Dynamic spectrum access (DSA), also referred to as dynamic spectrum management (DSM), is a set of spectrum utilization techniques that adjusts frequency in real time based on fluctuating circumstances. Examples of circumstances that might affect spectrum allocation in DSA include energy conservation, battery life, interference, changes in environmental or external regulations and quality of service (QoS).
DSA also provides the ability to share wireless channels between primary, or licensed, and secondary, or unlicensed, users. Primary users always receive the priority, but secondary users can use licensed bands as long as it does not create interference. The goal is to utilize each spectrum more efficiently.
While DSA is still a newer concept that is under development, it is already recognized as a vital component in the introduction of 5G wireless networks. Other developing technologies that facilitate the implementation of DSA include flexible modeling languages and detailed radio access network (RAN) environment maps. The Dynamic Spectrum Alliance is a global organization that oversees the expansion, advocacy and regulations for spectrum utilization.
How DSA works
While the specific method of dynamic spectrum access can vary depending on the service provider, application or hardware vendor, overall, it follows the same process. DSA technology allows radios to share multiple frequency bands without interfering with other systems by combining digital signal processing (DSP), networking and detection capabilities with software algorithms.
DSA focuses on three characteristics- frequency, location and time. Devices continually use spectrum sensors to assess the radio spectrum environment and dynamically allocate or adjust frequencies as needed. Depending on the availability of frequencies in a given location and time, DSA will move users to unoccupied channels. This allows multiple network operators to use the same spectrum in different geographic locations as well as deploy more than one application per spectrum band.
Additionally, implementations of DSA can use principles associated with cross-layer optimization, artificial intelligence (AI), machine learning (ML), link adaptation, bandwidth management and interference estimation.
Benefits of DSA
There are several benefits to using dynamic spectrum access:
- Enables the adoption of technology such as cognitive radio (CR), multi-user MIMO (MU-MIMO) and 5G.
- Allocates networking resources more efficiently.
- Solves signal interference issues.
- Helps manage radio frequency spectrum white space.
- Improves the performance of communication networks and systems.
- Relieves problems associated with spectrum efficiency and scarcity.
- Decreases network deployment time.
- Lowers the barrier to entry for new service providers.
- Increases coverage among rural and urban areas.