My Sample Article 1
In the 1990s, the International Telecommunication Union - Telecommunication Standardization Section (ITU-T) began work on a vision of the future for public land mobile telecommunications systems. The resulting product was called International Mobile Telecommunications-2000 (IMT-2000). As an aside, the "2000" was added to imply that these services would be available around the year 2000. But these services became available during 2002.
IMT-2000 is much more than a set of services, it fulfills the dream of anywhere and anytime communications. To do this, it provides a framework for the integration of terrestrial and/or satellite-based networks. Moreover, IMT-2000 discusses the networks aspects of wireless Internet, convergence of fixed and mobile networks, mobility management (roaming), mobile multimedia functions, internetworking, and interoperability.
As specified, the 3G systems should work in a universally acceptable spectrum range and provide voice, data, and multimedia services. For the technically stationary user operating in a picocell, the data rate would be up to 2.048 Mbps. For a pedestrian user operating in the microcell, the data rates would be up to 384 kbps. For a user with vehicular mobility operating in the macrocell, the data rates would be up to 144 kbps. A critical part of this system is providing packet switched data services. The evolution from 2G to 3G begins with the creation of robust, packet based data services.
My Sample Article 2
ITU-T's Signaling System No.7 (SSN7) has been implemented near by world wide as the signaling system for the Digital Trunk Networks (DTNs). CCITT Rec.Q.700 states that the over all objective of SSN7 is to provide an internationally standardized general purpose Common Channel Signaling (CCS) system that:
Is optimized for operation in digital telecommunication networks in conjunction with Stored Program Control (SPC) exchanges.
Can meet present and future requirements of information transfer for inter processor transactions with in telecommunication networks for call control, remote control, management and maintenance signaling.
Provide a reliable means for transfer of information in correct sequence and with out loss and duplication.
Applications supported by SSN7 are:
Public Switched Telephone Network (PSTN)
Integrated Services Digital Network (ISDN)
Interaction with network data bases
Service control points for service control
Public Land Mobile Network (PLMN)
Operations Administration and Maintenance (OAM) of network
SSN7 components:
There are three components of SSN7:
Signal Transfer points (STPs)
Service switching points (SSPs)
Service control points (SCPs)
Now we explain these components one by one.
Signal Transfer Points (STPs):
These are packet switches that route signals between central offices and specialized databases. In SSN7 network the messages are sent between network points in variable length packets with the destination address attached. Signal transfer switches only read the address portion of the packets and forward them accordingly. STP route queries and responses between central offices and databases in service control points.
Service Switching Points (SSPs):
These points enable central offices to initiate queries to databases and specialized computers. SSP consists of software that sends specialized messages to databases and ports connected to SSN7 network. It also converts the central office machine language to SSN7 language. When signals are received from the signaling network then it converts the SSN7 language to the language acceptable by the central office switch.
Service Control Points (SCPs):
Service control points contain databases with call routing instructions. They also contain services like network based voice mail, fax applications and voice activated dialing on service control points or intelligent peripherals. The billing and customer information databases are the strong features of SCPs.