Categories
EPC EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 2. UE Connection to the Network

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. One of the common themes we cover over and over in the 4G discussion is the desire to preserve energy on the UE […]

Categories
EPC EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Management of Sporadic Data Flows – 1. Attach and Detach Procedures

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. A LTE UE has permanent IP connectivity for as long as it is connected. As soon as the UE powers up it requests […]

Categories
EPC EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Management of Data Flows – 7. NAS and Global View of Protocol Stack

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. The LTE architecture compartmentalises the roles in the mobile network. For example the eNB concentrates on radio connection management, while the MME focuses […]

Categories
EPC EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Management of Data Flows – 5/6. S1AP Connection

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. Each MME can manage millions of UEs. To handle this load the requirements of each subscriber for the MME must be as minimal […]

Categories
EPC EUTRAN LTE Mobile Networks RF

IMTx: NET02x (4G Network Essentials) – Management of Data Flows – 4. Transmitting Packets in a Tunnel

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. Establishing a GTP Tunnel When a new tunnel is setup between two nodes, GTP-C will be used to setup the tunnel and the […]

Categories
EPC EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Management of Data Flows – 3. Identifying & Managing Tunnels

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 talked about traffic to and from UEs is encapsulated in GTP-U tunnels, with the idea that by encapsulating data destined for […]

Categories
EPC EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Management of Data Flows – 2. GTP Protocol

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. When a packet arrives from an external network, like the internet, it is routed to the P-GW. The P-GW takes this packet and […]

Categories
EPC EUTRAN LTE Mobile Networks RF

IMTx: NET02x (4G Network Essentials) – Management of Data Flows – 1. Principle of Encapsulation

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. Mobile networks are by definition, mobile. In a fixed network, if I were to connect my laptop to my network at home, I’d […]

Categories
EPC EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Radio Interface – 7. PDCP & Global Vision

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. The Packet Data Convergence Protocol PDCP protocol stack sits ontop of the radio interface stack, and manages the connection the EPC. There is […]

Categories
EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Radio Interface – 6. Random Access

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. LTE mostly relies on reservation based protocols, meaning resources are broken up into smaller elements which are reserved and allocated dynamically as needed. […]

Categories
EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Radio Interface – 5. RLC Protocol

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 just discussed the MAC layer multiplexes streams from the RLC layer. This allows mutliple streams of data to share the same […]

Categories
EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Radio Interface – 4. Transmission Reliability in Radio

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. Radio is always subject to interference, we talked before about how coding is used on the physical layer to try and correct these […]

Categories
EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Radio Interface – 3. Packet Allocation

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. Allocation Tables To inform UEs of which resources are allocated to it, the eNB regularly publishes Allocation Tables with this information. Resources are […]

Categories
EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Radio Interface – 2. Resource Blocks & Sub-Frames

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 spectrum is sparse and expensive, so it must be used wisely and shared across multiple users. LTE shares spectrum in both frequency […]

Categories
EUTRAN LTE Mobile Networks Notes RF

IMTx: NET02x (4G Network Essentials) – Radio Interface – 1. Radio Transmission

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. The E-UTRAN relies on Phase Shift Keying to modulate data. The downlink uses orthogonal frequency division multiplex (OFDM) while the uplink uses SC-FDMA […]

Categories
EPC Linux LTE Mobile Networks RF

Magma – Facebook’s Open Source LTE / 4G EPC/OSS Platform

In February Facebook announced they’d open sourced their Magma project, Magma provides a software-centric distributed mobile packet core and tools for automating network management. Open-sourcing Magma to extend mobile networks Magma’s modular software based architecture means you can scale up extra resources as needed, with no need to have physical hardware to run your EPC. […]

Categories
EPC LTE Mobile Networks Notes RFCs & Standards Security Software Voice over IP

All About IMS Authentication (AKAv1-MD5) in VoLTE Networks

How the AKAv1-MD5 algorith derives keys and how it’s used in IMS Networks