Internet Engineering Task Force (IETF)
Request for Comments: 7528
Category: Informational
ISSN: 2070-1721
P. Higgs
J. Piesing
HbbTV Association
April 2015

A Uniform Resource Name (URN) Namespace

for the Hybrid Broadcast Broadband TV (HbbTV) Association


This document describes a Uniform Resource Name (URN) namespace for the Hybrid Broadcast Broadband TV (HbbTV) Association for naming persistent resources defined within HbbTV specifications. Example resources include technical documents and specifications, Extensible Markup Language (XML) Schemas, classification schemes, XML Document Type Definitions (DTDs), namespaces, style sheets, media assets, and other types of resources produced or managed by HbbTV.

Status of This Memo

This document is not an Internet Standards Track specification; it is published for informational purposes.

This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see Section 2 of RFC 5741.

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  URN Specification for the HbbTV Namespace Identifier (NID)  .   3
   3.  Examples  . . . . . . . . . . . . . . . . . . . . . . . . . .   5
   4.  Namespace Considerations  . . . . . . . . . . . . . . . . . .   5
   5.  Community Considerations  . . . . . . . . . . . . . . . . . .   6
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1. Introduction

HbbTV (Hybrid Broadcast Broadband TV) is a new industry standard providing an open and business-neutral technology platform that seamlessly combines TV services delivered via broadcast with services delivered via broadband and also enables access to Internet-only services for consumers using connected TVs and set-top boxes. The founding members of the HbbTV consortium together with a large group of supporters jointly developed the HbbTV specification to create a global standard for hybrid entertainment services. Version 1.2.1 of this specification was published by ETSI as ETSI TS 102 796 [HbbTV12] in November 2012.

The HbbTV specification is based on existing standards and web technologies including the Open IPTV Forum (OIPF), Consumer Electronics Association (CEA), Digital Video Broadcasting (DVB), and World Wide Web Consortium (W3C). The standard provides the features and functionality required to deliver feature-rich broadcast and Internet services. Utilizing standard Internet technology, it enables rapid application development. It defines minimum requirements simplifying the implementation in devices and leaving room for differentiation; this limits the investment required by consumer electronics manufacturers to build compliant devices. The HbbTV Association is a pan-European initiative aimed at providing an alternative to proprietary technologies and delivering an open platform for broadcasters to deliver value-added on-demand services to the end consumer.

HbbTV has a wide range of supporters from across the broadcaster and consumer electronics industries.

HbbTV would like to assign unique, permanent, location-independent names based on URNs for some resources it produces or manages. These URNs will be constructed according to the URN syntax defined in [RFC2141]. This namespace specification is for a formal namespace to be registered according to the procedures set forth in [RFC3406].

2. URN Specification for the HbbTV Namespace Identifier (NID)

This section provides the information required to register a formal namespace according to the registration procedure defined in [RFC3406]. The URNs conform to the syntax defined in [RFC2141].

Namespace ID:


Registration Information:

      Version:  1
      Date:  2014-08-07

Declared registrant of the namespace:

      Name:          Mr. Peter Macavock
      Title:         Administrator
      Affiliation:   HbbTV Association
      Address:       L'Ancienne-Route 17A, CH-1218 Grand-Saconnex,
      Phone:         + 41 22 717 27 14

Declaration of structure:

URNs assigned by HbbTV will have the following structure based on the organizational structure of the resources specified in the HbbTV specifications:


where the syntax of "<NSS>" is specified in Section 2.2 of the URN Syntax requirements [RFC2141].

The individual URNs will be assigned by HbbTV through the process of development of the HbbTV specifications.

Relevant ancillary documentation:


Identifier uniqueness considerations:

HbbTV will establish unique identifiers as appropriate and will ensure that an assigned string is never reassigned.

Identifier persistence considerations:

HbbTV is committed to maintaining the accessibility and persistence of all resources that are officially assigned URNs by the organization. The registration tables and information will be published and maintained by HbbTV on its web site.

Process of identifier assignment:

The assignment of identifiers is fully controlled and managed by HbbTV.

Process of identifier resolution:

Not applicable; the "hbbtv" namespace is not listed with a Resolution Discovery System.

Rules for Lexical Equivalence:

The "<NSS>" is case-insensitive.

Conformance with URN Syntax:

No special considerations.

Validation mechanism:

None specified. URN assignment will be managed completely and published by HbbTV.



3. Examples

The following example of schemas and classification schemes is taken from the current HbbTV specification [HbbTV12].


The following examples of schemas and classification schemes are under consideration for inclusion in a future version of the HbbTV specification currently under development.


4. Namespace Considerations

A unique formal namespace is required by HbbTV in order to specify how the various existing standards can be linked in order to create a true end-to-end ecosystem for standards-based IPTV deployments and to provide the necessary system-wide resources.

URN assignment procedures:

The individual URNs shall be assigned through the process of development of HbbTV specifications by the Hybrid Broadcast Broadband TV Association. The latest information about HbbTV- defined specifications can always be found at the owner's website at


URN resolution/delegation:

The resolution and delegation shall be determined through the process of development of specifications by the HbbTV Association.

Since the implementations envisaged cover a wide range of devices with quite different access methods and capabilities, no single resolution or delegation mechanism can be referenced in this document.

Type of resources to be identified:

Types of resources to be identified include XML schema definition files, classification schemes, and identification systems defined and published by HbbTV. These resources being identified constitute a metadata system to describe digital multimedia broadcast services or content conveyed as part of such services.

The latest HbbTV-defined specifications can always be found at


5. Community Considerations

URNs defined by HbbTV will be used by implementers of hybrid broadcast/broadband systems, services, products, and applications based on the HbbTV specification. They are an essential component of the open ecosystem that is being facilitated by HbbTV.

HbbTV specifications are developed through a consensus-based process by member organizations representing most aspects of the digital television ecosystem. A full list of HbbTV members can be found at


6. Security Considerations

There are no additional security considerations other than those normally associated with the use and resolution of URNs in general, which are described in [RFC1737], [RFC2141], and [RFC3406].

This document registers a namespace for URNs. HbbTV may assign special meaning to certain of the characters of the Namespace Specific String (NSS) in its specifications. Any security consideration resulting from such assignment is outside the scope of this document.

7. IANA Considerations

This document defines a URN NID registration of "hbbtv". IANA has included it in the "Uniform Resource Names (URN) Namespaces" registry.

8. References

8.1. Normative References

   [RFC1737]  Sollins, K. and L. Masinter, "Functional Requirements for
              Uniform Resource Names", RFC 1737, December 1994,
   [RFC2141]  Moats, R., "URN Syntax", RFC 2141, May 1997,
   [RFC3406]  Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom,
              "Uniform Resource Names (URN) Namespace Definition
              Mechanisms", BCP 66, RFC 3406, October 2002,

8.2. Informative References

   [HbbTV12]  ETSI, "Hybrid Broadcast Broadband TV", ETSI TS 102 796
              v1.2.1, November 2012.

Authors' Addresses

   Paul Higgs
   HbbTV Association
   c/o Ericsson Inc, 6 Concourse Parkway, suite 400
   Atlanta, GA  30328
   United States
   Phone: +1-650-580-1731

Jonathan Piesing
HbbTV Association
c/o TP Vision Belgium - Innovation Site Europe, Technologiepark-Zwijnaarde 19,
9052 Gent

   Phone: +32 484 430 060