[CB Specification]

Cell Broadcast Service에 대한 스팩을 정리한 내용이다.

 

●CB Message Parameter

Octet Number(s)	Field
12	Serial Number
34	Message Identifier
5	Data Coding Scheme
6	Page Parameter
788	Content of Message

 

●Serial Number

●GS(Geographical Scope)

GS Code	Display Mode	Geographical Scope
00	Immediate	Cell wide
01	Normal	PLMN wide
10	Normal	Location Area wide in GSM, Service Area wide in UMTS
11	Normal	Cell wide

 

• only cell wide : which means that any CBS message if received in the next cell is regarded as "new"
• PLMN wide : which means that the Message Code and/or Update Number must change in the next cell for the CBS message to be "new"
• Location Area wide (in GSM) : which means that a CBS message with the same Message Code and Update Number may or may not be "new" in the next cell according to whether the next cell is in the same Location Area as the current cell
• Service Area Wide (in UMTS) : which means that a CBS message with the same Message Code and Update Number may or may not be "new" in the next cell according to whether the next cell is in the same Service Area as the current cell

 

●Message Code

The Message Code differentiates between CBS messages from the same source and type (i.e. with the same Message Identifier). Message Codes are for allocation by PLMN operators.

The Message Code identifies different message themes. For example, let the value for the Message Identifier be "Automotive Association" (= source), "Traffic Reports" (= type). Then "Crash on A1 J5" could be one value for the message code, "Cow on A32 J4" could be another, and "Slow vehicle on M3 J3" yet another.