Signal Atlas

Research library

Smart cities & sensing everywhere

Sensors and connected systems in streets, buildings and infrastructure, and what they have actually delivered for cities. What 6G adds: the network itself can act as a sensor, and connect millions of devices per square kilometre.

Of 62 findings in this theme, 38 are real today, 16 designed, 4 forecast and 4 disputed.

Real today 38

  • 5G 'RedCap' devices serve city cameras and sensors now. 3GPP Release 17 created RedCap, a cheaper 5G device class with 20 MHz bandwidth and one antenna, aimed at industrial sensors, video surveillance and wearables. Release 18 adds improvements explicitly for smart-city coverage.
  • AT&T's 5G towers tracked drones near a stadium. In July 2026, AT&T and Ericsson used existing cell towers and massive-MIMO radios at several sites outside AT&T Stadium in Texas to detect and track drones flying at 300-400 feet, reporting their location, speed and height in real time.
  • Amsterdam makes owners register sensors placed in public space. Amsterdam was the first Dutch city to require anyone running cameras, counters or other sensors in public space to register them on a public map. Dutch municipalities have since studied a national sensor register; Apeldoorn alone runs over 1,000 sensors.
  • Barcelona built an open-source city sensor platform others reuse. Barcelona's Sentilo is free, open-source software that collects data from city sensors on pedestrian and bike flows, noise, temperature and air quality, and any city can adapt it. The city is opening the network to public experimentation.
  • Battery-free tags could talk to cell towers. 3GPP Release 19 defined 'Ambient IoT' tags that use about 1 microwatt at peak, reflecting a radio signal rather than transmitting, for indoor inventory and simple commands. Release 20 targets more capable tags, including some with tiny amplifiers and low-cost active ones.
  • Bridgewater retrofits cut home energy use 22-39%. Bridgewater, Nova Scotia, used its Smart Cities prize to fight energy poverty (38% of households). By February 2025 over 180 homes were upgraded with 22-39% energy cuts, and a new pilot streams home energy and air-quality data over a LoRaWAN network.
  • Calgary built and owns a city-wide LoRaWAN sensor network. Calgary says it was the first Canadian city to build and own a low-power wireless IoT network, with near city-wide coverage. Battery sensors can run for years and send data kilometres, used for air quality and river levels for flood warnings.
  • Canada's Smart Cities Challenge paid only for proven outcomes. Ottawa committed $300 million over 11 years. In 2019 it named Montreal ($50M, mobility and food), Guelph-Wellington ($10M, circular food economy), Nunavut communities ($10M, suicide prevention) and Bridgewater ($5M, energy poverty), with prize money tied to proving results.
  • Chicago audit: few gunshot alerts found gun crimes. Chicago's Inspector General reviewed 50,176 ShotSpotter alerts police responded to in 2020-2021. Only 4,556 (about 9%) turned up evidence of a gun-related offence, and about 2% led to an investigatory stop.
  • China Mobile uses 5G-A sensing to watch low airspace. China Mobile describes 5G-Advanced base stations working as distributed radar in pilot or commercial projects in Anhui, Guangdong and Henan, including low-altitude corridors in Hefei, a city drone pilot in Shenzhen, and airport monitoring of drones, birds and debris.
  • Deutsche Telekom's drone detection still uses separate sensors. Deutsche Telekom showed live drone detection in Cologne in September 2026, but it relied on passive radio-frequency sensors that hear a drone's remote control, plus optional cameras, microphones and radar. It says 5G and 6G networks are expected to detect drones in future and is researching this.
  • Dubai cut government paper use about 83%. Dubai's Paperless Strategy moved government transactions online. By early 2021 participating entities had cut paper use 82.82%, saving 269.8 million sheets, about AED 1.13 billion and 12.1 million work hours, according to Smart Dubai.
