The discovery scheme of BLE adopts a periodic-interval based technique, for which upper bounds on the discovery latency can be inferred for most parametrizations.

Bluetooth 4.0 Speed Bluetooth Low Energy

The original specification was developed by Nokia in 2006 under the name Wibree, 4 which was integrated into Bluetooth 4.0 in December 2009 as Bluetooth Low Energy.

The results were published in 2004 using the name Bluetooth Low End Extension.

One change on the marketing side is that the point number was dropped, so it is now just called Bluetooth 5 (and not Bluetooth 5.0 or 5.0 LE like for Bluetooth 4.0).

This decision was made to simplify marketing, and communicate user benefits more effectively.

On the technical side, Bluetooth 5 will quadruple the range by using increased transmit power or coded physical layer, double the speed by using optional half of the symbol time compared to Bluetooth 4.x, and provide an eight-fold increase in data broadcasting capacity by increasing the advertising data length clarification needed of low energy Bluetooth transmissions compared to Bluetooth 4.x, which could be important for IoT applications where nodes are connected throughout a whole house.

An advertising packet in Bluetooth parlance is the information that is exchanged between two devices before pairing, i.e.

For e.g., advertising packets is what let you see the name of a Bluetooth device before you can pair it.

Bluetooth 5 will increase the data length of this advertising packet.

The length of this packet in Bluetooth 4.x was 31 bytes (for broadcast topology).

Mesh specification enables using Bluetooth Low Energy for many-to-many device communications for home automation, sensor networks and other applications.

Manufacturers are expected to implement the appropriate specifications for their device in order to ensure compatibility.

Each device can pass the information forward to other Bluetooth Low Energy devices creating a mesh effect.

For example, switching off an entire building of lights from a single smartphone.

Term model is used in mesh specifications instead of profile to avoid ambiguities.

The Continua Health Alliance consortium promotes these in cooperation with the Bluetooth SIG.

Physical proximity can be estimated using the radio receivers RSSI value, although this does not have absolute calibration of distances.

Typically, an alarm may be sounded when the distance between the devices exceeds a set threshold.

This service will allow exposure notification services on wearable devices to communicate with and be controlled by client devices such as smartphones.

Bluetooth 4.0 Speed Software Radio So

These ICs commonly use software radio so updates to the specification can be accommodated through a firmware upgrade.

Instead of the classic Bluetooth seventy-nine 1-MHz channels, Bluetooth Low Energy has forty 2-MHz channels.

Within a channel, data is transmitted using Gaussian frequency shift modulation, similar to classic Bluetooths Basic Rate scheme.

The bit rate is 1 Mbits (with an option of 2 Mbits in Bluetooth 5), and the maximum transmit power is 10 mW (100 mW in Bluetooth 5).

Further details are given in Volume 6 Part A (Physical Layer Specification) of the Bluetooth Core Specification V4.0.

Note that power consumption is not part of the Bluetooth specification.

This is done using 3 separate channels (frequencies), in order to reduce interference.

The advertising device sends a packet on at least one of these three channels, with a repetition period called the advertising interval.

For reducing the chance of multiple consecutive collisions, a random delay of up to 10 milliseconds is added to each advertising interval.

The scanner listens to the channel for a duration called the scan window, which is periodically repeated every scan interval.