DSRC: Infrastructure-Free Design and Real-World Deployment

DSRC (Dedicated Short Range Communications) — known as WAVE (Wireless Access in Vehicular Environments) in North American deployments — operates on the IEEE 802.11p physical and MAC layer standard paired with the IEEE 1609 upper-layer protocol family, and its defining characteristic is fully infrastructure-independent, peer-to-peer broadcast communication. According to Chongqing University of Posts and Telecommunications’ reconfigurable V2X terminal patent (2019), DSRC targets end-to-end latency of approximately 100 ms, typical transmission distances of 50–500 meters, packet sizes under 100 bytes for V2V links, and under 340 bytes for V2I links.

A key operational advantage of DSRC is its minimal access latency arising from its contention-based MAC layer. Because DSRC does not require a cellular base station or eNB association procedure, messages can be broadcast without network registration delays. Beijing Tusimple Future Technology’s autonomous driving platoon communication method (2018) identifies DSRC’s principal advantages for vehicle-to-vehicle use as its low obstruction sensitivity and low latency — properties that allow a lead truck to rapidly disseminate speed and trajectory data to following vehicles in a convoy, with DSRC deployed as the primary communication channel and Visible Light Communication (VLC) reserved only as a fallback when DSRC is unavailable.

In real autonomous driving architectures, DSRC typically takes the form of On-Board Units (OBUs) mounted at multiple positions around a vehicle. Otoco Intelligent Technology (Nanjing)’s 2021 patent describes deploying four OBU units — front, rear, left, and right — each handling DSRC radio transmission and reception, with a domain controller managing DDS protocol as the network layer atop DSRC. This architecture enables dynamic ad-hoc network topology construction among nearby autonomous vehicles and delivers real-time vehicle state information — including type, position, speed, heading, and predicted path — to the central autonomous driving decision algorithm.

DSRC also underpins real-time occupancy map generation. Qualcomm’s 2018 real-time occupancy mapping patent (JP) describes each autonomous vehicle periodically broadcasting a small payload via DSRC — containing GPS origin/endpoint coordinates, vehicle dimensions (length, width, height), and orientation unit vectors — so that nearby vehicles can reconstruct relative positions and occupancy spaces of all neighbours. The filing confirms that this data density and broadcast frequency are achievable within DSRC’s bandwidth envelope, enabling cooperative spatial awareness at the vehicle level without any network dependency.

C-V2X: Scheduled Resources, Cellular Uplink, and 5G Evolution

C-V2X (Cellular Vehicle-to-Everything) is a 3GPP-defined standard that encompasses both direct communications via the PC5 sidelink interface — operating without network infrastructure — and network-assisted communications via the Uu interface through an eNB or gNB. Its first generation was standardised in 3GPP Release 14 as LTE-V2X, with enhanced NR-V2X following in Release 16. Qualcomm’s 2018 LTE-D Communications for V2X Application patent (IN) establishes the foundational scheduling and transmission architecture for LTE-based V2X.

A fundamental differentiator of C-V2X is its PC5 Mode 4 semi-persistent scheduling (SPS) mechanism. Jiangnan University’s 2023 federal edge learning vehicle selection patent provides a detailed technical description: each subframe is 1 ms in duration, vehicles use a sensing window of the preceding 1000 ms to monitor SCI (Sidelink Control Information) broadcast by other vehicles, identify occupied resources, and then reserve and select transmission resources from a selection window extending from packet generation time to the resource reservation interval. Transmission blocks are encoded using QPSK or 16-QAM, and each TB occupies 2 RBs of sidelink control information in the same subframe. This self-organised resource selection under Mode 4 allows C-V2X to operate without cellular infrastructure — but with network-aware, scheduled resource allocation rather than DSRC’s contention-based CSMA/CA approach, which theoretically yields lower collision rates at high vehicle densities.

C-V2X’s integration with 5G NR provides a pathway to higher data throughput and lower latency than achievable with legacy DSRC. Samsung Electronics’ 2019 V2X Communication Method and Device patent (KR) explicitly frames C-V2X within a 5G IoT convergence framework, noting applicability to smart cities, connected vehicles, and autonomous driving use cases where 5G’s higher data rates and lower latency over 4G are essential. The network-assisted Uu interface mode of C-V2X further enables wide-area coordination through cloud and edge computing infrastructure — a capability absent from standalone DSRC.

Youngeun System’s 2025 Intelligent Pedestrian Safety System Based on C-V2X patent (KR) demonstrates C-V2X’s suitability for heterogeneous actor coordination beyond car-to-car scenarios: the system uses C-V2X to link CCTV cameras, vehicle OBUs, signal devices, and pedestrian terminals into a unified safety network around crosswalks, allowing real-time video ingestion and signal timing adjustment. This type of rich, multi-party, cloud-assisted coordination is architecturally constrained in DSRC deployments, which lack native uplink/downlink interfaces to cloud infrastructure.

Head-to-Head: Where Each Standard Wins and Loses

The most directly comparative evidence in the patent data comes from Samsung Electronics, which has filed an internationally consistent patent family for a dual-module electronic device integrating both DSRC and C-V2X on a shared antenna via a hardware switch. The processor selects between DSRC and C-V2X by periodically comparing received signal metrics including Packet Error Rate (PER), Packet Reception Rate (PRR), latency (in milliseconds), and signal strength — and switching to whichever standard provides superior performance in the current deployment area. This dynamic switching logic implicitly acknowledges that neither standard universally dominates.

“V2V communication is typically based on wireless communication protocols such as Dedicated Short Range Communications (DSRC) or Cellular Vehicle-to-Everything (C-V2X) technology” — Volvo Car Corporation, 2024, treating both as legitimate and coexisting implementation choices rather than asserting one as superior.

