DVB-CI2 USB (Second Generation Common Interface) - Universal Serial Bus
Second Generation Common Interface; Implementation Using the Universal Serial Bus (USB)
The DVB Common Interface (DVB-CI) specifications CENELEC EN 50221 and ETSI TS 101 699 describe a system whereby a removable Conditional Access CICAM, given the appropriate rights, unscrambles protected content and routes it back to the Host over the same interface. These DVB Common Interface specifications were extended by the CI Plus specification, developed by CI Plus™ LLP, which provides common methods (i.e. methods that are independent of the up-stream CA system) for mutual authentication of the CICAM and Host, and link encryption over the return interface from the CICAM to the Host. The first generation Common Interface connector was an industry standard PCMCIA slot. The connector for the second generation Common Interface as described in the present document is an industry standard USB Standard-A connector USB 2.0 and USB 3.2.
The first generation DVB-CI system defined two interfaces between the CICAM and the Host: a command interface, and a Transport Stream interface.
The USB makes use of so-called endpoints for all data transfers. Generally, these endpoints are uni-directional (i.e. they can either send or receive data, but not both). The only exception is the special, bi-directional endpoint zero which is used for discovery and control of USB devices. The present document makes use of USB endpoint zero and of six further USB endpoints in each device. Since USB endpoints are implemented in the hardware of USB chipsets, they are a scarce resource and keeping their number to a minimum is important.
The present document defines USB physical, link and transport layers for the DVB Common Interface to replace the PC Card interface defined in CENELEC EN 50221 . The present document also profiles and extends the application layer defined in CENELEC EN 50221, ETSI TS 101 699 and CI Plus specification to cater for the use over USB.