Low Power Wide Area Networks (LPWANs) from Universitat Politècnica De Catalunya

eetac

Escola d'Enginyeria de Telecomunicació i Aeroespacial de Castelldefels UPC UNIVERSITAT POLITÉCNICA DE CATALUNYA BARCELONATECH EETAC Mobility, Networks and Services

Table of Contents

• 1. Introduction
• 2. LoRaWAN
• 3. Sigfox
• 4. LTE-M
• 5. NB-IOT

MXS - Unit 6 - LPWANs

Introduction to LPWAN (I/IV)

• Traditional IoT technologies:
  Rather short range links: ~ 10 m to ~100 m
  Examples: IEEE 802.15.4, Bluetooth Low Energy,
  etc.
  Problem
  High amount of infrastructure required to cover
  large areas
  Multihop topologies: mesh, tree ...

@ Low Power Wide Area Networks (LPWAN) Long range, star topology Low cost infrastructure deployment, maintenance 4 billion LPWAN devices expected by 2025-2030 Main technologies: D LoRaWAN, Sigfox, NB-IOT, LTE-M

LoRa® TM sigfox 3GPP A GLOBAL INITIATIVE MXS - Unit 6 - LPWANS

Introduction to LPWAN (II/IV)

a Comparison Sensor Router Gateway MXS - Unit 6 - LPWANs

LPWAN Comparison (II/IV)

a Comparison Sensor Router Gateway Short range (e.g. IEEE 802.15.4) MXS - Unit 6 - LPWANs

LPWAN Technologies Comparison (II/IV)

a Comparison Sensor Router Gateway Short range (e.g. IEEE 802.15.4) MXS - Unit 6 - LPWANs

LPWAN and Short Range Comparison (II/IV)

a Comparison Sensor Router Gateway Short range (e.g. IEEE 802.15.4) LPWAN MXS - Unit 6 - LPWANs

Introduction to LPWAN (III/IV)

Long link range: May be greater than 1 km, up to ~10 km a Depending on the scenario Achieving long link range: In some cases, sub-GHz bands @ Lower frequency means greater received power D E.g. 868 MHz (Europe), 915 MHz (US) Low receiver sensitivity Some typical values in short-range IoT technologies: · IEEE 802.15.4: - 85 dBm Bluetooth Low Energy: - 70 dBm Some typical values in LPWAN technologies: · LoRaWAN: - 137 dBm · Sigfox: - 142 dBm . NB-IOT: - 141 dBm · LTE-M: - 141 dBm Low physical layer bit rate @ Between ~100s of bit/s and ~100s of kbit/s a Suitable for IoT applications, also allows to support many devices MXS - Unit 6 - LPWANs

Introduction to LPWAN (IV/IV)

• Market share
  Terrestrial LPWA connections (Millions)
  1000
  LoRa
  100
  NB-IOT
  LTE-M
  Other
  Sigfox
  10
  SOURCES: IHS Markit
  2019, Kepler, loT
  Analytics
  1
  2017 2018 2019 2020 2021 2022 2023

MXS - Unit 6 - LPWANs

LoRaWAN Overview

LoRa Alliance' TM Introduction Wireless technology specified by the LoRa Alliance @ Consortium of ~500 member entities First version in 2015 Based on a PHY layer called LoRa (invented 2009) a LoRa stands for "Long Range" D Use of unlicensed spectrum Advantage: low cost Disadvantage: coexistence with other technologies a Open approach . Anyone can build a complete LoRaWAN network o No need to rely on operators, but some do exist MXS - Unit 6 - LPWANs

LoRaWAN Network Architecture

D End-to-end communication between EDs and the NS o Spatial diversity: A packet sent by an ED may be received by several gateways and forwarded to the NS Y wireless IP over Ethernet, Wi-Fi, 5G, etc. NS App End-Devices (EDs) (e.g. sensors) Gateways Network server Application Defined by LoRa WAN MXS - Unit 6 - LPWANs

LoRaWAN Protocol Stack

D LoRaWAN mostly defines MAC layer functionality on top of a PHY layer Customer application Customer application LoRaWAN LoRaWAN Message forwarding Backhaul IP Stack Backhaul IP Stack PHY PHY MAC/PHY MAC/PHY LoRa or FSK Modulation Ethernet, Wi-Fi, 5G, etc. End-Device Gateway Network server MXS - Unit 6 - LPWANs

