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What is ACK and NACK in LTE?

What is ACK and NACK in LTE?

LTE Quick Reference Go Back To Index Home : www.sharetechnote.com. Ack Nack Repetition. As you may guess from the terminoloty itself, ACK NACK repetition is a method in which a sender (UE in current specification) transmit ACK/NACK multiple times in a row. In an aspect, we can say it is similar concept to TTI Bundling.

What is HARQ LTE?

HARQ stands for Hybrid Automatic Repeat Request. HARQ = ARQ + FEC (Forward Error Correction)/Soft Combining. ARQ refers to Automatic Repeat Request i.e. if sender doesn’t receive Acknowledgement (ACK) before timeout, the receiver discards the bad packet and sender shall re-transmits the packet.

What are max no of HARQ retransmission in LTE fdd?

In FDD systems, multiple HARQ processes can be activated in both downlink and uplink directions. Due to the fixed timing associations between the original and the retransmission on the uplink, the maximum number of HARQ processes has been set to eight.

What is ACK NACK in network?

An Acknowledgement (ACK) or Negative Acknowledgement (NACK) is a short message sent by the receiver to the transmitter to indicate whether it has correctly or incorrectly received a data packet, respectively.

What are channels in LTE?

What is a Channel in LTE? The information flows between the different protocols layers are known as channels. These are used to segregate the different types of data and allow them to be transported across different layers.

What is the use of NACK signal?

NACK, or NAK, an abbreviation for negative acknowledgment or not acknowledged, is a signal used by computers or other devices to indicate that data transmitted over a network was received with errors or was otherwise unreadable.

What means ACK?

Acknowledge. ACK is also used to mean “Acknowledge,” as in to confirm receipt or understanding of a message. It may also be based on data communication protocols, many of which are “ACK based,” meaning that they automatically acknowledge receipt of messages by sending a coded reply.

How is ACK NACK repetition similar to TTI bundling?

As you may guess from the terminoloty itself, ACK NACK repetition is a method in which a sender (UE in current specification) transmit ACK/NACK multiple times in a row. In an aspect, we can say it is similar concept to TTI Bundling.

Which is the advantage of ACK NACK repetition?

Overall Ack Nack Repetition flow can be illustrated as shown below. The advantage and disadvatage of Ack/Nack repetition is similar to that of TTI bundling. In short, the advantage is that it increase the probability of Ack/Nack information at destination.

How are physical channels used in LTE network?

The following list describes LTE downlink physical channels and physical signals. Downlink physical channels carry layer 2 information but downlink physical signals are only used by the physical layer. Carries the DL-SCH and PCH. DL-SCH contains actual user data.

How does LTE basic procedure go back to index home?

LTE Basic Procedure Go Back To Index Home : www.sharetechnote.com Downlink Data Transmission Process (HARQ ACK/NACK) i) Network High Layer ( RRC or TE) -> Lower Layer : Transmit the data toward the lower layer. ii) Network -> UE : Transmit the data via PDSCH