Norpak - TES3/NABTS

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EIA516 NABTS MODULE

NABTS Data Broadcast Software for Norpak Encoder Platforms

OVERVIEW

The EIA516 NABTS Module is a software module for the Norpak TES family of TV Data Encoder platforms. The module accepts an incoming data stream, encodes and inserts it into any of the world’s standard TV signals. One of the unique features of the NABTS Module is that both 525 and 625 line TV systems are supported. Multiple data streams can be efficiently multiplexed by the Encoder onto the VBI of a single television signal. Norpak’s Encoders have two configurations. The serial version allows up to four data broadcast modules while the LAN version supports up to eight modules. A single NABTS Module is capable of data rates up to 268.8 Kbps.

Standards Compliant

NABTS/IETF/ATVEF Industry Standards: The EIA 516 NABTS Module is fully compliant with the established open North American Basic Teletext Specification (EIA516) and international standard (CCIR653 System C) for transmission of data on the TV signal. The module functions in NTSC, PAL, SECAM, 525 and 625 line TV systems. This format, along with the Norpak FEC, form the basis of the Internet Engineering Task Force (IETF) "IP over VBI" standard. This standard is also in use by the Advanced TV Enhancement Forum (ATVEF).

High Speed Data Broadcast

High Data Rates: The NABTS module will encode and insert a digital data stream at speeds up to 268.8 Kbps using up to 16 lines. TES encoders can be cascaded together, in blocks of 16 lines, to use the entire TV picture area.

Flexible and Convenient

Multiple Modes of Operation: The module provides flexibility to optimize forward error correction (FEC) and data transmission rate to suit specific application needs and reception site hardware capabilities.
Data Formatting: The NABTS module will implement all FEC, packet addressing and other NABTS formatting so a host PC is not burdened with special processing.
Individually Selectable VBI Lines: Each module can be enabled for all, or any subset, of any block of 16 video lines (eg. 10-25 for the VBI) for maximum configuration flexibility. Individual fields and frames are also selectable.
Waveform Control: the user in non-standard video environments can control amplitude and start-time of the teletext waveform.
Built-in Test Facility: Bit Error Rates (BER) statistics can be gathered for both raw (uncorrected) and FEC processed data to test new installations.
Bandwidth Control: The software provides comprehensive and flexible control mechanisms for allocating bandwidth to each module.

Private, Secure and Reliable

Built-in Error Correction (FEC): Two levels of built-in, sophisticated forward error correction guarantee maximum data integrity. The Norpak FEC is now an open standard and part of the IETF standards.
Flow Control: The module manages an incoming data stream utilizing a large buffer and XOFF/XON, hardware protocol flow control or TCP/IP flow control.

Operation

Each module accepts a data stream from a data source, converts it to NABTS packet format, adds FEC protection and inserts it in the television VBI. The TES encoder adds the primary level of addressing (packet address) according to the encoder set-up.

This computer data source can either be co-located with the encoder at, for example, the broadcast site or remotely located. Up to eight (LAN version) data streams representing different applications, services or organizations, can be handled simultaneously on a single TES encoder using multiple NABTS software modules. The NABTS software module can run concurrently (in the same encoder) with software modules of other types such as EIA 608 Captioning or WST.

In multiple data stream applications, where peak data transmission needs may exceed instantaneous available bandwidth, priority is pre-defined by the module settings. Low priority data streams are buffered until bandwidth becomes available. Flow control prevents the buffer from overflowing.

The TES encoder can be configured for insertion in any block of 16 video lines (eg. 10-25 for the VBI). In basic NABTS format, each video line has the capacity to accept data at the rate of 16,800 bps. If one of the built-in Norpak forward error correction modes is implemented, it does not affect the data throughput, but it will lower the capacity per line. The mode and options are selected according to the specific application needs including the reception site device and the level of forward error correction required.

Data Rate per VBI Line


Number of Lines	28 Byte	27 Byte	Norpak	Norpak
	No FEC	No FEC	Packet FEC	Bundle FEC
1	16,800	16,200	15,600	13,650
2	33,600	32,400	31,200	27,300
3	50,400	48,600	46,800	40,950
4	67,200	64,800	62,400	54,600
5	84,000	81,000	78,000	68,250
6	100,800	97,200	93,600	81,900
7	117,600	113,400	109,200	95,550
8	134,400	129,600	124,800	109,200
9	151,200	145,800	140,400	122,850
10	168,000	162,000	156,000	136,500
11	184,800	178,200	171,600	150,150
12	201,600	194,400	187,200	163,800
13	218,400	210,600	202,800	177,450
14	235,200	226,800	218,400	191,100
15	252,000	243,000	234,000	204,750
16	268,800	259,200	249,600	218,400

Data Modes & Lines Required

Transparent Modes: Data is received from a source computer in 27, 28, 30 or 33-byte blocks of data. Data in either the 30-Byte or 33-Byte Transparent Mode must be in a NABTS compliant format before being sent to the Encoder. The transparent modes are usually only implemented when using customer specific system level application software.
8-Bit FEC Modes: Data to be transmitted must be 8-bit data (or 7-bit with parity). The data can be sent in asynchronous serial format or using Norpak system-level application software. The Encoder adds two bytes of redundant FEC data to every 26 bytes of data to form a 28 byte packet. The 8-Bit "Packet FEC" Mode corrects a single bit error in a packet. The 8-Bit "Bundle FEC" Mode (IETF standard) goes further. In this mode, the 28-byte packet is used and for every 14 packets of data, 2 redundant packets are added to form a bundle. More single bit errors are corrected, and up to two damaged packets per bundle are corrected.

Company Profile

Norpak Corporation is the leading supplier of TV data solutions including Interactive TV and metadata with over 28 years of experience and 6,000 headends in 42 countries. Norpak is the only supplier of a complete line of TV data broadcast products, with analog, serial digital, HD and MPEG2 encoders, bridges and receivers supporting all world data standards. Its data monitoring, filtering and substitution products provide broadcasters a full line of multistandard data solutions. Norpak�s products and technology have been adopted worldwide for use by major TV broadcasters, cable TV system operators, content creators, systems integrators, value-added service providers and OEM equipment suppliers.

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