DTS Mobile System (DMS) works in exactly the same way as a macro network like Vodafone, in that it has the ability to transmit and receive voice calls, SMS messages, and even data files between GSM mobile users and GSM mobile and PSTN (Public Switched Telephony Network) users.

DMS accomplishes this by leveraging software Mobile Switching Centre (MSC), an integrated Base Transceiver Station (BTS), and an embedded Base Station Controller (BSC). Additional components of DMS include:

• Home Location Record (HLR)

• Authentication Center (AUC)

• Equipment Identity Register (EIR)

• Serving GPRS Support Node (SGSN)

• Gateway GPRS Support Node (GGSN)

• Private Branch Exchange (PBX)

The software MSC’s (Mobile Switching Centre) main function is to manage and co-ordinate the set up of calls. The MSC is a sophisticated switching engine that provides IP connectivity, mobility management, and GSM services to the mobile phones roaming within the area that it serves. This means voice and data services, as well as SMS and call divert. The core intelligence in the DMS is contained in the MSC. The following list highlights some of the functions performed by the MSC.

• Paging

• Co-ordination of call set up from all DMS mobile subscribers in its area

• Dynamic allocation of resources

• Location registration

• Interworking function with different networks

• Handover management

• Signaling exchange between different interfaces

• Gateway to Short Message Service Centre (SMSC)

• Management Station Controllers

• Operating system Linux

Within the DMS infrastructure is the Home Location Register (HLR) - an Oracle database that stores data related to a given set of subscribers. The HLR is a reference database for subscribers parameters, some of those parameters include:

• International Mobile Subscribers Identity (IMSI)

• Messages waiting data (used in conjunction with SMS)

When integrating with the DTS Core Network or an MNO (Mobile Network Operator) network a central DMS HLR is used as the network hub with remote DMS updating the central HLR and handling local registration and location information. This ensures that presence information can be shared across the entire network and real-time updates are provided from the Core Network as remote DMS come online.

Base Station Controller (BSC) acts as a switch dynamically creating and tearing down the connections between the links serving the BTS (Base Transmission System) radio channels and the MSC. It manages handovers between BTS under its control, and between itself and other BSC. Handover is required to allow calls to be made and received whilst on the move. The network must support cell-to-cell handover as the user travels across a site, and it is essential that the handover be transparent to the user. There are 2 types of handover

• Intra BSC - Device remains under the control of the same BSC but changes BTS

• Inter BSC - Device changes BSC as well as BTS

There are 4 purposes of handover

1. Maintenance of high signal quality

2. Recovering co-channel interference from another cell

3. Traffic balancing among cells

4. Recovering the failure of a control channel

A Short Message Service Controller (SMSC) is a network element in the GSM telephony network which delivers SMS messages. When a text message (SMS message up to 160 characters long) is sent from one user to another user, the phone actually sends the message to the SMSC. The SMSC stores the message and then delivers it to the destination user when they are available. This is a store and forward operation. The SMSC has a configurable time limit for how long it will store the message before removing it from the store. Messages can also be sent from PC based user that interface into the SMSC via Short Message Peer to Peer (SMPP v3.4)

A prerequisite for most DMS solutions, as it would be for any telecommunications service, is to establish a network interoperable switching centre where all mobile network numbers for the network can be terminated and where calls made on the mobile network can be connected into the Public Switch Telephone Network (PSTN) and calls from the PSTN can be connected to the mobile network.

As the conditions of spectrum usage vary from Country to Country DTS DMS integrates with a number of different radio access technologies so that it can leverage the same core network components whilst using best in class radio access network solutions. These include Femto, Pico, Micro and Macro Cell solutions that provide coverage from 100 metres to 20 kilometres.

DMS will provide edge of network or in-fill solutions for the armed forces tactically highly secure network where cost of deployment and overall solution footprint is at a premium.