September 23, 2011

R&S®AEM100 Emission Multiplexer Featuring New Redundancy Option Increases Availability of ATSC Mobile DTV Emissions


A new redundancy solution for the R&S®AEM100 emission multiplexer allows ATSC Mobile DTV transmitter networks to be better protected against faults and outages. The concept offered by Rohde & Schwarz is unique on the market: A bit-identical signal is applied synchronously to the outputs of two redundant R&S®AEM100 multiplexers. If errors occur on one R&S AEM100, the Mobile DTV data stream is switched interrupt-free to the other multiplexer without the user noticing anything on the mobile receiver.

Network operators can use the R&S®AEM100 multiplexer to expand their existing ATSC transmitter networks to include ATSC Mobile DTV – without a major installation effort. As a key component in mobile digital networks, the R&S®AEM100 feeds the mobile data into the existing ATSC multiplex. A multiplexer for ATSC Mobile DTV is part of the active signal path, for which failsafe, redundant configurations are common. Rohde & Schwarz has enhanced the R&S®AEM100 accordingly with a 1+1 redundancy option.

The new solution ensures that a bit-identical signal is applied synchronously to the outputs of the two multiplexers. A higher-level redundancy controller is not needed: The two multiplexers check each other’s results. The two instruments communicate with each other. If, due to an error, one of the multiplexers does not receive the input signals completely or processes them incorrectly, the error is immediately detected and eliminated. This ensures interrupt-free transmission. Viewers receive their Mobile DTV program without any noticeable effect on transmission quality.