LPWAN –LPWANLow Power indigoo.com LOW POWER WIDE AREA NETWORK

OVERVIEW OF EMERGING TECHNOLOGIES FOR LOW POWER WIDE AREA NETWORKS IN AND M2M SCENARIOS

Peter R. Egli

INDIGOO.COM1/11 © Peter R. Egli 2015 Rev. 1.00 LPWAN – Low Power Wide Area Network indigoo.com Contents 1. The sweet spot for LPWANs 2. LPWAN requirements and characteristics 3. The need for long range connectivity 4. LPWAN network topology 5. Link budget for LPWAN devices 6. Receiver sensitivity for LPWAN devices 7. Technologies for LPWAN

2/11 © Peter R. Egli 2015 Rev. 1.00 LPWAN – Low Power Wide Area Network indigoo.com 1. The sweet spot for LPWANs Different wireless technologies cover different applications with regard to range and bandwidth. Long-range applications with low bandwidth requirements that are typical for IoT and M2M scenarios are not well supported by these existing technologies.

LPWAN technologies are targeted at these emerging applications and markets.

802.11ac High BW 802.11ad 802.11n 4G 802.11a 802.11b 3G 802.11g Medium BW 2G VSAT

BlueTooth ZigBee / BLE 802.15.4 WBAN Low BW 802.15.6 WPAN LPWAN RFID / 802.15.3 NFC Key: BW: Bandwitch IoT: Internet of Things Short Range Medium Range Long Range M2M: Machine to Machine 3/11 © Peter R. Egli 2015 Rev. 1.00 LPWAN – Low Power Wide Area Network indigoo.com 2. LPWAN requirements and characteristics (1/2) The needs of IoT and M2M applications pose some unique requirements on LPWAN technologies as shown in the comparison with other wireless technologies: Range Geographical Power Coverage, Penetration Consumption LPWAN

ZigBee Transmission 802.15.4 Bandwidth Latency

3G/4G/5G Number of Base Stations Radio Chipset Costs Radio Subscription Costs

4/11 © Peter R. Egli 2015 Rev. 1.00 LPWAN – Low Power Wide Area Network indigoo.com 2. LPWAN requirements and characteristics (2/2)

Characteristic Target Value for LPWAN Technologies Long range 5 – 40km in the open field Ultra low power Battery lifetime of 10 years Depends on the application, but typically a few hundred Throughput bit / s or less Radio chipset costs $2 or less Radio subscription costs $1 per device and year Not a primary requirement for LPWAN. IoT applications are Transmission latency typically insensitive to latency. Required number of base Very low. LPWAN base stations are able to serve thousands stations for coverage of devices. Excellent coverage also in remote and rural areas. Good in- Geographic coverage, building and in-ground penetration (e.g. for reading power penetration meters).

5/11 © Peter R. Egli 2015 Rev. 1.00 LPWAN – Low Power Wide Area Network indigoo.com 3. The need for long range wireless connectivity Devices in IoT applications (the “things”) are typically installed in the field on residential premises, public places like restaurants or cafés or on industrial plant sites.

Using short range radio connectivity complicates the IoT setup due to the implications of wired on-site connectivity (firewalls, NAT, port and protocol filtering).

Short range radio connectivity for IoT devices:

End Customer Premises Access Network / Cloud, Apps .Short range radio devices (SRD) Internet such as ZigBee require using a A gateway for long-range backhaul. Wired Cloud .The gateway is typically hooked network A SRD up to some on-site wired network Gateway A which is not under control of the IoT provider.

Direct long range connectivity (LPWAN) for IoT devices:

End Customer Premises Access Network / Cloud, Apps .Long range connectivity allows Internet direct access to the devices in A the field. Cloud A .The base station typically serves a large number of devices thus Base A Station greatly reducing costs.

6/11 © Peter R. Egli 2015 Rev. 1.00 LPWAN – Low Power Wide Area Network indigoo.com 4. LPWAN network topology (1/2) The wireless portion of LPWAN networks uses a star topology. This obviates the need for complicated wireless mesh routing protocols which would greatly complicate the implementation of end devices and drive up power consumption.

A. Direct device connectivity (base station):

LPWAN Connectvitiy Access Network / Cloud & Servers Applications Internet A A Cloud A Base A Station

Star topology for long Wired backhaul, range radio connectivity TCP/IP based (e.g. MQTT)

. A base station provides connectivity to a large number of devices.

. The traffic is backhauled to servers (cloud) through TCP/IP based networks (Internet).

. The base station is responsible for protocol translation from IoT protocols such as MQTT or CoAP to device application protocols.

