Transcend GMLC

Transcend Distributed GMLC Gateway Overview

Precise location definition without specialized apps and widgets.

The Transcend Distributed GMLC Gateway is a telecom node that provides the functionality required to support location-based services (LBS). A single Public Land Mobile Network (PLMN) can have multiple GMLCs. This functionality is integrated through SIGTRAN for 2G/3G, and through DIAMETER for 4G and GMLC 5G networks.

GMLC can be integrated with LBS to locate any user that is connected to the network at a given time. It can provide network services and authorize third parties with standardized subscriber location information access.

As with all the Transcend Distributed Communication products, this messaging platform has significantly better scalability than Restcomm, its predecessor.  It is based on a distributed architecture using Kafka-based network, with MongoDB as its DMBS.  It features an elegant graphical user interface enabling centralized management as well as better documentation.  Additionally, the perpetual pricing is TPS-based and much more cost-effective.   When you need to scale to handle more transactions, you simply add another instance for a specific number of transactions or unlimited transactions.  To overcome your application’s bottlenecks, you can use multiple unlimited versions of the platform.

transcend GMLC gateway

The GMLC may request routing information from the HLR (Home Location Register) or HSS (Home Subscriber Server). After performing registration authorization, it sends positioning requests to either the VMSC (Visited Mobile Switching Centre), SGSN (Serving GPRS Support Node) MSC (Mobile Switching Centre) Server or MME (Mobility Management Entity) and receives final location estimates from the corresponding network node.

Some GMLC real-time applications can include the usage of location services in smart weather reporting.   GMLC can also improve advertisements by pushing area-related advertisements. It can also help telecom companies to generate mobile alerts when a user is in a specific area or introduce tracking, e.g., fleet tracking. The location information can also be of prime importance to LEAs, in emergency situations such as medical help, accidental reporting, etc.

How GMLC works in communication

With Diameter

Diameter provides a Java implementation of the Diameter standard for Authentication, Authorization, and Accounting (AAA). It implements the Base Protocol as well as numerous paramount and widely used applications. Transcend Diameter enables fast development of IMS components, such as SIP AS, IM SSF, OSA SCS, CAMEL, Home Subscriber Server (HSS), Call Session Control Function (CSCF), Subscriber Location Function (SLF), and more.

Extensible GMLC architecture feature efficiently supports new applications and the stack’s core functionalities adaptation to a fully customized solution.


The main functionality of the GMLC is to communicate the current location of the CSP subscriber to predefined endpoints. This data includes cell ID and subscriber status. This functionality is integrated via SS7/Sigtran protocols for 2G/3G networks.

Transcend Distributed GMLC uses legacy E1/T1 links via Dialogic SS7 cards and connectivity to MSC/HLR via SIGTRAN links (M3UA) for 2G and 3G-based deployments.


Can GMLC interface with HLR/MSC/SGSN?

GMLC can interface with any HLR/MSC/SGSN that supports 3GPP 29.002. According to the 3GPP LCS architecture, the interface between GMLC and HLR is known as the Lh interface, and the interface between GMLC and MSC/SGSN is known as the Lg interface. The GMLC uses the Lh interface to obtain routing information of a target terminal. It uses the Lg interface to request the positioning information of a target terminal from the radio network via the core network.

Which MAP LCS standard messages are supported?

The following MAP LCS standard messages are supported:

  • MAP-SendRouting InfoforLCS (SRI-LCS)
  • MAP-ProvideSubscriberLocation (PSL)
  • MAP-AnyTimeInterrogation(ATI)
  • MAP-SubscriberLocationReport (SRI)
  • MAP-SendRoutingInfoForSM (SRI-SM)
  • MAP-ProvideSubscriberInformation (PSI)
  • MAP-SubscriberLocationReport (SLR)

Features and Benefits

Mobile Network Connection 

Transcend Distributed GLMC can connect to any Mobile Network Operator or Mobile Virtual Network Operator core network over SS7 MAP

HTTP Integration 

Transcend Distributed GLMC is easy to integrate over HTTP for any proper solution

Core Location 

Transcend Distributed GLMC includes Cell-ID of MSISDN and current status (busy, available, etc.)

SS7 Support 

Transcend Distributed GLMC supports SS7 for 2G and 3G based deployments

Diameter Support 

Transcend Distributed GMLC supports Diameter for 4G and LTE based deployments 

TDM and SIGTRAN Support 

Transcend Distributed GMLC uses legacy E1/T1 links via Dialogic SS7 cards and connectivity to MSC/HLR via SIGTRAN links (M3UA) for 2G and 3G based deployments

Geolocation API 

Transcend Distributed GMLC enables location-based services in web, IOS, and Android apps via Geo-API

Carrier-Grade Performance 

A single GMLC node can process thousands of requests per second and can be adapted to meet the needs of all telecom service providers to reduce CAPEX and OPEX costs significantly


Transcend Distributed GMLC may be deployed on dedicated hardware, private cloud infrastructure or public cloud services such as Amazon Web Services

Load Balancing and Transparent Failover 

Multiple GMLC nodes can be arranged in a cluster across one or more geographically distributed data centers to scale up throughput and provide various levels of redundancy, high availability and fault tolerance

Extensible and Modern Platform 

Transcend Distributed GMLC is built on the JAIN-SLEE platform, automatically provides out-of-the-box integration with various communication protocols for connectivity to External Short Messaging Entity

Communications Platform