Pdp Activation Wcdma - classifieds-app32’s diary

Secondary PDP Activation. gprs; umts; posted Sep 23, 2014 by anonymous. Promote This Article GPRS is the packet data core network for 3G systems EDGE and WCDMA.

The GPRS core network is the central part of the general packet radio service GPRS which allows 2G, 3G and WCDMA mobile networks to transmit IP packets to external networks such as the Internet. The GPRS system is an integrated part of the GSM network switching subsystem.

The network provides mobility management, session management and transport for Internet Protocol packet services in GSM and WCDMA networks. The core network also provides support for other additional functions such as billing and lawful interception. It was also proposed, at one stage, to support packet radio services in the US D-AMPS TDMA system, however, in practice, all of these networks have been converted to GSM so this option has become irrelevant.

PRS module is an open standards driven system. The standardization body is the 3GPP.

Contents

1 GPRS tunnelling protocol GTP

2 GPRS support nodes GSN

2.1 Gateway GPRS support node GGSN

2.2 Serving GPRS support node SGSN

2.2.1 Common SGSN functions

2.2.2 GSM/EDGE specific SGSN functions

2.2.3 WCDMA specific SGSN functions

3 Access point

4 PDP context

5 Reference points and interfaces

5.1 Interfaces in the GPRS network

6 See also

7 References

8 External links

9 Main Reference

GPRS tunnelling protocol GTP edit

Main article: GPRS Tunnelling Protocol

GPRS Tunnelling Protocol is the defining IP-based protocol of the GPRS core network. Primarily it is the protocol which allows end users of a GSM or WCDMA network to move from place to place while continuing to connect to the Internet as if from one location at the Gateway GPRS support node GGSN. It does this by carrying the subscriber s data from the subscriber s current serving GPRS support node SGSN to the GGSN which is handling the subscriber s session. Three forms of GTP are used by the GPRS core network.

GTP-U

for transfer of user data in separated tunnels for each Packet Data Protocol PDP context

GTP-C

for control reasons including:

setup and deletion of PDP contexts

verification of GSN reachability

updates; e.g., as subscribers move from one SGSN to another.

GTP

for transfer of charging data from GSNs to the charging function.

GGSNs and SGSNs collectively known as GSNs listen for GTP-C messages on UDP port 2123 and for GTP-U messages on port 2152. This communication is direct within a single network, or in the case of international roaming, via a GPRS roaming exchange GRX.

The charging gateway function CGF listens to GTP messages sent from the GSNs on TCP or UDP port 3386. The core network sends charging information to the CGF, typically including PDP context activation times and the quantity of data which the end user has transferred. However, this communication which occurs within one network is less standardized and may, depending on the vendor and configuration options, use proprietary encoding or even an entirely proprietary system.

GTP version zero supports both signalling and user data under one generic header. It can be used with UDP User Datagram Protocol or TCP Transmission Control Protocol on the registered port 3386. GTP version one is used only on UDP. The control plane protocol GTP-C Control using registered port 2123 and the user plane protocol GTP-U User using registered port 2152.

GPRS support nodes GSN edit

A GSN is a network node which supports the use of GPRS in the GSM core network. All GSNs should have a Gn interface and support the GPRS tunneling protocol. There are two key variants of the GSN, namely Gateway and Serving GPRS support node.

Gateway GPRS support node GGSN edit

The gateway GPRS support node GGSN is a main component of the GPRS network. The GGSN is responsible for the internetworking between the GPRS network and external packet switched networks, like the Internet and X.25 networks.

From an external network s point of view, the GGSN is a router to a sub-network, because the GGSN hides the GPRS infrastructure from the external network. When the GGSN receives data addressed to a specific user, it checks if the user is active. If it is, the GGSN forwards the data to the SGSN serving the mobile user, but if the mobile user is inactive, the data is discarded. On the other hand, mobile-originated packets are routed to the right network by the GGSN.

The GGSN is the anchor point that enables the mobility of the user terminal in the GPRS/UMTS networks. In essence, it carries out the role in GPRS equivalent to the home agent in Mobile IP. It maintains routing necessary to tunnel the protocol data units PDUs to the SGSN that services a particular MS mobile station.

The GGSN converts the GPRS packets coming from the SGSN into the appropriate packet data protocol PDP format e.g., IP or X.25 and sends them out on the corresponding packet data network. In the other direction, PDP addresses of incoming data packets are converted to the GSM address of the destination user. The readdressed packets are sent to the responsible SGSN. For this purpose, the GGSN stores the current SGSN address of the user and his or her profile in its location register. The GGSN is responsible for IP address assignment and is the default router for the connected user equipment UE. The GGSN also performs authentication and charging functions.

Other functions include subscriber screening, IP pool management and address mapping, QoS and PDP context enforcement.

With LTE scenario the GGSN functionality moves to SAE gateway with SGSN functionality working in MME.

Serving GPRS support node SGSN edit

A serving GPRS support node SGSN is responsible for the delivery of data packets from and to the mobile stations within its geographical service area. Its tasks include packet routing and transfer, mobility management attach/detach and location management, logical link management, and authentication and charging functions. The location register of the SGSN stores location information e.g., current cell, current VLR and user profiles e.g., IMSI, address es used in the packet data network of all GPRS users registered with it.