7/11 © Peter R. Egli 2015 Rev. 1.00 LPWAN – Low Power Wide Area Network indigoo.com 4. LPWAN network topology (2/2) B. Indirect device connectivity through a LPWAN gateway:

Short Range Conn. LPWAN Connectvitiy Access Network / Cloud & Servers Applications Internet A A Gateway Cloud A Base A Station

Short range Star topology for long Wired backhaul, local connectivity range radio connectivity TCP / IP (e.g. MQTT)

. In setups where devices cannot be directly reached through LPWAN, a local gateway bridges LPWAN connectivity to some short range radio (SRD) technology (e.g. ZigBee, BLE).

. The gateway typically runs on mains power since it serves a larger number of devices and must convert between LPWAN and SRD radio technologies and protocols.

. Gateways may help to improve security since more powerful security algorithms can be implemented on the gateway than is possible on the constrained devices.

8/11 © Peter R. Egli 2015 Rev. 1.00 LPWAN – Low Power Wide Area Network indigoo.com 5. Link budget for LPWAN devices Link budget: As in most radio systems, the link budget is an important measure for power calculation. The link budget calculates the power received at the receiver and accounts for gains and losses along the transmission path. 푷푹푿 = 푹풆풄풆풊풗풆풅 풑풐풘풆풓 풅푩풎 푷푹푿 = 푷푻푿 + 푮푻푿 − 푳푻푿 − 푳푭푺 − 푳푴 + 푮푹푿 − 푳푹푿 푷푻푿 = 푺풆풏풅풆풓 풐풖풕풑풖풕 풑풐풘풆풓 풅푩풎 푮푻푿 = 푺풆풏풅풆풓 풂풏풕풆풏풏풂 품풂풊풏 풅푩풊 푳푻푿 = 푺풆풏풅풆풓 풍풐풔풔풆풔 풄풐풏풏풆풄풕풐풓풔 풆풕풄. 풅푩 푳푭푺 = 푭풓풆풆 풔풑풂풄풆 풍풐풔풔 풅푩 푳푴 = 푴풊풔풄. 풍풐풔풔풆풔 풎풖풍풕풊풑풂풕풉 풆풕풄. 풅푩 푮푹푿 = 푹풆풄풆풊풗풆풓 풂풏풕풆풏풏풂 품풂풊풏 풅푩풊 +dB L 푳 = 푹풆풄풆풊풗풆풓 풍풐풔풔풆풔 풄풐풏풏풆풄풕풐풓풔 풆풕풄. 풅푩 GTX TX 푹푿 [dBi] [dB] 푺푹푿 = 푹풆풄풆풊풗풆풓 풔풆풏풔풊풕풊풗풊풕풚 풅푩풎

PTX [dBm]

L 0dB FS Transmission [dB] Path PRX [dBm] SRx [dBm] L GRX RX Gain [dBi] [dB] LM Loss -dB [dB]

9/11 © Peter R. Egli 2015 Rev. 1.00 LPWAN – Low Power Wide Area Network indigoo.com 6. Receiver sensitivity for LPWAN devices Receiver sensitivity: The required receiver sensitivity for a LPWAN device is derived from the calculated link budget. The wireless link can be closed (communication between sender and receiver is possible) if the

receiver sensitivity SRX equals or is lower than (numerically in dB) the received power PRX.

푺푹푿 <= 푷푹푿

Due to the long transmission paths that are typical for LPWAN systems, free space loss (path loss) is the dominant factor that greatly reduces the received power at the receiver.

Therefore it is essential that LPWAN receivers, particularly device nodes, have a very good receiver sensitivity (<= -140dBm), i.e. are able to receive signals levels that are 7 orders of magnitude or more smaller than the transmission level at the sender.

10/11 © Peter R. Egli 2015 Rev. 1.00 LPWAN – Low Power Wide Area Network indigoo.com 7. Technologies for LPWAN In the still evolving IoT and M2M markets, a few competing radio technologies are emerging.

Common to these technologies is the use of lower frequencies than 2.4GHz or 5.8GHz to achieve better penetration into buildings or underground installations.

Work is still in progress in most of these technologies.

LPWAN Standard / Range Spectrum Technology Specificiation Any unlicensed spectrum such as ETSI LTN ETSI GS LTN 001 - 003 40 km in open field ISM (433MHz, 868MHz, 2.4GHz) Any unlicensed spectrum 2-5km in urban areas LoRa Alliance 868MHz (Eu) LoRaWAN <15km in suburban LoRaWAN 915MHz (US) areas 433MHz (Asia) <5km in urban areas Weightless-N Weightless SIG 800MHz – 1GHz (ISM) 20-30km in rural areas

Proprietary (On-Ramp <65km line of sight Wireless), planned to RPMA 2.4GHz become an IEEE <20km non line of standard sight

11/11 © Peter R. Egli 2015 Rev. 1.00