The table below distils the key technical differences across eight dimensions, drawn directly from the patent data analysed:

The tension between the two technologies is also visible in handover scenarios. ZTE Corporation’s 2017 OBU target area selection patent identifies the critical problem of service continuity when a vehicle traverses between DSRC coverage areas and LTE coverage areas in mixed-deployment environments. DSRC operates only within its fixed RSU coverage footprint; LTE/C-V2X can maintain vehicle connectivity across geographically wide areas via the cellular network. The solution proposed is for the OBU to dynamically select the V2X access technology based on its connectivity state — a problem that does not arise in purely C-V2X deployments, as noted by standards bodies including ETSI.

In the context of vehicle maneuver planning, Qualcomm’s patent family on intersection coordination explicitly references CV2X (Cellular V2X) as the basis for inter-vehicle spacing, intersection priority, and lane-change negotiation. The Method and Apparatus for Vehicle Maneuver Planning and Messaging patent (Qualcomm, TW, 2021) utilises external CV2X input to determine inter-vehicle spacing, intersection priority, lane change behaviour, and other autonomous vehicle behaviours — indicating an architectural preference within Qualcomm’s autonomous driving V2X stack for C-V2X as the primary data exchange protocol for coordination tasks.

The Dual-Mode Convergence: Why Industry Is Choosing Both

The clearest signal from the patent data is that leading OEMs and chipset vendors are converging on dual-mode hardware that operates both DSRC and C-V2X — either by switching between them or running them simultaneously. Samsung Electronics’ dual-module electronic device (US, 2023; CN, 2025; IN, 2024) uses real-time PER/PRR/latency comparisons to dynamically select the better-performing standard, reflecting industry consensus that neither standard universally outperforms the other across all deployment environments.

The service continuity problem in mixed-standard deployments is a persistent architectural challenge. ZTE’s 2017 OBU target area selection patent identifies that DSRC operates only within its fixed RSU coverage footprint, while LTE/C-V2X can maintain vehicle connectivity across geographically wide areas via the cellular network. When a vehicle traverses between DSRC and LTE coverage zones, the OBU must dynamically select the V2X access technology based on its connectivity state (idle or connected) to ensure seamless V2X service continuity — a problem that does not arise in purely C-V2X deployments.

The Korean automotive industry’s approach is particularly instructive. Yeungnam University’s 2025 two-way link device for V2X-based autonomous cooperative driving detects and dynamically adapts to the communication standard used by shared roadside infrastructure — reflecting a national strategy of supporting both standards in parallel rather than mandating a single standard. Nanjing Linghang Transportation Technology’s 2023 smart vehicle on-board unit patent explicitly lists 4G, 5G, 6G, DSRC, and C-V2X as communication options for a Vehicle Intelligent Unit (VIU) interoperating with a Cooperative Automated Driving System (CADS) — treating C-V2X as the cellular-network-integrated complement to infrastructure-independent DSRC rather than its replacement.

Key Patent Holders and the Innovation Landscape

Analysis of assignee frequency and technical scope across the 50+ patent filings spanning CN, KR, US, JP, TW, and IN jurisdictions reveals four primary innovation clusters, with Qualcomm Incorporated, Samsung Electronics, TuSimple (Beijing Tusimple Future Technology), Baidu USA, and Chongqing University of Posts and Telecommunications as the most prolific assignees.

Qualcomm Incorporated is the most prolific assignee in the dataset, with patent families filed across TW, KR, CN, IN, and US jurisdictions covering intersection management, maneuver negotiation, vehicle autonomy level coordination, and C-V2X sidelink communication. Qualcomm’s filings — including Vehicle Maneuver Estimation Accuracy Conveyance (TW, 2021) and Efficient Inclusion of Path History within Safety Messages (KR, 2024) — demonstrate a clear strategic orientation toward C-V2X and 3GPP-based standards as the preferred V2X physical layer for autonomous driving.

Samsung Electronics has developed the most technically detailed dual-mode DSRC + C-V2X switching architecture, with active patents in US, KR, CN, and IN. The consistent theme across Samsung’s filings is dynamic selection between DSRC and C-V2X at the hardware level, enabling vehicles to exploit whichever standard offers superior link performance in a given geographic area. Beijing Tusimple Future Technology (TuSimple) focuses on practical platoon communication reliability, specifically using DSRC as the primary vehicle-to-vehicle channel — representing the clearest patent-documented application of DSRC in a production-oriented autonomous trucking context.

Chemtronics (KR) and the Korea Automotive Technology Institute represent the emerging trend toward simultaneous dual-mode V2X and cooperative vehicle-road information fusion, reflecting the Korean industry’s approach of supporting both standards in parallel. This is echoed by Yeungnam University’s 2025 patent, which detects and dynamically adapts to the communication standard used by shared roadside infrastructure. According to ITU reports on intelligent transport systems, this multi-standard approach is increasingly reflected in national deployment roadmaps globally.

The long-term trajectory signalled by the patent data is clear: C-V2X, with its native 3GPP evolution path to 5G NR and cellular integration, is positioned as the long-term standard for high-level autonomous driving coordination. DSRC, however, remains operationally entrenched in markets and fleets already equipped with 802.11p hardware — and its infrastructure-independent broadcast model continues to offer advantages for platoon communication and ad-hoc safety messaging that the industry has not yet fully replicated in C-V2X deployments. As SAE International‘s connected vehicle standards work illustrates, the practical path forward for most deployments will involve managing both standards in parallel for the foreseeable future.