Telecommunications Applications and Services

Overview
Telephone applications are the processes or programs that provide specific features and benefits for the customer that involve the transfer of information through communication systems. Telecommunications services are the underlying communications processes that provide information for telecommunications applications. It is common to use the word services in place of applications, especially when the service is very similar to the application. Examples of communication applications include voice mail, email, and web browsing.

Telephone services include voice, data, and video transmission. Voice services can be categorized into quality of service and voice privacy. Data services use either circuit-switched (continuous connection) data or packet-switched (dynamically routed) data. Video transmission is the transport of video (multiple images) that may be accompanied by other signals (such as audio or closed-caption text).

Telecommunication services may be provided (distributed) to one or more users of information. Distribution of services can be categorized into broadcast, multicast, and point-to-point delivery. Broadcast service delivers the same information to all users in a network. Multicast distribution service distributes information to specific users within a network. Point-to-point service transfers information between two specific users or devices within a network.

The transfer of information between users can be unmodified or modified. Telecommunication services that only involve the transport of information are called bearer services. Services that require information processing (such as store and forward) in the network are called teleservices. Services that combine bearer services and teleservices into a new unique services are called supplemental services.

System features and services are typically provided by call-processing software in the telephone network that interacts with end-user equipment. As a result, some telephone equipment may be only able to operate some system features (e.g., call forwarding) while some service features require device capabilities and software (e.g., calling number identification presentation). To help ensure the correct operation of services and device interaction, industry standards are created.