A Short Tour of Wi-Fi

Dr. Srikanth Subramanian, CKO, Nanocell Networks

Wi-Fi overview

802.11 & WiFi

RF bands

WiFiNetwork

type

Technology Evolution

Wi-Fi deployments

Future WiFi

Wi-Fi present in all laptops/APs

Wi-Fi in almost all Phones and

tablets

Wi-Fi's next wave – presence in all CE devices and more

(IOT)

Wi-Fi Traffic trends

Wi-Fi – A Wireless Success Story

Source: Cisco

Significant traffic to come

from non-computing

devices

Wi-Fi Calling

WLANs(Wireless local area networks )

IEEE 802.11

Wi-Fi Alliance

Technical specs

• Industry Consortium• Focus on Inter-operability

and certification

Interactions

Popularly known as Wi-Fi

Originally designed to mimic Ethernet

IEEE

Globally reputed organization for technical activities

Driven by applications, regulations and other factors

Standards and Interoperability

2.5 GHz

2.4 GHz

4.9 GHz

5.8 GHz

5.0 GHz

60 GHz

Frequency (GHz)Most popular

Wi-Fi bandGraduallybecoming

mainstream

Used to be Japan

specific

Future band

Wi-Fi Spectrum

Unlicensed band in most developed

markets

Popular Bluetooth

band

More PAN and video centric

than LAN

Sub 1GHz

3.5

GHz

Outdoor/flexible use in some countriesSensor/smart grid

Application Layer

Transport Layer

Network Layer

Data Link Layer

Physical Layer

Define PHY and MAC layers for WLAN operation

Emulate wired LAN (Ethernet)

IEEE 802.11

Web browsing, E-mail, YouTube

TCP/UDP

IP

Remains the same as in wired scenarios

IEEE 802.11

Max. channel bandwidth

22 MHz 20 MHz20 MHz40 MHz

80 MHz (160 MHz optional)

1.8 GHz

802.11b(1999)

802.11a(1999)

802.11g(2003)

802.11n(2009)

802.11ac(2013E)

802.11ad

11 Mbps 54 Mbps 54 Mbps600 Mbps

Upto 7 GbpsUp to

7 Gbps

2.4 GHz

5 GHz

2.4 GHz 2.4 GHz

5 GHz 5 GHz

60 GHz

Max. PHY layer Data rate

Spectrum

Technology DSSS (CCK)

OFDM OFDM MIMO + OFDM

MIMO (SU/MU) + OFDM

Beam forming+SC/OFDM

Wi-Fi Technology Evolution – Rates and Speeds

FHSS/DSSS

22 MHz

2 Mbps

2.4 GHz

802.11(1997)

IEEE Standard

• Backward compatibility is always kept in perspective

802.11ax

OFDMAUpto 10 Gbps

2.4 GHz

5 GHz

Wi-Fi Network Types

Infrastructure Network Ad-hoc Networks

802.11 ad-hoc

Wi-Fi Direct

• Used in homes, offices & hotspots

• Used in some gaming devices

Mesh Networks

• Planned for wide-area/large campus deployments; now used for extending coverage in large homes

• Wi-Fi alliance initiative for easy to use peer-to-peer connections

STA 3

Basic Service Set (BSS)

Bridge between

802.11 networks andnon 802.11

networks

All communications on the wireless network are routed

via Access Point (AP)

Most popular type of 802.11 network

used in homes, offices, and hotspots

STA 2

STA 1

Wi-Fi Infrastructure Network

Even a phone can serve as AP

BSSID/SSID are network identifiers

How is your Wi-Fi made?

Analytics

• Give AP boards based on reference design and customized versions

• Cisco• D-Link• Mojo

• Liton• Act-on• Sinao

• Qualcomm • Broadcomm• Marvell

AP OEMs

ODM vendors

Chipsets

AP Evolution Story

Typically 1 antenna, 2.4 GHz radio, multiple Ethernet ports, 802.11b/g

days

Multiple antennas, multiple radios (2.4 and 5 GHz, dual band concurrent radios), multiple Ethernet ports, integrated

cable/DSL/.. For retail markets

Lots of antennas, 3 radio support, sensing/traffic generator plus normal AP

functionality, application layer monitoring features

MP 2

MP 3

MP 1

MP 4

MP = Mesh Point

Forwarding Path

High poweroutdoor MP

Normal Wi-Fi connection

InternetWide area coverage for city-wide and

campus networksCommercially used in large campus

and enterprise deployments

Mesh connectivity for backhaul using Wi-Fi radios

Normal Wi-Fi connection

Wi-Fi Mesh Network

Mesh becoming popular for home

products for better range

Wi-Fi Repeaters and Extenders

Source: Cablelabs

Wi-Fi and IoT

Wi-Fi AP present in homes , hotspot, retail ,enterprise

etc.

