ANT+ is the standard protocol for communication with sports sensors such as speedometer, heart rate sensor, cadence meter etc., and sports computers. Every serious bike computer should support it.
TriPO will supply data about power and cadence when connected to your bike computer via ANT+.
Bluetooth Low Energy
The common Bluetooth 2 is very power consuming and small batteries in miniature devices (such as power meters) cannot provide enough energy for hour-long rides.
Luckily, the recent versions of bluetooth have a battery saving low-energy mode, also called Bluetooth Smart or Bluetooth Low Energy (BLE). It needs a fraction of power required by classic Bluetooth.
Connecting TriPO to your phone via BLE (check if your phone supports Bluetooth 4.0, Bluetooth Smart or BLE) can not only provide you with real-time data about power and cadence but also with other statistics like force distribution in a single revolution, difference between left and right leg (TriPO Double), history, statistics, merging with GPS data, …
Which Protocol Should I Choose?
If you prefer your existing ANT+ bike computer, choose that.
If you want more data and you can use your phone, choose BLE.