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5G MSG3 – PUSCH Scheduled Transmission by RAR UL grant

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1. 5G:

5G refers to the fifth generation of mobile network technology. It promises faster data rates, lower latency, increased reliability, and better connectivity compared to its predecessors (4G, 3G, etc.). One of the key aspects of 5G is its ability to handle a massive number of devices and diverse use cases, from IoT to high-definition streaming.

2. MSG3:

MSG3 is a specific message in the 5G RACH (Random Access Channel) procedure. The RACH procedure is used by user devices (like smartphones or IoT devices) to request resources or establish an initial connection with the 5G network.

3. PUSCH:

PUSCH stands for Physical Uplink Shared Channel. It's a channel in the 5G air interface that carries user data from the user equipment (UE) to the base station (gNodeB).

4. Scheduled Transmission:

In the context of 5G, a scheduled transmission means that the transmission time and resources (like frequency and bandwidth) are pre-allocated by the network to the user equipment (UE). This is in contrast to unscheduled transmissions, where the UE may have to contend for resources.

5. RAR UL Grant:

RAR stands for Random Access Response, and UL stands for Uplink. When a UE initiates a connection or data transfer, it sends a random access preamble to the gNodeB. The gNodeB responds with a RAR message, which includes the UL grant. The UL grant specifies the resources (like frequency, time, and power) allocated for the UE to transmit its data.

5G MSG3 – PUSCH Scheduled Transmission by RAR UL grant:

  1. MSG3 in the RACH Procedure: When a UE attempts to establish a connection with the 5G network, it follows a sequence of steps called the RACH procedure. The MSG3 is a specific message within this sequence where the UE provides additional information like its identity and the reason for the request.
  2. PUSCH Scheduled Transmission: Once the gNodeB receives the MSG3 and determines that it needs to allocate resources for the UE, it schedules a PUSCH transmission. This means the gNodeB tells the UE when and how to transmit its data on the uplink shared channel (PUSCH).
  3. RAR UL Grant: After processing the MSG3 message, the gNodeB responds with a RAR message that contains the UL grant. This UL grant provides the UE with specific instructions on how to send its data on the PUSCH. The instructions will include details like the frequency, time duration, power level, and any other necessary parameters.