LTE and 5G technologies

enabling the Internet of Things

Romeo Giuliano

Department of Innovation & Information Engineering

Guglielmo Marconi University

r.giuliano@unimarconi.it

Topics

IoT introduction and market

IoT market: connectivity and economic impact

General requirements

LPWA introduction, proprietary technologies and main standards

Introductions to LPWA Applications

Comparison with other technologies

Objectives and goals

Standards and proprietary technologies LoRa, SigFox

IEEE, ETSI, IETF

3GPP standards for LPWA

Evolution to MTC (Rel-12)

Enhanced MTC (Rel-13)

Narrow Band IoT

Network enhancements

Enhancements in Rel-14

Other enhancements related to IoT

Challenges and Conclusions

Challenges

Conclusions

References

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IoT market: connectivity

IoT Connections: 780 million (2016) 3.3 billion (2021)

IoT devices: 400 million (2016) 2.1 billion (2022)

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Global M2M Growth and Migration from 2G to 3G and 4G+.

[Visual Networking Index, Cisco, March 2017]

Global Connected Devices.

[Ericsson Mobility Report, June 2017.]

IoT market: economic impact

4 Unlocking the Potential of the Internet of Things,

McKinsey Global Institute report, June 2016.

IoT Global Market Valuation 2020.

[Cisco, 2014]

Main IoT use cases

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Main IoT use cases

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IoT evolution: from M2M to IoT

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IoT evolution: general requirements

The provisioning of IoT services requires objects with a mobile, flexible and ubiquitous connectivity to the network

Step 1 (‘premium M2M market segment’): connection to expensive devices (e.g. cars, machineries), cost of modem relatively small

Step 2 (‘larger M2M market’): requirements such as low cost, energy efficient, ubiquitous and scalable devices Mesh topology, short range, network coordinator nodes (e.g. ZigBee)

Issues: routing, deploying (and maintenance) of powered coordinator nodes

Step 3: Low Power Wide Area (LPWA) Favored by developments for power amplifier and RF

A star connectivity to quite far Base Stations (BSs)

Moving the complexity and energy requirements on BSs from end devices

Tradeoffs with throughput, packet length, activity cycle, latency, mobility

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Massive IoT and Critical IoT

Massive IoT: tens of billions of objects requiring ubiquitous connectivity. Req.:

low-cost, low energy consumption and good coverage.

Critical IoT: applications demand for high reliability, high availability, and low

latency; smaller volumes; higher business value

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LPWA introduction,

proprietary technologies

and main standards

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Introduction to Low Power Wide Area (LPWA) networks

Complement traditional cellular and short range wireless technologies

Business sectors

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LPWA intro: comparison with other technologies

Short range wireless networks

Local area coverage, not providing mobility

Traditional cellular systems

Complex waveforms optimized for voice, high speed data, messages

LPWA

Coverage extended by dense deployment devices and gateways for relaying

Low power devices and low energy transmission protocols

Suitable for things with low-power, low-cost, low throughput, higher latency,

not-frequent transmission

Suitable for Massive IoT but not for Critical IoT

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LPWA intro: goals

Long range

Frequencies sub-1GHz, optimized modulations (narrow and spread spectrum)

Ultra low power operation

Topology (star not mesh), duty cycling (power save mode), lightweight MAC (CSMA,

Aloha, CSMA/CA, …), offloading complexity from end device (complexity in the BS,

processing data instead of transmitting data)

Low cost

Minimal infrastructure, reduced hardware complexity (simple waveform)

Scalability

Diversity, densification, link adaptation

Quality of Service

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Standards and proprietary technologies for LPWA

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LPWA proprietary technologies: SIGFOX

Architecture: end device, proprietary BS, IP-based network, application server

Range: 10 km in urban and 50 km in rural

Wireless link: BPSK in UL GFSK in DL, ultra narrow (100 Hz) Sub-GHz ISM band carrier.

