Content for TS 44.118 Word version: 16.0.0

3.1 Definitions 3.2 Abbreviations 3.3 Random values 3.4 Specification Notations 4.1 RRC Functions 4.2 RRC Services provided to upper layers 5.1 Services required from layer 2 and physical layers 5.2 Signalling Radio Bearers
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3 Definitions, symbols and abbreviations Word‑p. 18

3.1 Definitions

The following terms are used in this Technical Specification:

A/Gb mode:

mode of operation of the MS when connected to the Core Network via GERAN and the A and/or Gb interfaces.

Access Stratum (AS):

defined in TS 23.101.

Active Transport Channel:

a transport channel is active during a TTI if it carries a transport block.

"channel set":

is used to identify TCHs that carry related user information flows, e.g., in a multislot configuration used to support circuit switched connection(s), which therefore need to be handled together.

Dynamic attributes:

for one transport channel, the values of the dynamic attributes are different among transport formats. They are configured by Layer 3 and can change on a TTI basis under the control of the MAC sublayer.

Empty Transport Format:

a transport format such that no transport block is carried over the transport channel (i.e. the transport channel is inactive).

Empty Transport Format Combination:

a transport format combination that is made up only of empty transport formats.

Inactive Transport Channel:

a transport channel is inactive during a TTI if it does not carry a transport block (i.e. the transport block size is zero).

Iu mode:

mode of operation of the MS when connected to the Core Network via GERAN or UTRAN and the Iu interface.

Non Access Stratum (NAS):

defined in TR 21.905.

RR idle:

defined in TS 44.018.

RR:

Radio Resource control plane protocol for radio resource management that is used when a mobile station is operating in A/Gb mode.

RRC:

Radio Resource control plane protocol for radio resource management that is used when a mobile station is operating in Iu mode.

RRC Connection:

A point-to-point bi-directional connection between RRC peer entities in the MS and the GERAN characterised by the allocation of a G-RNTI. An MS has either zero or one RRC connection.

RRC-Idle mode:

In RRC-Idle mode, the MS has no established RRC connection.

RRC-Connected mode:

In RRC-Connected mode, the MS has an established RRC connection.

Inter-RAT handover:

indicates the transfer of the connection, under the control of the network, between the MS and two different radio access technologies (e.g. UMTS to GERAN Iu mode).

Inter-mode handover:

indicates the transfer of the connection, under the control of the network, between the MS and GERAN Iu mode to/from GERAN A/Gb mode.

Retransmission number (R = 0 for first transmission, R = 1 for first retransmission, …, R = n for the nth retransmission). When there is no retransmission, R = 0 always.

RR group receive mode:

defined in TS 44.018.

RR dedicated mode:

defined in TS 44.018.

RR group transmit mode:

defined in TS 44.018.

RR packet idle mode:

defined in TS 44.018.

RR packet transfer mode:

defined in TS 44.018.

RR dual transfer mode:

defined in TS 44.018.

RLC/MAC block:

A RLC/MAC block is the protocol data unit exchanged between RLC/MAC entities, see TS 44.060.

Semi-static attributes:

for one transport channel, the values of the semi-static attributes are common to all transport formats. They are configured by Layer 3 and can only be changed by Layer 3 signalling.

Transport Block (TB):

block exchanged on a transport channel between the physical layer and the MAC sublayer.

Temporary block flow (TBF):

is defined in TS 44.060.

Transport Channel (TrCH):

a transport channel is offered by the physical layer to the MAC sublayer for exchange of transport blocks. A transport channel is used to carry with a certain quality of service, a data flow over the radio interface.

Transport Format (TF):

configuration of a transport channel, including for instance channel coding, CRC size, etc.

Transport Format Combination (TFC):

allowed combination of transport format(s) of the different transport channels that are multiplexed together on a basic physical subchannel.

Transport Format Combination Indicator (TFCI):

layer one header that indicates the transport channel combination that has been selected for each radio packet.

Transport Format Combination Set (TFCS):

set of allowed transport format combinations on a basic physical subchannel.

Transport Format Indicator (TFIN):

index identifying a particular transport format within the transport format set.

Transport Format Set (TFS):

set of all transport formats defined for a particular transport channel.

Transmission Time Interval (TTI):

rate at which transport blocks are exchanged between the physical layer and the MAC sublayer on a transport channel.

The network modes of operation for GERAN Iu mode are:

NMO I:

the network has a Gs interface. The network sends CS paging and PS paging messages for an attached MS via the SGSN and the Iu-ps interface to GERAN Iu. Paging co-ordination is achieved at the SGSN thanks to the Gs interface. GERAN Iu pages the MS on PACCH if available, else PCCCH. MS can initiate combined procedures according to its capabilities.

