IRCICA 19 Juin 2018 - Rohde & Schwarz · Instead a power supply, this setup is using a real 3.8V lithium battery Power Consumption Analysis with CMW/RTO 3.8V GND RF Analyse the embedded

L'optimisation des consommations de puissance

IRCICA

19 Juin 2018

Challenges in a very dynamic and demanding market environment

Power Consumption Analysis with CMW/RTO 2

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Power Consumption Analysis with CMW/RTO

Up to10 years battery life?

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It‘s all about connecting everything – wireless & cordlessbattery

Battery

capacity

5 Ah

0 Ah

10 Ah

15 Ah

101100 102 103 104 105

Day Week Month Year 10 years

High demand for cordless IoT devices using energy storage and/or harvesting technologies

• Battery is a cost factor: • Battery costs depend on

capacity

• Cost of battery replacement

• Design for replacement

• In some cases the battery lifetime defines the lifetime of the device

m3

P

Smart meter

Park sensor

Plant monitor

Container tracking

Phone

66

Watch Health monitor

Battery lifetime in hours


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The low-power design challenge

• Low power architecture

• Low power components

• Sleep power minimization

• Active power optimization

• …..

Low-power hardware design

• Operating system

• Communication protocol

• Operational model

• Maintenance model (upgrade)

• ……

Low-power software design

Low-power wireless communication

LP-PAN

Bluetooth, …

LP-LAN

Wi-Fi HaLow, .., ZigBee, Thread, ..

LP-WAN

Sigfox, LoRa, …LTE Cat M1/NB1…

Considering/modelling all relevant aspects impacting power consumption


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Basic principles to realize low power communication networks

Streamlined signaling

• Minimize the necessary signaling (e.g. resume connections, connectionless)

• Optimize communication (e.g. IP header compression)

Receiver optimization

• Implement application for an

uplink-only communication

• Minimize time spend in

receiving mode

Efficient transmission

• Apply reliable communication (lower order modulation, repetitions, frequency hoping)

• Use power efficient transmission modes (single tone transmission)

• Functional limitations

• Responsiveness

• Quality of service

• Security

• Delay

• Data rate (power)


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3GPP ecosystem is addressing the LP-WAN market as well

LTE Cat M1 NB-IoT (Cat NB1)

DeploymentIn-band LTE

In-band LTE

Guard-band LTE

Standalone

Downlink OFDMA [15 kHz] OFDMA [15 kHz]

UplinkSC-FDMA [15 kHz]

Single-tone [15/3.75 kHz]

SC-FDMA [15 kHz]

Peak rate DL: 1 Mbps

UL: 1 Mbps

DL: 250 kbps

UL: 20 kbps (ST)

UE receiver BW 1.4 MHz 200 kHz

UE TX power 23 or 20 dBm 23 or 20 dBm

Power saving PSM, eDRX PSM, eDRX


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Optimized RRC signaling

CIoT-Uu

Optimized network architecture to minimize signaling efforts

MME

HSS

S-GW

SCEF

App

App

P-GW

T6a

S5

S1-U

S1-MMEMME

SMS

GW

REST API

IPv4/v6

CIoTBS

UE

Non-IP messages via C-plane

IP messages via C-plane

IP/non-IP messages via User Plane

Data transmission over control plane


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Power Saving Mode (PSM) for deep sleep operation

activ

e

Tx

activ

e

I-DRX (<2.56 s) TAU

T3324

T3412…; 54 min;....; 310 hours; … Send data

Pow

er c

onsu

mpt

ion

PSM ModeIdle

UE remains registered with the network and there is no need to re-attach or re-establish

PDN connections – saves power, but UE isn’t reachable in PSM Mode

Attach / TAU Request

(T3324, T3412 ext. value)

Attach / TAU Accept

(T3324, T3412 ext. value)

RRC Connection Release

PSM Mode [T3412]

Idle Mode [ T3324]

MMEUE1 eNB


Tx

Rx

sleep

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Extended discontinuous reception (eDRX) to save power

activ

e

Tx

activ

e

eMTC: 5.12 s; 10.24 s … 2621.44 sSend data

I-eDRX I-eDRX I-eDRX I-eDRX

Idle Mode

Pow

er c

onsu

mpt

ion

Energy consumption can be reduced significantly with longer cycles for discontinuous

reception (DRX), if certain degree of mobile terminating services reachability is acceptable.

Attach / TAU Request

(Extended DRX parameters)

Attach / TAU Accept

(Extended DRX parameters)

Idle Mode

MMEUE1 eNBExample: extended DRX in Idle Mode

NB-IoT: 20.48 s; 40.96 s … 10 486.76 s

RRC Connection Release


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It becomes more complex to optimize the power consumption

Extended DRX(Idle Mode)

UE power class

UE categoryPower saving mode (PSM)

Coverage enhancement

Conditions

Data exchange architecture

Cat NB1

Cat M1

Cat 0

Cat 1

20 dBm

23 dBm

U-Plane

Non-IP

IP

5.12 s

10.24 s

43.69* min

6 min

12 min

310 h

Level 0

Level 1

Level 2

Design decision Negotiation w/ network

* eDRX timer for eMTC; for NB-IoT up to 175 min


14 dBm

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Need for precise power measurements and detailed views

on all relevant aspects under reproducible network conditions

IoT

app.

