RFDVB-S vs DVB-S2: Key Differences Explained
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This page compares DVB-S and DVB-S2, highlighting the similarities and differences between these two digital video broadcasting technologies.
Introduction
Both DVB-S and DVB-S2 are standards used in the digital television industry for digital video broadcasting. DVB-S was initially introduced in 1995 and modified until 1997.
DVB-S Evolution Timeline
DVB-S
The DVB-S standard was developed by ETSI and is documented in EN 300 421. It defines the frame format, channel coding, and modulation for 11/12 GHz services. The DVB-S system takes input from an MPEG-2 transport multiplexer and converts the signal to comply with satellite channel characteristics.
The satellite channel adapter includes an RS outer code and a convolutional inner code, in addition to convolutional interleaving, baseband shaping, and a QPSK modulator.
DVB-S Block Diagram
Figure 2 depicts the DVB-S block diagram with the blocks mentioned above. It supports SCPC and MCPC modes. DVB-S is directly compatible with MPEG-2 coded TV signals. The modem transmission frame is synchronous with MPEG-2 multiplex transport packets.
DVB-S2
DVB-S2 is the successor to the DVB-S version. The specifications are documented in ETSI EN 302 307. It takes direct input from one or many MPEG-2 TS streams. It is backward compatible with DVB-S (used for end users) and DVB-DSNG (used for backhauls and electronic news gathering).
Common use cases of DVB-S2 include television broadcasting services (SDTV, HDTV), interactive services, data transmission by cable, satellite uplink, mobile wireless, data multiplexing in real-time, transmission in the VHF/UHF band, and large-scale data content distribution.
The table below compares various physical layer parameters and system parameters of DVB-S2 versus DVB-S. The major benefits of DVB-S2 are as follows:
- DVB-S2 offers 2 to 2.5 dB better FEC performance compared to DVB-S.
- It offers 30% higher spectral efficiency compared to DVB-S.
- It offers increased data throughput or bit rate in a given bandwidth.
Difference between DVB-S and DVB-S2
The following table summarizes the differences between DVB-S and DVB-S2.
| Features | DVB-S | DVB-S2 |
|---|---|---|
| Input interface | Single TS (Transport Stream) | Multiple TS and GSE (Generic Stream Encapsulation) |
| Modes | CCM/ VCM/ ACM | CCM (Constant Coding and Modulation) VCM (Variable Coding & Modulation) / ACM (Adaptive Coding & Modulation) (for IP data) |
| FEC techniques | Reed Solomon coding with different rates | LDPC and BCH with different rates from 0.25 to 0.9 |
| Modulation | BPSK, QPSK | QPSK, 8PSK, 16APSK, 32 APSK |
| Interleaving | Bit interleaving | Bit interleaving |
| Pilots | Not applicable | Pilot symbols are used |
| Spectral efficiency (Max.) | 1.61 | 4.44 |
| Block size | ~ 32 Kbit | 16 Kbit, 64 Kbit |
| Roll off | 0.35 | 0.20, 0.25, 0.35 |
| Implementation complexity | Low | Very high |
| Stream adaptation | MPEG | MPEG and programmable |
| Symbol rate | 27.5 Mbauds (ROF 0.35) | 30.9 Mbauds (ROF 0.20) |
| Bit rate | 33.8 Mbps | 46 Mbps (+36%) |
| Channels | 7 SDTV MPEG2, 15 SDTV h.264, 1 HD MPEG2. 3 HD h.264 | 10 SDTV MPEG2, 21 SDTV h.264, 2 HD MPEG2. 5 HD h.264 |