  • India's 100 smart cities finished about 95% of projects. India's Smart Cities Mission (2015 to March 2025) funded about 8,000 projects in 100 cities. In August 2025 the housing minister told Parliament about 95% were complete, worth over 1.5 lakh crore rupees, and every city has a command-and-control centre.
  • LED streetlights cut Los Angeles lighting energy 64%. Los Angeles converted about 160,000 streetlights to LED, finishing in 2019. The City reports 64% energy savings (114 GWh a year), about $10 million a year saved and 67,000 tonnes less CO2.
  • London's cheap air sensors worked, with about 35% error. Breathe London ran 100 low-cost nitrogen dioxide sensors across Greater London for two years. Checked against reference stations, they had about 35% average error but still showed reliable trends, daily patterns and pollution episodes.
  • Masdar's zero-carbon city was scaled back and delayed. Masdar City in Abu Dhabi was launched in 2006 as a $22 billion car-free, carbon-neutral city for about 40,000-50,000 residents by 2016. In 2010 it dropped the plan to make all its own power, and by 2023 about 15,000 people lived or worked there on under a sixth of the planned area.
  • More sensor data does not mean more truth. Sensor networks need fusion, calibration, time alignment and quality checks; bad inputs give confident but wrong answers. Every system also has a visibility gap of things it never measures.
  • NSF funded smart-lighting research from 2008. Boston University dates NSF's Smart Lighting Engineering Research Center to 2008. The centre describes research on optical Internet access, lighting and environmental sensing.
  • Ontario privacy watchdog: laws too old for smart cities. In his 2019 annual report Ontario's Information and Privacy Commissioner said provincial privacy law predates sensors, big data and AI. He asked for a full review and stronger oversight powers, saying his office could not properly oversee smart-city projects without them.
  • Ottawa, not cities, decides disputed antenna sites. Under ISED's CPC-2-0-03, carriers must consult the local land-use authority and the public, normally within 120 days, but ISED makes final decisions in disputes. Antennas on existing lamp posts or buildings skip consultation if the structure grows no more than 25%; the under-15 m exemption does not apply to carriers.
  • Outside China, cities lean on LoRaWAN more than NB-IoT. Cellular IoT reached about 4.5 billion of 22.3 billion IoT devices in 2025. NB-IoT had about 1.3 billion connections, roughly 90% in China; AT&T shut its NB-IoT network. Cities building their own sensor networks often choose LoRaWAN instead.
  • Phone and Wi-Fi signals combined to sense people indoors. InterDigital and Turk Telekom reported in February 2026 that fusing cellular and Wi-Fi sensing on a preliminary 6G architecture detected human presence indoors in near real time, more reliably than either network alone.
  • Pipe microphones find water leaks, but evidence is thin. Acoustic sensors fixed to water pipes listen for leaks so crews can fix them before they surface. An Illinois state-funded pilot reported measurable water savings within a year, but most published results are vendor case studies.
  • Pittsburgh's self-timing traffic lights cut travel time 25%. A Carnegie Mellon field test of the Surtrac system ran 9 intersections in Pittsburgh's East Liberty with lights that continuously re-plan their timing from live traffic. Measured against the old timing, travel time fell about 26%, stops about 31%, waiting about 41% and estimated emissions about 21%.
  • Radar can watch breathing without touching you. Circadia's monitor, cleared by the FDA in 2020, uses radar and AI to measure breathing through the air, and an IEC white paper covers radar-based activity recognition for assisted living.
