NTT DOCOMO, serving 93 million subscriptions across a network of 250,000 base stations, is now applying quantum computing to a challenge that has long stymied the telecommunications industry: simultaneously optimizing paging and location-registration signals. A network segment with just 333 base stations presents 28991 possible configurations, a complexity exceeding the capacity of traditional computing methods.
“DOCOMO is showing telecom operators around the world what production quantum adoption looks like: move beyond a single use case and apply the technology to distinct, increasingly complex operational challenges,” says D-Wave CEO Alan Baratz. The carrier reports building on earlier success to tackle this broader optimization problem.
D-Wave’s CQM Hybrid Solver Optimizes Telecom Signaling
NTT DOCOMO used D-Wave’s constrained quadratic model (CQM) hybrid solver to optimize paging and location-registration signals across its network, a task previously intractable for classical computing methods. The carrier formulated a multi-objective optimization problem using real device-movement data aggregated from base stations nationwide, allowing the system to address competing signal demands simultaneously, D-Wave says. This approach builds on an earlier deployment that reorganized 270 base stations into 21 TA-Lists, a process that previously required 27 hours but completed in just 40 seconds using D-Wave’s platform.
The expanded optimization tackled a segment of 333 base stations, encompassing three TA-Lists and nine TAs, completing the task in approximately five minutes. DOCOMO’s classical methods could not solve this configuration within the timeframe necessary for production use, highlighting the quantum system’s speed advantage.
This latest application lowers the network’s control-plane load and frees up capacity to accommodate the increasing number of connected devices relying on the infrastructure. The resulting reductions in signaling contribute to improved network performance and efficiency, according to Baratz, who also notes, “Telecom networks are highly complex, resource-constrained environments, and these results demonstrate how D-Wave’s annealing quantum computing technology can help operators improve network performance and efficiency today.” This expansion of quantum computing applications within DOCOMO’s network demonstrates a move beyond initial proof-of-concept projects toward sustained, operational use of the technology.
The initial success, which reduced peak-period paging signals by roughly 15%, provided an estimated 20% increase in network capacity for connected devices, establishing a foundation for tackling more complex optimization problems. Shuichi Fukuda, a researcher at NTT DOCOMO, will discuss the company’s production use of quantum computing for network optimization at Qubits Asia in Seoul on October 28.
DOCOMO is showing telecom operators around the world what production quantum adoption looks like: move beyond a single use case and apply the technology to distinct, increasingly complex operational challenges.
DOCOMO Reduces Network Signals by 65.3% with Quantum Computing
NTT DOCOMO achieved a 65.3% reduction in daily peak location-registration signals across a segment of its national network through the deployment of a quantum computing application, a feat previously considered unattainable by the carrier’s engineers. The application, built on earlier successes with D-Wave’s technology, simultaneously optimized base station assignments to minimize both location-registration and paging signals, a complex balancing act for efficient network operation, according to the company. This latest deployment expands on a prior effort that reorganized 270 base stations, demonstrating a progression toward tackling increasingly detailed optimization challenges.
By strategically avoiding registration boundaries along high-traffic transit routes, the application minimizes unnecessary signaling bursts from fast-moving devices, lessening the load on base stations and improving overall network stability. Hiroshi Kawakami, Senior Manager at NTT DOCOMO, explained that the application “balances two competing network requirements, significantly reducing location-registration signaling while also lowering paging signals,” and allows for more efficient infrastructure use. DOCOMO further enhanced the application with a map-based visualization tool, enabling regional branch offices to review proposed base station reassignments and projected signal reductions before implementation across the live network.
This collaborative approach ensures practical feasibility and allows for informed decision-making at the local level. The company plans to present details of this production use of quantum computing at Qubits Asia, with researcher Shuichi Fukuda scheduled to discuss the advancements.
The application balances two competing network requirements, significantly reducing location-registration signaling while also lowering paging signals. Together with our first production application, it demonstrates how quantum computing can help us address multiple aspects of network optimization and use our infrastructure more efficiently.
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