Low-cost GSM telephony in the Amazon region based on open-source / open-hardware projects

摘要

This work presents an on-going project that consists in providing low-cost telephony services in remote areas in the Amazon region, North Brazil. The idea is to build GSM networks using open-source and open-hardware projects, such as: OpenBTS, Openmoko, IP04, Asterisk and USRP. The NavegaPará Program, which currently connects thirteen cities in the state, provides the backbone network with optical fiber and digital radios. This paper summarizes the project and discusses the strategy adopted to circumvent a specific problem: the establishment of know-how on GSM technologies among engineering (electrical and computer) students. Several handson experiments in GSM technologies are being currently used and some are described here. For example, the work discusses how the Matlab toolkit GSMsim can be used to analyze digitized GSM waveforms. It also describes the development of a QAM modulator for better understanding the basics of GNU Radio. The success of the project will be measured by the effect in the life of citizens who, currently, do not have any access to a phone for basic communication needs.