Bandwidth Part Configurations

Introduction:

Bandwidth Part (BWP) configurations are used in 5G New Radio (NR) to dynamically adjust the system bandwidth to meet varying service requirements. It is a feature that helps in achieving efficient spectrum utilization, which is critical for providing high-speed connectivity to millions of devices.

The 5G NR supports bandwidths ranging from 5 MHz to 400 MHz. The BWP configurations help in partitioning the system bandwidth into smaller sub-bands, thereby enabling flexible allocation of radio resources to different services. In this article, we will discuss the various BWP configurations and their technical aspects.

Bandwidth Part (BWP) Configuration:

The BWP is defined as a contiguous set of resource blocks (RBs) in the frequency domain. The size of the BWP is determined by the maximum bandwidth that can be supported by the device or network. It is divided into a set of Resource Block Groups (RBGs), which can be further divided into Resource Blocks (RBs).

The BWP can be configured in various ways, depending on the requirements of the service. The different BWP configurations are as follows:

Contiguous BWP:

The contiguous BWP configuration uses a single BWP that covers the entire system bandwidth. It is the simplest BWP configuration and is used for services that require the full system bandwidth. The contiguous BWP is used when there are no constraints on the available spectrum, and the device or network can use the full bandwidth.

Non-Contiguous BWP:

The non-contiguous BWP configuration uses multiple BWPs that are not contiguous. It is used when the available spectrum is limited, and there is a need to partition the system bandwidth into smaller sub-bands. The non-contiguous BWP configuration helps in achieving efficient spectrum utilization and enables the allocation of radio resources to different services based on their requirements.

Intra-Band Contiguous BWP:

The intra-band contiguous BWP configuration uses multiple BWPs that are contiguous within a particular frequency band. It is used when there is a need to allocate different services to different parts of the frequency band. For example, one BWP can be used for voice services, while another BWP can be used for data services.

Intra-Band Non-Contiguous BWP:

The intra-band non-contiguous BWP configuration uses multiple BWPs that are non-contiguous within a particular frequency band. It is used when there is a need to allocate different services to different parts of the frequency band, but the available spectrum is limited. The intra-band non-contiguous BWP configuration helps in achieving efficient spectrum utilization and enables the allocation of radio resources to different services based on their requirements.

Inter-Band Contiguous BWP:

The inter-band contiguous BWP configuration uses multiple BWPs that are contiguous across multiple frequency bands. It is used when there is a need to allocate different services to different frequency bands. For example, one BWP can be used for voice services in the lower frequency band, while another BWP can be used for data services in the higher frequency band.

Inter-Band Non-Contiguous BWP:

The inter-band non-contiguous BWP configuration uses multiple BWPs that are non-contiguous across multiple frequency bands. It is used when there is a need to allocate different services to different frequency bands, but the available spectrum is limited. The inter-band non-contiguous BWP configuration helps in achieving efficient spectrum utilization and enables the allocation of radio resources to different services based on their requirements.

BWP Configuration Parameters:

The BWP configuration is defined by several parameters that determine the size and location of the BWP within the system bandwidth. The parameters are as follows:

BWP ID:

The BWP ID is a unique identifier for each BWP within the system bandwidth. The BWP ID is used to differentiate between different BWPs and is used by the device or network to determine which BWP to use for a particular service.

BWP size:

The BWP size is the number of RBs that are allocated to the BWP. The BWP size can range from 5 MHz to 100 MHz, depending on the maximum bandwidth supported by the device or network. The BWP size determines the amount of radio resources that are allocated to the BWP and is used to meet the service requirements.

BWP start RB:

The BWP start RB is the index of the first RB in the BWP. The BWP start RB determines the location of the BWP within the system bandwidth and is used to partition the system bandwidth into smaller sub-bands.

BWP subcarrier spacing:

The BWP subcarrier spacing is the spacing between adjacent subcarriers within the BWP. The subcarrier spacing can be 15 kHz, 30 kHz, 60 kHz, or 120 kHz, depending on the service requirements. The subcarrier spacing is used to determine the data rate and latency of the service.

BWP cyclic prefix length:

The BWP cyclic prefix length is the length of the cyclic prefix that is added to each OFDM symbol within the BWP. The cyclic prefix length can be 0, 1, or 2, depending on the service requirements. The cyclic prefix is used to mitigate the effects of multi-path propagation and is used to improve the signal quality.

BWP Operation:

The BWP operates in conjunction with the carrier aggregation (CA) feature of 5G NR. The CA feature enables the device or network to combine multiple carriers to increase the system bandwidth and meet the service requirements. The CA feature enables the device or network to use multiple BWPs simultaneously to meet the service requirements.

The device or network selects the BWP to use based on the service requirements and the available radio resources. The device or network can use the full system bandwidth by using a contiguous BWP, or it can partition the system bandwidth into smaller sub-bands by using a non-contiguous BWP. The device or network can allocate different services to different BWPs based on their requirements and can adjust the BWP parameters to meet the changing service requirements.

Conclusion:

In conclusion, the Bandwidth Part (BWP) configurations in 5G NR are used to partition the system bandwidth into smaller sub-bands and enable the allocation of radio resources to different services based on their requirements. The BWP configurations are defined by several parameters, including the BWP ID, BWP size, BWP start RB, BWP subcarrier spacing, and BWP cyclic prefix length. The different BWP configurations, including contiguous BWP, non-contiguous BWP, intra-band contiguous BWP, intra-band non-contiguous BWP, inter-band contiguous BWP, and inter-band non-contiguous BWP, are used based on the service requirements and the available radio resources. The BWP operates in conjunction with the carrier aggregation (CA) feature of 5G NR, and the device or network can use multiple BWPs simultaneously to meet the service requirements. The BWP configurations enable efficient spectrum utilization and provide high-speed connectivity to millions of devices.