In Long-Term Evolution (LTE), the channel architecture refers to the organization and allocation of different types of channels used for communication between the User Equipment (UE) and the Evolved NodeB (eNB). LTE employs a flexible and efficient channel architecture to support various services and optimize resource utilization. Here are key components of the channel architecture … Read more
Mobile WiMAX frame structure Unlike Fixed WiMAX, which uses OFDM frames, Mobile WiMAX uses OFDMA frames. OFDMA allows multiple users to receive data from the base station at the same time. In this type of system, the downlink bursts from the base station are divided by a time offset and a frequency offset (sub-channel offset). … Read more
The 3G LTE uses 3 Quadrature Amplitude Modulations (QAMs) depending on the radio quality. QAM uses both the amplitude and the phase. LTE devices use QPSK, 16QAM and 64QAM to modulate data and control information. The eNodeB supports all of these modulation techniques for the downlink direction. However, 64QAM is optional in the uplink direction. … Read more
How Physical channel of LTE works in UL & DL?A distinction has to made between: The Physical channel The Physical signal The DL physical channels are: Physical DL Shared Channel (PDSCH) It is a shared channel used to carry user data, radio & core network, system information (BCH), paging message. Physical DL Control Channel (PDCCH) … Read more
Transport channels are then mapped on the physical channels which are sent over the air interface A CRC is calculated and appended to each TB. It allows the receiver to detect errors. It is used by retransmission mechanisms like H-ARQ Depending on the Transport Format and the radio quality, the TB is coded and interleaved. … Read more
A transport channel defines how and with what characteristics the information is transmitted. Inherited from the WCDMA, data on the transport channel is organized into “Transport Blocks”, TBs. A Transport block can be transmitted every TTI = 1 ms The “Transport Format”, TF, defines how the blocks can be transmitted: Transport block size, it depends … Read more
The following control logical channels have been defined by the 3GPP: BCCH, Broadcast Control Channel, used for the transmission of system control information. A UE needs to decode it before requesting a connection. PCCH, Paging Control Channel, is a downlink channel that transfers paging information and system information change notifications. This channel is used for … Read more
There are different band in different country but most of commonly used band we will discuss here. Main bands : means basic band when 3G commercial launch by Private or public sector. 1920 ~ 1980MHz / 2110 ~ 2170MHz Supplementary bands: different country maybe different as per government selling in auction. 1850 ~ 1910 MHz / 1930 MHz … Read more
The MAC protocol provides the following services: Logical Channel to Transport channel mapping Scheduling: There is no dedicated channel allocated to a UE. Time and frequency resources are dynamically shared between the users in DL and UL. The scheduler is part of the MAC layer and controls the assignment of uplink and downlink resources. Multiplexing/Demultiplexing … Read more
The Radio Link Control (RLC) protocol provides the following services: Segmentation of SDU according to the size Re-Segmentation of PDU Radio Bearer to logical channel mapping Transfer of data in 3 modes: TM Transparent Mode Without retransmission. For real-time service. UM Unacknowledged Mode Without retransmission, but error statistics (BLER) It can be used for the … Read more