6.4 Permitted channel combinations

05.023GPPMultiplexing and Multiple Access on the Radio PathTS

6.4.1 Permitted channel combinations onto a basic physical channel

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):

i) TCH/F + FACCH/F + SACCH/TF

ii) TCH/H(0,1) + FACCH/H(0,1) + SACCH/TH(0,1)

iii) TCH/H(0,0) + FACCH/H(0,1) + SACCH/TH(0,1) + TCH/H(1,1)

iv) FCCH + SCH + BCCH + CCCH

v) FCCH + SCH + BCCH + CCCH + SDCCH/4(0..3) + SACCH/C4(0..3)

vi) BCCH + CCCH

vii) SDCCH/8(0 .7) + SACCH/C8(0 . 7)

viii) TCH/F + FACCH/F + SACCH/M

ix) TCH/F + SACCH/M

x) TCH/FD + SACCH/MD

xi) PBCCH+PCCCH+PDTCH/F+PACCH/F+PTCCH/F

xii) PCCCH+PDTCH/F+PACCH/F+PTCCH/F

xiii) PDTCH/F+PACCH/F+PTCCH/F

where CCCH = PCH + RACH + AGCH + NCH.

and PCCCH=PPCH+PRACH+PAGCH+PNCH.

xiv) CTSBCH + CTSPCH + CTSARCH + CTSAGCH

xv) CTSPCH + CTSARCH + CTSAGCH

xvi) CTSBCH

xvii) CTSBCH + TCH/F + FACCH/F + SACCH/CTS

xviii) E-TCH/F + E-IACCH/F + E-FACCH/F + SACCH/TF

xix) E-TCH/F + E-IACCH/F + E-FACCH/F + SACCH/M

xx) E-TCH/F + E-IACCH/F + SACCH/M

xxi) E-TCH/FD + E-IACCH/F + SACCH/MD

xxii) CFCCH + CSCH + CPBCCH + CPCCCH + PDTCH/F + PACCH/F + PTCCH/F

  1. CPCCCH+PDTCH/F+PACCH/F+PTCCH/F
  2. TCH/H(0,1) + FACCH/H(0,1) + SACCH/TH(0,1) + PDTCH/H(1,0) + PACCH/H(1,0)

NOTE 1: Where the SMSCB is supported, the CBCH replaces SDCCH number 2 in cases v) and vii) above.

NOTE 2: A combined CCCH/SDCCH allocation (case v) above) may only be used when no other CCCH channel is allocated.

NOTE 3: Combinations viii), ix) and x) are used in multislot configurations as defined in clause 6.4.2.

NOTE 4: Combinations xiv), xv), xvi) and xvii) shall be used in CTS ; combinations xiv), xvi) and xvii) shall be mutually exclusive ; combinations xiv) and xv) shall also be mutually exclusive.

NOTE 5: Combinations xxii) and xxiii) shall be used for COMPACT on serving time groups.

NOTE 6: Combinations i), ii), iii), v), xiii or xxiv) shall be used for single timeslot operation in DTM.

6.4.2 Multislot configurations

A multislot configuration consists of multiple circuit or packet switched traffic channels together with associated control channels, allocated to the same MS. The multislot configuration occupies up to 8 basic physical channels, with different timeslots numbers (TN) but with the same frequency parameters (ARFCN or MA, MAIO and HSN) and the same training sequence (TSC).

6.4.2.1 Multislot configurations for circuit switched connections

Two types of multislot configurations exists, symmetric and asymmetric. The symmetric case consists of only bi-directional channels. The asymmetric case consists of both bi-directional and unidirectional downlink channels.

The occupied physical channels shall consist of the following channel combinations as defined in clause 6.4.1.

one main channel of type viii) +

x secondary channels of type ix) +

y secondary channels of type x)

where 0<= x <= 7, y = 0 for symmetric multislot configuration

0<= x <= 6, 1 <= y <= 7, x+y <= 7 for asymmetric multislot configuration

The main channel is the bi-directional channel that carries the main signalling (FACCH and SACCH) for the multislot configuration. The position of the main channel is indicated by the allocation message (GSM 04.08). Secondary channels may be added or removed without changing the main channel.

The allocation of channels to a Multislot Configuration must always consider the multislot capability of the MS, as defined by the multislot class described in annex B.

There is no limitation in this TS to the possible TCH types (see clause 3.2) which may be used in a Multislot Configuration.

High Speed Circuit Switched Data (HSCSD) is one case of multislot configuration. The full rate traffic channels of a HSCSD configuration shall convey the same user bit rate (see clause 3.2.3).

NOTE: For the maximum number of timeslots to be used for a HSCSD, see GSM 03.34.

6.4.2.2 Multislot configurations for packet switched connections

An MS may be allocated several PDTCH/Us or PDTCH/Ds for one mobile originated or one mobile terminated communication respectively. In this context allocation refers to the list of PDCH that may dynamically carry the PDTCHs for that specific MS. The PACCH may be mapped onto any of the allocated PDCHs. If there are m timeslots allocated for reception and n timeslots allocated for transmission, there shall be Min(m,n) reception and transmission timeslots with the same TN. For a multislot class 1 to 12 MS for a packet switched connection, Tra (see appendix B) shall always apply.

The occupied physical channels shall consist a combination of configurations xi, xii and xiii as defined in clause 6.4.1. For COMPACT, the occupied physical channels shall consist of a combination of configurations xiii), xxii), xxiii), and xxiv) as defined in clause 6.4.1. The network shall leave a gap of at least one radio block between the old and the new configuration, when the allocation is changed and PDCHs with the lowest numbered timeslot are not the same in the old and new configuration. For multislot class type 1 MS, the gap shall be left in both uplink and downlink when the lowest numbered timeslot for the combined uplink and downlink configuration is changed. For multislot class type 2 MS, the gap shall be left in the link (uplink and/or downlink) where the lowest numbered timeslot has been changed.

6.4.2.3 Multislot configurations for dual transfer mode

For DTM, a multislot configuration consists of a single traffic channel (TCH) and one or more full rate packet data traffic channels (PDTCH/F) together with associated control channels allocated to the same mobile station. This multislot configuration may occupy up to 3 basic physical channels.

The network shall leave a gap of at least one radio block between the old and the new configuration, when the allocation is changed and PDCHs with the lowest numbered timeslot are not the same in the old and new configuration. For multislot class type 1 MS, the gap shall be left in both uplink and downlink when the lowest numbered timeslot for the combined uplink and downlink configuration is changed.