MoCA - Multimedia over Coax Alliance
Technology Overview
The Multimedia over Coax Alliance (MoCA) defines specifications that allow the distribution of multimedia and data over existing coaxial cable infrastructures.
MoCA uses 50 MHz channels in the 850 MHz to 1500 MHz frequency range. Within the physical layer, orthogonal frequency division modulation (OFDM) subcarriers are adaptive-modulated by modulation schemes ranging from binary phase shift keying (BPSK) to 256 quadrature amplitude modulation (256QAM). The medium access control (MAC) layer uses a distributed mesh network architecture with time division multiple access (TDMA) for scheduled access. Both prioritized and parameterized quality of service (QoS) are available in the latest release (MoCA 1.1).
Deployment Scenario
MoCA is especially designed for home entertainment networking applications, where diverse types of data and multimedia streams from different technologies and applications are seamlessly delivered within the home environment over a single common medium. Cable, satellite and telecom operators are expected to benefit from this technology. The first MoCa product was certified in 2006. More than 25 million MoCA nodes had been shipped to date.
Rohde & Schwarz Test Solutions
Rohde & Schwarz test solutions are based on the R&S®FSQ signal analyzer together with the R&S®FSQ-K96 PC software option and the R&S®SMBV signal generator. The R&S®FSQ combines two instruments in one. It offers signal analysis at a demodulation bandwidth of up to 120 MHz and a high-end spectrum analyzer with an outstanding dynamic range. The R&S®FSQ-K96 software expands the R&S®FSQ signal analyzer to include modulation measurements on user-definable OFDM signals, for which a MoCA configuration file is available. The R&S®SMBV can be equipped with an internal baseband generator to allow the generation of a number of digital standards and modulations. The resulting wide frequency range from 9 kHz to 6 GHz covers all essential bands for digital modulation.
Key Parameters
The Multimedia over Coax Alliance (MoCA) defines specifications that allow the distribution of multimedia and data over existing coaxial cable infrastructures.
| MoCA | |
|---|---|
| Frequency | 850 MHz - 1500 MHz |
| Duplex | TDD |
| Modulation |
adaptive constellation multitone (bit-loaded OFDM) each subcarrier modulated from BPSK to 256QAM |
| Channel Bandwidth | 50 MHz |
| Peak Data Rate | approx. 100 Mbps (MoCA 1.0), 175 Mbit/s (MoCA 1.1) |
| Multiple Access | TDMA |
Standardization
All standardization activities are carried out by MoCA. MoCA has been standardized according to MoCA 1.0 (ratified in 2007) and MoCA 1.1 (ratified in 2008). MoCA 2.0 is expected to be ratified by end of 2009.
A related standard, the ITU-T G.hn, aims to be the future universal wired home networking standard worldwide. It will provide an evolution path from today’s wired home networking technologies including MoCA. (there is no evolutionary path as their is no backward compatibility between g.hn and other wired standards including MoCA. MoCA does not endorse g.hn for a variety of reasons.
Standardization forum: www.mocalliance.org
