5G NR

Registration Management is used to register or deregister UE to the network and create a user context in the network. We know that UE needs to…

In this chapter we shall understand what is ARQ and HARQ. ARQ: ARQ stands for Automatic Repeat Request. It is used in Data Link Layer. It is…

A single Central Unit can be connected to multiple Distributed Units. CU-CP will have RRC, PDCP CU-UP will have SDAP, PDCP Distributed Units…

Above image shows overall architecture from 3GPP TS 38.300 specification. Xn interface exists between 2 base stations. Xn-U stands for Xn User…

In previous chapter we shall learned about RRU, BBU, CU, DU fronthaul, midhaul; In this chapter we shall learn about: D-RAN C-RAN cloud RAN…

Fronthaul, Midhaul and Backhaul are used to connect RU, DU and CU and the core network together. They tells us about the transport network…

In this chapter we shall have a look at the functionalities of different RRC States. There are 3 RRC states in 5G NR. 1. RRC Connected 2. RRC…

PDCCH Order will be initiated by network to trigger a Random Access procedure. This is initiated when there is an upstream loss. When gNB has…

UE access procedure is as below: Step 1: UE is Switched ON Step 2: PLMN Selection PLMN Introduction PLMN stands for Public Land Mobile…

Cell Search and Cell Selection 1. When a UE is powered on, it searches for a specific frequency according to Synchronization Raster as defined…