Mobile Application Part

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The Mobile Application Part (MAP) is an SS7 protocol that provides an application layer for the various nodes in GSM and UMTS mobile core networks and GPRS core networks to communicate with each other in order to provide services to users. The Mobile Application Part is the application-layer protocol used to access the Home Location Register, Visitor Location Register, Mobile Switching Center, Equipment Identity Register, Authentication Centre, Short message service center and Serving GPRS Support Node (SGSN).

Contents

Facilities provided

The primary facilities provided by MAP are:

Published specification

The Mobile Application Part specifications were originally defined by the GSM Association, but are now controlled by ETSI/3GPP. MAP is defined by two different standards, depending upon the mobile network type:

In cellular networks based on ANSI standards (currently CDMA2000, in the past AMPS, IS-136 and cdmaOne) plays the role of the MAP a similar protocol usually called IS-41 or ANSI-41 (ANSI MAP). Since 2000 it is maintained by 3GPP2 as N.S0005 and since 2004 it is named 3GPP2 X.S0004.

Implementation

MAP is a Transaction Capabilities Application Part (TCAP) user, and as such can be transported using 'traditional' SS7 protocols or over IP using Transport Independent Signalling Connection Control Part (TI-SCCP); [1] or using SIGTRAN.

Yate is a partial open source implementation of MAP.

MAP signaling

In mobile cellular telephony networks like GSM and UMTS the SS7 application MAP is used. Voice connections are Circuit Switched (CS) and data connections are Packet Switched (PS) applications.

Some of the GSM/UMTS Circuit Switched interfaces in the Mobile Switching Center (MSC) transported over SS7 include the following:


There are also several GSM/UMTS PS interfaces in the Serving GPRS Support Node (SGSN) transported over SS7:

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Insert Subscriber Data is a Subscriber Data Handling procedure in LTE services. This procedure is used to manage the subscription data of subscriber in MME and SGSN over S6a/S6d interface. IDR is invoked by Home Subscriber Server for subscription data handling. IDR is MAP subscriber management service utilized in GSM/UMTS networks, standardized by 3GPP, and defined in the MAP specification, TS 29.002. This service is used to provide specific subscriber data in the following environments: by an HLR to update a VLR, by an HLR to update a SGSN, and by an HSS to update a MME via IWF in an EPS. This service is primarily used by the home subscriber management entity to update the serving subscriber management entity when there is either a change in a subscriber parameter, or upon a location updating of the subscriber.

The Mobile Telephone Switching Office (MTSO) is the mobile equivalent of a PSTN Central Office. The MTSO contains the switching equipment or Mobile Switching Center (MSC) for routing mobile phone calls. It also contains the equipment for controlling the cell sites that are connected to the MSC.

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References

  1. ITU-T Recommendation Q.2220, Transport Independent Signalling Connection Control Part (TI-SCCP).