Cell Locator
Cell Locator estimates device position from the cellular signals a handset or modem already hears — serving and neighbour cells, signal strength and timing advance — matched against a geo-tagged reference survey. Every estimate includes an honest accuracy radius and a confidence score.
Typical accuracy: low hundreds of metres in surveyed areas (sometimes better). Performance depends on survey coverage; expect larger errors and lower confidence where the reference has little or no data. Cell Locator is complementary positioning for GNSS-denied, GNSS-untrusted, or coarse area-guidance use — not a turn-by-turn GNSS replacement.
Reference architecture - resilient navigation
Cell Locator can be employed as an independent positioning source within a resilient navigation architecture, alongside GNSS and an optional IMU / INS.
A lightweight Navigation SDK — provided as a reference implementation, with navigation sample code included in the Professional Developer Kit — fuses the available sources using a standard Extended Kalman Filter (EKF). GNSS remains the primary source while it is available and trusted. Cell Locator provides a continuous, GNSS-independent position with an explicit accuracy radius and confidence, bounding drift when GNSS becomes unavailable or low integrity. An optional IMU / INS contributes high-rate motion prediction between positioning updates. The output is a simple, continuous position, heading and speed, with associated uncertainty, suitable for a flight controller or other navigation consumer.
Because every Cell Locator estimate carries an explicit confidence and covariance, the EKF can weight it appropriately against the other sources — so the reported uncertainty stays honest as conditions change. Within this architecture, Cell Locator provides graceful degradation and coarse guidance during GNSS denial, within the accuracy envelope described above; it is not a precision navigation source.
Design principles
- Cellular RF positioning remains fully independent of GNSS.
- The EKF is the sole fusion point; each source stays independent up to that point.
- Continuous navigation output without position jumps.
- Graceful degradation through GNSS denial, and seamless recovery when GNSS returns.
The innovation in this architecture is the independent cellular RF positioning source, not the filter: the Navigation SDK is deliberately a simple, auditable reference implementation that integrators can adopt, adapt or replace.
Developer kits
Three SKUs cover evaluation through on-prem integration and full source licensing. Prices are list prices in GBP, exclusive of VAT. Professional and custom coverage engagements are quote-based.
SKU-CL-EVAL
Evaluation Kit
Free
No charge · fair-use limits
Try Cell Locator on Android against the Melrose shared Cell Locator cloud service. Prove accuracy on your routes before committing to a developer kit.
- Android sample app (sideload APK)
- Access to shared cloud locate API (API guide)
- Up to 2 registered devices
- Fair-use query limits; surveyed regions only
- Evaluation / non-production use
- Best-effort support
Download Android sample app (APK)
SKU-CL-ENTRY
Entry Developer Kit
£2,950
One-time licence · 12 months updates
Integrate Cell Locator into your own collectors and run the estimation engine yourself. Binary distribution for pilots and early products.
- Everything in Evaluation, plus:
- Front-end sample code (Android; Raspberry Pi / external modem)
- Back-end binary and library
- API documentation and integration guide
- Up to 10 registered devices
- Licence to run privately for the licensee
- Standard email support for 12 months
SKU-CL-PRO
Professional Developer Kit
From £27,500
Licence + annual maintenance · quote
Full engine source for unlimited licensee devices, private survey pipelines, and production deployments that need control and auditability.
- Everything in Entry, plus:
- Back-end source code under commercial licence
- Navigation sample code
- Unlimited devices for the licensee’s deployments
- Right to run private survey / learn pipelines
- Priority support
- 12 months software maintenance included; thereafter typically 20% of licence / year
What each kit includes
Optional add-ons
- Hosted locate service — metered API or monthly device seats on Melrose-operated infrastructure (for customers who prefer not to run the engine themselves).
- Survey / coverage packs — licensed reference data for additional corridors or cities, or paid survey campaigns for a defined area.
- Professional services — integration support, accuracy validation against your routes, and deployment hardening.
Licence summary
- Evaluation: free of charge for evaluation and non-commercial testing. No redistribution of the service, APK branding for resale, or production deployment.
- Entry: commercial use by the named licensee; binary and samples may not be redistributed outside the licensee organisation; device and update entitlements as above.
- Professional: commercial source licence for the named licensee; no open redistribution of Melrose source; sublicensing and OEM embedding by written agreement only.
Full terms are provided with the order. Research datasets remain under the Melrose Networks Responsible Use Licence (MNRUL) unless a separate commercial data licence is agreed.
Coverage is part of the product. Accuracy claims apply where a suitable reference survey exists. Unsurveyed areas are not a supported operating envelope without a coverage add-on or your own survey under a Professional licence.
Survey guidance
Read the guidance on survey data.
Who it is for
- Integrators building GNSS-denied or GNSS-resilient coarse positioning
- Fleet, IoT and edge devices with cellular modems (e.g. Raspberry Pi class)
- Telecom-native situational awareness and complementary PNT programmes
- Organisations that need an auditable, survey-backed cell fingerprint fix with explicit confidence — not a black-box consumer location SDK
Contact
Sales and licensing: contact@melrosenetworks.com
Product support: support@melrosenetworks.com