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Internet Engineering Task Force (IETF)                       C. IshikawaRequest for Comments: 6588                 YRP Ubiquitous Networking LabCategory: Informational                                       April 2012ISSN: 2070-1721A URN Namespace for ucodeAbstract   This document describes a Uniform Resource Name (URN) namespace for   ucode, an identifier system for objects and places.  ucode technology   is used in many applications, and this document provides a URN   namespace for ucode to enable its use in Internet-related devices and   software.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; seeSection 2 of RFC 5741.   Information about the current status of this document, any errata,   and how to provide feedback on it may be obtained athttp://www.rfc-editor.org/info/rfc6588.Copyright Notice   Copyright (c) 2012 IETF Trust and the persons identified as the   document authors.  All rights reserved.   This document is subject toBCP 78 and the IETF Trust's Legal   Provisions Relating to IETF Documents   (http://trustee.ietf.org/license-info) in effect on the date of   publication of this document.  Please review these documents   carefully, as they describe your rights and restrictions with respect   to this document.  Code Components extracted from this document must   include Simplified BSD License text as described in Section 4.e of   the Trust Legal Provisions and are provided without warranty as   described in the Simplified BSD License.Ishikawa                      Informational                     [Page 1]

RFC 6588                 URN Namespace for ucode              April 20121.  Introduction   ucode [UCODE] is an identifier to be stored in many types of tags   (not limited to Radio Frequency Identification (RFID) tags).  Its   allocation and management is handled by the Ubiquitous ID Center   [UIDC].  The embedding of ucode in many types of tags (RFID tags,   optical code, infrared markers, and even sound source) is also   specified by the Ubiquitous ID Center.   The basic length of ucode is 128 bits, but it is extensible in units   of 128 bits if necessary.   ucode has been devised to identify objects and places where existing   standards do not fit the application needs or the scope of the   applications or where the allocation policy of existing standards is   too limited for Small and Medium Enterprises (SMEs), small-scale   research laboratories at academic institutions, or individual users.   Applications that use ucode take advantage of the Internet   extensively.  Use of ucode is open to anybody.  Those who wish to   have ucode allocated can do so either by having ucode subspace   allocated to them directly from the Ubiquitous ID Center [UIDC] or by   obtaining tags that have pre-stored ucode from so called "providers"   [UCDMIP].  Such tags are certified as ucode tags [UIDTAG], and the   reader specifications are published so that there will be many   readers available for such tags.   By having a URN for ucode, we can facilitate the use of ucode in many   Internet-related devices and software for the benefit of existing and   future users of ucode and people who will access such tags attached   to objects and places.  Since an application based on ucode can run   across organizational boundaries and spread across regions and   countries, a formal URN Namespace Identifier (NID) assignment for   'ucode' is requested.2.  'ucode' Registration Template   Namespace ID:   'ucode' requested   Registration Information:   Registration Version Number: 1   Registration Date: 2011-12-21Ishikawa                      Informational                     [Page 2]

RFC 6588                 URN Namespace for ucode              April 2012   Declared registrant of the namespace:   T-Engine Forum   2-20-1, Nishi-Gotanda   Shinagawa, Tokyo, 141-0031   Japan   office@t-engine.org   Tel: +81-3-5437-0572   Declaration of syntactic structure:   The structure of the namespace for 'ucode' using the hexadecimal   representation of the identifier is as follows using ABNF [RFC5234].   UCODE-URN = "urn:ucode:" ucode-name   ucode-name = "_" ucode-number   ucode-number = 1*ucode-value   ucode-value = 32HEXDIG   HEXDIG         =  DIGIT / "A" / "B" / "C" / "D" / "E" / "F"   DIGIT          =  %x30-39                  ; 0-9   NOTE 1:  "1*" at the start of the ucode-number definition is not a   typo.  Although the currently used ucode [UCODE] is 128 bits (16   octets), thus requiring 32 hexadecimal characters to represent   serially, ucode is designed to be extensible in increments of 128   bits.  So, in the distant future, we may need to repeat the chunks of   128 bits.  This is why "1*" precedes ucode-value.   NOTE 2:  ucode-name starts with a "_" because it is also intended to   be used as an identifier for XML [W3CXML].  Because an XML tag can't   start with a digit, an "_" (underscore) is inserted at the beginning   to make sure ucode-name starts with a non-digit.  For example, the   128-bit ucode value 0123456789ABCDEF0123456789ABCDEF, expressed in a   series of hexadecimal digits, is as follows:   urn:ucode:_0123456789ABCDEF0123456789ABCDEF   Relevant ancillary documentation:   ucode, the identifier expressed by ucode-number, is managed by the   Ubiquitous ID Center [UIDC], which is a sub-organization of the   T-Engine Forum [TEF].  The document "Ubiquitous Code: ucode" [UCODE]   defines this identifier system.Ishikawa                      Informational                     [Page 3]

