If you’ve ever received an SMS from your operator, and the sender was the Operator name for example, you may be left wondering how it’s done. In IMS you’d think this could be quite simple – You’d set the From header to be the name rather than the MSISDN, but for most SMSoIP deployments, the […]
USSD Gateway with Osmocom
Unstructured Supplementary Service Data or “USSD” is the stack used in Cellular Networks to offer interactive text based menus and systems to Subscribers. If you remember topping up your mobile phone credit via a text menu on your flip phone, there’s a good chance that was USSD*. For a period, USSD Services provided Sporting Scores, […]
Looking at the basic components that make up our SS7 Networks.
Taking a look at the basics of the SS7 Protocol Stack.
5G introduces Network Slicing, or does it? A look at slicing mechanisms widely used in pre-5G networks.
Configuring the Osmocom Serving Gateway Support Node (SGSN) for 2G/3G networks.
Using a NanoVNA to analyse antenna performance for SDR driven Base Stations for GSM / LTE.
Twenty years of the Nokia 3310
1 September 2000 was when the 3310 was released…
GSM with Osmocom: Handovers
A look at the Handover process between Cells / BTSs in GSM using the Osmocom stack.
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 […]
Depending on if you’re wearing a tin foil hat or not, silent SMS and silent calls could be a useful tool to for administering the network or a backdoor put in to track citizenry! Regardless of it’s reasons for existence, let’s take a look at what it actually does, and how we can use it. […]
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 […]
GSM with Osmocom: SS7 & Sigtran
SS7 Basics and Osmo-STP as a Signaling Transfer Point
GSM with Osmocom: NanoBTS
Setting up ipaccess NanoBTS on Osmocom’s OsmoBSC
Sending SMS over LTE using OsmoMSC and OsmoHLR and the SGs interface for SMSoS
Looking into the SGi interface for Circuit Switched Fallback in LTE to use GSM/UMTS networks for Calls & SMS
How call routing in GSM works and it’s application in the Osmocom suite
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 […]
Setting up the Mobile Switching Centre for a GSM network using OsmoMSC.