  • San Diego's smart streetlights became a police-camera fight. San Diego's LED upgrade added 3,200 sensor nodes with cameras, which police used for investigations. After public pushback the city switched off all sensors in 2020, passed a surveillance-technology ordinance, and in 2023 approved 500 cameras with licence-plate readers under strict rules.
  • San Francisco's parking sensors made spaces easier to find. SFpark put sensors on about 7,000 metered spaces and changed prices block by block to keep some spaces free. SFMTA's evaluation found easier parking, lower average rates, less driving around and lower emissions, and the scheme became permanent in 2014.
  • Sidewalk Labs' Toronto smart district was cancelled in 2020. Sidewalk Labs withdrew from Toronto's Quayside on 7 May 2020 after years of debate over data collection and who would govern it. Waterfront Toronto restarted, choosing Dream and Great Gulf in 2022 for a plan led by 800+ affordable homes and zero-carbon buildings rather than sensors.
  • Singapore judged sensor-laden lampposts impractical at scale. Singapore once aimed to wire its 110,000 lampposts with sensors. After trials from 2017, the government said in 2023 a large-scale rollout was not practical and mobile sensors are cheaper and more flexible; its 2024 Smart Nation 2.0 plan centres on trust, AI and digital skills instead.
  • Smart systems combine sensing, communication and computing. A sensor only measures; communication moves the reading; computing interprets it. Standards work describes IoT as this whole system, bundling networking, cloud, AI, digital twins, cybersecurity and data governance.
  • Standard model for radio sensing published 2025. 3GPP added a shared model of how radio echoes behave around targets and background clutter to its channel model (TR 38.901, Release 19, June 2025), so companies can test sensing designs the same way.
  • Tiny MEMS sensors made sensing mass-market. Microelectromechanical sensors moved from specialist uses such as catheter pressure and car airbags into phones and everyday objects, with sensor volumes growing fast between 2007 and 2012. Once cheap and small, sensing starts to behave like infrastructure.
  • Today's 5G towers are already tracking drones. A Saab-Ericsson project in Sweden raised 5G-based drone radar from lab concept to field-tested (TRL 6) by November 2025, and Ericsson demonstrated drone tracking at a Helsinki harbour in September 2026 using existing 5G radios.
  • Toronto expands adaptive signals but publishes no results. Toronto has used adaptive signals since 1992 (SCOOT, about 400 intersections at peak). After a 2018-2019 SCATS pilot in Scarborough the City rolled SCATS out to 187 intersections and plans 58 more by the end of 2026.
  • Toronto police dropped gunshot microphones over Charter concerns. Toronto had planned to buy ShotSpotter in 2018, but in February 2019 police shelved it after legal advice that always-on street microphones could breach the Charter's protection against unreasonable search.
  • Toronto rations street antenna poles as 'unsightly'. Toronto's right-of-way policy for carrier antenna poles under 15 m prefers wide arterial roads, about 20 m from tall structures, no more than one per block, underground equipment boxes, and no blocking of tree planting. The City states it considers such poles unsightly.
  • Toronto set principles for tech in public spaces. In April 2022 Toronto Council unanimously adopted the Digital Infrastructure Strategic Framework. It sets principles (equity, privacy and security, transparency, digital autonomy and more) for any technology or data project the City runs or allows in streets, parks and City buildings.
  • Wi-Fi sensing became an official IEEE standard in 2025. IEEE published 802.11bf in September 2025, an amendment that lets Wi-Fi devices measure their surroundings, for example to detect motion or presence, in bands from 1 to 7.125 GHz and above 45 GHz.

