The R&S AEM100 multiplexer from Rohde & Schwarz enables network operators to expand their existing ATSC transmitter networks for ATSC Mobile TV quickly and reliably, according to the company (see the figure, below). R&S also says that the R&S AEM100 is the only multiplexer on the market that allows operators to leverage their existing network infrastructure.

The multiplexer can be integrated into the operator’s system and is compatible with all commercially available transmitters. The new standard, which Rohde & Schwarz played a major role in developing, makes it possible to set up frequency-efficient single-frequency networks (SFNs) that can be easily implemented using transmitters from the company.

Rohde & Schwarz already offers a complete product portfolio for the ATSC Mobile DTV standard, which will be adopted by the end of the year. In addition to the main ATSC transport stream, ATSC Mobile DTV transmits video and audio data for mobile receivers. As a key component for handling ATSC Mobile DTV, the R&S AEM100 inserts the mobile data into the existing ATSC multiplex.

A special error-protection technique ensures interference-free reception on the mobile user equipment. Using complex error-correction algorithms (Reed-Solomon and turbo codes), the R&S AEM100 creates this protection and generates the required robust transport stream, which is output via a standard asynchronous serial interface (ASI) or via Ethernet. The Ethernet interface allows network operators to use a conventional IP infrastructure for signal distribution, so no additional costs are incurred.

The R&S AEM100 includes all of the required functions for ATSC Mobile DTV. ATSC network operators can upgrade their equipment to this new standard quickly and easily, Rohde & Schwarz says, by inserting the multiplexer into the existing system between the ATSC headend and transmitter. The customer’s ATSC headend and its components do not have to be replaced. 

Also, the R&S AEM100 comes with the SFN function already integrated. This function, which can be optionally activated, makes it possible to simultaneously supply the ATSC Mobile DTV transport stream from the multiplexer to several transmitters. This enables simultaneous transmission on the same frequency in SFNs, increasing the range for network operators and covering more viewers without needing to apply for additional frequencies.

The complete ATSC Mobile DTV functionality can be configured, controlled, and monitored using a Web browser locally or remotely. All commands for automatic monitoring and for the instrument settings are available over a Simple Network Management Protocol (SNMP) interface.

The R&S AEM100, consisting of the R&S AEM100BU base unit and the R&S AEM100I IP encapsulator, is now available. Designers can pair it with the R&S AVE264 encoder for coding the audio/video data stream and the R&S AVP264 multiplex manager, which uses statistical methods for better utilization of channel capacity, to transmit up to 40% more programs, the company says.

Rohde & Schwarz