RFC 6588                 URN Namespace for ucode              April 2012   Identifier uniqueness considerations:   The 'ucode' namespace is managed by the Ubiquitous ID Center.  The   Ubiquitous ID Center assigns the identifier, ucode, in such a way   that the uniqueness of the 'ucode' namespace will be maintained.   Identifier persistence considerations:   The assignment process guarantees that names are not reassigned and   that the binding between the name and its resource is permanent,   regardless of any standards or organizational changes or the   assignment period.   Process of identifier assignment:   Names are assigned by the Ubiquitous ID Center and by any entities   that are sub-delegated by the Ubiquitous ID Center.  This assignment   process is based on "ucode Management Implementing Procedures"   [UCDMIP] established by the Ubiquitous ID Center.   Process of identifier resolution:   The process of identifier resolution is currently based on the "ucode   Resolution Protocol" [UCSURP].  It will be enhanced by using newer   recommendations from ITU-T and/or standards from ISO.   Rules for lexical equivalence:   The entire UCODE-URN is case-sensitive.   NOTE: This is an additional restriction imposed on the ucode   namespace by the requirements of some major applications of ucode in   existence.  Only capital "A", "B", "C", ..., "F" are allowed as part   of hexadecimal characters.   Conformance with URN syntax:   There are no special reserved characters.  The URN of this namespace   conforms toRFC 2141 [RFC2141] andRFC 3986 [RFC3986].   Validation mechanism:   No special considerations.   Scope:   Global.Ishikawa                      Informational                     [Page 4]

RFC 6588                 URN Namespace for ucode              April 20123.  IANA Considerations   One URN Namespace registration for 'ucode'  (46) has been entered   into the IANA "Formal URN Namespaces" sub-registry for URN NIDs.4.  Namespace Considerations   ucode, the identifier expressed by ucode-number, is a unique   identification number to identify a tangible object or a place.   Additionally, ucode can be assigned to "content" or "information"   that does not exist in the real world or a "concept" that is yet more   abstract.   ucode has been devised to identify objects and places where existing   standards do not fit the application needs or the scope of the   applications or where the allocation policy of existing standards is   too limited for SMEs, small-scale research laboratories at academic   institutions, or individual users.   ucode is only an identification number, and its value (or its sub-   bitfields) does not contain any pre-assigned meaning.  Any relevant   information about the object or place to which a ucode is assigned is   stored in a data server that can be reached after a "resolution   process" [UCSURP].  This resolution process usually occurs over the   Internet.   ucode can be assigned to an object to be identified regardless of the   type of application.  ucode is expected to be stored in any kind of   tags (2D optical code, RFID, etc.), and it provides a framework where   anyone can obtain unique numbers for identification purposes.   ucode has been designed to provide the services outlined in ITU-T   Recommendation F.771 [ITU-T-F771] and to operate in the framework of   ITU-T Recommendation H.621 [ITU-T-H621].   ucode architecture is general enough to cover many applications for   the users.5.  Community Considerations   This namespace enables ucode to be stored in tags that are designed   to store URN.  Also, ucode-related information can be described as   metadata using the URN namespace.  Thus, the namespace facilitates   the exchange of descriptions regarding objects and places among   multiple organizations.Ishikawa                      Informational                     [Page 5]

