tech-invite   World Map     

IETF     RFCs     Groups     SIP     ABNFs    |    3GPP     Specs     Gloss.     Arch.     IMS     UICC    |    Misc.    |    search     info

3GPP Glossaries



Network entities











Here          Top

PCEF     # PCRF     # P-CSCF     # PDF     # PDG     # PDN-GW     # PLMN     # PNA     # Presence List Server     # Presence Watcher     # Presentity Presence Proxy     # ProSe Application Server     # ProSe Function     # ProSe-enabled UE     # PS     # PS Domain     # PUA    


PCEF  —  Policy  Enforcement  Rules  Function

[PCC  R7]+

The PCEF acts as a policy enforcement point for policy and charging control of IP bearer resources.

This functional entity is located at the Gateway (e.g. GGSN in the GPRS case) and in the PDN-GW (for EPS). The functionality of PCEF is described in TS 23.203, TS 23.401 and TS 23.402.

Source:   TS 23.002, clause 4a.18

Up       Top

PCRF  —  Policy and  Charging  Rules  Function

[PCC  R7]+

The PCRF acts as a policy decision point for policy and charging control of service data flows and IP bearer resources. The PCRF selects and provides the applicable policy and charging control decision to the PCEF.

When Gxx interface applies, the PCRF maintains the correlation between the GW control session and the IP-CAN session. The PCRF also acts as an information exchange point between BBERF and PCEF to forward event triggers, which can't be transferred directly between the BBERF and PCEF.

PCRF functions are described in more detail in TS 23.203 – clause 6.2.1.

Source:   TS 23.002, clause 4a.17

Up       Top

P-CSCF  —  Proxy    Call  Session  Control  Function

[IMS  R5]+

The P-CSCF is the first contact point within the IM Core Network subsystem. Its address is discovered by UEs using procedures based on DNS/DHCP. As defined in RFC 3261, the P-CSCF behaves like a Proxy, i.e. it accepts requests and services them internally or forwards them on.

Source:   TS 23.228, clause 4.6.1

Up       Top

PDF  —  Policy  Decision  Function

[pre-PCC  R6]

The PDF acts as a Policy Decision Point for service based local policy control. The PDF makes the policy decisions based on the session and media related information obtained from the AF via the Gq interface. The PDF shall exchange the decision information with the GGSN via the Go interface.

Source:   TS 23.009, Rel-6

Up       Top

PDG  —  Packet  Data  Gateway

[I-WLAN  R6]+

The PDG provides access to PS based services for a WLAN UE. It resides either in the home (for access to home services) or in the visited 3GPP network (for access to local services).

Source:   TS 23.002, clause 4a.13.5

Up       Top

PDN-GW  —  Packet  Data  Network    GateWay

[EPC  R8]+

The PDN GW is the gateway which terminates the SGi interface towards the PDN.

If a UE is accessing multiple PDNs, there may be more than one PDN GW for that UE, however a mix of S5/S8 connectivity and Gn/Gp connectivity is not supported for that UE simultaneously.

The PDN GW provides PDN connectivity to both GERAN/UTRAN only UEs and E-UTRAN capable UEs using any of E-UTRAN, GERAN or UTRAN. The PDN GW provides PDN connectivity to E-UTRAN capable UEs using E-UTRAN only over the S5/S8 interface. The PDN GW may also provide PDN connectivity to UEs using non-3GPP access networks with the procedures defined in TS 23.402.

For detailed PDN GW functions, see TS 23.401 and TS 23.402.

Source:   TS 23.002, clause

Up       Top

PLMN  —  Public  Land  Mobile  Network


A PLMN is established and operated by an administration or Recognized Private Operating Agency (RPOA) for the specific purpose of providing land mobile telecommunications services to the public.

