Terminology » BLE coded PHY vs 1M PHY vs 2M PHY modes:Key Differences

BLE coded PHY vs 1M PHY vs 2M PHY modes:Key Differences

bluetooth low energy ble PHY coded phy 1m phy 2m phy difference between

Introduction : With the introduction of Bluetooth Low Energy (BLE), new physical layer (PHY) modes were defined to balance speed, range and robustness. The 1M PHY serves as the default, 2M PHY offers higher throughput and Coded PHY extends range using error correction. Let us compare these modes to understand how BLE adapts to different application needs, from wearables to IoT sensors.

BLE 1M PHY

  • Data Rate: 1 Mbps
  • Modulation: GFSK
  • Default PHY for BLE connections.

BLE 2M PHY

  • Data Rate: 2 Mbps
  • Modulation: GFSK
  • Higher throughput, shorter range.
  • Introduced in Bluetooth 5.0.

BLE Coded PHY

  • Purpose: Long Range / Extended Range
  • Uses Forward Error Correction (FEC) with coding to increase range at cost of data rate.
  • Introduced in Bluetooth 5.0.
  • Variants:
    • S=8 coding (125 kbps effective rate) – maximum range.
    • S=2 coding (500 kbps effective rate) – balance of range and speed.

Key differences

FeatureCoded PHY (S=2/S=8)1M PHY2M PHY
Symbol rate1 Msym/s1 Msym/s2 Msym/s
Data rate500 kbps (S=2), 125 kbps (S=8)~ 1 Mbps~~ 2 Mbps
ModulationGFSK with FEC + codingGFSKGFSK
RangeLonger than 1M (Up to 4 times)Medium (by default)Shorter than 1M PHY
ReliabilityHighest (due to error correction use in Physical layer)NormalLower than 1M PHY mode
Use caseLong range IoT, beaconsGeneral BLE linksHigh throughput apps

Conclusion: Ultimately, the choice between 1M, 2M and Coded PHY depends on application requirements: 1M for general use, 2M for faster transfers and Coded for long range and robust links. This flexibility ensures BLE can serve both low power short range devices and long distance communication scenarios efficiently.