Bluetooth Mesh, Thread and Zigbee Network Performance

Silicon Labs have a useful web site, webinar and slides on “Benchmarking Bluetooth Mesh, Thread, and Zigbee Network Performance”.

The two main measures of performance are throughput, the rate data transfer that can be achieved (in bits per second) and latency, the time taken for data to cross the network.

With a typical implementation of 6+ hops, throughput converges to a similar order of magnitude for all the protocols:

In real use these protocols only support of the order of low thousands of bits (not bytes!) per sec and should therefore only be used for sending small amounts of data that don’t change very often.

For a small payload with 192 nodes, Zigbee has lowest latency and Bluetooth has greatest variation of latency of 20ms to 200ms:

For a larger payload, the Bluetooth latency has a larger range of up to 750ms:

Whether the variation of latency matters depends on your particular solution. Which technology is best depends on what you need to accomplish. For example, in a Bluetooth lighting scenario you might not want some lights to come on immediately and far ones to come on up to a second later. For sensing, the delay usually doesn’t matter.

You also need to consider other factors such as interoperability, scalability, security, reliability and ease of deployment. For example, Zigbee is less scalable and Silicon Labs recommends a maximum of seven hops otherwise the network becomes congested due to re-tries. Bluetooth has especially good interoperability because it is ubiquitous on smartphones and other devices. It also works reliably in industrial situations and has double encryption.

All protocols can be difficult to deploy due to the lack of off-the-shelf general solutions outside specific verticals such as lighting and home automation.

Silicon Labs have a more specific paper on Bluetooth Mesh Network Performance.

Read about Beacons and the Bluetooth Mesh

Sending Your Own Custom Bluetooth Advertising

We sometimes get asked if it’s possible to send custom advertising. All Bluetooth advertising is based on Bluetooth standards and our post on the Cheat Sheet shows some examples such as iBeacon and Eddystone.

The first question is why you might want to send your own advertising. Using the iBeacon or Eddystone protocol is sufficient in the majority of cases where you just want to a unique id at the Bluetooth LE receiver (usually but not always an app or gateway). The most common case of custom advertising is sensor beacons that need to send their own sensor data.

Nevertheless, some projects use custom advertising that signifies something extra other than a unique id. This is project specific and might, for example, indicate something about location, asset or person. Very few beacons support custom advertising without full re-programming (as opposed to setup). Re-programming involves replacing the SoC firmware and is a significant undertaking. Some of the MeeBlue beacons support setup of a custom channel that can contain any data.

iB003N Supports a Custom Channel

Bettercap for Debugging Bluetooth LE

There’s a useful tool called bettercap that claims to be the “Swiss Army knife for WiFi, Bluetooth Low Energy, wireless HID hijacking and Ethernet networks reconnaissance and MITM attacks”.

While you might want to use it to test Bluetooth LE security, a more interesting use is for debugging Bluetooth LE. If you are scanning for advertising or creating or using GATT, for example with a beacon, it’s sometimes useful to have a separate way of exercising Bluetooth LE.

Bettercap is written in Go and runs on GNU/Linux, BSD, Android, Apple macOS and the Microsoft Windows. However, a bug in Windows and macOS prevents the Bluetooth commands from working. Hence, it’s for Linux or Android only.

Better caps runs in the browser and you can create scripts.

UPDATE: There’s a tutorial on Medium.

Bluetooth Mesh and IIoT in Factories and Warehouses

Dialog Semiconductor, the manufacturer of the SoC chip in some beacons, has an informative article on How Bluetooth Mesh and IIoT are Reimagining Factories and Warehouses. It explains how the recent introduction of Bluetooth mesh has created new opportunities in the Industrial Internet of Things (IIoT).

“The manufacturing industry is absolutely ripe for potential with Bluetooth mesh”

IDC

“Industrial sensors and smart buildings among other use cases, are expected to outpace the overall Bluetooth LE market by 3X through 2022”

Research and Markets

The article mentions preventive maintenance, air quality sensing, asset tracking, robot control systems and traditional air conditioning as possible applications for Bluetooth Mesh. However, a key insight is that once a mesh network is in place it can be used for applications beyond those originally envisaged.

Read about Beacons and the Bluetooth Mesh

Updated Solutions Directory

We have re-implemented our Beacon Solutions Directory making it easier to use and more up to date:

We have removed listings for solutions that no longer exist, updated solutions that have changed focus and added some newer solutions that use generic beacons.

We found that a considerable number of marketing/retail solutions no longer exist and only the stronger ones remain. This is mainly due to the demise of Eddystone URL.

There’s an upsurge in checkin/checkout solutions presumably partly due to recent ruling by the European Court of Justice that said that EU companies must have something in place to provide an “objective, reliable and accessible system” that allows the duration of time worked each day to be measured.

The use of beacons in visitor spaces is also a growing area with solutions ranging from single use kiosks to event management platforms.

Generally, support for beacons is being added to existing, mature solutions rather than, as previously, new solutions being created solely around beacon functionality.

Bluetooth AoA Direction Finding Antenna Design

We have previously mentioned that antenna design is a complex area that will slow the rollout of Bluetooth AoA direction finding solutions. What are the issues?

Theodoros Prokic of the KTH Royal Institute of Technology has a new paper on the Antenna Design for Angle of Arrival Measurement in Access Control Applications (pdf) that explores the antennas needed for two sides of an in an inside-outside scenario.

The paper provides an analysis of the challenges the antenna designer faces when creating an AoA solution. Issues include orientation and polarization, matching, coupling, reflections, phase center, and physical size. Designing and creating antennas can easily lead to inconsistent results due to the affects of hardware, cables and other testing equipment in the vicinity.

IoT Priority and Asset Tracking

Gartner has a new report Hype Cycle for the Internet of Things 2019, in which they say:

“The Priority Matrix shows that many IoT technologies are 5 years from mainstream adoption. However only one innovation profile will reach maturity in 2 years, indoor location for assets.

So why is ‘indoor location for assets’ more likely to achieve mainstream adoption sooner than other technologies? It’s because there are clear benefits for most companies and off-the-shelf software such as our BeaconRTLS™ is already available.

Our work with companies shows they are nevertheless cautious. Companies are taking time to understand the competing asset tracking technologies and are performing, sometimes lengthy, trials to determine how new systems will integrate with existing systems. They are considering the implications of SAAS vs on-premise solutions, the availability of second-sourced beacon hardware and the compromises of accuracy vs system complexity and cost.