to the MPEG-2 transport stream standard. Any value in error is flagged in red. The Analyzer searches for errors in the interpreted view and automatically displays the first one it finds. An explanation of the error is available when the semantic value is double-clicked.

A graphical display, as shown in Figure 3, is used to express the timing. All the relevant information about the PCR is available by double-clicking on the clock icon. You can also display the PCRs in a table format listing the parameters for all the PCRs in the selected display.

The placement of the PTS and DTS in the packet headers (Figure 4) has its own graphical interface. It gives the placement of the PTS, DTS, and access unit arrival times. The video access unit content type (I, P, or B frame) can be determined from this display. If you prefer, display the PTS/DTS in a table format listing the values of the parameters.

Display the percentage of the multiplex rate each PID is using in a pie chart, using the Multiplex Allocation command. This feature is useful to view all PIDs in the system and how much time is being used by each one.

The Analyzer can extract portions of a transport stream and save it to a file for further evaluation or reuse. The following parts of a transport stream are available for extraction:

• Transport packet/payloads (all or only a specific PID)
• Tables (view them using the PSI and SI Table Editor application)
• PES packets (all or only a specific stream type)
• Individual elementary streams

Multiple windows are available in the Analyzer application. You can display the hierarchical view, interpreted views, and timing displays simultaneously.

Multiplexer

The Multiplexer application allows you to generate transport streams to rigorously test your own equipment. This guarantees a "good" signal as the starting point for any system test.

The Multiplexer can create transport streams with up to 20 programs. Each program can have a maximum of 10 elementary streams, with a maximum of 5 of any one elementary stream type.

Figure 5 shows the hierarchic view of the Multiplexer. This view allows you to see the structure of the multiplex while you are creating it.

The standard structure contains the PSI (Program Specific Information) configuration including: the PAT (Program Association Table), PMT (Program Map Table), NIT (Network Information Table), and the Programs with their elementary streams. There is also a DVB configuration (Figure 6) that includes additional information for digital broadcasting in Europe. The SI (System Information) includes: NIT (moved from the PSI), BAT (Bouquet Association Table), SDT (Service Description Table), and EIT (Event Information Table). (These tables can use their default values, or customize them using the PSI and SI Table Editor application.)

As you fill the multiplex, the bar graph on the left keeps you abreast of the amount of data rate left in the multiplex. It displays the highest usage rate.

The dynamic display (Figure 7) gives insight into the timing relationships between the programs in the multiplex. It allows you to see the start and stop times for each program and the data rate all programs contribute to the multiplex at a selected time.

The Multiplexer does not create the transport stream as you add and adjust the parameters, rather it makes a configuration file. This speeds up the application and allows you to create slight variations to the transport stream easily. Before creating the transport stream, the program checks for errors and allows you to correct any it finds. The Multiplexer generates the transport stream on either the system disk or the Data Store Disks. While it generates the transport stream, the Multiplexer gives information about the estimated final system clock time and the running time.

Within the Multiplexer application the following parameters are user adjustable:

• Multiplex Rate of the transport stream
• Global start time of the transport stream (system clock value)
• PSI insertion period
• NIT insertion period
• PAT values for the program PIDs
• PMT information (using the PSI and SI Table Editor application)
• The PCR period for a program
• The program start time (relative to system clock)
• ES rate
• PES size
• DTS offset (for a video elementary stream)
• PTS offset (for an audio elementary stream)

The following parameters are displayed, although they are not user adjustable:

• Video elementary stream information:
• Resolution
• Picture rate
• MPEG-1 or -2 video
• Profile/level
• Running time
• Audio elementary stream information:
• Layer
• Protection
• Sampling frequency
• Mode
• Running time

The Multiplexer automatically calls the PSI and SI Table Editor application whenever required to edit the table parameters.

PSI and SI Table Editor

DVB-specific (Digital Video Broadcasting) tables add information enabling DVB IRDs (Digital Video Broadcasting Integrated Receiver Decoders) to automatically tune to a particular service and allows grouping of services into categories with relevant schedule information. These tables provide the EPG (Electronic Program Guide) information. Data necessary for the DVB IRD to automatically configure itself is available in the NIT, SDT, BAT, and EIT tables.

The PSI and SI Table Editor allows the user to change the data in the SI and PSI tables to fit their requirements. Table 1 gives the parameter types available for each of the table types.

Table 1 – The parameters available for each table

Nearly all the parameters described in ETS 300 468 October 1995 are editable in this application.

Global View (Figure 9) from this application shows the interrelationship between selected NIT, SDT, and EIT files. These files can have some interrelationship or none at all. (The illustration shows files with a high amount of interrelationships.) The association between the files is explained below:

• NIT contains the transport streams.
• Transport streams define transport stream ID.
• SDT must have the same transport stream ID.
• SDT contains services.
• Services contain service descriptors and service IDs.
• EIT must have the same service ID and transport stream ID to be interrelated to the SDT and NIT.

The PSI and SI Table Editor provides a coherence check of all open tables. It checks both the inter- and intra-table parameters for coherence to the standard.

Channel Coding/Decoding

The European Digital Broadcasting Project (DVB) has specified a baseline system for satellite broadcasting. The channel coding portion of the specification has the following coding flow:

• Energy dispersal (randomizing) (If not used, it is replaced by a "B8" sync byte coding scheme.)
• Reed-Solomon Code RS (204, 188) (can be customized)
• Convolutional interleaver
• Viterbi Code (1/2, 2/3, 3/4, or 7/8)

The decoding flow is:

• De-interleaving
• Reed-Solomon decoding and error correction
• Energy dispersal removal

This application allows you to chain the coding or decoding together to meet the DVB coding requirements or break the chain to test your own coder or decoder.

Packet Jitter

To aid in the design and evaluation of the decoder PLL, knowledge of the specific amount of jitter introduced into a system is mandatory. This jitter would represent the time variance of the transmission system. The Packet Jitter application accomplishes this by modulating the PCR data away from the correct values. The modulation can take the form of a sine wave, square wave, step, or random variations. Define the period and amplitude of the jitter to meet your own requirements.

Transport streams created with this application allow for real-time tests of the decoder. The receiver PLL is stressed as it tries to filter out these variations to produce a stable reference clock.

Data Store Manager

The Data Store Manager application controls the real-time generation and acquisition of the transport streams. It determines which of the ports are active at any given time and all the variables (bit rate, control signals, and clocks).

This application also manages file storage on the Data Store Disks. It performs general housekeeping functions such as moving files, deleting files, and managing the disk space on the Data Store Disks.