A common piece of middleware, which grew out of the CableLabs OpenCable process as a way to make interactive TV applications as portable as the devices they run on.

Put another way, OCAP is a software layer that resides above an incumbent operating system, and below any applications, such as electronic program guides, on-demand wares, or clickable items that come along with a specific TV program.

OCAP requires an 8×16 memory footprint (8 Megabytes of flash memory, 16 Megabytes of dynamic random access memory, or DRAM). In processing power, it requires at least a 130 MHz processor (the faster, the better).

OCAP 1.0, the first version of the specification, includes three main parts. First is the Java Virtual Machine, or JVM. Its role is to “unfold and run” interactive applications; technologists often call this “the executable engine.”

Second is a set of Java “packages,” which is Java-speak for the software modules that enable application program interfaces, or APIs. APIs are the programming calls available to developers when making interactive applications.

Third, OCAP 1.0 needs a mechanism for applying business policies, such as via a “monitor app” (see definition). A monitor application handles resource allocation, such as software downloads and overall applications management.

In 2008, OCAP was re-branded to “Tru2way,” for consumer devices, like HDTVs, with OCAP inside. The body of technical specifications that is OCAP will remain under the OCAP name; anything consumer-facing but reliant on OCAP is now called “tru2way.”

The device in a hybrid fiber/coax network that converts lightwave signals, traveling on optical fibers, back into radio frequency signals for the final ride over coaxial cable, to homes and businesses. Also known as an “optical node.” In general, the closer the ONU/node is to the home, the higher the reliability, and speeds delivered, in terms of data communications. ONUs are also used in telco/DSL networks, to advance fiber deeper toward homes.

The group within CableLabs, and shepherded by CableLabs’ member cable companies, responsible for advanced digital set-top box technology, policy and process. Begun in 1997, OpenCables aim is to produce “an ongoing set of interface specifications that define the next generation of digital cable television set-top boxes, and other digital devices to be deployed by cable operators in North America,” according to the groups published charter.

Key to these interface specifications was the definition of a removable security module, which was the basis for making the devices fully portable from one cable system to another regardless of the network operator. This milestone — and federal mandate — was met by its deadline of July, 2000.

In addition to crafting the interface specifications, OpenCable also oversees the processes and facilities necessary to test and certify the interoperability of OpenCable devices. Web site: www.opencable.com

A suite of software that instructs silicon hardware how to communicate with other chips, and corresponding applications. In cable broadband lexicon, operating systems almost always correlate with digital set-top boxes. (Operating systems weren’t required in analog set-tops, because those units didn’t contain many applications that couldn’t be handled solely at the component level).

The easiest way to visualize what a set-top operating system does is to consider the PC operating system — such as Microsoft Windows, Unix, and MacOS. PC operating systems do the heavy lifting across several fronts, including the control of: the CPU chip, the movement of data to and from hard disks, printers, floppy disks, and other peripheral devices; memory usage, and file systems/data storage.

Because digital set-tops generally don’t contain the firepower of a standalone PC, the set-top operating system, by necessity, must run lean. The hardware components lining the inside of the digital set-top box, such as CPU and memory chips, are smaller and slower than in PCs. All things managed by the set-top OS must be capable of happening in real time, and without delays of more than a few nanoseconds — otherwise, the TV viewer will likely become disengaged and resentful. (Imagine your reaction if channel up/down took seconds to complete.)

Notably, however, cable providers are increasingly specifying “middleware” software, such as OCAP (OpenCable Applications Platform) which runs on top of a set-top operating system, to manage a widening list of interactive applications. This is primarily because cable providers were and are wary of ceding too much applications control to the operating system provider community.

An umbrella term that covers the devices and technologies used to distribute broadband communications (voice, video and data) from a laser transmitter launch point, through fiber optic cable, to companion receivers.

Usage: Most of the first upgrade was about adding opto-electronics into the system, for reliability and segmentation.

A seven-layer chart that is as entwined with the world of data communications as the alphabet is to language. “OSI” stands for “Open Systems Interconnect,” developed by the International Standards Organization (ISO). The seven layers define how different types of data interact with other types of data. The ultimate goal of OSI is that any vendors data system, connected to any network, can share information with any other suppliers system. In that sense, the OSI stack is a sort of recipe for interoperability.

Cable first dipped its toes into the world of OSI stacks when it, through CableLabs and DOCSIS, established an interoperable cable modem specification. So far, cable broadband generally sticks to the bottom two layers — Physical link and Data link. The layers, best visualized to correspond with the children’s jingle “the neck bone’s connected to the backbone” (because one layer doesnt exist well without the others,) are described below:

7 (top layer): Application: Defines common applications and how to link them, over a system, to a user.

6: Presentation: Establishes a common syntax between applications, so that apps can run independently, but in a coordinated fashion.

5: Session: Describes the control structure for intra-application communications (how an application talks to another application, like the billing interface). Defines how cooperating applications establish, manage and end communication.

4: Transport: Describes how to reliably transfer information from one end point to another, while describing end-to-end error recovery and flow control.

3: Network: Establishes how to switch and route packets; describes how to establish, maintain and terminate connections.

2: Data Link: Defines how information is reliably transferred over the physical link (wires), and describes how chunks of data (known as “frames”) should be synchronized, how transmission errors are controlled, and how data flows.

1: Physical: Defines how bits move over physical media (wires), and organizes mechanical, electrical, functional and procedural characteristics inherent to those wires.

A tried-and-true signal method between set-tops and headend equipment. Setting up a work session, for example, between a set-top and server requires two things: Bi-directional (two-way) plant, and a way to use it. One method is the “out of band” path, in use for over two decades; another is the “in-band” path. Whats “out” in the out of band path is its spectral location, which is unrelated to the frequencies that carry video. Nor is the out of band channel correlated to any specific channel. The out-of-band path dates back to analog, addressable converters, when it was devised as a control channel. Mostly, the out-of-band passageway shuttles the secrets of scrambled channels, delivers software updates, and couriers electronic program guide data to the box.