Message-Id: <365E97F5.DD6C2F15@natlab.research.philips.com> Date: Fri, 27 Nov 1998 13:15:49 +0100 From: Warner ten Kate <firstname.lastname@example.org> To: email@example.com Subject: URL proposal Through this message I propose To adopt the DAVIC specified general URL scheme as the general scheme to which TV Broadcast URLs must comply. Wrt. the DAVIC specification I made the following adaptations: - I added an explicit <time-period> field (semantics explained below). The field is optional and it corresponds to the DVB URL as also specified by DAVIC. - I made the <file> field optional to the <dir>-tree. Both adaptations do not turn this scheme incompatible with the DAVIC scheme. The proposed scheme reads: <protocol>://<service>[;<time-period>][/<dir1>/.../<dirN>/[<file>]] [square brackets] indicate optional fields. <angle brackets> indicate fields; the name of the field written between the brackets. The allowed character set is specified in RFC 2396. The remaining characters are literal parts of the URI scheme. The fields have the following semantics: <protocol> identifies that it concerns a TV Broadcast service and which access mechanism in that TV Broadcast system is to be used. (Candidates are "dvb", "atsc", "tv".) <service> identifies a particular channel service in the TV Broadcast system. It can be a name (string) or a number (integer sequence). The number corresponds to the ID of the service as used by the TV Broadcast system identified by <protocol>. <time-period> identifies the time-period within which the resource will be available in the service identified by <service>. It is an optional field. <dir1>/.../<dirN> identify a hierarchical path to the resource. The semantics of that path is defined by the TV Broadcast system identified by <protocol>. <file> identifies a resource in the service. <dir1>/.../<dirN>/<file> is an optional part of the URI. when the <file> is omitted, the resource identified is all the content available at and downwards from the hierarchy level <dirN>. Main motivation of this proposal is: - The DAVIC scheme is the only URI scheme in the TV Broadcast area existing which has been approved and consolidated by an official standardization body. It is in use. - It meets our requirements. - It sets a framework, leaving open to specify various flavors according to (application/system) specific details. Warner.