4 Primitives of the physical layer

04.043GPPLayer 1 - General RequirementsRelease 1999TS

The Physical layer interacts with other entities as illustrated in figure 2.1. The interactions with the data link layer of Dm channels and the interactions with the RLC/MAC layer of packet data physical channels are shown in terms of primitives where the primitives represent the logical exchange of information and control between the physical layer and adjacent layers. They do not specify or constrain implementations. The interactions between the physical layer and layer 1 entities for Bm/Lm channels are for further study. For the physical layer two sets of primitives are defined:

– Primitives between physical layer and data link layer and RLC/MAC layer respectively:

PH ‑ Generic name ‑ Type: Parameters.

– Primitives between layer 1 and the RR‑management layer 3 entity:

MPH ‑ Generic name ‑ Type: Parameters.

4.1 Generic names of primitives between layers 1 and 2 for the transfer of layer 2 frames and RLC/MAC blocks

The following primitive generic names are defined on the SAPs between the physical layer and the data link layer:

a) PH‑DATA:

The PH‑DATA primitives are used on a SAP to pass message units containing frames used for data link layer and RLC/MAC layer respective peer‑to‑peer communications to and from the physical layer.

b) PH‑RANDOM ACCESS:

The PH‑RANDOM ACCESS (PH‑RA) primitives are used on the SAP of the RACH and the PRACH to request and confirm (in the MS) the sending of a random access frame and to indicate (in the network) the arrival of a random access frame. The random access protocols are specified in 3GPP TS 04.08 and 3GPP TS 04.60 respectively.

c) PH‑CONNECT:

The PH‑CONNECT primitive is used on a SAP to indicate that the physical connection on the corresponding control channel or packet data physical channel has been established.

d) PH‑READY‑TO‑SEND:

The PH‑READY‑TO‑SEND primitive is used by the physical layer to trigger, if applicable, piggy backing, the start of timer for the data link layer or the RLC/MAC layer and the forwarding a data unit to the physical layer. It is passed to the upper layer just before a new physical block is transmitted.

e) PH‑EMPTY‑FRAME:

The PH‑EMPTY‑FRAME primitive can be used by the data link layer and the RLC/MAC layer to indicate that no frame has to be transmitted after receiving the PH‑READY‑TO‑SEND primitive. It enables polling of several upper layer entities by the physical layer and support DTX.

4.2 Generic names of primitives between layer 1 and the RR‑management entity of layer 3

The following primitive generic name is defined between layer 1 and the RR‑management entity of layer 3:

‑ MPH‑INFORMATION:

MPH‑INFORMATION (MPH‑INFO) primitives are used for the control of the physical layer by the RR‑management of layer 3. This information activates and deactivates, configures and deconfigures, through connects and disconnects physical and logical channels. It is also used for the transfer of measurements and measurement control information from layer 1 to layer 3.

4.3 Primitive types

The primitive types defined in the present document are:

a) REQUEST:

The REQUEST primitive type is used when a higher layer is requesting a service from a lower layer.

b) INDICATION:

The INDICATION primitive type is used by a layer providing a service to notify the next higher layer of activities in the layer. This activities are directly related to the occurrence of a REQUEST primitive on the peer‑protocol side.

c) RESPONSE:

The RESPONSE primitive type is used by a layer to acknowledge receipt from the INDICATION primitive type.

d) CONFIRM:

The CONFIRM primitive type is used by the layer providing the requested service to confirm that the activity has been completed.

4.4 Parameter definition

Primitives contain a variable amount of parameters. The primitives with included parameters are listed in table 4.1.

Table 4.1: Primitives of the physical layer

message unit

channel control parameters

system information

absolute frame No.

primitive

entity

direction

measurement

MPH‑INFO‑REQ

MS/BS

RR(L3)

PH(L1)

x

x

MPH‑INFO‑CON

MS/BS

PH(L1)

RR(L3)

x

x

MPH‑INFO‑IND

MS/BS

PH(L1)

RR(L3)

x

x

x

PH-CONNECT-IND

MS/BS

PH(L1)

DL(L2) RLC/MAC

x

PH‑READY-TO-SEND

MS/BS

PH(L1)

DL(L2) RLC/MAC

x

x

PH-EMPTY-FRAME

MS/BS

DL(L2) RLC/MAC

PH(L1)

x

PH‑DATA‑REQ

MS/BS

DL(L2) RLC/MAC

PH(L1)

x

x

PH‑DATA‑IND

MS/BS

PH(L1)

DL(L2) RLC/MAC

x

x

x

PH‑RA‑REQ

MS

DL(L2) RLC/MAC

PH(L1)

x

PH‑RA‑IND

BS

PH(L1)

DL(L2) RLC/MAC

x

x

PH‑RA‑CON

MS

PH(L1)

DL(L2) RLC/MAC

x

x

Parameters involved in the primitive exchange with the physical layer are:

a) Message unit:

The message unit contains peer‑to‑peer information of a layer. It is transferred by the physical layer to the peer layer.

b) Channel control parameters:

These parameters contain information for channel control, specified in 3GPP TS 04.08 and 3GPP TS 04.60.

c) System information:

This information is exchanged in the cell/PLMN selection procedures. It may also contain control information for DRX (sleep mode, see 3GPP TS 03.13).

d) Absolute Frame Number:

The absolute frame number is used (in combination with a random access identifier) to uniquely identify a random access.

e) Measurements:

This parameter is used to report the quality of a dedicated physical channel (MS and network) and to report the quality of surrounding BCCH carriers (MS only).