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This repository contains a variety of different projects related toE1/TDM hardware interfaces

• icE1usb (fully-fledged USB E1 interface adapter)
• osmo-e1-tracer (fully integrated passive raw bitstream tracer)
• osmo-e1-tap (passive high-impedance E1/T1 tap)
• osmo-e1-xcvr (E1 LIU + magnetics)https://osmocom.org/projects/e1-t1-adapter/wiki/Osmo-e1-xcvr

The Osmocom icE1usb project is an open source hardware, gateware and firmwareproject implementing a USB-attached interface for E1 circuits. Use thisif you want to implement a system speaking to an E1 circuit, such as

• a GSM BSC (usingOsmoBSC) talking Abis/E1 to a GSM Base station,
• usingosmo-gbproxy to convert classing Gb/E1 to Gb/IP
• talking to legacy ISDN PRI equipment such as PBX, RAS servers, etc.
• connecting legacy ISDN PRI equipment such as PBX, RAS servers, etc. totheOCTOI comminity TDMoIP network

Depending on your USB host controller, it supports one or two E1circuits. Most host controllers can only support one E1 circuit.

In order to provide a stable E1 clock reference, it contains a GPS disciplined oscillator.

Seehttps://osmocom.org/projects/e1-t1-adapter/wiki/IcE1usb for more details.

Fully assembled units can be purchased at thesysmocomwebshop

Check thehardware/icE1usb,firmware/ice40-riscv/icE1usb directories in this repository.

The host software is provided either

• viaosmo-e1d, or
• via theicE1usb DAHDI driver

This is a fully integrated design that allows you to obtain bi-directional high-impedancebitstream E1 traces. It features an iCE40 FPGA with USB + E1 cores from Sylvain Munaut,as well as two E1 LIUs.

Seehttps://osmocom.org/projects/e1-t1-adapter/wiki/E1_tracer for more details.

Fully assembled units can be purchased made-to-order fromsysmocom.

Check thehardware/e1-tracer,firmware/ice40-riscv/e1-tracer andsoftware/e1-tracerdirectories in this repository.

This was a simple hardware project that aims to generate a reusable modulefor interfacing E1/T1/J1 lines from various custom FPGA/CPLD/microcontrollerprojects. Consider it part of an earlier R&D setup before icE1usb andosmo-e1-tracer were around.

The board contains transformers, the analog circuitry, the LIU (line interfaceunit), an oscillator as well as an integrated transceiver chip.

It exposes the control interface (SPI) as well as the decoded synchronousRx/Tx bitstreams each on a 2x5pin header.

Framer, Multiplexer, HDLC decoder or anything like that is out-of-scope fornow. The idea really is to provide an interface as low-level as possible.

One of the ideas is to create a "soft E1" interface, where the Rx/Tx bitstreamsare interfaced with the SSC of an AT91SAM3S and subsequently passed into a PCvia USB. The 2Mbps signal is very low-bandwidth, so that a pure softwareimplementation should be absolutely no problem for todays computing power.

Seehttps://osmocom.org/projects/e1-t1-adapter/wiki/Osmo-e1-xcvr for more details

Check thehardware/e1-xcvr directory in this repository.

This is a small passive board that allows you to perform high-impedance tracing on an E1or T1 line.

Fully assembled units can be purchased at thesysmocomwebshop.

Check thehardware/e1-tap directory in this repository.