Functionality of eNB MME selection based on Relative Capacity IE
Using SDR hardware to view the LTE System Information Block’s contents.
What the Origin-State-Id AVP does and how it is used to track if a Diameter peer restarts.
Why the BaiCells PLMN changes?
A look into the signalling messages between Network elements in an Evolved Packet Core exchanged during the Attach Procedure
These posts focus on the use of Diameter and SIP in an IMS / VoLTE context, however these practices can be equally applied to other networks. The Registration-Termination Request / Answer allow a Diameter Client (S-CSCF) to indicate to the HSS (Diameter Server) that it is no longer serving that user and the registration has […]
Note: I’m running version 19.12.0 which I installed from the repos due to issues with 20.4.0 (latest when I wrote this) and stability on LimeSDR. I wrote the other day about installing SRS LTE stack, But installing it is one thing, meeting all the requirements to use it with your SDR hardware turns out to […]
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
Using Wireshark to view and analyze MAC layer LTE traffic
Accessing the Field Testing suite on an iOS Device
Multi-tenancy on the RAN side of the network, allowing an eNB to broadcast multiple PLMN IDs (MCC/MNC) in the System Information Block (SIB).
Lessons learned about setting up VoLTE / IMS Networks at small scale.
Configuring BaiCells Neutrino eNB
How the P-CSCF address is assigned to a UE in Protocol Configuration Options (PCO) during bearer establishment.
Using SRS LTE Stack with the BladeRF x40 Software Defined Radio (SDR)
An update to PyHSS to support IMS Authentication for VoLTE
The exchange between a UE and P-CSCF to put SIP traffic into IPsec encapsulated payloads.
Viewing the payload of an Encapsulated Security Payload in Wireshark.
Unlocking the built in IMS Debugging tool in Samsung’s Sysdump Utility