White SpacesAn Autonomous Scientific Society of

Department of Electronics & Information TechnologyMinistry of Communications & Information Technology, GoI

22nd Jan 2016

ERNET India(Education and Research Network)

Agenda

What are White Spaces & Global Directions

Dynamic Spectrum Access

ERNET Experiments on TV Whitespces

Next Steps

India Centric Solution for White Spaces

2

What is White Space (WS)?

White space (WS): In a spectrum band that is licensed to primary users, the part of spectrum that

is unused by the primary user at specific locations and sometimes at specific time.

Example: Television Channels – not every channel is used in every town

TV White Space is the unused gaps in the terrestrial TV spectrum bands below 1 GHz (400-700MHz)

White space allows secondary users to use the portions of spectrum not actually used by the

primary user. This increases the amount of available spectrum

A key requirement is to protect the primary user from any interference.

5 10 15 20 25 30 35 40 45TV Channel

Rec

eived

Sig

na

l S

tren

gth

White space

Occupied TV Channels

(at given location)

Can be used to extend NOFN

3

Dynamic Spectrum Access (DSA)

• Determine available spectrum (white spaces)

• Transmit in “available frequencies”

• Detect if primary user appears

• Move to new frequencies

• Adapt bandwidth and power levels

Pow

er

Frequency

PU1

PU2

PU4

PU3

4

4

Global Directions

Industry readiness for TVWS Radios: Adaptrum, 6Harmonics, Carlsson, Redline, Broadcom, Mediatek, Qualcom, Marvell,

Aruba, NICT, Saankhya Labs etc

Databases available for free channels: Spectrum Bridge, Ericsson, Google, Microsoft. Database companies map available channels.

It also help database providers to ensure interference--free operation

Available channels vary from one location to another

Some TVWS equipment scans horizon of spectrum and pick best channels

Worldwide Deployments: Kenya, Singapore, Philippines, Tanzania,

South Africa, USA, UK, Bhutan, Japan and India

Some countries framed the policies to use TVWS Singapore released the country's regulatory framework for TV white space to drive

commercial deployments

Evolving Standards: 802.22, 802.11af,

5

ERNET Experiment on TV Whitespaces

Hypothesis tested as part of POC

The range covered by White Spaces(10-16 km radius) together with losses

Impact of Weather

Faster implementation together with lower Total Cost of Ownership(TCO)

Stability of implementation

Good Video Collaboration with other locations

No interference with TV or other transmissions

Experiment

ERNET applied for (i) Frequency assignment; (ii) Experimental license & (iii) License to

Import Radio equipment's in WPC seeking permission for experimenting with TV

Whitespaces in 500-560MHz range.

ERNET obtained licenses from WPC-DoT; 60 MHz allocated

Band used: 500-510Mhz, 518- 568Mhz

10 Mbps Internet Bandwidth from BSNL is used to feed Internet to connected client

stations

6

Contd…7

Microsoft facilitated TVWS Radios & Accessories of Adaptrum make;

ERNET setup following TVWS PoC testbed in rural area of Srikakulam, A.P.

ICT labs with LAN Infra., Mounted Wireless radios over pole in 5 schools in radius

of 5-16 Km.

10 Mbps Internet Bandwidth (Fiber) at Base station (ZPH School, Voppangi )

Wi Fi hotspot in 3 schools campus for Internet access

Various Frequencies used for PoC:

503,509,521,527,533,539,545,551,557,563Mhz

Channel Bandwidth : 6Mhz

Agg. Data Rate (UL+DL)/6 MHz =1-16 Mbps

The testing of TVWS by setup of last mile Internet connectivity in 5 schools

has been conducted from July, 2015

Computer

Lab

Computer

Lab

Computer

Lab

Computer

Lab

A.P’s

LAN Switch

PC1 PC2 PC10

Computer Lab PoE

10 Mbps

Bandwidth

Singupuram

Village

Sativada

VillageFareedpeta

Village Voppangi

Village

Vomaravalli

Village

20 ft

20 ft

12 ft

bldg roof

from Grnd

City

ERNET Testbed Setup for experiment8

Results & Next Step

Client SitesDL Bandwidth (Mb) UL Bandwidth (Mb)

