2 Set of channels

05.013GPPGeneral descriptionPhysical layer on the radio pathTS

The radio subsystem provides a certain number of logical channels that can be separated into two categories according to 3GPP TS 04.03 [5], 3GPP TS 03.64 [15] and 3GPP TS 03.52 [17]:

1) The traffic channels (TCH): they are intended to carry two types of user information streams: encoded speech and data. The following types of traffic channels are defined: Bm or full‑rate (TCH/F), Lm or half‑rate (TCH/H), cell broadcast (CBCH), full rate packet data (PDTCH/F) and half rate packet data (PDTCH/H) traffic channels. For the purpose of this series of technical specifications, the following traffic channels are distinguished:

– full rate speech TCH (TCH/FS);

– enhanced full rate speech TCH (TCH/EFS)

– half rate speech TCH (TCH/HS);

– adaptive full rate speech TCH (TCH/AFS);

– adaptive half rate speech TCH (TCH/AHS);

– 28,8 kbit/s full rate data E-TCH (E-TCH/F28.8);

– 32,0 kbit/s full rate data E-TCH (E-TCH/F32.0);

– 43,2 kbit/s full rate data E-TCH (E-TCH/F43.2);

– 14,4 kbit/s full rate data TCH (TCH/F14.4);

– 9,6 kbit/s full rate data TCH (TCH/F9.6);

– 4,8 kbit/s full rate data TCH (TCH/F4.8);

– 4,8 kbit/s half rate data TCH (TCH/H4.8);

– £ 2,4 kbit/s full rate data TCH (TCH/F2.4);

– £ 2,4 kbit/s half rate data TCH (TCH/H2.4);

– cell broadcast channel (CBCH);

  • full rate packet data traffic channel (PDTCH/F) ;
  • half rate packet data traffic channel (PDTCH/H).

Adaptive speech traffic channels are channels for which part of the radio bandwidth is reserved for transmission of in band signalling to allow in call adaptation of the speech and channel codec. 8 full rate and 6 half rate block structures are defined for the adaptive traffic channels.

All channels are bi‑directional unless otherwise stated. Unidirectional downlink full rate channels, TCH/FD are defined as the downlink part of the corresponding TCH/F. Unidirectional uplink full rate channels are FFS.

The allocated uplink and downlink PDTCH are used independently of each other. Dependent allocation of uplink and downlink is possible.

Multislot configurations for circuit switched connections are defined as multiple (1 up to 8) full rate channels allocated to the same MS. At least one channel shall be bi‑directional (TCH/F). The multislot configuration is symmetric if all channels are bi‑directional (TCH/F) and asymmetric if at least one channel is unidirectional (TCH/FD).

High Speed Circuit Switched Data (HSCSD) is an example of multislot configuration, in which all channels shall have the same channel mode.

NOTE: For the maximum number of timeslots to be used for a HSCSD configuration, see 3GPP TS 03.34.

Multislot configurations for packet switched connections are defined as multiple (1 up to 8) PDTCH/Us and one PACCH for one mobile originated communication, or multiple (1 up to 8) PDTCH/Ds and one PACCH for one mobile terminated communication respectively, allocated to the same MS. In this context allocation refers to the list of PDCH that may dynamically carry the PDTCHs for that specific MS. The PACCH shall be mapped onto one PDCH carrying one PDTCH/U or PDTCH/D. That PDCH shall be indicated in the resource allocation message (see 3GPP TS 04.60).

Multislot configurations for dual transfer mode are defined as one bi-directional, traffic channel (TCH/H, TCH/F or E-TCH/F) and one packet channel combination. The packet channel combination may consist of one PDTCH/U and one PACCH for one mobile originated communication, or multiple (1 or 2) PDTCH/Ds and one PACCH for one mobile terminated communication respectively, allocated to the same MS. The PACCH shall be mapped onto one PDCH carrying one PDTCH/U or PDTCH/D. That PDCH shall be indicated in the resource allocation message (see 3GPP TS 04.60).

An MS capable of dual transfer mode (DTM) shall support, as a minimum, DTM multislot class 5, which utilises the two-timeslot channelisation method, i.e. a single TCH/F plus a single PDTCH/F. In addition, the MS supporting DTM shall support TCH/H + PDCH/F configuration with the adaptive multirate (AMR) speech coder for voice coding.

2) The signalling channels: these can be sub‑divided into (P)BCCH ((packet) broadcast control channel), (P)CCCH ((packet) common control channel), SDCCH (stand‑alone dedicated control channel), (P)ACCH ((packet) associated control channel), packet timing advance control channel (PTCCH) and CTSCCH (CTS control channel). An associated control channel is always allocated in conjunction with, either a TCH, or an SDCCH. A packet associated control channel is always allocated in conjunction to one or multiple PDTCH, concurrently assigned to one MS. Two types of ACCH for circuit switched connections are defined: continuous stream (slow ACCH) and burst stealing mode (fast ACCH). For the purpose of this series of technical specifications, the following signalling channels are distinguished:

– stand-alone dedicated control channel, four of them mapped on the same basic physical channel as the CCCH (SDCCH/4);

– stand-alone dedicated control channel, eight of them mapped on a separate basic physical channel (SDCCH/8);

– full rate fast associated control channel (FACCH/F);

– enhanced circuit switched full rate fast associated control channel (E-FACCH/F);

– half rate fast associated control channel (FACCH/H);

– slow, TCH/F or E-TCH/F associated, control channel (SACCH/TF);

– slow, TCH/H associated, control channel (SACCH/TH);

– slow, TCH/F or E-TCH/F associated, control channel for multislot configurations (SACCH/M);

– slow, TCH/F associated, control channel for CTS (SACCH/CTS);

– slow, SDCCH/4 associated, control channel (SACCH/C4);

– slow, SDCCH/8 associated, control channel (SACCH/C8);

– packet associated control channel (PACCH);

– packet timing advance control channel (PTCCH);

– broadcast control channel (BCCH);

– packet broadcast control channel (PBCCH);

– random access channel (i.e. uplink CCCH) (RACH);

– packet random access channel (i.e. uplink PCCCH) (PRACH);

– paging channel (part of downlink CCCH) (PCH);

– packet paging channel (part of downlink PCCCH) (PPCH);

– access grant channel (part of downlink CCCH) (AGCH);

– packet access grant channel (part of downlink PCCCH) (PAGCH);

– notification channel (part of downlink CCCH) (NCH);

– packet notification channel (part of downlink PCCCH) (PNCH);

– CTS beacon channel (part of downlink CTSCCH) (CTSBCH-FB and CTSBCH-SB);

– CTS paging channel (part of downlink CTSCCH) (CTSPCH);

– CTS access request channel (part of uplink CTSCCH) (CTSARCH);

– CTS access grant channel (part of downlink CTSCCH) (CTSAGCH).

All associated control channels have the same direction (bi‑directional or unidirectional) as the channels they are associated to. The unidirectional SACCH/MD is defined as the downlink part of SACCH/M.

When there is no need to distinguish between different sub‑categories of the same logical channel, only the generic name will be used, meaning also all the sub‑categories (SACCH will mean all categories of SACCHs, SACCH/T will mean both the slow, TCH associated, control channels, etc.).

The logical channels mentioned above are mapped on physical channels that are described in this set of technical specifications. The different physical channels provide for the transmission of information pertaining to higher layers according to a block structure.