In 5G channel allocation is very flexible unlike 4G in both time and frequency.

• SSBurst/PBCH can be allocated anywhere in the frequency, it need not to be allocated at the center of the carrier. It also has multiple locations in time.
• PDCCH is normally at the start of the slot in symbol 0,1,2 but need not to be. In frequency it can be anywhere.
• PDSCH and PUSCH are completely flexible in both time and frequency. They can have min. 1 PRB to 273 PRBs and from 1 symbol to 14 symbols.
• PUCCH is mostly at the end of the slot if it not occupying fill slot in time. It is also mostly transmitted at the starting or last PRB.

Ofcourse there are certain rules for resource allocation for physical channels in 5G, but allocation comes with huge flexibility.

RRH stands for Remote Radio Head. It is a type of equipment used in wireless communication systems, particularly in cellular networks. A RRH is a radio transceiver that is typically located on a tower or other tall structure, and is connected to a baseband unit (BBU) via a fiber optic cable.

RRH is a separate unit from the Baseband Unit (BBU), which is responsible for processing the signals, while the RRH is responsible for transmitting and receiving the radio signals to and from mobile devices. This separation of the radio functions from the baseband functions allows for more efficient use of the network resources and more flexibility in network deployment.

The RRH is usually mounted near the antenna to reduce transmission line losses. The RRH has two parts, a transmit part and a receive part.

The transmit part usually consists of a DAC, Mixer, Power Amplifier and Filters. A digital signal is received via a CPRI interface, converted to analog, upconverted to an RF Frequency, amplified, filtered and then sent out via an antenna.

The Receive part consists of a filter, Low Noise Amplifier, Mixer and an ADC. It receives a signal from the antenna, filters it, amplifies it, down-converts it to an IF Frequency and then converts it to a digital signal, before sending it out via the CPRI to a fiber for further processing.

In 5G New Radio (NR) cellular networks, the User Equipment (UE) still uses random access to initiate communication with the network. However, the PRACH process has been updated to include several new features and enhancements.

In 5G NR, the UE decides when to send a PRACH request based on various factors such as its own traffic requirements, the state of the network, and the availability of resources. For example, the UE may decide to send a PRACH request when it needs to initiate a new session or when it wants to send data. The UE may also send a PRACH request periodically to maintain its connection with the network.

The UE also decides where to send the PRACH request by selecting a preamble from a set of preambles that are defined by the network. The preambles in 5G NR are grouped into different subsets, and the UE selects the appropriate subset based on the current network conditions and its own capabilities. The UE also selects a specific preamble from within the selected subset based on its own random choice.

In 5G NR the PRACH resources are divided into different frequency-time locations called “PRACH occasion”, and each of them have different characteristics like the number of preambles available and the maximum transmit power. The UE should select the appropriate PRACH occasion based on the current network conditions and its own capabilities.

In summary, in 5G NR, the UE still decides when to send PRACH request based on its own requirements, and also decide where to send the PRACH request by selecting a preamble from a set of preambles defined by the network and selecting the appropriate PRACH occasion based on the current network conditions and its own capabilities.

In Long-Term Evolution (LTE) networks, a “bearer” is a logical channel that is used to transport data between the mobile device and the network. There are two types of bearers in LTE: dedicated bearers and default bearers. A dedicated bearer is a unique, dedicated connection that is established between the mobile device and the network for a specific application or service. A default bearer, on the other hand, is a shared connection that is used by multiple applications or services on the device.

An “event” in LTE refers to a specific occurrence or change in the network or on a mobile device that triggers a particular action or response. Examples of events in LTE include a change in radio conditions, the arrival of a new packet, or the expiration of a timer. Events can be triggered by the network or by the mobile device, and they are used to control various aspects of the LTE system, such as handover, scheduling, and resource allocation.

6G is the next generation of wireless technology that is currently under development. It is expected to build upon the capabilities of 5G, which is the current generation of wireless technology, by providing even faster speeds, lower latency, and improved reliability.

Some of the potential benefits of 6G include:

• Even faster data speeds: 6G is expected to offer download speeds of up to 1 terabyte per second, which is significantly faster than the maximum speeds currently available with 5G.
• Increased capacity: 6G is expected to be able to handle a much larger number of connected devices than 5G, which will be important as more and more devices become connected to the internet.
• Lower latency: Latency is the time it takes for a signal to travel from one point to another. 6G is expected to have extremely low latency, which will be important for applications such as virtual reality and autonomous vehicles.
• More advanced security: As with any new technology, 6G is expected to have more advanced security features to protect against potential cyberattacks.
• Increased energy efficiency: 6G is expected to have more energy-efficient technologies, which will help to reduce the power consumption of connected devices.

It’s worth noting that 6G is still in its early stages of development and the actual implementation and benefits may vary.