Throughput: 100 bit/s with 140 12-byte messages in UL and 600 bit/s with 4 8-byte messages in DL

MAC: unslotted ALOHA

Reliability: ACKs not supported, frequency diversity, message retransmissions (default 3 times), encryption not supported

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LPWA proprietary technologies: LoRa

Architecture: end device, proprietary BS (multiple links star-of-stars), IP-based network, application server

Range: 5 km in urban and 15 km in rural

Wireless link: proprietary chirp spread spectrum (CSS), supported 7-12 SF with FEC, Sub-GHz ISM band at 430, 868, 915 MHz

Throughput: 300 bit/s – 37.5 kbit/s with LoRa, 50 kbit/s in FSK

MAC: unslotted ALOHA and several chirp codes

Other characteristics: frequency diversity, a time difference of arrival (TDOA) based localization technique is supported, encryption at AES 128.

Three device types: class A, class B, class C

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LPWA standards: IEEE

IEEE 802.15.4k (Low Energy, Critical Infrastructure Monitoring or LEICM Networks):

Topology: star; Range: 5 km

Wireless link: DSSS and FSK, in ISM bands (Sub-GHz and 2.4 GHz), with channel bands from 100 kHz to 1 MHz.

MAC: conventional CSMA/CA and CSMA with without priority channel access (PCA), and ALOHA with PCA, capable of exchanging asynchronous and scheduled messages.

Data rate: 300bit/s, 1.2kbit/s, 50kbit/s based on sensitivity, with Ptx=15dBm

INGENU LPWA technology is compliant

IEEE 802.15.4g (Low-Data-Rate, Wireless, Smart Metering Utility Networks):

PHY: FSK, OFDMA, offset QPSK, in ISM bands (Sub-GHz, 2.4 GHz)

Data rates: from 40 kbit/s to 1 Mbit/s for 1500-byte frame

MAC: CSMA/CA as defined by IEEE 802.15.4e

Topology: star, mesh, peer (see 15.4); Range: few kms

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LPWA standards: IEEE

Aim: extending range and decreasing power consumption for WLANs

IEEE 802.11ah:

Sub-GHz ISM band; Range: 1 km in outdoor

Data rate: 100 kbit/s

PHY: OFDM 10 times slower than IEEE 802.11ac

MAC: overheads of frames, headers and beacons are reduced, tailored to support the connection of 8191 end devices

End devices are enabled with mechanisms to save energy during the inactive periods but yet retain their connection/synchronization with the access points: good results but not enough to enlist IEEE 802.11ah as a LPWA technology.

IEEE 802.11 Long Range Low Power (LRLP)

The Topic Interest Group is at early stage: just defined some use cases and functional requirements. Closed!

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LPWA standards: IETF

6LoWPAN (Low power Wireless Personal Area Networks)

Extension of IPv6 stack to IEEE 802.15.4

Characteristics of LPWA applications and technologies limit the applicability

of 6LoWPAN

6LPWA (IPv6 stack for Low-Power Wide Area Networks)

Addressed issues:

Header compression

Fragmentation and reassembly

Management of end devices, applications, base stations, and servers. Need for ultra-

lightweight signaling protocols able to operate efficiently over the constrained layer 2

technology

Security, integrity, and privacy.

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3GPP Standards for LPWA

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LTE evolution to Machine Type Communications (MTC)

LTE is expected to cover 75% of world population by 2021 (Ericsson Mobility

Report. June 2016)

What’s for IoT?

Aim:

1. Trade-offs between cost, coverage, data rate, and power consumption;

2. Maximizing the re-use of the existing cellular infrastructure and owned radio spectrum.

LTE evolution to Machine Type Communications (MTC)

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LTE evolution for MTC

Rel-11: LTE for MTC (Cat.1), introduction of Extended Access Barring (EAB)

Rel-12:

MTC introduces Cat. 0 UE to reduce device complexity

Power Saving Mode (PSM) functionality

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LTE for MTC: Cat. 0 UE in Rel-12

Reduced data rate by implicit restriction

Downlink channel bandwidth for the data channel is reduced

DL control channels are still allowed to use the carrier bandwidth; UL unchanged

maximum Transport Block Size (TBS) of 1000 bits for unicast, 2216 bits for broadcast,

(optional) 4584 bits for Multimedia Broadcast Multicast Services (MBMS)

Optional half-duplex FDD with relaxed switching time

Single-receive antenna with reduced data rate capability

Many operators choose to go directly to Rel-13 eMTC and/or NB-IoT by

skipping Category 0 deployments.