LoRaWAN Physical Layer

e.g. increase freq: "1", decrease freq: "0" O Based on LoRa (chirp spread spectrum) modulation FSK modulation supported as one option Operational band . EU: 868 MHz, 3 default channels · Duty-cycle limited to 1% (uplink), 10% downlink Symbol 1 0 -1 0 1 2 3 4 5 Configuration Different Spreading Factors (SF) and Data Rates (DR) supported: DR Configuration PHY Bit Rate (bit/s) Modulation Spreading Factor (SF) Bandwidth Mandatory 0 LoRa SF12 125 kHz 250 1 LoRa SF11 125 kHz 440 2 LoRa SF10 125 kHz 980 3 LoRa SF9 125 kHz 1760 4 LoRa SF8 125 kHz 3125 5 LoRa SF7 125 KHz 5470 6 LoRa SF7 250 kHz 11,000 7 FSK -- 50,000 8-14 Reserved for Future Use time MXS - Unit 6 - LPWANs

LoRaWAN Message Transmission

Most typically, transmission is ED-initiated Downlink transmission requires the ED to perform an uplink transmission first This way, the ED can be in sleep mode by default NS GW (Uplink) (Downlink) TX RX1 RX2 ED t > RECEIVE_DELAY1 ( 1 s) A RECEIVE_DELAY2 ( 2 s) MXS - Unit 6 - LPWANs

LoRaWAN Transmission Types

• For each message, the ED may choose:
  Confirmed transmission
  Unconfirmed transmission
• Confirmed transmission
  After transmission, the ED awaits an ACK in either
  RX1 or RX2
  If the ACK is not received, ED retransmits
• Unconfirmed transmission
  Receive Windows (RX1 and RX2) must be open
  anyway since there may be downlink (data)
  messages for the ED

MXS - Unit 6 - LPWANs

Sigfox (I/V)

French company called Sigfox Founded in 2009 acquired by UnaBiz (2022) Network operator Technology also called Sigfox o "Global 0G network" . IoT devices D Coverage 75 countries current operation under deployment sigfox rctic Ocean Greenland Iceland Sweden Russia Norway Moscow Canada United Kingdom O Ukraine France Kazakhstan Mongolia orth United States New York Greece cific Atlantic Ocean Morocco Iraq, Iran Fean Pakistan Mexico Cuba Oman Mauritania Niger Cambodia Ethiopia Colombia Maldives Kenya Tanzania Brazil Angola Bolivia Madagascar Namibia Indian South Chile Rio de Janeiro South Africa Ocean Perth North Spain Beijing Turkmenistan China Libya Egypt Bangladesh Cameroon Malaysia Indonesia Peru Svalbard MXS - Unit 6 - LPWANs

Sigfox Network Architecture (II/V)

Network architecture Authorizes network access of devices O Reg. Authority O O C Manages base stations, devices and data O O Internet Service Center Applications C O 1 O Core network Devices Base stations Space diversity MXS - Unit 6 - LPWANs

Sigfox Technical Details (III/V)

D Use of unlicensed spectrum o Europe: 868 MHz band Uplink: 868.00 MHz to 868.60 MHZ . Downlink: 869.40 MHz to 869.65 MHZ D North America: 902 MHz band Ultra Narrow Band (UNB) Bandwidth and modulation of a frequency channel Uplink: 100 Hz (Europe) or 600 Hz (North America), DBPSK mod. Downlink: 1.5 kHz, GFSK modulation Bit rate Uplink: 100 bit/s (Europe) or 600 bit/s (North America) Downlink: 600 bit/s Duty cycle regulations (Europe) = 1% (uplink), 10% (downlink) Per Sigfox device: 140 messages/day, payload of 12 bytes (uplink) @ 4 messages/day, payload of 8 bytes (downlink) MXS - Unit 6 - LPWANs

Sigfox Message Exchange (IV/V)

