Change requests to GSM (phase 2 & Phase 2+) on BCCH scheduling

Transcription

1 ETSI TC SMG Tdoc SMG 603/96 Meeting no 20 Sophia Antipolis, France 7-11 October 1996 Source: SMG2 Change requests to GSM (phase 2 & Phase 2+) on BCCH scheduling These change request introduces a more flexible mechanism for scheduling of Sytem Information messages on the BCCH. CR Phas e Cat Subject Page Status CR A009 rev 1 2 F BCCH Scheduling 3 CR A010 rev 1 2+ C BCCH Scheduling This document contains 10 pages

2 CHANGE REQUEST No. A 009 rev.1 Technical Specification GSM version Submitted to SMG for approval [ ] without presentation ("non-strategic") with presentation ("strategic") [ ] Status at SMG [ ]: Approved [ ] Rejected [ ] Postponed [ ] Phase 1: [ ] Phase 2: [ x ] Phase 2+: [ ] Work item: Other phase(s) affected: [ x ] If yes, linked CR(s): CR A010 Proposed change affects: SIM [ ] ME [ x ] Network [ x ] Source: SMG2 Date: 6 september 1996 Subject: Category: F - Correction [ x ] A - Corresponds to a Phase 2 correction [ ] B - Addition of Feature [ ] C - Functional modification of Feature [ ] D - Editorial modification [ ] Reason for change: GSM is ambiguous on scheduling of BCCH messages. Different interpretations in mobile stations and network might lead to problems in the cell selection process. Sections affected, and additional explanation of details of change (if needed): If other core Specifications are affected, necessary (and attached) Joint CRs: No. If other core Specifications are affected, necessary (and attached) Joint CRs: Affects MS Test Specifications [ ] BSS Test Specifications [ ] O&M Specifications [ (possibly): Attached CRs?: Cross Phase Compatibility: Change affects operation of: Phase 1 MS in Phase 2(+) NW [ ] Phase 2(+) MS in Phase 1 NW [ CR to attached: Change affects operation of: Phase 1 SIM in Phase 2(+) ME[ ] CR to attached: Other comments: - Phase 2(+) SIM in Phase 1 ME [ CR to attached:

3 Page 19 Draft prets : March 1996 (GSM version 4.7.0) and hence the same TDMA frame number can appear more than once (see GSM 05.03). It should be noted that the frame mapping for the SACCH/T channel differs according to the timeslot allocated in order to lower the peak processing requirements of the BSS Mapping of TCH/F9.6, TCH/F4.8, TCH/H4.8 and TCH/H2.4 This paragraph has been deleted Mapping of BCCH data In order to facilitate the MS operation, it is necessary to transmit some System Information messages in defined multiframes and defined blocks within one multiframe, as follows (where TC = (FN DIV 51) mod (8)): System Information Message Sent when TC = Allocation Type 1 0 Type 2 1 Type 2 bis 5 Type 2 ter 5 or 4 Type 3 2 and 6 Type 4 3 and 7 Type 7 7 BCCH Ext Type 8 3 BCCH Ext This subclause defines requirements on minimum scheduling: the network may send any System Information message when sending of a specific System Information message is not required. The following rules apply: i) It is optional which SI message is sent when TC = 4 or 5 for. BCCH Ext may share the resource with PCH and AGCH (see section 6.5.1). ii) iii) System Information Type 1 need only be sent if frequency hopping is in use. An MS should look for System Information Type 1 when TC = 0. If it the MS finds another message when TC = 0, it can assume that System Information Type 1 is not in use. System iinformation ttype 2 bis or 2 ter messages are sent if when needed, as determined by the system operator. If only one of them is needed, it is sent when TC=5. If both are needed, 2bis is sent when TC=5 and 2ter at least in every 4th occurrence of TC=4when (but not necessarily each time when) TC=4. A System Information 2 message will shall always be sent at least every time TC=1. iv) The definitions of and BCCH Ext are given in section 7 Table 3 of 5. v) Use of System Information type 7 and 8 is not always necessaryneed not always to be sent. It is necessary if They are sent when System Information type 4 does not contain all information needed for cell selection;. All the allowable timeslot assignments in a frame (see Table 3 of 5 in Section 7) shall contain the same information.

4 6.3.5 Mapping of SID Frames Page 20 Draft prets : March 1996 (GSM version 4.7.0) When the DTX mode of operation is active, it is required to transmit Silence Descriptor (SID) information, or equivalent dummy information, during the SACCH/T block period (104 TDMA frames). As the SID frames do not constitute a logical channel and their use is specific to DTX operation, the mapping of SID frames onto the TDMA frames is specified in GSM Permitted channel combinations The following are the permitted ways, as defined by GSM 04.03, in which channels can be combined onto basic physical channels (numbers appearing in parenthesis after channel designations indicate sub-channel numbers; channels and sub-channels need not necessarily be assigned):

