EWSD (Electronic Worldwide Switch Digital, or, in German, Elektronisches WaehlSystem [Digital]) is a widely-installed telephonic switch system developed by Siemens. Siemens says that EWSD performs switching for over 160 million lines in more than 100 countries. EWSD is a modular system in which some switches in the system can be installed in a telephone company's centrex facility and other switches can be located at the customer.
Important features of EWSD include the following:
- Advanced Intelligent Network ( AIN ) 0.1 and 0.2 capabilities allow switching services to be added at Service Control Points, meaning that new services can be added and performed by the switching system without the customer having to buy new equipment.
- In addition to AIN capabilities, EWSD provides ISDN , CLASS, SS7 , and centrex services.
- Digital and analog lines can be combined in the same line groups, allowing full interoperability between digital and analog terminals.
- Carriers using EWSD can provide Automatic Call Distributor services for customers with call center s.
- EWSD provides both Bellcore AIN 0.2 and Global System for Mobile ( GSM ) communications for personal communications services .