VoLTE Introduction 1. VoLTE stands for Voice Over LTE. 2. Until VoLTE was launched, all the calls made from LTE network used to go to Circuit Switched Network. 3. VoLTE was launched after LTE was launched. 4. As 4G is fully PS service, to make calls …
ARQ procedure is performed by RCL AM entity For ARQ procedure, we need to concentrate on 3 topics: 1. Retransmission 2. Polling 3. Status Reporting 1. Retransmission: 1. The Tx side of AM RLC entity can receive NACK for an AMD PDU or a portion of …
It will preform segmentation, reassembly, retransmission of RLC SDU. RLC Headers are added and removed. It will guarantees delivery of RLC PDU. Note: In RLC AM mode, it will receive/sends AMD PDU or AMD PDU segment. This is RLC data PDU. In RLC AM mode, it …
RLC UM mode is used to deliver/receive the messages from DL/UL DTCH, MCCH and MTCH. Here segmentation and reassembly of RLC SDUs will be performed. RLC Headers are added/removed. It will not guarantee delivery. Functions performed by RLC UM Transmitting Entity 1. It will receive …
1. Understanding contention based random access procedure. If 2 UE choose the same preamble sequence and send this sequence to eNB at the same time, this leads to collision. For example, if 2 UE send the same preamble sequence at the same time, there are 2 …
Introduction: RACH stands for Random Access CHannel. UE will perform power on procedure for DL synchronization. UE will perform RACH procedure for UL synchronization. In LTE there is a separate channel called as PRACH (Physical Random Access CHannel) that is provided for initial access to network. …
MAC Scheduler is used to assign bandwidth to UE in uplink and downlink channels. eNB will decide for which UE how many resources to be allocated. MAC scheduler will also enforce QOS like priority, bit rate and latency for different UE connections. How MAC Scheduler works? …
What is the need of timing Advance command? UE will not be in stationary position. It will be moving far away or moving near with respect to eNB. The difference in the distance will reflect in UL transmission time. Because of this, eNB will face interference …
