Sign in Subscribe

LAA (License-Assisted Access)

Last updated on 

Introduction:

License-Assisted Access (LAA) is a wireless technology that enables the use of unlicensed spectrum, like the 5GHz band, to increase the capacity and improve the performance of cellular networks. LAA is a vital component of 5G networks that allows carriers to provide more data to their customers by using both licensed and unlicensed spectrum simultaneously.

LAA operates in the unlicensed spectrum, which means that it doesn't require a license to operate. However, it still needs to adhere to specific rules and regulations set by the regulatory authorities in the countries where it is deployed. LAA is a carrier aggregation technology, which means it can combine the bandwidth of multiple frequency bands, including licensed and unlicensed bands, to provide a better user experience.

LAA Overview:

The LAA technology works by allowing cellular networks to access unlicensed spectrum in a shared manner with other wireless networks. It uses Listen-Before-Talk (LBT) protocol, which is a form of Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), to avoid collisions with other wireless networks that may be operating in the same frequency band.

LAA technology relies on a licensed LTE anchor carrier to ensure that the LBT protocol is followed and that the device is allowed to use the unlicensed spectrum. The licensed LTE anchor carrier is used to exchange control signaling between the network and the device. The device then uses this signaling to listen to the channel and determine whether it is clear to transmit or not.

Once the channel is clear, the device can transmit data using the unlicensed spectrum. If the channel is not clear, the device must wait and listen again before attempting to transmit data. This ensures that the LAA technology doesn't interfere with other wireless networks operating in the same frequency band.

LAA technology uses carrier aggregation to combine the bandwidth of the licensed and unlicensed spectrum. Carrier aggregation is a technique used in LTE networks to combine multiple carriers to increase the bandwidth available to the user. LAA technology uses this same technique to combine the licensed and unlicensed spectrum to provide better performance and higher capacity to users.

Benefits of LAA:

  1. Increased Capacity: The LAA technology allows carriers to use unlicensed spectrum to increase the capacity of their cellular networks. This means that carriers can provide more data to their customers, which leads to a better user experience.
  2. Improved Performance: By combining the licensed and unlicensed spectrum, LAA technology provides a better user experience by increasing the available bandwidth. This results in higher data rates and improved network performance.
  3. Better Coverage: LAA technology can also improve network coverage by providing additional capacity in areas where the licensed spectrum is congested or unavailable.
  4. More Efficient Spectrum Use: LAA technology enables the more efficient use of spectrum by allowing carriers to use unlicensed spectrum to complement their licensed spectrum.
  5. Seamless User Experience: The use of LAA technology is transparent to the user, and they won't notice any difference in the network performance when switching between licensed and unlicensed spectrum.

Challenges of LAA:

  1. Interference: One of the main challenges of LAA technology is the potential for interference with other wireless networks operating in the same frequency band. To avoid this, LAA technology uses LBT protocol, which requires devices to listen to the channel before transmitting data.
  2. Regulatory Issues: LAA technology needs to adhere to specific rules and regulations set by the regulatory authorities in the countries where it is deployed. This can create challenges for carriers, as regulations vary from country to country.
  3. Complexity: The LAA technology is more complex than traditional cellular networks, which can lead to additional costs and resources required for deployment and maintenance.
  4. Coexistence with Wi-Fi: The unlicensed spectrum used by LAA technology is also used by Wi-Fi networks. This means that LAA technology must coexist with Wi-Fi networks operating in the same frequency band. To avoid interference, LAA technology uses LBT protocol, which requires devices to listen to the channel before transmitting data. However, this can still cause conflicts with Wi-Fi networks, especially in areas where Wi-Fi networks are heavily utilized.
  5. Availability of Unlicensed Spectrum: The availability of unlicensed spectrum varies from country to country. Some countries have more unlicensed spectrum available than others, which can limit the deployment of LAA technology in those countries.
  6. Cost: The deployment of LAA technology can be costly for carriers, as it requires additional infrastructure and resources. This can make it challenging for smaller carriers to deploy LAA technology.

Deployment of LAA:

LAA technology has been deployed by carriers around the world, including in the United States, Europe, and Asia. The deployment of LAA technology requires carriers to have access to both licensed and unlicensed spectrum, as well as the necessary infrastructure to support the technology.

To deploy LAA technology, carriers must first ensure that they have access to unlicensed spectrum in the 5GHz band. They must also ensure that they have the necessary infrastructure, such as small cells and base stations, to support the technology.

Once carriers have access to the necessary spectrum and infrastructure, they can begin deploying LAA technology. The deployment process involves integrating LAA technology into the existing LTE network and configuring the network to support carrier aggregation between licensed and unlicensed spectrum.

Conclusion:

LAA technology is an essential component of 5G networks that allows carriers to increase the capacity and improve the performance of their cellular networks. By using unlicensed spectrum in a shared manner with other wireless networks, LAA technology provides carriers with the opportunity to provide more data to their customers and improve the user experience.

While LAA technology offers significant benefits, there are also challenges that carriers must overcome. These challenges include potential interference with other wireless networks, regulatory issues, complexity, coexistence with Wi-Fi, availability of unlicensed spectrum, and cost.