Add Wi-Fi/Retro fit

Wi-Fi

People comfortable with

Wi-Fi

Cost effective solutions available

Power not a big issue in some cases

Reliable connection to Internet

Planned Wi-Fi deployments have

good coverage New sub 1GHz solution(Wi-Fi HaLow) announced for

low-power devices

Using Multiple Wireless Technologies for IOT

BLE Radio

Wi-Fi AP

Internet

Sensors

Sensors

Smart Home/Enterprise Gateway

TabletSensors

Phone

BB Interface

• Ability to access server data

• AP vendors including BLE in home / enterprise APs

Thread/Zigbee

Thread/ZigbeeCapable

Thread/ZigbeeCapable

Wi-Fi capable Wi-Fi capable

BLE capable BLE capable

Wi-Fi calling - Motivation?

Internet

PSTNAP

eNB/NB/BTSWi-Fi and cellularradios present

Roaming charges on cellular leads to users using OTT apps (skype/viberover Wi-Fi)

• Lots of voice calls made from indoor locations

• Poor signal in many indoor locations

Cannot use the cellular phone number

Wi-Fi calling

Internet

Core Network

AP

eNB/NB/BTS

• Use of Wi-Fi for calling /receiving using phone credentials (No apps)

Handover to cellular to be taken care

• Any AP which allows access OK

Operator Supported

PSTN

Wi-Fi Competition; LTE in Unlicensed SpectrumWi-Fi Competition; LTE in Unlicensed Spectrum

18

EPC

Unlicensed Spectrum-5GHz Secondary

Cell

Primary Cell

Aggregation of Licensed + Unlicensed

• Control signaling

• User data

• Control signaling• Mobility• User data

Combined use of BW for dataAnchor in the

licensed carrier

LTE and Unlicensed - approachesLTE and Unlicensed - approaches

Wi-Fi Offload LTE-U/LAA/MuLtefireLTE Wi-FI

Aggregation (LWA)

LTE Wi-FIaggregation with

IPSEC(LWIP)

Not a lot of momentum

but some deployments

happening

Lots of interest

from carriers

Wi-Fi camp’s response to LTE-unlicensed approaches

LTE and Wi-Fi together – LWALTE and Wi-Fi together – LWA

20

EPC

R13 covers DL option alone; specifications completed• Carrier grade AP

• Needs interface to communicate with LTE eNB

Licensed Band

Unlicensed Band

Unlicensed Band

Scheduling of Wi-Fi downlink done by LTE

eNBAggregating Wi-Fi and LTE @ radio level

Both co-located and non

co-located cases of eNB and Wi-Fi AP

considered

Star Trek Wi-Fi?

• Potential future band due to large bandwidth availability

• Challenging RF overcome by beamforming

• Cable replacement technology for high

bandwidth aplications

Device 1

Device 2

60 GHz 802.11ad

Future – 802.11ax

• Majority of deployments will evolve towards high density scenarios in the near future..

• To increase the real world throughputachieved by users.

• 2.4 and 5 GHz bands

• To improve power efficiency for the battery powered devices…better IOT

Wi-Fi Big Picture

Home and

Internet access

2.4 & 5 GHz Wi-Fi

Enterprise network access

Interactions with cellular

Peer-to-peer

access

Displays, Set top boxes

Adopt higher

speed Wi-Fi

More usage of

5 GHz Wi-Fi

Smooth interaction with carrier

MBO and OCE

60 GHz Wi-Fi usage ?

Ripe for Innovation; Wi-Fi

Aware

Potential Bluetooth

replacement

Wi-Fi Calling

LWA and LWIP

802.11ax