MME

S-GW

SCEF

P-GW

MMECIoTBSDUTPMIC LTE

µP

GPIO1.8 V

3.3 V

2.8 V

• Communication behavior

• Timer (eDRX, PSM)

• Power modes

V

I

• Feature support (PSM,…)

• Coverage conditions

• Communication modes

• Throughput

• Delay, jitter

• Loss

• Communication behavior

• Device triggering

• Maintenance actions

• Power monitoring and analysis of whole system incl. battery, without specific power supply and on multiple channels

• Very high dynamic range and high time resolution of I, V and P measurements

• Possibility to correlate with signaling/network events


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The demo test setup


3.8V

RF

The evaluation board drives the module per USB, which

needs power.

Additional components (LEDs) needs also power.

Other interface, e.g. USB to COM converter needs power.

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The functions of the instruments and DUT


Voltage(V)

Current(I)

Power = V x I

Tx signal at antenna

3.8V

RF

System emulator for Cat-M1

network

Message logging

DL/UL power control

Power Save Mode

Paging cycle and eDRX

connected/idle

…

DUT is configured by AT

commands before attach

DUT is tested without additional

interface (USB, COM)

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Multi-channel power probe designed for large range measurements


l Digital control of range, amplification/attenuation

l Input voltage range: ±15 V to GND (CM + differential), not floating

l Variable gain and attenuation in the same signal path

R&S®RT-ZVCxxAHigh dynamic range, 18bit resolution

3 internal shunts and external shunt

1MHz bandwidth, 5Msample/s

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Auto-Ranging for High-Dynamic Current Sensing


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Instead a power supply, this setup is using a real 3.8V lithium

battery


3.8V

GND

RF

Analyse the embedded system incl. battery is

more close to the reality.

As key part of the whole embedded system,

the battery has impact on the power

consumption behaviour.

The internal resistance of batteries is a non-

LTI (linear time invariant) systems. The value

is changed with temperature, charging etc.

3.8V

0.1- 0.3Ω

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Power consumption v.s. time


Tx/Rx Rx

Idle modeConnected mode

Rx at paging cycle 2.56s

The behaviour of battery voltage is related to the internal

resistance.

435

mW390

mW56 mW

168

mW

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Power consumption v.s. UL transmission power


Tx power -2dBm 3dBm 8dBm 13dBm 18dBm

Consumption 435.68mW 441.39mW 447.68mW 468.68mW 498mW

(Base Station) Cell power and power control setting has impact on the DUT UL(Tx)

power at area tracking update.

The UL transmission has impact on system power consumption.

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Power consumption v.s. Connected DRX


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Power consumption v.s. Connected DRX

UE listen to PDCCH


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Power consumption v.s. Paging cycle


The UE active the Rx and listen the PDCCH channel at paging cycle.

Paging 640ms Paging 2560ms

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Power Consumption v.s. eDRX (Idle)


eDRX disable eDRX enable

Paging 2.56s Paging 5.12s

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Power consumption v.s. Power Save Mode


DUT waking up

consume power

T3324 is initiated by

UE (AT command)

The sleep period has extreme low power consumption (52uW)

The DUT goes this mode, only when T3412 > 120s.

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Take away

Battery internal resistance UL TX

DRX (connected)

eDRX (Idle)

Power Save Mode

For 10 years?Other features

Coverage enhancement (CE)

U-Plane/C-Plane IP/non-IP

...


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Power consumption measurement solution from Rohde & Schwarz


Channel 2

PMIC GPIO

µP

LTE

1.8 V

3.3 V

2.8 V

MinMaxAvgRMS

X

Current

Voltage

Power V

I Dec

imin

atio

nA/D

A/D

Channel 1

Device under test (DUT)R&S®CMW500 network emulator

R&S®RT-ZVC power probe

to Ch.#2

R&S®CMWrune.g. LTE-Cat1

IoT

app.

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R&S®CMWrun: power consumption monitor with signaling events


Test sequencertool

Power consumption monitor

Voltage

Power

Current

UL Power: 0 dBm

UL Power: 10 dBm

UL Power: 23 dBm

Event Marker

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CMWrun power consumption and IP monitoring testplan


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Both, deep-dive multi-domain measurements and long-run analysis/

optimization with a universal power probe R&S®RT-ZVCxxA


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Your Partner in testing the Internet of Things


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Documents

IRCICA 19 Juin 2018 - Rohde & Schwarz · Instead a power supply, this setup is using a real 3.8V lithium battery Power Consumption Analysis with CMW/RTO 3.8V GND RF Analyse the embedded