# Performance Evaluation of Bluetooth Low Energy: A Systematic Review
## 4 Discussion
These models are accurate, but they still need a concrete and systematic evaluation of the real energy consumption of the BLE IC, during the different operations (e.g., _broadcasting, listening, connections_), varying the protocol settings (e.g., _connInterval_, _scanInterval_, _advInterval_), throughput and the radio power. Moreover, it would be very interesting to investigate how the power consumption depends on the different vendor BLE ICs existing on the market, since it could be slightly dependent on the specific HW and FW. Of particular interest will be the experimental validation of throughput in correlation with the number of _slaves_. As a matter of fact, it is interesting to understand what is the limit in terms of bitrate and how it changes in relation with a variable number of nodes, with different connection parameters, such as _connInterval_, but also using different network topologies. It will be useful also to measure these data, varying the distance between nodes and the radio power, in order to verify the existing models. Finally, a detailed analysis of power consumption in relation to the variations of all these parameters could help to identify the optimal configuration of BLE networks for different applications. Another important topic relative to BLE, which needs deep investigations, is node synchronization. As a matter of fact, as already said in Section 3.2, many applications that involve sensor networks need a precise time synchronization between the different nodes. The architecture of BLE provides non-deterministic delays, which make synchronization hard to implement. These analyses will help to understand what is the effective pool of possible applications in which BLE could work, exalting its capacities and behaviours between the several wireless communication technologies. This work has been partly supported by STMicroelectronics, which funds [PERSON]'s Ph.D. and cover the costs of this open access publication. Some of the authors are employees of STMicroelectronics, which produces and commercializes BLE IC, and it is a member of Bluetooth SIG. Moreover, the Ph.D. of [PERSON] is funded by STMicroelectronics itself. The following abbreviations are used in this manuscript:  
6 LoWPAN  
IPv6 over Low power Wireless Personal Area Networks  
AA  
Access Address  
ACK  
Acknowledgment  
AdvA  
_Advertise_'s device Address  
AdvData  
_AdvInterval_  
Advertising Interval  
AES  
Advanced Encryption Standard  
App  
Application Layer  
ATT  
Attribute Protocol  
BER  
Bit Error Rate  
BLE
Bluetooth Low Energy  
BR/EDR  
Bluetooth Basic Rate/Enhanced Data Rate or Classic Bluetooth  
ChSel  
Channel Selection
ConnData  
Connection Data  
Connection Event  
_ConnInterval_  
Connection Interval  
Conn Slave Latency  
Connection Slave Latency  
_Conn SupervisionTimeout_  
CRC  
Cyclic Redundancy Check  
CPU  
Central Process Unit  
FW  
Firmware  
GAP  
Generic Access Profile  
GATT  
Generic Attribute Profile  
HCI  
Host Control Interface  
HW  
Hardware  
IC  
Integrated Circuit  
IETF  
Internet Engineering Task Force  
IoT  
Internet of Things  
IPv6  
Internet Protocol version 6  
ISM  
Industrial Scientific and Medical  
L2 CAP  
Logical Link Control and Adaptation Protocol  
LE  
Low Energy  
LE 1M PHY  
Low Energy 1 Mbps Physical Layer data rate  
LE 2M PHY  
Low Energy 2 Mbps Physical Layer data rate  
LL  
Link Layer  
LLID  
Logical Link Identifier  
LM  
Link Manager  
MANET  
Mobile Ad hoc Networks  
MD  
More Data  
MIC  
Maximum Transmission Unit