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 […]
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 […]
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 […]
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 […]
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 […]
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 […]
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 saw when a terminal moves to ECC-Idle while in EMM-Registered state, it releases it’s radio resources, so what happens when […]
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 […]
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 […]
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 […]
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 […]
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 […]
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 […]
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 […]
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. […]
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 […]
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 […]
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 […]
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 […]
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 […]