Radio Bearer in LTE In Long-Term Evolution (LTE) wireless communication, a “Radio Bearer” serves as a crucial link between the user equipment (UE) and the evolved NodeB (eNodeB), facilitating the exchange of data. Radio Bearers are classified into two main categories: Control Radio Bearers (CRBs) and Data Radio Bearers (DRBs). CRBs are responsible for transmitting … Read more
Eps bearer LTE EPS is a connection-oriented transmission network and, as such, it requires the establishment of a “virtual” connection between two endpoints (e.g. a UE and a PDN-GW) This virtual connection is called an “EPS Bearer” It provides a “bearer service”, i.e. a transport service with specific QoS attributes. The LTE QoS parameters associated … Read more
After the power on, the UE knows: the UE category and capability. the preferred PLMN. the carriers. The UE needs to know: The frame synchronization to be able to decode the DL radio frame. The cell parameters to be able request a connection. The UE can use: The PSS: Primary Synchronization Signal. The SSS: Secondary … Read more
Synchronization & BCH for TDD Frame in LTE Synchronization: Purpose: Achieves alignment between the base station (eNodeB) and User Equipment (UE) in LTE Time-Division Duplex (TDD) frames. Methods: Time synchronization ensures proper timing, and frequency synchronization aligns the carrier frequency. Importance: Synchronization is critical for avoiding interference and optimizing signal reception. Broadcast Channel (BCH): Function: … Read more
When the UE has obtained system information, it has to request an RRCconnection. Like it has no dedicated resources, the UE requests the connection using the Random Access Procedure using common uplink resources. At the end of the procedure, the UE is RRC connected UE and eNodeB are able to exchange data using dedicated radio … Read more
Different modulation methods corresponding to different transmitting abilities in air interface. R99/R4: QPSK HSDPA: QPSK or 16QAM The UTRAN air interface uses QPSK modulation in the downlink, although HSDPA may also employ 16 Quadrature Amplitude Modulation (16QAM). 16QAM requires good radio conditions to work well. As seen, with 16QAM also the amplitude of the signal … Read more
Step of RRC Connection Setup in LTE When the UE is powered up, it has to be RRC connected to be able to exchange data and signaling with the network. After the RRC connection, the Initial network attach allows to establish all the bearers to carry the data from the UE to the gateway. After … Read more
Logical Channel = information container Defined by is transferred. Transport Channel = characteristics of transmission Described by and with data is transmitted over the radio interface . Physical Channel = specification of the information global content providing the real transmission resource, maybe a frequency ,a specific set of codes and phase. In terms of protocol … Read more
Purpose of Channelization Code & Scrambling Code in WCDMA Purpose of Channelization Code & Scrambling Code in WCDMA Channelization Codes in WCDMA: Channelization codes, also known as Walsh codes, serve a critical purpose in WCDMA (Wideband Code Division Multiple Access) networks. These codes are used for the spreading of user data over a wide frequency … Read more
How Process Gain works in 3G? Process Gain = 10 Log (Chip rate/Bit Rate) Process gain differs for each service. If the service bit rate is greater, the process gain is smaller, UE needs more power for this service, then the coverage of this service will be smaller, vice versa. For common services, the bit … Read more