Upload
trinhduong
View
213
Download
0
Embed Size (px)
Citation preview
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
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