GSM

2G / Global System for Mobiles

GSM
Mobile Networks

GSM with Osmocom: NanoBTS

Setting up ipaccess NanoBTS on Osmocom’s OsmoBSC

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EPC
EUTRAN
GSM
LTE
Mobile Networks

OsmoMSC and Open5GS MME – SGs Interface for CSCF / InterRAT Handover

Looking into the SGi interface for Circuit Switched Fallback in LTE to use GSM/UMTS networks for Calls & SMS

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GSM
Mobile Networks
Voice over IP

GSM with Osmocom: Call routing in GSM

How call routing in GSM works and it’s application in the Osmocom suite

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GSM
Mobile Networks
RF

GSM with Osmocom Part 9: Calls & SMS at last!

So now we’ve covered the basics of what’s involved let’s get some traffic on our network. For starters we’ll need to start each of our network elements and bring up whichever BTS hardware we’re using. In order for our calls to have audio, we’ll need to set a parameter on the Media Gateway. We’ll cover […]

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GSM MSC Architecture
GSM
Mobile Networks

GSM with Osmocom Part 8: The Mobile Switching Center

Setting up the Mobile Switching Centre for a GSM network using OsmoMSC.

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OsmoHLR - Update Location Request
GSM
Mobile Networks

GSM with Osmocom Part 7: The HLR – Home Location Register (and Friends)

The Home Location Register serves the AAA functions in a GSM / UMTS (2G/3G) network as well as locating which Mobile Switching Center (MSC) a subscriber is being served by. The HLR is the equivalent of the Home Subscriber Server in LTE (I’ve written a fair bit about the role of the HSS in LTE […]

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GSM
Mobile Networks

GSM with Osmocom Part 6: Integrating our LimeSDR BTS with OsmoBSC

In the last post we covered the config required to provision a new BTS in our BSC. We’re going to do roughly the same thing this time around, as we connect our SDR based BTS to our BSC. Before we fire up the BTS side of things make sure you’ve stopped the virtual BTS and […]

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GSM
Mobile Networks

GSM with Osmocom Part 5: Software BTS with LimeSDR & osmo-bts-trx

Osmo-BSC accepts Abis over IP connections from a number of different sources, There’s a list of supported BTS hardware that can talk out of the box to the Osmo-BSC, such as the Ericsson RBS series, ip.access nanoBTS, Nokia and Siemens units and even a virtual BTS so you can simulate the connections. If you’re using […]

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GSM
Mobile Networks

GSM with Osmocom Part 4: The Base Station Controller (BSC)

So in our last post we finished setting up a Base Transceiver Station (BTS) but it’s no use unless it can home itself to a Base Station Controller (BSC). So what does a BSC do? The BSC acts as a central controller for one or more BTS. In practice this means the BSC configures most […]

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Basic GSM Architecture
GSM
Mobile Networks

GSM with Osmocom Part 3: Introduction to Osmo Software & Virtual BTS

So this series of posts will focus on using Osmocom software to create a GSM network, so let’s get some Osmocom software installed, and talk about how we run and configure each network element / node. Osmocom Packages For this tutorial series I’ll be using Ubuntu 18.04 and trying where possible to use packages from […]

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GSM base Station
GSM
Mobile Networks

GSM with Osmocom Part 2: BTS Basics

By far the most visable part of any mobile network (apart from your phone!) is the Base (Transciver) Stations. Dotted around the countryside, on masts, towers and monopoles, whether you notice them or not, base stations are everywhere. The Architecture The RF side of LTE has an eNodeB, which is a smart device. – You […]

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Osmocom Logo
GSM
Mobile Networks

GSM with Osmocom Part 1: Intro

Intro to our post series on GSM using the Osmocom stack

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Magic SIM Card Art
GSM
Mobile Networks
RF
Security

16 in 1 Magic SIM Card Revisited

Quick look at cheap “Magic SIM Cards”, what they do, how they do it, and the amazing graphics they use.

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EPC
EUTRAN
GSM
LTE
Mobile Networks
Software

Building Android APN / Carrier Config

How Android OS autoprovisions APN settings and how to set your own for your unique MCC & MNC.

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