NMO II:

the network has no Gs interface. For an attached MS, the network sends CS paging messages, via the MSC plus the Iu-cs interface, and sends PS paging messages, via the SGSN plus the Iu-ps interface to GERAN Iu. GERAN Iu performs paging co-ordination and pages the MS on PACCH if available, else PCCCH. MSs cannot initiate combined procedures.

3.2 Abbreviations Word‑p. 19

Abbreviations used in this specification are listed in TR 21.905.

3.3 Random values

In a number of places in this Technical Specification, it is mentioned that some value must take a "random" value, in a given range, or more generally with some statistical distribution. Such cases interest only the Mobile Station.

It is required that there is a low probability that two MSs in the same conditions (including the case of two MSs of the same type from the same manufacturer) will choose the same value. Moreover, it is required that, if it happens that two MSs in similar conditions choose the same value, the probability of their choices being identical at the next occasion is the same as if their first choices had been different.

The meaning of such a specification is that any statistical test for these values, done on a series of similar events, will obtain a result statistically compatible with the specified distribution. This shall hold even in the cases where the tests are conducted with a subset of possible events, with some common parameters. Moreover, basic tests of independence of the values within the series shall pass.

Data against which correlation with the values shall not be found are the protocol state, or the IMSI, or identities or other unrelated information broadcast by the network, or the current TDMA frame number.

3.4 Specification Notations Word‑p. 20

For the purposes of the present document, the following notations apply:

Procedure

When referring to an elementary procedure in the specification the Procedure Name is written with the first letters in each word in upper case characters followed by the word "procedure", e.g. RRC Estabilshment procedure.

Message

When referring to a message in the specification the MESSAGE NAME is written with all letters in upper case characters followed by the word "message", e.g. CELL UPDATE message.

When referring to an information element (IE) in the specification the Information Element Name is written with the first letters in each word in upper case characters and all letters in Italic font precedeed by the abbreviation "IE", e.g. IE "Initial MS Identity".

Value of an IE

When referring to the value of an information element (IE) in the specification the "Value" is written as it is specified in sub-clause 9.2 enclosed by quotation marks, e.g. "Abstract Syntax Error (Reject)" or "Geographical Coordinates"

4 RRC Functions and Services provided to upper layers

4.1 RRC Functions

RRC performs following functions. A more detailed description of the functions can be found in TS 43.051.

Broadcast of information provided by the Non-Access stratum (Core Network)
Broadcast of information related to the access stratum
Establishment, re-establishment, maintenance and release of an RRC connection between the MS and GERAN
Establishment, reconfiguration and release of Radio Bearers
Assignment, reconfiguration and release of radio resources for the RRC connection
RRC connection mobility functions
Release of signalling connections
Paging/notification
Listening to BCCH
Routing of higher layer PDUs
Control of requested QoS
MS measurement reporting and control of the reporting
Power control
Control of ciphering
Integrity protection
Support for Location Services
Timing advance control

4.2 RRC Services provided to upper layers Word‑p. 21

The RRC offers the following services to upper layers (NAS), a description and primitives of these services are provided in TS 43.051 and TS 23.110.

General Control;
Notification;
Dedicated control.

The RRC layer provides the MS GERAN portion of signalling connections to the upper layers to support the exchange of upper layer's information flow. The signalling connection is used between the mobile station and the core network to transfer upper layer information. For each core network domain, at most one signalling connection may exist at the same time. The RRC layer maps the signalling connections for one MS on a single RRC connection. For the upper layer data transfer on signalling connections, the RRC layer supports the discrimination between two different classes, named "High priority" (corresponding to "SAPI 0" when using RR) realised using SRB3 and "Low priority" (corresponding to "SAPI 3" when using RR) realised using SRB4.

5 Services expected from lower layers

5.1 Services required from layer 2 and physical layers

RRC uses RLC/MAC as layer 2 in the control plane, except for operation on the BCCH, where the data link layer as specified in TS 44.006 is used (see TS 43.051).

5.2 Signalling Radio Bearers

The Radio Bearers used for transferring signalling messages are called Signalling Radio Bearers (SRBs). The SRBs are defined as:

SRB1 is used to carry RRC signaling performed in support of Access Stratum specific needs (RLC operates in unacknowledged mode).
SRB2 is used to carry RRC signaling performed in support of Access Stratum specific needs (RLC operates in acknowledged mode).
SRB3 is used to carry RRC signaling performed in support of Non-Access Stratum specific needs (RLC operates in acknowledged mode).
SRB4 is used to carry RRC signaling performed in support of Non-Access Stratum specific needs (RLC operates in acknowledged mode).