How will sidelink bring a new level of 5G versatility?
As the journey toward intelligently connecting virtually everyone and everything to the cloud continues, the need to create innovative wireless technologies that enable high-performance connectivity is paramount.
Current 5G systems operate primarily on a network-to-device communication model, on which all data transmissions flow between the network (i.e., base station) and devices (e.g., smartphone). However, to fully deliver on the original 5G vision of supporting a wide range of devices, services, and deployment scenarios, expanding the 5G topology is essential to reach new levels of performance and efficiency.
That is why sidelink device-to-device communication (as opposed to the traditional downlink and uplink communications) — designed to facilitate direct communication between devices independent of connectivity via the cellular infrastructure — was introduced in 3GPP standards. This new topology not only benefits automotive communication (i.e., C-V2X), but it also enhances many 5G use cases, such as IoT, mobile broadband, public safety, and more.
Expanding the connected intelligent edge with sidelink
Sidelink is a core topology of the 5G system design that enables direct communication between two devices without the participation of a base station in the transmission and reception of data traffic.
We envisioned 5G to support diverse devices, services, spectrum, and deployments, and sidelink has been part of this vision from the very beginning. It presents a natural expansion opportunity that can bring new system values and possibilities, complementing existing network-to-device communication.
Since sidelink extends beyond network-to-device communications to connect more devices at the edge — closer to the end-users, it naturally expands the connected intelligent edge that fuels cloud economy growth with new classes of services and experiences.
New 5G versatility brought by sidelink
Sidelink is being designed to deliver a broad set of benefits for the overall 5G system. It can operate in different spectrum configurations such as dedicated, in-band licensed, and unlicensed, providing the flexibility for it to be adopted in diverse settings. Furthermore, it can support a wide range of devices that facilitates a diverse ecosystem of use cases. For instance, sidelink can effectively enable:
- Transportation safety: allowing devices and infrastructures to connect and communicate amongst themselves, enhancing overall performance and efficiency
- Public safety communication: enabling device-to-device communication for disaster scenarios when multiples agencies need to communicate with each other with and without the cellular infrastructure
- Range extension: extending coverage via device-to-device communication (e.g., massive IoT devices such as meters) with multi-hop mesh relays
- Expanded capacity: expanding industrial IoT system capacity with direct communications between automation controllers and sensors/actuators
- Wearable connectivity: creating a high-performance personal area network to connect the smartphone directly to wearables such as smart watches, XR, and more
- Ranging: improving positioning accuracy for diverse situations, including challenging scenarios such as dense urban areas and tunnels
- Data offload: providing high throughput to devices in proximity to each other, enabling data-intensive use cases such as gaming and data backup
Sidelink continues to evolve in 5G Advanced and beyond
The sidelink technology journey began more than a decade ago. Device-to-device communication was first introduced in LTE advanced (i.e., 3GPP Rel-12/13), and it initially enabled proximity services and public safety applications. It then evolved and commercialized in Releases 14 and 15 for new verticals such as automotive, bringing the realization of enhanced road safety.
5G sidelink builds on the LTE sidelink foundation and brings many improvements, including lower latency, wider bandwidth, and higher reliability. In Rel-16, sidelink was introduced to support 5G NR, and in Rel-17, which has already been completed, enhanced sidelink capabilities were included to provide superior resource allocation, improved power savings, and coverage extension.
For 5G Advanced and beyond, the evolution of sidelink aims at providing improved performance and efficiency to enable new use cases and access to unlicensed spectrum. For instance, Rel-18 sidelink is targeted to support increased data rate with carrier aggregation and expanded sidelink relay capabilities.
We are leading the way
Qualcomm Technologies has long been the pioneer of device-to-device communication. We showcased LTE-Direct proximity services with over-the-air demos back at the Mobile World Congress (MWC) in 2013. Since then, we have led the mobile ecosystem to improve 5G sidelink system design, showcased key demonstrations of sidelink technology and its benefits for a wide range of use cases, and will continue to drive the evolution of sidelink into 5G Advanced and beyond.
