Herald App (Herald Protocol) Results 2020-11-28


A formal test on 4 phones (2 iOS, 2 Android) carried out on 27 Nov 2020 by Adam Fowler of the Herald Protocol development team as a pre-release test for Herald v1.1.0. These are the same 4 phones used for all Herald minor version and beta version performance regression tests.

Herald v1.1.0 made improvements in connection stability and reliability between iOS and Android. Additional logic was also added to Android in order to limit the number of Apple devices Android attempts to connect to. These are non-iPhone devices. This means less communication and less ‘interference’ with the protocol’s work communicating with devices.

This resulted in only a single 30 second window being missed between the 4 phones in the test during a full 8 hour period. This also meant a longevity score of 100%.

The results are impressive given they are deliberately ran on known problem phones. A Samsung A10 on Android 29, Samsung A20 on Android 28, and two iPhones on iOS 12.1.4 and 12.4.5.

Completeness has not been recalculated, but is too likely to be higher. We have used the current known value for this until a full 10 device test can be ran.

Updated 1 Dec 2020: Added results breakdown and images, below.

Updated 11 Jan 2021: Added battery level image, below.


Measure Result Notes
Overall Efficacy 41.37% Effective
(UK MAX 46.57%)
Probability of detection 94.37% Formal RISK detection
Phone Detection 100% Includes iOS in the background
Continuity 99.991% Full continuity
Completeness RT1 98.36%
Completeness RT2 TBD Not yet calculated from data
Completeness CE 95.95%
Accuracy 95.95% RSSI accuracy
Longevity 100.00% 8 hour test
Mean time
between readings
Country UK
Have BLE Phones 72.53% OFCOM reports
Hardware Support 98.19% BBC data
Software/OS Support 98.00% BBC data
Overall Pspec 69.79%
Pspec squared 48.71%

Phones tested

PhoneId Phone Make and Model OS and version Known issues
1 Samsung A10 (SM-A105FN) Android 28 A10s knowingly rotate their BLE MAC address with every request. Herald uses an ephemeral ID that rotates every 15 minutes as a performance improvement
2 Samsung A20 (SM-A202F) Android 29 Same issue as A10, above
3 iPhone 6S iOS 12.1.4 (phone name is Denmark)
4 iPhone 6+ iOS 12.4.5 (phone name is Netherlands)

Fair Efficacy Stats Summary

Phones Max Pairs Pairs Detected Detection Percent Max 30 second windows 30 second windows achieved Missed windows percentage Longevity change over 8 hours
4 12 12 100% 11520 11519 0.00868% 0%

Phone detection and distance estimation reports

The below 4 charts show discoveries, ID (data payload) reads, and RSSI (distance estimation) readings as individual dots.

A10 results A20 results iPhone 6S results iPhone 6+ results

The below chart shows RSSI variation over time. In a formal 8 hour test these will mostly be static.

A10 RSSI A20 RSSI iPhone 6S RSSI iPhone 6+ RSSI

The below chart shows battery charge remaining over time.

Battery Level

Getting Started

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