Message exchanges are device-initiated . Allows the device to stay by default in sleep mode Uplink transmission . Three transmissions of the same message a First transmission and two replicas a Each transmission uses a different frequency channel a Time, frequency and space diversity o Downlink transmission . Only in response to an uplink transmission Requires the device to trigger the procedure by sending an uplink . If requested by the device, indicated in the uplink frame header MXS - Unit 6 - LPWANs

Sigfox Message Exchange Details (V/V)

D Message exchanges Space, time and frequency diversity - Unidirectional Uplink frame Uplink frame replicas ty: 1.20 s to 2.08 s (Europe) 7 < t time - Bidirectional Uplink frame Uplink frame replicas Downlink frame Confirmation frame 7 > < > > time T DL WIN START (20 s) JACK (1.5 s) Downlink receive window (≤ 25 s) 20

LTE-M Overview

0 LTE-M is a set of 3GPP specifications intended for IoT/MTC applications Based on LTE @ Therefore, licensed! IoT = Internet of Things MTC = Machine Type Communication o Goals Reduced device cost Only SISO, but mobility and voice over LTE (VoLTE) still supported Lower bit rate Greater link range Greater battery lifetime @ Extended sleep intervals LTE-M O LTE-M versions Typically, LTE-M corresponds to LTE Cat M1 @ Defined in Release 13 (year 2016) Subsequent LTE-M versions (e.g. LTE Cat M2) have been defined Not so typically supported MXS - Unit 6 - LPWANs

LTE-M Technical Specifications

4 - Tslot - -i downlink slot As in LTE, LTE-M uses: OFDM (downlink) SC-FDMA (uplink) Resource Block: 7 symbols X 12 subcarriers (short CP) 6 symbols X 12 subcarriers (long CP) @ Channel bandwidth of 1.4 MHZ New subcarriers (One PRB) ---- 12 subcarriers Resource Element - 6 PRBS a Rest is guard bands User peak bit rate of ~1 Mbit/s @ UL and DL a 1008 bit per subframe (1 ms) Figure source: Habaebi, M. H., et al. "Comparison between scheduling techniques in long term evolution." IIUM Engineering Journal 14.1 (2013) MXS - Unit 6 - LPWANs

LTE-M Coverage Enhancement

Minimum in LTE Only 1.08 MHZ actually used x6 BW)4. LTE-M: coverage enhancement Reasons for extending link range: Less base stations (eNBs) needed To compensate coverage decrease due to LTE-M simplification (SISO) To compensate the fact that LTE-M devices can be located anywhere May be subject to worse radio quality conditions a Different from a human using a phone with LTE D Coverage Enhancement (CE) modes: CE mode A a Mandatory @ Provides up to 32 repetitions of the data channel CE mode B a Optional Provides up to 2048 repetitions of the data channel MXS - Unit 6 - LPWANs

NB-IoT Overview

Narrowband IoT (NB-IoT) is a set of 3GPP specifications intended for IoT/MTC applications Based on LTE @ Therefore, licensed! o Goals Reduced device cost and complexity Only SISO, no voice, no mobility Lower bit rate @ Lower than LTE-M Greater link range o May be greater than LTE-M @ Thanks to lower bandwidth NB-IOT TM Greater battery lifetime @ Extended sleep intervals (more than LTE-M) NB-IoT versions Typically, NB-IoT corresponds to LTE Cat NB1 @ Defined in Release 13 (year 2016) Evolved NB-IoT version (e.g. LTE Cat NB2) has been defined Not always supported MXS - Unit 6 - LPWANs

NB-IoT Technical Specifications

4 - Tslot - -i downlink slot As in LTE, NB-IoT uses : . OFDM (downlink) SC-FDMA (uplink) Resource Block: 7 symbols X 12 subcarriers (short CP) 6 symbols X 12 subcarriers (long CP) Channel bandwidth of 180 KHz New subcarriers -- 12 subcarriers - Resource Element . One PRB Peak bit rate 170 kbit/s (Downlink) a 250 kbit/s (Uplink) Effective bit rates are ~10s of kbit/s Figure source: Habaebi, Mohamed Hadi, et al. "Comparison between scheduling techniques in long term evolution." IIUM Engineering Journal 14.1 (2013) MXS - Unit 6 - LPWANs 25