Despite years of development and disappointment, interactive television could be closer to deployment across cable systems in the United States. At least that’s the plan. The Open Cable Application Platform was a hot topic at The Cable Show in Las Vegas. American Cable operators Comcast, Time Warner and Cox appear to be ready to roll out support for OCAP but they are still looking for compelling applications for interactive television.

The hope is that a common application programming interface will be able to span the separate service providers and disparate set-top boxes that constitute the current cable television landscape in the United States.

The major cable operators have previously pledged their commitment to deploying a standard middleware platform but they remain pre-occupied by their legacy problems of tens of millions of set-top boxes, largely based on incompatible systems from Motorola and Scientific Atlanta.

Comcast, the largest of the cable operators, has trials underway in several markets and says that the majority of its systems will have OCAP installed in 2008.

Time Warner Cable claims that its Scientific Atlanta based boxes, which make up the majority of its systems, will be OCAP ready within months. In its Motorola systems, the operator is planning to build a bridge between its legacy and OCAP boxes using Open TV middleware.

Cox has been a proponent of OnRamp, a subset of Java interfaces that supports applications that should be transferable to OCAP. Cox expects to support OnRamp in its Scientific Atlanta based markets by the end of 2007, extending to Motorola systems in 2008.

Zodiac Interactive is a backing the approach with its PowerRamp platform. This provides a downloadable Java virtual machine designed for limited legacy set-top boxes. With a modest memory requirement, Zodiac claims that PowerRamp can deliver three times better performance than other generally available set-top box implementations of Java. The idea is to provide a viable migration path to OCAP over time.

Having defined the CableLabs standard and committed to its deployment, the cable operators say they are still seeking compelling applications that will run reliably across all set-top boxes. Among their aspirations are so-called bound applications that enhance particular programmes, and propositions that link the video, voice and data components of their triple-play bundles.

For their part, programming executives claim that cable operators have been slow in deploying a standardised platform for interactive television.

Neither party apparently appreciates the practical operational issues involved in deploying interactive television services. A common application platform may be necessary, but it is not sufficient. Developing an application that will run across multiple set-top boxes is a challenge in itself, but delivering it nationally in conjunction with a particular channel or programme still appears to be an almost intractable problem in the United States.

Interactive television has been so long in coming to America while the world has moved on. It is video-on-demand that has been making all the running, while IPTV and broadband video have been attracting all the attention.

Nevertheless, there appears to be increasing industry support for OCAP. Both Motorola and Scientific Atlanta are planning to provide support for the platform.

Motorola is bringing out an OCAP simulator and software development kit. Running on Windows, it enables cable operators and developers to test applications without the need for a full cable head end.

Scientific Atlanta, now part of Cisco, has also announced an OCAP developer programme in conjunction with itaas, an interactive television services company.

OCAP is based on MHP, the Multimedia Home Platform standard originally developed in Europe for interactive television. There has been patchy adoption of MHP in Europe, which has otherwise led innovation in interactive television. Commitments to existing platforms, combined with concerns over patent royalties, have suppressed enthusiasm for the standard.

The real irony may be that if America finally lines up behind OCAP, Europe may be left lagging behind. Adoption of MHP, which is fundamentally compatible with OCAP, would provide a common platform for portable applications with a wider market for development tools.

At least there is a debate in the States, while Europe seems resigned to a patchwork of open and proprietary standards. Assuming that OCAP actually takes off in America, it could be time to re-appraise approaches to platform compatibility.