Designed, not deployed 16

  • 3GPP listed over 30 ways networks could sense. 3GPP's Release 19 feasibility study on integrated sensing and communication (TR 22.837) collected more than 30 use cases, such as detecting objects, monitoring environments and tracing trajectories. Its requirements moved into the service spec TS 22.137.
  • 6G networks are meant to sense, not just connect. ITU's integrated sensing scenario has the network detect objects, presence and movement, including things carrying no device. Typical uses include fall detection, gesture recognition, vehicle and pedestrian detection and rain or pollution monitoring.
  • 6G pitched as the answer to smart-city overload. A 2024 review argues that mobile traffic growth to 2030 and smart-city uses (XR, telemedicine, drones, connected vehicles) will exceed what 5G was designed for. It proposes 6G technologies such as integrated sensing and communication and non-terrestrial networks for smart grids, healthcare and waste management.
  • Cities that sense, predict and adapt themselves. The 'cognitive city' idea describes urban infrastructure that senses conditions, predicts problems and adjusts in real time, linked to climate networks such as C40.
  • European standards group mapped 18 sensing use cases. ETSI's ISAC industry group published 18 6G sensing use cases in 2025, such as human-motion recognition, emergency rescue and robot guidance, then reports on channel modelling and system architecture. In December 2025 it opened new work on AI and data handling and on security and privacy.
  • Halton set up one window for 5G pole permits. Halton's councils proposed a shared corporation, Halton Digital Access Services Corporation, so carriers get one permit for 5G attachments on poles and streetlights owned by the region, its four local municipalities and four hydro companies. Most of 94 public comments raised health worries; Health Canada advises low-level 5G exposure poses no known risk.
  • Mississauga readied its light poles for 5G small cells. In December 2021 Mississauga staff reported the city could host 5G small cells on street light poles in busy areas and downtown, with master pole-attachment agreements going to Council in 2022. The city says it co-owns, with Peel, Brampton and Caledon, Canada's largest public-sector fibre network (985 sites).
  • NIST published a cyber-physical systems framework in 2017. In June 2017 NIST released a shared framework and vocabulary for cyber-physical systems, which link computing with physical processes in vehicles, buildings, energy and medical devices.
  • Network sensing is arriving in 5G-Advanced, before 6G. 3GPP is now writing 5G-Advanced specifications for sensing, including a sensing architecture (TS 23.137) and a new core 'Sensing Function'. Its Release 20 radio study (TR 38.765) focuses on base stations detecting and tracking drones, and was placed under change control in June 2026.
  • Radio antennas can double as city-wide sensors. The 2017 IEEE scenario describes the antennas that connect phones, vehicles and things as sophisticated sensors that reveal traffic flows, crowds and resource use. Each city gets a measurable 'digital signature'.
  • Satellite constellations extend sensing and 5G everywhere. Papers in the research describe low-orbit mega-constellations working with ground networks to offer global 5G, and CubeSat networks (an 'Internet of Space Things') to link remote sensors and robots.
  • Smart-city sensing needs only metre-level accuracy, research says. A joint industry-academic 6G study classes smart-city uses like traffic monitoring as needing metre to sub-metre location accuracy with relaxed latency. That is far below the centimetre and millisecond targets 6G sets for factories and robots.
  • Standards report flags 15 security and privacy risks. ETSI's March 2026 report on 6G sensing found 19 key issues, 15 about security and privacy: unauthorised sensing, eavesdropping, sensing people who carry no device, sensitive places, and AI drawing private details from sensing data. The other 4 concern energy and environment.
  • Texas SH130 'intelligent corridor' was a 2021 plan. A 2021 trade article describes a proposed Texas highway corridor with edge computing, next-generation wireless, sensors and charging to support autonomous vehicles and drones.
  • Up to 100 million devices per square kilometre. ITU's massive communication scenario targets 1 million to 100 million connected devices per square kilometre, including sensors with no battery, for cities, health, energy, farming and the environment.
  • Vodafone pitched its network as a drone radar. At MWC 2025, Vodafone presented network sensing that could spot drones within about a 3 km radius of sites such as airports, including objects with no SIM card, and said it would feed results into 3GPP standards.

Forecast 4

  • 103 EU cities have approved 2030 climate-neutral plans. The EU Cities Mission picked 112 cities to aim for climate neutrality by 2030. By October 2025, 103 had an approved Climate City Contract, unlocking EIB advice and a dedicated EUR 2 billion lending envelope.
  • Forecast: tens of trillions of networked sensors. A 2014 IEEE talk that launched the 'trillion sensors' movement cited a forecast, from the book Abundance, of about 45 trillion networked sensors within 20 years for health, environment, food and energy.
  • Full cell coverage in TTC tunnels slips to 2027. Since 2023 riders of all carriers get service in every TTC station on Rogers' network. Federal conditions require 80% of tunnels by December 2025 and all by December 2026, but a TTC report projects 70% and 88% by those dates and completion in 2027.
  • Ontario's every-home internet promise moved from 2025 to 2028. Ontario is spending nearly $4 billion to bring high-speed internet to every community. As of April 2026, 96% have access and 157,000 homes and businesses were connected since 2021; Hydro One prepared over 62,000 poles for fibre. The finish date is now the end of 2028.

Disputed 4

  • Hangzhou's 'City Brain' results come mainly from Alibaba. Alibaba's City Brain uses intersection cameras and vehicle GPS to coordinate over 1,000 traffic signals in Hangzhou. Alibaba says the city fell from 5th to 57th in China's congestion ranking and ambulances arrive in half the time.
  • NEOM's 170 km The Line is now 'phased'. The Line was pitched as a 170 km mirrored city for 9 million people. It is widely reported to have been cut to a first 2.4 km phase for about 300,000 people, and NEOM's website now describes a phased, demand-led approach.
  • Songdo's built-from-scratch smart city struggled with real life. Songdo in South Korea was planned as a 'ubiquitous' high-tech eco-city. A peer-reviewed review found its closed, technology-first design coped poorly with the 2008 crash and left social needs and fair access to services out of the plan.
  • Study across 68 US counties found no shooting reduction. A peer-reviewed analysis of 68 large US metro counties from 1999 to 2016 found gunshot detection had no significant effect on firearm homicides or arrests overall. The vendor disputes the method because coverage zones are much smaller than whole counties.

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