The Industrial Wi-Fi Shop Podcast

The Industrial Wi-Fi Shop Podcast – Ep. 18 The Magic of BLE!

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IWS Episode 18 Show Notes –  The Magic of BLE!

Free 3D Printer Plans!

  • Oscium WiPry790x and Clarity/Lucid DIY bracket posted on Thingiverse. Bring your own hair ties.
    • https://www.thingiverse.com/thing:6991943

      • Upcoming Events!

      • Wi-Co 
        • UK South, London – 9/10-11
          • Register now!
          • https://www.eventbrite.co.uk/e/wi-co-gathering-the-herds-london-uk-tickets-1345627029669?aff=oddtdtcreator  
          • Montreal, Canada – 10/1
            • Register now!
            • https://www.eventbrite.co.uk/e/wi-co-bringing-the-herd-together-montreal-qc-ca-tickets-1297281677419  

              • METAGEEK UPDATE NEWS:

              • On Monday, July 14th, Metageek will be dropping their latest update for Chanalyzer. In this update they will have channel breakouts for both Bluetooth Standard/Classic (79) and Bluetooth Low Energy (40)

                • The Basics of Bluetooth

                Handy spectrum reference, Bluetooth channels included.

                https://spectrum.potatofi.com/

                Class 3

                • Maximum Power Output: 1 mW (0 dBm)
                • Typical Range: Up to 1 meter (3 feet)
                • Applications: Wearables, fitness trackers, and devices where low power is critical
                • Notes: Rarely used due to extremely limited range.

                  • Class 2

                  • Maximum Power Output: 2.5 mW (4 dBm)
                  • Typical Range: Up to 10 meters (33 feet)
                  • Applications: Most smartphones, tablets, laptops, and Bluetooth headsets
                  • Notes: Most common class for consumer electronics.

                    • Class 1.5

                    • Maximum Power Output: 10 mW (10 dBm)
                    • Typical Range: Up to 20 meters (65 feet)
                    • Applications: Some Bluetooth headsets and mid-range devices
                    • Notes: Not as common as other classes; sometimes grouped with Class 1 in specifications.

                      • Class 1

                      • Maximum Power Output: 100 mW (20 dBm)
                      • Typical Range: Up to 100 meters (330 feet)
                      • Applications: Industrial equipment, long-range wireless peripherals
                      • Notes: Both devices must be Class 1 to achieve maximum range.

                        • Key Points

                        • Range depends on both devices: The effective range is determined by the lower class (lower power) device in the connection.
                        • Power vs. Range: Higher power output allows for greater range but increases energy consumption.
                        • Class 2 is standard: Most consumer Bluetooth devices use Class 2 for a balance of range and battery life.

                          • All about BLE (in general)

                          • Ultra-Low Power Consumption:
                            BLE is optimized to use minimal energy, allowing devices to operate for months or even years on small batteries. It achieves this by keeping the radio off most of the time and transmitting data in short, infrequent bursts.
                          • Short-Range Communication:
                            BLE typically operates within a range of 10 to 50 meters indoors, but with Bluetooth 5.0 and newer, the range can extend up to 150 meters in open environments.
                          • Efficient Data Exchange:
                            BLE is designed for applications that require periodic transmission of small amounts of data, such as sensor readings or device status updates. It is not suitable for continuous, high-bandwidth tasks like audio streaming.
                          • Fast Connection and Low Latency:
                            BLE enables quick device discovery and connection, with latency as low as 6 milliseconds—much faster than classic Bluetooth, which has around 100 ms latency.
                          • Frequency and Channels:
                            BLE operates in the 2.4 GHz ISM band, using 40 channels (each 2 MHz wide), compared to 79 channels in classic Bluetooth. This helps reduce interference and improve efficiency.

                            • How BLE Works

                            • Advertising and Scanning:
                              BLE devices periodically broadcast small advertising packets on three primary channels. Other devices scan for these packets to discover and connect with peripherals.
                            • Connection Roles:
                              BLE uses an asymmetric design:
                              • Central: Typically a smartphone or computer, handles more processing and power.
                              • Peripheral: Usually a sensor or wearable, optimized for minimal energy use.
                              • Data Transmission:
                                Once connected, devices exchange data in short bursts, then return to sleep mode. This pulsed operation leverages battery recovery effects, further extending battery life.

                                • BLE employs two main channel selection algorithms for frequency hopping:

                                1. Algorithm #1 (CSA #1)

                                • Introduced in the original BLE specification.
                                • Uses a simple, incremental approach to select the next channel.
                                • The sequence is uniform and deterministic, without randomization.
                                • Primarily used in earlier versions of BLE.

                                  • 2. Algorithm #2 (CSA #2)

                                  • Introduced in Bluetooth 5.0 to enhance security and randomness.
                                  • Generates a pseudo-random sequence of channels for each connection event.
                                  • Provides better distribution and reduces predictability, making it harder for attackers to track or jam communication.
                                  • Now the preferred algorithm in modern BLE devices.

                                    • Adaptive Frequency Hopping (AFH)

                                    • BLE divides the 2.4 GHz band into 40 channels (each 2 MHz wide), with 37 used for data and 3 for advertising.
                                    • AFH continuously monitors the radio environment for interference.
                                    • Channels identified as “bad” (due to high interference or error rates) are excluded from the hopping sequence.
                                    • The channel map, updated dynamically, ensures only “good” channels are used for hopping.

                                      • How It Works

                                      • At each connection event, the devices select the next channel using the current channel selection algorithm and the updated channel map.
                                      • The hopping sequence is synchronized between connected devices, ensuring reliable and interference-avoiding communication.
                                        • FeatureAlgorithm #1 (CSA #1)Algorithm #2 (CSA #2)IntroductionOriginal BLE specBluetooth 5.0Selection MethodIncremental, deterministicPseudo-random, more secureRandomizationNoneYesInterference AvoidanceBasicImprovedCurrent UsageLegacy devicesModern BLE devices

                                        Key Takeaways

                                        • BLE uses adaptive frequency hopping (AFH) with either Algorithm #1 or Algorithm #2 for channel selection.
                                        • Algorithm #2 is now the standard for newer BLE versions, offering improved security and interference mitigation.
                                        • Channels are dynamically assessed and “bad” channels are avoided in real time to maintain reliable connections.

                                          • General questions about Aunex BLE

                                          Do the Dataeagle series of radios use BLE as per the standard set forth by the Bluetooth SIG or do they modify it in any fashion?

                                          How does Aunex get such crazy ranges/distances out of BLE?

                                          • Special software?
                                          • Low level chip access?
                                          • Proprietary marshmallow magic?

                                            • What kind of latency do you see for data transport? 

                                            • 100ms? 
                                            • 50ms? 
                                            • Less?

                                              • What other products 

                                              If you would like to connect with Tobias or learn more about his employer, Aunex, then check the following:

                                              Tobias Meyer – https://www.linkedin.com/in/tobimeyer/ 

                                              Aunex Inc. – https://aunex.io/en-us/  

                                              If you would like to connect with Scott or learn more about his employer, Global Process Automation (GPA), then check the following:

                                              Scott McNeil – https://www.linkedin.com/in/americanmcneil/ 

                                              GPA – https://www.global-business.net/ 

                                              If you would like to connect with Jeremy or learn more about his employer, Prism Systems Inc, then check the following:

                                              Jeremy Baker – https://www.linkedin.com/in/jeremyabaker/ 

                                              Prism Systems Inc – https://www.prismsystems.com/  

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                                              The Industrial Wi-Fi Shop PodcastBy Scott McNeil & Jeremy Baker
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