5 CHANGE REQUEST No. A010 rev.1 Technical Specification GSM version Submitted to SMG for approval [ ] without presentation ("non-strategic") with presentation ("strategic") [ ] Status at SMG [ ]: Approved [ ] Rejected [ ] Postponed [ ] Phase 1: [ ] Phase 2: [ ] Phase 2+: [ x ] Work item: TEI Other phase(s) affected: [ ] If yes, linked CR(s): Proposed change affects: SIM [ ] ME [ x ] Network [ ] Source: SMG2 Date: 6 September 1996 Subject: BCCH scheduling Category: F - Correction [ ] A - Corresponds to a Phase 2 correction [ x ] B - Addition of Feature [ ] C - Functional modification of Feature [ x ] D - Editorial modification [ ] Reason for change: In phase 2, the scheduling of BCCH information is defined in two steps: TS GSM defines the allowed schedulings of SYSTEM INFORMATION TYPE x messages, and then TS GSM defines the possible contents of the messages. This scheme seems too restricted for future development, e.g. in the case where information (like time, pretty name of operator, etc.) is broadcast less often. It is therefore proposed here to enable a network to indicate scheduling of information (any kind: messages, information elements, fields, and others). The information types are numbered in a TS (in TS GSM 04.08), a message on the BCCH tells in what positions of the BCCH the information is contained. The corresponding modification of GSM was approved at SMG#18: A new SYSTEM INFORMATION TYPE 9 message is introduced which indicates when certain information is sent on the BCCH. When SYSTEM INFORMATION TYPE 9 occurs is announced in SYSTEM INFORMATION TYPE 3. Let us take an example! SYSTEM INFORMATION TYPE 3 indicates WHERE = 5. This means that SI9 occurs in all blocks of BCCH norm for which (FN DIV 51) mod 8) = 4 and (((FN DIV 51) DIV 8) mod (5+1)) = 0, in other words from all blocks of BCCH norm for which TC = 4, every 6th is taken for transmission of SI9. SI 9 might for example indicate that actual time information is given on BCCH-ext in each 51-f-multiframe with number = (3 mod 16) This seems to be the last chance to create an extendible BCCH, in particular because all positions on BCCH norm are already in use.

6 Page 19 GSM version 5.0.0: May 1996 Sections affected, and additional explanation of details of change (if needed): Attached revised pages: Page 19. If other core Specifications are affected, necessary (and attached) Joint CRs: - If other core Specifications are affected, necessary (and attached) Joint CRs: Affects MS Test Specifications [ ] BSS Test Specifications [ ] O&M Specifications [ ] (possibly): Attached CRs?: Cross Phase Compatibility: Change affects operation of: Phase 1 MS in Phase 2(+) NW [ ] Phase 2(+) MS in Phase 1 NW [ ] CR to attached: Change affects operation of: Phase 1 SIM in Phase 2(+) ME[ ] CR to attached: Other comments: Phase 2(+) SIM in Phase 1 ME [ ] CR to attached:

7 Page 19 GSM version 5.0.0: May 1996 noted that the frame mapping for the SACCH/T channel differs according to the timeslot allocated in order to lower the peak processing requirements of the BSS Mapping of TCH/F9.6, TCH/F4.8, TCH/H4.8 and TCH/H2.4 This paragraph has been deleted Mapping of BCCH data In order to facilitate the MS operation, it is necessary to transmit some System Information messages in defined multiframes and defined blocks within one multiframe, as follows (where TC = (FN DIV 51) mod (8)): System Information Message Sent when TC = Allocation Type 1 0 Type 2 1 Type 2 bis 5 Type 2 ter 5 or 4 Type 3 2 and 6 Type 4 3 and 7 Type 7 7 BCCH Ext Type 8 3 BCCH Ext Type 9 4 This subclause defines requirements on minimum scheduling: the network may send any System Information message when sending of a specific System Information message is not required. The following rules apply: i) It is optional which SI message is sent when TC = 4 or 5 for. BCCH Ext may share the resource with PCH and AGCH (see section 6.5.1). ii) iii) Except when the NCH is present in a cell, ssystem Information Type 1 need only be sent if frequency hopping is in use or when the NCH is present in a cell. An MS should look for System Information Type 1 when TC = 0. If it the MS finds another message when TC = 0, it can assume that System Information Type 1 is not in use. System information type 2 bis or 2 ter messages are sent if when needed, as determined by the system operator. If only one of them is needed, it is sent when TC=5. If both are needed, 2bis is sent when TC=5 and 2ter at least in every 4th occurrence of when TC=4. A SI 2 message will always be sent at least every time TC=4. iv) The definitions of and BCCH Ext are given in section 7 Table 3 of 5. v) Use of System Information type 7 and 8 is not always necessaryneed not always to be sent. It is necessary if They are sent when System Information type 4 does not contain all information needed for cell selection; vi) System Information type 9 is sent in those blocks with TC = 4 which are specified in system information type 3 as defined in TS GSM All the allowable timeslot assignments in a frame (see Table 3 of 5 in Section 7) shall contain the same information.

8 6.3.5 Mapping of SID Frames When the DTX mode of operation is active, it is required to transmit Silence Descriptor (SID) information, or equivalent dummy information, during the SACCH/T block period (104 TDMA frames). As the SID frames do not constitute a logical channel and their use is specific to DTX operation, the mapping of SID frames onto the TDMA frames is specified in GSM Permitted channel combinations The following are the permitted ways, as defined by GSM 04.03, in which channels can be combined onto basic physical channels (numbers appearing in parenthesis after channel designations indicate sub-channel numbers; channels and sub-channels need not necessarily be assigned):