RFC 6588                 URN Namespace for ucode              April 2012   It is expected that many small-scale providers will offer ucode tags   to small users and that large scale providers will hand out millions   of tags to users.   The resolution servers and applications will be available to general   users with appropriate access control over the Internet.  The   published specification for resolver and access services for 'ucode'   allows the creation of client software for many types of computers   including small mobile terminals and ever-popular smartphones.6.  Security Considerations   There are no additional security considerations other than those   normally associated with the use and resolution of URNs in general.7.  References7.1.  Normative References   [UCODE]      T-Engine Forum, Ubiquitous ID Center, "ucode: Ubiquitous                Code", UID-00010,                <http://www.uidcenter.org/spec#UID-00010>.   [UCDMIP]     T-Engine Forum, Ubiquitous ID Center, "ucode Management                Implementing Procedures", UID-00034,                <http://www.uidcenter.org/spec#UID-00034>.   [UCSURP]     T-Engine Forum, Ubiquitous ID Center, "Simplified ucode                Resolution Protocol", UID-00005,                <http://www.uidcenter.org/spec#UID-00005>.   [UIDTAG]     T-Engine Forum, Ubiquitous ID Center, "ucode Tag                Architecture", UID-00017,                <http://www.uidcenter.org/spec#UID-00017>.   [RFC2141]    Moats, R., "URN Syntax",RFC 2141, May 1997.   [RFC3986]    Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform                Resource Identifier (URI): Generic Syntax", STD 66,RFC3986, January 2005.   [RFC5234]    Crocker, D., Ed., and P. Overell, "Augmented BNF for                Syntax Specifications: ABNF", STD 68,RFC 5234, January                2008.Ishikawa                      Informational                     [Page 6]

RFC 6588                 URN Namespace for ucode              April 2012   [ITU-T-F771] ITU-T, "Service description and requirements for                multimedia information access triggered by tag-based                identification", ITU-T Recommendation F.771,                <http://www.itu.int/rec/T-REC-F.771-200808-I>.   [ITU-T-H621] ITU-T, "Architecture of a system for multimedia                information access triggered by tag-based                identification", ITU-T Recommendation H.621,                <http://www.itu.int/rec/T-REC-H.621-200808-I>.7.2  Informative References   [W3CXML]     W3C, "Extensible Markup Language (XML) 1.1",                <http://www.w3.org/TR/xml11/>.   [UIDC]       Ubiquitous ID Center, <http://www.uidcenter.org/>.   [TEF]        T-Engine Forum, <http://www.t-engine.org/>.8.  Acknowledgments   The author would like to thank Peter Saint-Andre, the Document   Shepherd/Responsible Area Director for this document, for providing   valuable suggestions.  The author would also like to thank the   following people who helped to improve this document:   Adrian Farrel   David Harrington   Pete Resnick   Stephen Farrel   Ted Hardie   Wesley Eddy   The author would also like to thank the members of T-Engine Forum who   have built prototype and real-world applications using ucode and   offered valuable feedback.  Application examples from these members   can be found on the Ubiquitous ID Center web site [UIDC] and on   www.youtube.com (search for "uidcenter" without the quotes).Ishikawa                      Informational                     [Page 7]

RFC 6588                 URN Namespace for ucode              April 20129.  Contributors   Ken Sakamura   Noboru Koshizuka   Katsunori Shindo   Tomonori Usaka   Past and current members of the uID architecture group at the   University of Tokyo and the YRP Ubiquitous Networking Laboratory (YRP   UNL)Author's Address   Chiaki Ishikawa   YRP Ubiquitous Networking Laboratory   2-20-1, Nishi-Gotanda   Shinagawa, Tokyo, 141-0031   Japan   Tel: +81-3-5437-2270   FAX: +81-3-5437-2271   EMail: chiaki.ishikawa@ubin.jpIshikawa                      Informational                     [Page 8]