The Mobile Application Part (MAP), one of protocols in the SS7 suite, allows for the implementation of mobile network (GSM) signaling infrastructure. The premise behind MAP is to connect the distributed switching elements, called mobile switching centers (MSCs) with a master database called the Home Location Register (HLR). The HLR dynamically stores the current location and profile of a mobile network subscriber. The HLR is consulted during the processing of an incoming call. Conversely, the HLR is updated as the subscriber moves about the network and is thus serviced by different switches within the network.
MAP has been evolving as wireless networks grow, from supporting strictly voice, to supporting packet data services as well. The fact that MAP is used to connect NexGen elements such as the Gateway GPRS Support node (GGSN) and Serving Gateway Support Node (SGSN) is a testament to the sound design of the GSM signaling system.
MAP has several basic functions:
- Mechanism for a Gateway-MSC (GMSC) to obtain a routing number for an incoming call
- Mechanism for an MSC via integrated Visitor Location Register (VLR) to update subscriber status and routing number.
- Subscriber CAMEL trigger data to switching elements via the VLR
- Subscriber supplementary service profile and data to switching elements via the VLR.
Protocol Structure
| 8 bits | 16 bits |
| Operation specifier | Length |
| MAP Parameters | |
Length - The length of the packet.
MAP parameters - Various parameters dependent on the operation.
Operation specifier - The type of packet. The following operations are defined:
- AuthenticationDirective
- AuthenticationDirectiveForward
- AuthenticationFailureReport
- AuthenticationRequest
- AuthenticationStatusReport
- BaseStationChallenge
- Blocking
- BulkDeregistration
- CountRequest
- FacilitiesDirective
- FacilitiesDirective2
- FacilitiesRelease
- FeatureRequest
- FlashRequest
- HandoffBack
- HandoffBack2
- HandoffMeasurementRequest
- HandoffMeasurementRequest2
- HandoffToThird
- HandoffToThird2
- InformationDirective
- InformationForward
- InterSystemAnswer
- InterSystemPage
- InterSystemPage2
- InterSystemSetup
- LocationRequest
- MobileOnChannel
- MSInactive
- OriginationRequest
- QualificationDirective
- QualificationRequest
- RandomVariableRequest
- RedirectionDirective
- RedirectionRequest
- RegistrationCancellation
- RegistrationNotification
- RemoteUserInteractionDirective
- ResetCircuit
- RoutingRequest
- SMSDeliveryBackward
- SMSDeliveryForward
- SMSDeliveryPointToPoint
- SMSNotification
- SMSRequest
- TransferToNumberRequest
- TrunkTest
- TrunkTestDisconnect
- Unblocking
- UnreliableRoamerDataDirective
- UnsolicitedResponse
Related Terms: ASP, BICC, BISUP, DUP, ISUP, MTP, SCCP, TCAP, TUP
Sponsor Source: MAP is ITU-T (http://www.itu.int/ITU-T/) standards defined in the Q.700 documents.
Reference Links:
http://www.cisco.com/univercd/cc/td/doc/product/tel_pswt/vco_prod/ss7_fund/: SS7 Fundamentals
http://www.itu.int/rec/recommendation.asp?type=folders&lang=e&parent=T-REC-Q.700: Introduction to Signaling System No. 7