The Change Request (CR) procedure is used by the 3GPP to create revised versions of 3GPP specifications after their initial approval. The two main reasons why a change might be required is either to add a new feature or to correct/clarify an existing feature. This page gives a summary of:
How are change requests are proposed, elaborated and approved?
Where to find step-by-step instructions about how to write a CR?
Where to find status or other information about existing change requests.
A CR is a document (tdoc) which specifies in precise detail, changes which are proposed to the specification. It consists of a CR coversheet which, amongst other things, describes why a change is needed and summarises how the change is made. Attached to this are the parts of the specification affected by the change, with the changes being identified using the Microsoft Word "Track Changes" (revision marks) feature.
A change request can be proposed by any 3GPP member company. They need they submit it for discussion to the Working Group (WG) responsible for the specification (see the status list to determine the relevant WG). Once the WG has agreed that the change request is both valid and required (often if may be revised several times before reaching this stage), it get forwarded to their TSG plenary group (who meet four times a year) for final approval. After final approval at TSG level, the 3GPP support team (MCC) incorporates it and any other CRs into a new version of the specification, normally within 2 weeks of the meeting.
The full CR procedure is included in a report called TR 21.900 "Technical Specification Group working methods". To get TR 21.900, see the download page. A comprehensive introduction to the lifecycle of a specification, including change requests, can be found in this PowerPoint presentation, "The change control cycle".
Step by Step Instructions describing how to actually write a CR can be found here.
CRs are normally identified by a specification number and a CR number. e.g. CR 31.102-095 is CR number 095 to specification 31.102. Every change request which is presented to a TSG plenary meeting for approval is recorded in the CR database. This database, in Microsoft Access 97 format, lists the status of each change request, and, if was approved, indicates which version of the specification was subsequently created. The contains records about every change request to GSM or 3G specifications from GSM phase 2 onwards (i.e. from about 1995 onward). For assistance about tracing even older CRs (including GSM phase 1), see the historical information page .
A second, often simpler method of finding information about CRs is to look at the last page of every 3GPP specification. This contains a history box of every CR which has been approved for that particular specification.
As an example, to find CR 31.102-095. First, look in the CR database and find the the record for the CR and read the "meeting-1st-level" field (TP-12 in this example) and the "Document-1st-level" field (TP-010107 in this example). Then do the following steps:
Note that the starting URLs for the other four TSGs are as follows: