Interview: MHL's Dr. Judy Chen Discusses The MHL 3.0 Specification

Sept. 16, 2013

MHL announced its latest MHL 3.0 specification to address the latest consumer trends for connecting a mobile device to displays over MHL (mobile high-definition link). Technology Editor talks with the MHL Consortium's President, Dr. Judy Chen.

Judy Chen, Ph. D

The MHL (mobile high-definition link) is a way to connect devices like smartphones and tablets to high-definition displays. MHL connections can be found on a number of devices and displays. The latest specification, MHL 3.0, from the MHL Consortium can handle the emerging 4K displays.

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To find out about the latest specification, I talked with the MHL Consortium's President, Dr. Judy Chen.

Wong: Please briefly tell us about the MHL 3.0 specification.

Chen: On August 20, MHL announced its latest MHL 3.0 specification to address the latest consumer trends for connecting a mobile device to displays, marking major advancements in the areas of audio and video transmission over an MHL link. With double the bandwidth compared to the previous specification, MHL 3.0 delivers 4K (Ultra HD) resolution and a wider color gamut to create a more brilliant visual experience, solidifying MHL’s growing presence in the living room.

Wong: What’s new with MHL 3.0 versus previous specifications?

Chen: All of the features listed below are new or enhanced features:

4K (Ultra HD): Support of 4K formats up to 2160p30
Simultaneous high-speed data channel
Improved Remote Control Protocol (RCP) with support for peripherals such as a touch screen, keyboard and mouse
Power charging up to 10W
Backward compatible with MHL 1 and MHL 2
Latest HDCP 2.2 content protection
Enhanced 7.1 surround sound with Dolby Tried and DTS-HD
Support for simultaneous multiple displays
Connector agnostic – uses as few as five pins

Wong: How does your technology work over just five pins?

Chen: Two of the five pins provide charging supply and ground. The charging pin Voltage Bus (VBUS) provides up to 10W of power in MHL 3.0 to charge an MHL source, for example a smartphone or tablet.

One of the key innovations of MHL is that it uses only a pair of pins to carry video, audio content along with the pixel clock using TMDS. Before transmission to the physical pins, the signals are encrypted with HDCP protocol.

The last but not least, one pin is dedicated to transport bi-directional data which includes EDID, HDCP synchronization, reading and writing register settings and sharing device capabilities

Wong: When do you expect the first products to come out with MHL 3.0?

Chen: Release dates are completely up to each manufacturer’s product life cycle but our expectation is that products will appear some time in 2014.

Wong: You mentioned that MHL 3.0 can support multiple monitors, how do you do that?

Chen: Yes, we support multiple monitors, which is new to our specification. A single MHL 3.0 link can support multiple video streams and those independent streams that can be split out to multiple displays (including MHL) via an accessory such as a dock or a dongle.

Wong: Can I use my existing MHL products with MHL 3.0 products once they arrive?

Chen: Yes, all MHL 3.0 devices will be backward compatible to devices supporting the MHL 2.x and MHL 1.x specification.

About the Author

Judy Chen, Ph. D | President

As president of the MHL Consortium, Dr. Judy Chen is charged with the general management of the Consortium and its ongoing efforts in licensing and promotion of the MHL standard. With more than 15 years of experience in high-technology markets, Chen brings a proven track record of promoting and furthering adoption of mobile and wireless technology standards.

Prior to her appointment as president, Chen served as the senior director of marketing and business development for the Consortium, where she was responsible for raising awareness of the MHL standard across the Consortium’s broad ecosystem of retailers, application developers and mobile device carriers. Under her leadership, the MHL Consortium now was more than 200 adopters and an installed base of more than 330 million products.

Chen’s previous appointments include director of strategic marketing at Rambus, Inc., and senior product line manager and strategic marketing manager at Intel, Inc.

Judy Chen holds a bachelor’s of science, master’s of science and a doctorate in electrical engineering from the Massachusetts Institute of Technology.