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ETSI
ETSI TS 124 007 V14.0.0 (2017
3GPP TS 24.007 version 14.0.0 Release 14
4.3.3 Protocols and peer-to-peer communication
By use of the services provided by lower (sub-)layers, peer entities in a (sub-)layer in the MS and the network exchange
information. Exchange of information between two peer entities is performed according to the
corresponding (sub-)layer protocols. A protocol is a set of rules and formats by which the information (control
information and user data) is exchanged between the two peers. The information is exchanged by use of messages
which are defined in the protocol. (Therefore, the messages are also called Protocol Data Units, PDUs).
There are several protocols of the RR sublayer, one protocol of the LLC sublayer, three protocols of the MM sublayer,
and several protocols of the CM sublayer. For each functional block of the CM sublayer as defined in subclause 4.1
there is one protocol. The CM protocols are specified in the Technical Specifications identified in subclause 4.3.4.
In the model used in the present document, there are:
1) for non-GPRS services:
- one RR sub-layer entity in the MS and one RR sub-layer entity in the network;
- one MM sub-layer entity in the MS and one MM sub-layer entity in the network;
- for each functional block of the CM sublayer as defined in subclause 4.1 which is supported in the MS (in the
network), there are, depending on the protocol, one or more entities in the MS (in the network). Two different
entities of the same functional block in the MS (in the network) are called parallel entities. The entities of the
same functional block in the MS correspond in a one-to-one relation to the entities of the functional block in
the network. The corresponding entities are called peer entities;
2) for CTS services (in addition to non-GPRS services):
- one RR sub-layer entity in the MS and one in the CTS fixed part. These RR sub-layers include one CTS-RR
sub-entity on each side;
- one MM sub-layer entity in the MS and one in the CTS fixed part These MM sub-layers include one CTS-
MM sub-entity on each side;
- for each functional block of the CM sublayer as defined in subclause 4.1 which is supported in the MS (in the
fixed part), there are, depending on the protocol, one or more entities in the MS (in the fixed part). Two
different entities of the same functional block in the MS (in the fixed part) are called parallel entities. The
entities of the same functional block in the MS correspond in a one-to-one relation to the entities of the
functional block in the fixed part. The corresponding entities are called peer entities;
3) for GPRS services supporting Class C MSs:
- one RR sublayer entity (RR) in the MS and one RR sublayer entity in the network;
- six LLC sublayer entities (QoS1-QoS4, signalling, SMS) in the MS and six LLC sublayer entities in the
network;
- one MM sublayer entity (GMM) in the MS and one MM sublayer entity in the network (GMM);
- one SM entity in the MS's CM sublayer and one SM sublayer entity in the network's CM sublayer;
- one or more GSMS functional blocks in the CM sublayer if supported;
4) for non-GPRS and GPRS services supporting Class A and Class B MSs:
- two RR sublayer entities (RR) in the MS and two RR sublayer entities in the network;
- six LLC sublayer entities (QoS1-QoS4, signalling, SMS) in the MS and six LLC sublayer entities in the
network;
- two MM sublayer entities (GMM + MM) in the MS and one or two MM sublayer entities in the network
(GMM or MM);
- one SM entity in the MS's CM sublayer and one SM entity in the network's CM sublayer;