Min Max Min Max

Singupuram 1.37 9.27 0.25 7.01

Sativada 0.70 5.02 0.13 3.58

Vomaravalli 1.36 4.57 0.09 2.48

Fareedupeta 0.69 4.10 0.25 2.48

9

Channel List Frequency in MHz

19 503

20 509

22 521

23 527

24 533

25 539

26 545

27 551

28 557

29 563

For testing selecting channel with

Channel ID 19 & 23

• TVWS Radio equipment from Voppangi Base station is successfully communicated to 4 client

stations with TVWS equipment between 5 km to 15.9 Km.

• At Voppangi Base station, 10 Mbps Internet Bandwidth from BSNL is used to feed Internet to

connected client schools.

• After successfully connecting the links bandwidth achieved [DL/UL] by individual client stations

is indicated in table above.

• Other parameters are being observed & will be placed in the report.

India Centric Solution for White Spaces

In case Policy to use TVWS technology is in place; it would be

useful solution for :

Last mile solution for NOFN & NII(National Information Infrastructure) : Schools,

Police post, Panchayat etc.

Usage of TV whitespaces in difficult and unhabituated areas

10

Thank You

11

Modalities

To make upto 60+ sectors based of TV Whitespace

availability variations in the country.

Repacking of spectrum to induce maximum contiguity and

auction of available bandwidth.

Auction process participation should involve TV broadcasters,

Mobile operators, ISPs, Cable operators and Digital India (

govt.)

Process :-

1. Reverse auction ( TV broadcasters would be able to exchange band or relinquish

bands).

2. Bands relinquished would go for forward auction.

3. Repacking of TV bands and auctioned bands. (Idea is to make it more contiguous.

12

Next Step

1. Extension of Experiment license for period of six more months for:

Testing by varying pole heights, w.r.t. UL/DL, Noise Level, Power, SNR, Temperature,

Modulation Technique etc

Extension of TVWS connectivity in more schools or at block level

Current experiments are with 60 degree directional Antenna. Testing with

omnidirectional antenna

Manual/Automatic channels selections within a set of available channels, study of TV

channels in the area to verify & ensure no interference

Impact of Distance, Bandwidth(shared/ non-shared), Transmission Power, Antenna

Alignment, Weather etc.;

To test Quality of channels vs throughput w.r.t. BER(Bit Error Rate), PER(Packet Error

Rate) etc

Attempt to Creation of TVBD database at Srikakulam

Cumulative Distribution Function (CDF) of SNR in NLOS(Non line of Sight) scenarios

Link throughput versus SNR, TCP throughput versus SNR and traffic load;

Power spectral density and adjacent channel leakage ratio

Response of CPE(Customer Premises Equipment) in moving vehicle or boat within

coverage area of Transmitter (Base)

13

TV Whitespace Experiment at Varanasi

Background:

BHEL desired to setup a TV White space PoC in Varanasi where BHEL has adopted a village

under CSR scheme

ERNET has also helped BHEL in obtaining experimental license from WPC/DOT

TVWS PoC Setup :

Achievement:

ERNET India configured & installed the TVWS devices at BHEL Plant and in KK Inter

college after pole erections on 7.11.2015

After establishing of connectivity between both ends, the throughput of 4.49 Mbps (D/L) and

4.72 Mbps (U/L) achieved at client site which is about 2 Km away from plant

Poles Used: 20 Ft. at roof (Bdng Height = 40 Ft. Approx.)

TVWS device : Adaptrum (BASE@BHEL,

Client@College)

Backhaul : 4.8 Mbps at BHEL plant

Arial distance : 1.88 Km between BHEL Plan &

KK Inter College

BHEL

Plant

4Mbps

Backha

ul

Arial distance 1.88 Km

D/L = 4.49

Mbps

U /L = 4.72

Mbps

BASE CLIENT

College