By Allen R. Schmitt-Gordon, Ph.D. and Frank Sandoval, Cable Television Laboratories, Inc.
The OpenCable Application Platform (OCAPTM) is a software middleware layer that resides functionally on top of the operating system of an OpenCableTM terminal. It provides an interface and enables application portability. A fundamental requirement is that applications written for OCAP be capable of running on any OpenCable hardware, without recompilation. Two profiles of OCAP have been identified. OCAP 1.0 is a minimal platform that supports procedural applications with an Execution Engine (EE). OCAP 2.0 is a super set of OCAP 1.0, and includes support for declarative content with the inclusion of a Presentation Engine (PE), that supports HTML, XML, ECMAScript, and a bridge between the PE and the EE. The bridge enables PE applications to obtain privileges and directly perform EE operations. OCAP 1.0 has been publically released, OCAP 2.0 is scheduled for around 1Q02. CableLabs plans to draft a family of OCAP specifications, each being backward compatible and defining different feature sets. The OCAP specifications are based upon the DVB MHP specifications with modifications for the North American Cable environment that includes a full time return channel. OCAP 1.0 corresponds to MHP 1.0.2, and OCAP 2.0 will correspond to MHP 1.1.