Importing Elevation data from ELVIS into Forsk Atoll
Category Archives: EUTRAN
Roll your own USIMs for Private LTE Networks
Adventures in getting USIMs to use on private LTE networks.
LTE / EUTRAN – Idle Detach
Overview of the packet flow for a UE Idle detach from the network.
Subscribed-Periodic-RAU-TAU-Timer
Periodic Tracking Area Update timer purpose
The case for Header Compression in VoIP/VoLTE
Robust Header Compression (ROHC) and it’s use for compressing RTP / VoLTE traffic headers.
Building Android APN / Carrier Config
How Android OS autoprovisions APN settings and how to set your own for your unique MCC & MNC.
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 … Continue reading PyHSS – Python 3GPP LTE Home Subscriber Server
Diameter Packet Structure
The packet structure of Diameter
Diameter Basics
A primer to the Diameter protocol and it’s usage.
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 … Continue reading Qos in LTE (4G) – ARP
QoS in LTE (4G) – MBR/AMBR/APN-MBR
MBR stands for Maximum Bit Rate, and it defines the maximum rate traffic can flow between a UE and the network. It can be defined on several levels: MBR per Bearer This is the maximum bit rate per bearer, this rate can be exceeded but if it is exceeded it’s QoS (QCI) values for the … Continue reading QoS in LTE (4G) – MBR/AMBR/APN-MBR
QoS in LTE (4G) – QCI
The QCI (Quality Class Indicator) is a value of 0-9 to denote the service type and the maximum delays, packet loss and throughput the service requires. Different data flows have different service requirements, let’s look at some examples: A VoLTE call requires low latency and low packet loss, without low latency it’ll be impossible to … Continue reading QoS in LTE (4G) – QCI
QoS in LTE (4G) – GBR & Non-GBR Bearers
GBR is a confusing concept at the start when looking at LTE but it’s actually kind of simple when we break it down. GBR stands for Guaranteed Bit Rate, meaning the UE is guaranteed a set bit rate for the bearer. The default bearer is always a non-GBR bearer, with best effort data rates. Let’s … Continue reading QoS in LTE (4G) – GBR & Non-GBR Bearers
Forsk Atoll – WMS Map Tiles
Adding online map tiles in Forsk Atoll
LTE (4G) – TMSI & GUTI
We’ve already touched on how subscribers are authenticated to the network, how the network is authenticated to subscribers and how the key hierarchy works for encryption of user data and control plane data. If the IMSI was broadcast in the clear over the air, anyone listening would have the unique identifier of the subscriber nearby … Continue reading LTE (4G) – TMSI & GUTI
IMTx: NET02x (4G Network Essentials) – Mobility Management – 3. Processing Location Updates
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. Let’s look at how the Tracking Area Updates work from the point of view of the network. Let’s take an example of a … Continue reading IMTx: NET02x (4G Network Essentials) – Mobility Management – 3. Processing Location Updates
IMTx: NET02x (4G Network Essentials) – Mobility Management – 4. Changing MME and SGW
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. As we’ve seen earlier, the eNB needs a connection to an MME and a S-GW. However different eNBs may connect to different S-GWs … Continue reading IMTx: NET02x (4G Network Essentials) – Mobility Management – 4. Changing MME and SGW
IMTx: NET02x (4G Network Essentials) – Mobility Management – 2. Balancing Location Update Load
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. As we saw before larger Tracking Areas minimize the number of UEs between terminals to update their location. The problem is the cells/eNBs … Continue reading IMTx: NET02x (4G Network Essentials) – Mobility Management – 2. Balancing Location Update Load
IMTx: NET02x (4G Network Essentials) – Mobility Management – 1. Managing Location
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. As we saw with the Network Triggered Service Request, the network needs to know which eNB / cell the UE is currently being … Continue reading IMTx: NET02x (4G Network Essentials) – Mobility Management – 1. Managing Location
IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 3. Standby Modes
These are my lecture notes from IMT’s NET02x (4G Network Essentials) course, I thought I’d post them here as they may be useful to someone. You can find my complete notes here. As we discussed before when no data has been sent by a UE for a period of time the eNB will switch from … Continue reading IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 3. Standby Modes
Random Posts on EUTRAN
SIP SIMPLE – Instant Messaging with SIP
FreeSWITCH – Incompatible Destination
LTE / EUTRAN – Idle Detach
Pre-5G Network Slicing
IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 3. Standby Modes
PyHSS – Python 3GPP LTE Home Subscriber Server
The Surprisingly Complicated World of SMS: Apple iPhone MT SMS
Handling multiple SIP headers with the same name in Kamailio
