About PSTN and ISDN

PSTN (Public Switched Telephone Network) and ISDN (Integrated Services Digital Network) are legacy telecommunication networks that, despite VoIP growth, are still the most used ones for fixed line telecommunications.

Bithium has gained significant experience in developing products with these interfaces. Although being legacy and a technology available for significant time, the development of terminal equipment using them still have some significant challenges.

What is new in PSTN compared with my grandmothers original telephone?

Analogue telephones can provide today support for caller-ID indication, parallel-phone detection and, in some cases, SMS and MMS support. Typical challenges in the design of a new telephone include the caller-ID detection (different in different countries), line echo-canceling and making sure the nest audio quality is attained (acoustics is a key part in this point).

Can Bithium develop specific corded or cordless terminals with PSTN interface?

Surely yes. The challenges on the telephone line interface (in the different world regions and countries) has been addressed. We can assist you in developing your product so that you will gain approval in the target markets that you address.

Some components of my product are being discontinued. Can Bithium help me in this?

Yes. Bithium can re-design your product with up-to-date hardware and make it a renewed success.

I would like to design an ISDN terminal to interface with my specific system. Can Bithium help?

Yes. Bithium has designed both standalone terminals and business ISDN equipment that integrate with the system as a whole. We have our own ISDN protocol stack which, if needed, we can tailor to meet specific special requirements.

Bithium's ISDN protocol stack for terminals (TE side) is available for Infineon PSB2150 (IPAC-X) and PSB21391 (SCOUT-P) ISDN processors.

At the moment it supports basic rate interface (BRI) and it is ETSI Euro ISDN DSS1 compliant (D-channel Protocol implementation).

The protocol stack runs on top of Bithium's TOS (Telecom OS) RTOS and is available both in library and source code formats.

Furthermore ISDN and DECT or CAT-iq protocols can be run on a single processor such as Sitel DECT baseband processors.