Common SGSN functions edit

Detunnel GTP packets from the GGSN downlink

Tunnel IP packets toward the GGSN uplink

Carry out mobility management as Standby mode mobile moves from one Routing Area to another Routing Area

Billing user data

GSM/EDGE specific SGSN functions edit

Enhanced Data Rates for GSM Evolution EDGE specific SGSN functions and characteristics are:

Maximum data rate of approx. 60 kbit/s 150 kbit/s for EDGE per subscriber

Connect via frame relay or IP to the packet control unit using the Gb protocol stack

Accept uplink data to form IP packets

Encrypt down-link data, decrypt up-link data

Carry out mobility management to the level of a cell for connected mode mobiles

WCDMA specific SGSN functions edit

Carry up to about 42 Mbit/s traffic downlink and 5.8 Mbit/s traffic uplink HSPA

Tunnel/detunnel downlink/uplink packets toward the radio network controller RNC

Access point edit

Main article: Access Point Name

An access point is:

An IP network to which a mobile set can be connected

A set of settings which are used for that connection

A particular option in a set of settings in a mobile phone

When a GPRS mobile phone sets up a PDP context, the access point is selected. At this point an Access Point Name APN is determined

Example: aricenttechnologies.mnc012.mcc345.gprs

Example: Internet

Example: mywap

Example: hcl.cisco.ggsn

This access point is then used in a DNS query to a private DNS network. This process called APN resolution finally gives the IP address of the GGSN which should serve the access point. At this point a PDP context can be activated.

PDP context edit

The packet data protocol PDP; e.g., IP, X.25, FrameRelay context is a data structure present on both the serving GPRS support node SGSN and the gateway GPRS support node GGSN which contains the subscriber s session information when the subscriber has an active session. When a mobile wants to use GPRS, it must first attach and then activate a PDP context. This allocates a PDP context data structure in the SGSN that the subscriber is currently visiting and the GGSN serving the subscriber s access point. The data recorded includes

Subscriber s IP address

Subscriber s IMSI

Subscriber s Tunnel Endpoint ID TEID at the GGSN

Subscriber s Tunnel Endpoint ID TEID at the SGSN

Reference points and interfaces edit

Within the GPRS core network standards there are a number of interfaces and reference points logical points of connection which probably share a common physical connection with other reference points. Some of these names can be seen in the network structure diagram on this page.

Interfaces in the GPRS network edit

The interface serves the CDRs accounting-records which are written in the GSN and sent to the charging gateway CG. This interface uses a GTP-based protocol, with modifications that supports CDRs Called GTP and GTP prime.

Interface between the base station subsystem and the SGSN the transmission protocol could be Frame Relay or IP.

Interface between the Radio Network Controller and the SGSN. The interface exchanges signaling and payload.

Interface between the GGSN and HLR so that the GGSN can get the location details of a mobile station. To avoid implementing MAP/SS7 in the GGSN, this interface is optional. When not present, the GGSN routes inquires to the HLR via an SGSN.

Interface between the SGSN and the SMS Gateway. Can use MAP1, MAP2 or MAP3.

The interface between the SGSN and the service control point SCP ; uses the CAP protocol.

The interface between the SGSN and the Equipment Identity Register EIR, used for checking the mobile s equipment identity number IMEI against a list of reported stolen mobile phones.

IP based interface between the GGSN and a public data network PDN either directly to the Internet or through a WAP gateway.

Gmb

The interface between the GGSN and the Broadcast-Multicast Service Center BM-SC, used for controlling MBMS bearers.

IP based interface between SGSN and other SGSNs and internal GGSNs. DNS also shares this interface. Uses the GTP Protocol.

IP based interface between internal SGSN and external GGSNs. Between the SGSN and the external GGSN, there is the border gateway which is essentially a firewall. Also uses the GTP Protocol.

Interface between the SGSN and the HLR. Messages going through this interface uses the MAP3 protocol.

Interface between the SGSN and the MSC VLR. Uses the BSSAP protocol. This interface allows paging and station availability when it performs data transfer. When the station is attached to the GPRS network, the SGSN keeps track of which routing area RA the station is attached to. An RA is a part of a larger location area LA. When a station is paged this information is used to conserve network resources. When the station performs a PDP context, the SGSN has the exact BTS the station is using.

The on-line policy interface between the GGSN and the charging rules function CRF. It is used for provisioning service data flow based on charging rules. Uses the diameter protocol.

The on-line charging interface between the GGSN and the online charging system OCS. Uses the diameter protocol DCCA application.

The off-line CDR-based charging interface between the GGSN and the Charging system Uses GTP.

The interface between the SGSN and the Gateway Mobile Location Center GMLC, used for location based services.

S6d

The interface between SGSN and Home Subscriber Server HSS. It is a Diameter based interface which is used for transferring subscription and authentication data of the user to HSS for authenticating and authorizing user access.

PDP Context Activation Activate PDP Context APN The GPRS mobile now initiates the PDP context activation procedure to obtain the IP address for the device. The.

Primarily it is the protocol which allows end users of a GSM or WCDMA network to move from place to place while GPRS attach and PDP context activation sequence.

A PDP address assigned permanently is called a static PDP address while a PDP address assigned during a PDP context activation is called a dynamic PDP address.

PDP Context vs. EPS Bearer – A Battle of the Data Session Setups. In a UMTS network the data session is established with a PDP Context Activation procedure.

Activate PDP Context Accept SM Cause 52. The setting specifies what value is sent in the SM Cause52 information element in the PDP Context Activation Accept Message.