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LTE for MTC: Rel-12 Power Saving Mode (PSM)

PSM is a new low-power mode that allows the device to enter a deep-sleep power state When turned off, the device would not have to monitor page messages or perform any

Radio Resource Management (RRM) measurements.

The device becomes unreachable when UE is in PSM

Better for device-originated or scheduled applications

Examples of applications: smart meters,

sensors and any IoT devices that periodically

push data up to the network.

PSM is applicable to Cat-0, Cat-M1 and

Cat-NB1 devices.

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Enhanced Machine Type Communications (eMTC)

Rel-13 eMTC introduces Cat. M1 UE:

Cost/complexity reduction, longer battery life, coverage enhancements MCL>155.7 dB

eMTC operation is limited to 1.08MHz (6 PRBs).

Limited throughput of up to 1Mbps in DL/UL, with TBS=1000 bits

Additional complexity saving is achieved by reduction in the number of DL

Transmission Modes (TM) and relaxed requirements on radio link quality

measurements and reporting.

Cat-M1 devices have the options to support 23 dBm or 20 dBm power classes: the

Power Amplifier can be integrated

Enhanced coverage: tradeoff between coverage and transmission data rates and

latency.

Transmission Time Interval (TTI) bundling and persistent assignment, which can be

set/modify during the connection setup and can be updated through event driven feedback.

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eMTC (2)

eMTC can be deployed to operate within a regular LTE carrier (up to 20 MHz) and coexist with other LTE services. The bandwidth reduction for Cat-M1 requires a new control channel (i.e., MTC Physical

Downlink Control Channel (MPDCCH) to replace the legacy control channels (i.e., PCFICH, PHICH, PDCCH).

Cat-M1 devices leverage legacy LTE synchronization signals (e.g., PSS, SSS, PBCH) in the center 1.08MHz of the LTE carrier, and introduce new system information (SIB1-BR).

eMTC network can configure multiple narrowband regions (with 6 PRBs each)

Support of frequency and time multiplexing between IoT and non-IoT traffic: flexibility in allocation

Long battery life to support 10 years by: Narrower bandwidth operation

Reduced processing requirements

Introducing Enhanced DRX (eDRX) feature

in Rel-13

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Narrow Band – IoT (NB-IoT)

NB-IoT introduces Cat. NB1 UE for low end devices (low-throughput, delay-

tolerant use cases with low mobility support, such as smart meters, remote

sensors and smart buildings) [completed in June 2016]: lower complexity and

coverage extended to 164 dB MCL

180 kHz bandwidth: reduction of RF/baseband complexity, costs and power consumption

LTE in-band (single PRB), LTE guard-band (unused PRBs) and standalone deployment

(in re-farmed spectrum from GERAN, 200 kHz)

Currently only for FDD and TDD for future releases

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NB-IoT (2)

Introduction of new control channels:

Synchronization signals (NB-PSS and NB-SSS), broadcast and access channels (NB-PBCH

and NB-PRACH), control channels (NB-PDCCH) and data channels NB-Physical Downlink

Shared CHannel (NB-PDSCH) and NB-Physical Uplink Shared CHannel (NB-PUSCH)

DL: QPSK for NB-PDSCH for OFDM with 15 kHz subcarrier spacing

UL: QPSK for multiple tone based on SC-FDMA with 15 kHz subcarrier spacing and BPSK for

single tone at 15 kHz and 3.75 kHz tone spacing for power gain

Downlink peak data rates: about 32 kbit/s (in-band), 34 kbit/s (standalone); uplink

peak data rates: about 66 kbit/s (multi-tone Tx), 16.9 kbit/s (single-tone)

Support of half-duplex FDD, single antenna, maximum PTx = 20 dBm

Limited support for voice (VoLTE or circuit switched services) and mobility (not

supported in connected mode i.e. no handovers, only cell reselection in idle).

