Models: DVS 4010

Features

· SFN time and frequency synchronization
· Serial ASI selectable inputs and outputs
· Bit rates adjusted with transmission mode
· Rear panel monitoring points for TS output and sync output
· Supports HP or LP streams for hierarchical mode

Overview

For the operation of digital terrestrial TV networks, DVB-T and/or DVB-H, where several transmitters broadcast the same programs on the same channel frequencies - Single Frequency Networks - the transmitters require precise time and frequency synchronization.
The UBS DVS 4010 SFN Adapter fulfils the task of inserting “synchronization marks” in a DVB transport stream (MIP insertion) in full accordance with DVB-T / DVB-H standards.

The basic functions performed by the DVS 4010 SFN adapter are:

· Inserts a megaframe initialization packet (MIP) into an MPEG transport stream
· Adjusts the bitrate of the transport stream to be synchronous with an external reference
and in accordance with the chosen COFDM transmission mode
· Provides signaling/mode data for the control of individual transmitter modulators

MIP insertion

The MIP insertion occurs once per megaframe, with a time interval dependent on the chosen guard band. The MIP indicates the start of the transmission of the first packet in a mega-frame (Synchronization Time Stamp, STS). The time reference is an external 1 pulse per second signal, easily available from a GPS.

Bitrate Adaptation

The DVS 4010 is provided with two serial (ASI) inputs. The input circuits accept an MPEG transport stream according to the DVB recommendations (188 or 204 byte packets). The output may also be configured as either 188 or 204 byte packets. The maximum net allowable bitrate is governed by the intended transmission mode, ref. DVB-T standard EN 300 744. As the transport rate is modified, the SFN adaptor performs PCR restamping.

Control

The operation of the DVS 4010 is controlled either locally, with a display and push-buttons, or remotely, using the serial RS232 and/or RS485 ports. An Ethernet (10/100 BaseT) interface is also available.