ESC 07 Fall Preview: Making sense of consumer electronics networking “standards”

Compared to a few years ago, when there were literally a dozendifferent ways – mostly proprietary – for embedded systems developersto add connectivity to their consumer electronics designs, life hasgotten a little simpler. But not necessarily easier.

Standards have emerged. Not just one, though, but a handful: UPnPA/V, HANA, DLNA and a number of others from the World Wide WebConsortium, the IETF, the Consumer Electronics Association. TheUniversal Plug and Play A/V spec and High Definition Audio/VideoNetwork Alliance (HANA) clearly are in the lead. But each of these arerich in complexity as they both rush toward trying to be all things toall CE developers.

In their upcoming class at the Fall ESC titled”Open Standards drive emerging digital homenetworking (ESC-448),” presenters Rich Schmitt of Blue Peachand C.C. Hung of Mentor Graphics go a long way toward sorting out thechoices, differences and alternatives available to developers.

While that alone would put it at the top of any list of classes toattend at the conference, their delineation of a unified approach thatcombines elements of UPnP and HANA makes this particular class a “mustsee.”

Interestingly, they point out, UPnP A/V and HANA are both based onmany of the same underlying technologies, albeit using them insignificantly different ways.

UPnP (Universal Plug 'n Play), said Schmitt, specifies a set of webbased services and protocols for discovery, content location, contentaccess, and device status and control. HANA (High DefinitionAudio/Video Network Alliance), said Hung, is based on more traditionalweb access using XHTML and style sheets that address many of the samerequirements of UPnP.

Both UPnP A/V and HANA each offer a compelling approach for controland distribution of digital content around the home, allowing thecontrolled devices to define their own user interfaces, so that devicescan differentiate and can offer non-standard functions to the consumer.

“UPnP A/V as architected, tends to provide a 'least commondenominator' experience,', said Schmitt. “A control point will belimited by the support it provides as well as the support that the endpoint device provides.”

On the other hand, said Hung, HANA devices depend on a rich displayto interact with the user while UPnP can offer many types of controldevices, including hand-helds, LED screens, and On Screen Displays(OSDs).

With UPnP, the entire home can be controlled from a single devicelocated anywhere, all devices will provide a common experience, and thecontrol device is free to present the information in any form.

Despite significant differences – which Schmidt and Hung describe indetail in their class – the authors suggest that embedded systemsdevelopers of consumer electronics devices can take advantage of thefact that HANA and UPnP A/V are more complimentary to each other thanexclusive.

To do that they suggest the use of a unified model that is similarto the UPnP-only model. All UPnP A/V Services (renderer, A/V Transport,and CDS) would include a HANA Logical Unit (status and control framesserved over HTTP). The UPnP DMC logic is integrated with the HANA TopLevel GUI for device browsing and selection. Underlying technologiessuch as SSDP, DOM-2, HTTP Client and HTTP Server are leveraged by HANA.

“Because of the parallels between the UPnP services and the HANALogical Units (LUs), additional leverage can be gained by integratingthe control interaction,” said Hung. “For instance, the Javascriptprovided by a HANA LU can utilize SOAP so that the HANA browser cancontrol the LU with UPnP transactions. In this way, the controlservicing of the LU can be identical to the UPnP service.”

If such a converged model emerges, they suggest consumer electronicsdevices will move even more rapidly into a new age of computing interms of how digital content such as data, voice, audio and video canbe transferred and shared between devices.

Other related wired and wireless connectivity classes on the agendaat the ESC 07 Boston conference include ExtremeWireless Networking (ESC-108] taught by Larry Mittag, Implementingan 802.11 b/g interface into an embedded design (ESC-228) presentedby Gary Marrs, USBfor embedded systems (ESC-248) from Christian Legare, and Bluetoothand ultrawideband work together (ESC-468) by Brian Senese.

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