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NB-IoT (3)

Key enabler techniques for deeper coverage include:

Redundant transmissions; Single-tone uplink; Lower-order modulation

extended Discontinuous Reception (eDRX) optimizes battery life for device-

terminated applications

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Extended Discontinuous Reception (eDRx)

Rel-13 introduces Extended Discontinuous Reception (eDRx)

Enhanced connected mode (C-DRX): extension of the maximum time between control

channel monitoring/data reception from the network in connected mode to 10.24 seconds

(optimized for device-terminated applications)

Idle mode discontinuous reception (I-DRX): extension of time between page monitoring

and Tracking Area Update (TAU) in idle mode up to 43.69 minutes for Cat-M1 and up to

about 3 hours for Cat-NB1

eDRX is applicable to both Cat-M1 and Cat-NB1

eDRX can also reduce signaling load compared to legacy DRX and/or PSM.

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LTE for MTC: network enhancements in Rel-13

Dedicated Communication Network: network elements dedicated to IoT

comms

Architecture Enhancements for Services capability exposer (AESE)

Optimizations to support high latency communication (HLCom)

Group Based Enhancements (GROUPE)

Monitoring Enhancements (MONTE)

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LTE for MTC: architecture

Interworking function MTC-IWF: provides security, charging and identifier translation (external-to-internal identifier)

MTC server (optional), MTC Application

Models: direct (Over-The-Top applications connects directly to MTC devices); indirect (MTC application connects through the MTC server – additional value-added services); hybrid (OTT connects directly but uses also value-added services)

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LTE for MTC: network enhancements in Rel-13

Architecture Enhancements for Services Capability Exposer (AESE): the Mobile Network Operators (MNO) can offer value added services by exposing these 3GPP service capabilities to external application providers, businesses and partners using web based APIs. Via one or more standardized APIs, e.g., the OMA-API(s).

Key issue 1: definition of the Service Capability Exposure Function (SCEF) in 3GPP core network. SCEF provides the means to securely expose the services

and capabilities for external parties through homogenous network API) defined by OMA, etc.

The SCEF abstracts the services from the underlying 3GPP network interfaces and protocols.

The SCEF is always within the trust domain of a network operator. An application can belong to the trust domain or may lie outside the trust domain.

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LTE for MTC: Rel-14 enhancements

Improved positioning capabilities: Observed Time Difference of Arrival (OTDOA) Positioning

Enhanced Multicast DL transmission,

Mobility enhancements

Support of higher data rates: intro of Cat. M2 (5 MHz, TBS=4000 bit, 10 HARQ, support of video)

VOLTE enhancements: supporting two-way communication (for example, for wearable devices, alarms and eHealth), and for customer service

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Rel-14: other enhancements related to IoT

Enhancements to LTE D2D

Support of V2V

Synchr. by GNSS

Resource reservation by distributed scheduling

(left) or by eNB (right)

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LPWA: challenges

Scalability to massive number of devices

Interference mitigation

Higher data rates

Interoperability between LPWA technologies

Localization

Link adaptation and optimization

Roaming and mobility

Integration with other technologies

Support for data analytics

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Conclusions

Characteristics of LPWA introduced in terms of applications, comparison with other technologies and objectives

Described the proprietary technologies such as LoRa, SigFox

Described of available and forthcoming LPWA standards developed by IEEE, ETSI, IETF and 3GPP

Presented possible challenges for LPWA

References

U. Raza, P. Kulkarni, M. Sooriyabandara, “Low Power Wide Area Networks: An Overview”, IEEE Communications Surveys & Tutorials, vol.19, no.2, Q2 2017, p.855-873

5G Americas whitepaper, LTE and 5G Technologies Enabling the Internet of Things. Dec. 2016

5G Americas whitepaper, LTE Progress Leading to the 5G Massive Internet of Things, Dec. 2017

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LTE and 5G technologies enabling the

Internet of Things Romeo Giuliano, r.giuliano@unimarconi.it

Department of Innovation & Information Engineering

Guglielmo Marconi University

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