A PLMN may be regarded as an extension of networks (e.g. ISDN, corporate and public PDNs, etc.); it is a collection of MSCs areas in CS domain and SGSN areas for GPRS and SGSN or MME areas for EPC in PS domain within a common numbering plan (e.g. same National Destination Code) and a common routing plan. The MSCs are the functional interfaces between the fixed networks and a PLMN for call set-up in CS domain. The GGSN and the SGSN are the functional interfaces between the fixed networks and a PLMN for packet transmission in GPRS PS domain. In case of EPC PS Domain, the PDN GW, Serving-GW and the SGSN and the MME are the functional interfaces between the fixed networks and a PLMN for packet transmission.

Functionally the PLMNs may be regarded as independent telecommunications entities even though different PLMNs may be interconnected through the ISDN/PSTN and PDNs for forwarding of calls or network information. A similar type of interconnection may exist for the interaction between the MSCs/SGSNs/MMEs of one PLMN.

The PLMN infrastructure is logically divided into a Core Network (CN) and an Access Network (AN) infrastructures.

Source:   TS 23.002, clause 3.1

Up       Top

PNA  —  Presence  Network  Agent

[Presence  R6]+

The PNA collects presence information about the presentity from a number of core network entities. The PNA can combine information from various core network entities to form more complete presence information.

Source:   TS 24.141, clause 5.3.5

Up       Top

[Presence  R6]+

The Presence List Server stores grouped lists of watched presentities and enables a Watcher Application to subscribe to the presence of multiple presentities using a single SUBSCRIBE transaction. Presence List Server also stores and enables the management of filters associated to presentities in the presence list. Presence list server shall attach associated filter to each individual SUBSCRIBE transaction. The Presence List Server is implemented as a SIP Application Server function as defined in TS 23.228. For the case where the Watcher Application resides in an IMS UE, the Presence List Server may support the Ut reference point to allow the user to manage his presence lists.

Source:   TS 23.141, clause 5.5

Up       Top

[Presence  R6]+

Source:   TS 23.141, clause 5.4

Up       Top

[Presence  R6]+

In order to support a presence service, in particular across PLMN borders, generic network functions are needed, e.g. routing and security. The presence proxies provide these functions. Presence proxies constitute the entry and exit point for presence requests between PLMNs.

The Presentity Presence Proxy shall provide the following functionality:
  • Determination of the identity of the presence server associated with a particular presentity;
  • Authentication of Watcher Presence Proxy;
  • Authentication of the Presence user Agent;
  • Generation of accounting information for updates to presence information.

Source:   TS 23.141, clause 5.3.3

Up       Top

[ProSe  R12]+

The ProSe Application Server supports the following capability:
  • Storage of EPC ProSe User IDs and ProSe Function IDs;
  • Mapping of Application Layer User IDs and EPC ProSe User IDs.

Source:   TS 23.303, clause 4.4.4

Up       Top

[ProSe  R12]+

The ProSe Function is the logical function that is used for network related actions required for ProSe. The ProSe Function plays different roles for each of the features of ProSe. In this version of the specification it is assumed that there is only one logical ProSe Function in each PLMN that supports Proximity Services.

Source:   TS 23.303, clause 4.4.1

Up       Top

[ProSe  R12]+

Any ProSe-enabled UE may support the following functions:
  • Exchange of ProSe control information between ProSe-enabled UE and the ProSe Function over PC3 reference point.
  • Procedures for open ProSe Direct Discovery of other ProSe-enabled UEs over PC5 reference point.

Source:   TS 23.303, clause 4.4.2

Up       Top

PS  —  Presence  Server

[Presence  R6]+

A PS is an entity that accepts, stores, and distributes presence information.

Source:   TS 24.141, clause 5.3.3

Up       Top

PS Domain  —  Packet-Switched  Domain

[PS Domain  R98]+

The PS domain refers to the set of all the CN entities offering "PS type of connection" for user traffic as well as all the entities supporting the related signalling. A "PS type of connection" transports the user information using autonomous concatenation of bits called packets: each packet can be routed independently from the previous one.

Source:   TS 23.002, clause 3.3.2

Up       Top

PUA  —  Presence  User  Agent

[Presence  R6]+

A PUA is an entity that provides presence information to a Presence Server.

Source:   TS 24.141, clause 5.3.1

Up       Top