4. 4
想定した2020年IoTコネクション数:NB-IoT(70%)+eMTC(25%)+4G(5%)
LPWA: Low Power Wide Area
Requirements
l <100kbps
l 20dB Coverage Gain
l 10+ Years Life
l <$5 Cost Per Module
CCTV(Camera)
In-vehicle Entertainment…
Market
Segment
3G/4G
Technology
2G/3G/Cat-1
eMTC
NB-IoT
l >10Mbps
l ~1Mbps
l Low power consumption
IoT Gateway Backhaul
Wearable
Connected Elevator
Sensors, Meters
Asset Tracking
Smart Parking
Smart agriculture
2B
0.8B
0.2B
Connections in 2020
(Billion)
5G
mMTC
6. 6
Downlink OFDMA with 15kHz Subcarrier Spacing
is chosen because it can fit In-Band scenario
Single-tone and Multi-tone are supported
Single-tone: 3.75kHz and 15kHz
Multi-tone: 15kHz Subcarrier Spacing
A 3種類のネットワーク構成
B Downlink
C Uplink
180k
GSM
180k
G/U/L
Standalone
180k
LTE
Guard Band
180k
LTE
In Band
6
NB-IoTとは(Narrow Band IoT)
8. 8
NB-IoT技術のメリットの詳細説明:カバレッジ拡大
GSM MCL=144
LTE MCL=142.7
NB-IoT MCL=164
PSD (電力密度)によるゲイン
再送によるゲイン
(DL 8 Times and UL
16 Times Repetition)
180 KHz 15 KHz
Up to 11dB
Coverage Extension SolutionCoverage Comparison
20dBカバレッジゲイン
Up to 9dB DL Gain
Up to 12dB UL Gain
GPRS
NB-IoT
GPRSより2つの壁が通れる
9. 9
NB-IoTの2種類の省電力モードにより双方向通信にも対応
Time
Idle State
Paging
PSM
UE Power
Up to 310hours
active timer
Transmit
DRX Cycle: 1.28s
Time
DRX
UE Power
eDRX
eDRX Cycle: up to 2.92h
DRX Cycle: 1.28s
PTW
PTW: Paging Transmission Window
PSM(Power Saving Mode)
eDRX(Extended Discontinuous Reception)