Project

General

Profile

Wiki » History » Revision 4

Revision 3 (laforge, 03/04/2020 08:35 PM) → Revision 4/5 (laforge, 08/22/2020 07:02 AM)

h1. Wiki 

 {{>toc}} 

 h2. Overview 

 This wiki describes work within the Osmocom community to develop E1/T1 hardware interfaces.    There were several different approaches taken, implemented to a verying degree and experimented with. 

 If you are a user and not a developer, there are so far only two hardware interface projects that have reached the stage where they can be cnsidered ready/usable: 
 * [[E1_tracer]] - a passive E1 tracer that can record the bi-directional bit-stream of an E1 line 
 * [[ICE40 E1 USB interface]] - an inexpensive, open source hardware, gateware, firmware and software interface for terminating E1 circuits. 


 h2. E1/T1 TDM technology 

 E1/T1 lines were pretty common in the 1990ies and up until about 2010, as they built the heart of many connections to the digital, circuit-switched telephony (ISDN) network. 

 Today (2019), E1/T1 are mostly only found in connection with GSM base stations (BTS), where the Abis interface of a BTS is still officially only specified over E1/T1. 

 Hardware for connecting E1/T1 to a (Linux) computer has always been expensive, and is rather difficult to find.    Also, it only comes in PCI and PCIe form-factor, making it unsuitable to many popular embedded Linux platforms (whether ARM or x86) which don't feature such interfaces. 

 We've been wokring on creating E1-USB adapters based on a variety of approaches, see further wiki pages for details. 

 h2. Sub-pages 

 {{child_pages}} 

 {{include(cellular-infrastructure:MacroCommercialSupport)}}
Add picture from clipboard (Maximum size: 48.8 MB)