ST Engineering iDirect’s Mx-DMA® is a patented, efficient and dynamic multiple- access waveform which enables service providers to share satellite capacity more efficiently over a group of satellite terminals.
The Mx-DMA return technology adjusts the frequency plan, the symbol rate, the modulation, coding and power in real-time for every terminal in the satellite network. These adjustments are based on the return traffic demand, the network Quality of Service (QoS) management and channel conditions for the terminal population in the network.
Within the Mx-DMA return link, each carrier is assigned to only one terminal, achieving SCPC- like maximum return efficiencies. At the same time, the flexibility of MF-TDMA can be maintained as Mx-DMA allocates bandwidth based on real-time demand from each terminals and QoS profiles. In other words, as the traffic demand for a remote terminal changes, bandwidth will be allocated on the fly. If the traffic within the terminal becomes more important, extra bandwidth will be assigned to the carrier assigned to the terminal based on QoS and priority rules. The entire allocation operation is performed seamlessly without any data packets being lost.
Mx-DMA leverages the highly efficient coding technique called HRC (High Resolution Coding) making it particularly well suited for low-to-medium rate applications between 32 kbps and 70 Mbps (20Msps). HRC provides a level of efficiency comparable to DVB-S2 with a 5% roll-off factor in order to get as many bits through the available bandwidth as possible. In contrast to DVB-S2, the HRC coding also handles low throughput speeds in SCPC mode without the harmful latency effects that could hamper voice traffic or video streaming services. HRC optimizes low-to-medium rate traffic and avoids latency over satellite by using short block codes. With the new Dialog Release 2.3 HRC will extend the maximum carrier size of MxDMA from currently 20Msps to 68Msps allowing up to 200 Mbps on the return for a terminal.