Categories
Mobile Networks RF

Converting Elevation Data (DEM) for Forsk Atoll

After headaches importing elevation (DEM) data into Forsk Atoll, I found a better mechanism for converting them, I’d been having issues with as soon as the elevation passed 255 meters, resetting to 0 in the PNG as it didn’t understand values beyond this. I was able to open the elevation data in GlobalMapper (You can […]

Categories
EUTRAN LTE Mobile Networks RF

Huawei BTS3900 – MML Basics

Learning Huawei’s flavour of MML – Man Machine Language for the BTS 3900 series Macro Base Stations.

Categories
Mobile Networks RF

DIY LTE RAN Adventure – POWER! (systems)

All the gear I’ve got so far for my DIY RAN Project requires -48vDC to power it up. Back to online auction websites and preso I’ve ended up with an Eltek MPSU3000, from the mid 2000s. The fellow I bought it from was even nice enough to throw a binder full of printed documentation, which […]

Categories
EUTRAN LTE Mobile Networks RF

DIY RAN Adventures – Antennas

Picking and validating antenna selection for the new RAN project in my lab.

Categories
GSM Mobile Networks RF

Using a NanoVNA to analyse SDR Base Station Antennas

Using a NanoVNA to analyse antenna performance for SDR driven Base Stations for GSM / LTE.

Categories
GSM Mobile Networks RF

GSM with Osmocom: Handovers

A look at the Handover process between Cells / BTSs in GSM using the Osmocom stack.

Categories
GSM Mobile Networks RF

GSM with Osmocom: Channel Types

When setting up the timeslots on the TRX for each BTS on your BSC, you’ll notice you have to set a channel type. So what do these acronyms mean, and how do they affect the performance of the network? GSM channels break down into one of to categories, control channels – used for signalling, and […]

Categories
GSM Mobile Networks RF

GSM with Osmocom: GPRS & Packet Data

So far we’ve focused on building a plain “2G” (voice and SMS only) network, which was all consumers expected twenty years ago. As the number of users accessing the internet through DSL, Dial Up & ISDN grew, the idea of getting this data “on the go” became more appealing. TCP/IP was becoming the dominant standard […]

Categories
RF

Dumb Lesson in RF Connectors

Learning a very dumb lesson in antenna selection.

Categories
GSM IMS / VoLTE 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 […]

Categories
GSM Mobile Networks RF SDM Security SIM Cards

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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GSM Mobile Networks RF Software

Configuring YateBTS for Software Defined GSM/GPRS

Configuring YateBTS NIPC with a BladeRF Software Defined Radio

Categories
RF Software

Compiling YateBTS NIPC for Software Defined GSM / GPRS

Setting up YateBTS GSM BTS in Ubuntu 18.04

Categories
EUTRAN GSM LTE Mobile Networks RF

Field Test on an iPhone

Accessing the Field Testing suite on an iOS Device

Categories
EPC EUTRAN LTE Mobile Networks RF SDM Security SIM Cards

HSS & USIM Authentication in LTE/NR (4G & 5G)

Exploring the how and why of Authentication in LTE & NR networks.

Categories
EPC LTE Mobile Networks Python RF SDM

Open5Gs- Python HSS Interface

Note: NextEPC the Open Source project rebranded as Open5Gs in 2019 due to a naming issue. The remaining software called NextEPC is a branch of an old version of Open5Gs. This post was written before the rebranding. I’ve been working for some time on Private LTE networks, the packet core I’m using is NextEPC, it’s […]

Categories
EPC EUTRAN IMS / VoLTE LTE Mobile Networks Python RF RFCs & Standards SDM

PyHSS – Python 3GPP LTE Home Subscriber Server

I recently started working on an issue that I’d seen was to do with the HSS response to the MME on an Update Location Answer. I took some Wireshark traces of a connection from the MME to the HSS, and compared that to a trace from a different HSS. (Amarisoft EPC/HSS) The Update Location Answer […]

Categories
EPC EUTRAN LTE RF RFCs & Standards Voice over IP

Diameter Packet Structure

The packet structure of Diameter

Categories
EPC EUTRAN LTE Mobile Networks RF RFCs & Standards SDM Voice over IP

Diameter Basics

A primer to the Diameter protocol and it’s usage.

Categories
EPC EUTRAN LTE Mobile Networks RF

Qos in LTE (4G) – ARP

ARP in LTE is not the Ethernet standard for address resolution, but rather the Allocation and Retention Policy. A scenario may arise where on a congested cell another bearer is requested to be setup. The P-GW, S-GW or eNB have to make a decision to either drop an existing bearer, or to refuse the request […]