Diese Präsentation wurde erfolgreich gemeldet.
Die SlideShare-Präsentation wird heruntergeladen. ×
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Anzeige
Wird geladen in …3
×

Hier ansehen

1 von 17 Anzeige
Anzeige

Weitere Verwandte Inhalte

Diashows für Sie (20)

Ähnlich wie LoRa and NB-IoT (20)

Anzeige

LoRa and NB-IoT

  1. 1. LoRa and NB-IoT Gagan Gupta, Darshan Patil gagan@kth.se, darshan@kth.se 13 October 2016
  2. 2. OUTLINE ● Background ● Motivation ● LoRa ● NB-IoT ● Conclusion
  3. 3. Background IoT- Billion of Connected Devices Radio Access ?? Different Applications have different set of Requirements ● Cost ● Data Rate ● Latency ● Energy Consumption ● Voice, Multimedia (high data rate) → Legacy cellular licensed solutions, unlicensed WLAN solutions ● Industrial, commercial, sensors and IoT (low data rate) → IEEE 802.15.4, LPWA, BT, ZigBee
  4. 4. Motivation ● IOT devices have requirements of wide area connectivity for low power and low data rate devices at economical cost ● Legacy cellular solutions- high throughput, long range, but high power and costly ● WLAN 802.11 a-n- high throughput, short range, moderate-high power and cost ● LPWA- Tradeoff between above (Some technologies like LoRa and NB-IoT) ● LPWA- For applications that require multi-year batteries and send small amount of data less frequently ● Also, involving long range communications with low power ● Applications like Smart meter, seismic sensors, environmental monitoring, smart grid etc.
  5. 5. LPWA standards ● LoRa / LoRaWAN- ○ Set up by industrial consortia ○ Unlicensed ● NB-IoT- Narrow band IoT ○ Set up by 3gpp ○ licensed Reference: Course textbook
  6. 6. LoRa ( Long Range) ● LoRa is the proprietary physical layer or the wireless modulation technique utilized to create long Range Communication Link ● Based on chirp spread spectrum modulation ● A single gateway or base station can cover entire cities or hundreds of square kilometers Chirp Signal
  7. 7. LoRaWAN (Long Range Wide Area Network) ● Star of Stars Topology ● Nodes connect to multiple gateways. ● No handover needed from gateway to gateway ● Nodes are asynchronous and communicate when they have data to send ● Device Classes-All nodes are not equal ● Division based on tradeoff between communication latency versus battery life time. ● Class A -Battery powered sensors ● Class B- Battery powered actuators ● Class C- Main Powered actuators
  8. 8. LoRaWAN (Long Range Wide Area Network)
  9. 9. NB-IoT (Narrow band IoT) ● Technology standardized by the 3GPP standards body ● Narrow band Technology designed for IoT which can be deployed in GSM and LTE Spectrum ● Also termed as cellular based IoT ● Standardization of NB-IoT completed with Release 13 of 3GPP published on 22 June 2016 ● To be launched in early 2017
  10. 10. NB-IoT (Narrow band IoT) ❖ Highest modulation scheme used- QPSK ❖ Minimal noise level inside a single narrowband ❖ Receiver does not require to add processing gain to decode ❖ Simple and inexpensive transceiver design ● Transmission schemes: ○ minimum system bandwidth for both downlink and uplink - 180 kHz ○ GSM carrier of 200 kHz, ○ 1 PRB (Physical Resource Block) inside an LTE carrier/ guardband could be replaced by NB-IoT carrier. ○ 12 subcarriers of 15 kHz in downlink using OFDM and 3.75/ 15 kHz in uplink using SC-FDMA ○ Various deployment options REDUCED POWER & LOW COST
  11. 11. NB-IoT (Narrow band IoT) ● To enable low-complexity UE implementation, NB-IoT allows only one HARQ process in both downlink and uplink, and allows longer UE decoding time ● Asynchronous, adaptive HARQ procedure is adopted to support scheduling flexibility. ● Physical Channel/ Resource mapping ○ Extensive reuse of current LTE (Long Term Evolution) specifications ○ Few changes to physical channels used in LTE (detailed review) ● Random Access : ○ *Contention based algorithm similar to LTE [*Source- A Primer on 3GPP Narrowband Internet of Things (NB-IoT)] UE N/W 1 2 3 4 1. Preamble 2. Response containing advance command and scheduling of the uplink resources for the UE to use 3. Identity to the network 4. Contention resolution message
  12. 12. NB-IoT (Narrow band IoT) ● Time acquisition and synchronization ○ Critical- (Low cost Oscillators, deployment style introduces additional frequency offsets) ○ Changes to the design of synchronization sequences in LTE ● Various pedagogical estimations and signal processing schemes are considered to estimate time delay and synchronization in LTE (detailed review and reference for figure)
  13. 13. NB-IoT (Narrow band IoT) Source: NB-IoT, Accelerating Cellular IoT, Huawei
  14. 14. LoRa and NB-IoT overview Feature LoRa NB-IoT Licensed/Unlicensed Spectrum Unlicensed Band Licensed Band Reuse of Cellular Network No Yes Development Status Existing Yet to develop Modulation SS chirp QPSK Bandwidth 500 Hz - 125 KHz 180 KHz Data Rate 290 bps- 50 kbps 250 kbps max Device cost/ complexity 1-5 $ (Ref- LPWA survey) < 5$ per module (Ref-IETF) Latency and Battery Lifetime > 10 years <10 seconds, >10 years battery (Ref-IETF) Type of Standard Proprietary open
  15. 15. Conclusion ● We have studied - ○ Why? ■ IoT is need of the time. ○ How it can be achieved? ■ LPWA standards like NB-IoT and LoRa were discussed and compared. ○ What? ■ Is LoRa: Entirely new technology adapted to the need of IoT platform ■ Is NB-IoT: Use of existing cellular infrastructure
  16. 16. References NB-IOT: Maximum-Likelihood Detection for Energy-Efficient Timing Acquisition in NB-IoT https://arxiv.org/pdf/1608.02427.pdf A Primer on 3GPP Narrowband Internet of Things (NB-IoT) https://arxiv.org/pdf/1606.04171.pdf NB-IoT by IETF https://www.ietf.org/proceedings/96/slides/slides-96-lpwan-7.pdf
  17. 17. Thank You !!

×