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).
The primary facilities provided by MAP are:
Mobility Services: location management (to support roaming), authentication, managing service subscription information, fault recovery,
Operation and Maintenance: subscriber tracing, retrieving a subscriber's IMSI
Call Handling: routing, managing calls whilst roaming, checking that a subscriber is available to receive calls
Supplementary Services
Short Message Service
Packet Data Protocol (PDP) services for GPRS: providing routing information for GPRS connections
Location Service Management Services: obtaining the location of subscriber
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:
MAP for GSM (prior to Release 4) is specified by 3GPP TS 09.02 (MAP v1, MAP v2)
MAP for UMTS ("3G") and GSM (Release 99 and later) is specified by 3GPP TS 29.002 (MAP v3)
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.
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); or using SIGTRAN.
Yate is a partial open source implementation of MAP.