4G LTE

States in RRC There are 2 states in RRC layer. 1. RRC_CONNECTED 2. RRC_IDLE A UE is in RRC_CONNECTED when an RRC connection has been…

1. Mapping between logical channels and transport channel. 2. Multiplexing of MAC SDU form one or more different logical channels onto the…

Channel Mapping in LTE LTE downlink channel mapping: Images: LTE Up link channel Mapping   LTE Uplink Information Flow: LTE Downlink…

In this chapter we shall see Radio Link Control layer in detail. Before that we shall see an example of Data Flow: SDU: Packets received by a…

HARQ stands for Hybrid Automatic Repeat Request (HARQ). This is a physical layer functionality in LTE. ARQ: Automatic Repeat Request. It…

LTE Physical Layer 2 radio frames are supported: 1. Type 1: FDD : Frequency Division Duplex 2. Type 2: TDD : Time Division Duplex For multiple…

In the last chapter we learn about LTE User Plane Protocol stack, in this chapter we shall see LTE Control Plane Protocol Stack. Below 2…

In LTE, depending upon User plane or Control Plane, the protocol stack has been divided into 2 different types. 1. LTE User Plane Protocol…

LTE security is an very important topic. In LTE we have 3 key pillars of security. They are 1. Authentication 2. Integrity 3. Encryption. 1.…

Below diagram shows the architecture of AIR interface: The above image shows the protocols used in the air interface with User Equipment…