Wireless Communication in airship Engineering

8/11/2019 Wireless Communication in airship Engineering

1/21

Welcome

To

Presentation

on

High Altitude Platform

(HAP)HAP


2/21

Wireless Communication

As the demand grows for communication services,wireless solutions are becoming increasinglyimportant. Wireless offers

Solution to the last mile problem.

Essential for mobile services and cellular

networks.

Capacity for broadband services and

rapid deployment

High bandwidth service provision


3/21

Cellular Concept

Fig 1: Cellular frequency reuse concept.

To provide bandwidth to a large number of users,frequency reuse strategy must be adopted

Base Station

At the center

The neighboring cells have

different frequency of

operation.

Frequency reuse depends

upon factorsLocal propagation

environment

Signal to interference

plus noise ratio


4/21

Limitations of existing system

Terrestrial systems

No proper LOS propagation

No microcellular structure

Sea Coverage not possible

Satellite systems

High Free space path loss

Lengthy propagation delay

Low Capacity

Solution : Use of very tall

base stations mast

Solution : Use of geostationary

systems but at low

altitude

HAP


5/21

High Altitude Platform

(HAPs)

Solar-powered aerial platforms, capable of long endurance

on-station up to several months or more.

operating in a quasi-stationary position at altitudes up to

some 22km

Hap technologies are

Airship

Aircraft

HALE : High Altitude Long Endurance

HAAP : High Altitude Aeronautical Platform


6/21

Airships Technology

Solar Powered

Unmanned

Helium Filled

Semi Rigid

Very Large(150m)

Mission Duration Up to Few Years

Situated at altitude of 1722 km (up to 70000 ft)


7/21

Airship Enabling Technology

Light weight solar cells

(


8/21

Aircraft Technology

Piloted Aircraft

Working in three8 hours shifts.

Pilot less Aircraft

Solar powered

Fig. 1 Fig. 2

Aircrafts are like man made aero plane.

They fly in roughly circular path.

Can be manned or unmanned.


9/21

Wind Speed Profile

Wind speed, m/s(depend on season and location

H

eight,km.

Altitude around 20 km.

Altitude selection for HAP

Should be abovecommercial air traffic

Air should be mild with

low wind speed


10/21

Footprint Diameter

Earth Radius

(R)

Earth

Altitude

(h)

D=2R.[ arccos( R.cos() / (R+h) ) -]

Diameter

(D)

Where,

D=Footprint DiameterR=Earth Radius(6378 km.),

=Minimum Elevation Angle

h=Altitude

For =15, D=152 km.

For =0, D=1033 km.

(values at h = 21 km)


11/21

Communication Applications

Inter HAP link

alternative backhaul via

satellite for remote areas

local backhaul links to base

stations for less remote areas

Remote

Hub

Fiber NetworkFiber Network 60400 km

General Communication Scenario

User Traffic

Satellite


12/21

Broadband Wireless Access (BWA)

Principle application as broadband fixed wirelessaccess or simply BWA.

Can provide potentially very high data rates to theuser.

Offers 600 MHz of bandwidth.for downlink 47.247.5 GHz

for uplink 47.948.2 GHz

Experimental Parameters:

Footprint Diameter = 60 km

Number of cells = 121

Nominal ground diameter = 5 km

Downlink HAP power = 1W/cell

Data Rates

Of

60 Mbps


13/21

3G/2G Application

Deployment of mobile cellular services

One Base station on HAP can serve a widearea with a wide beam width antenna

Alternatively, for smaller cells directionalantennas can be used

Elimination of much ground stationinstallation.

HAP Networks Number of inter linked HAPs deployed to

cover an entire area.

Inter-HAP links may be accomplished athigh EHF frequencies or using optical links.


14/21

Other Applications

Emergency services and Disaster relief

Oil/gas/mineral exploration

Positioning System

Remote Sensing

Flood detection

Seismic monitoring

Traffic monitoring and control


15/21

Comparison with Terrestrial/Satellite

Systems

TerrestrialSystem

HAPs Satellite System

Height over

ground level5 to 250 m Up to 22 km 50036000 km

Lifetime 15 years < 5years 15 yearsCapacity High Medium Low

Coverage Land and

shore only

Global Global

StationCoverage

< 1km Up to 200 km > 500 km

Cell Size (Dia) .1 - 1 km 1 - 10 km 50 km

Maximum Tx.

Rate

30 Mbps 25 - 155 Mbps < 2 Mbps


16/21

Advantages of HAP

Larger area coverage

Flexibility to respond larger area traffic.

Low cost Incremental Deployment

Rapid Deployment

Platform and Payload upgrading

Environment friendliness


17/21

Some Issues and Challenges

System level requirement Designs of cellular type structure

Frequency planning of different spot beam layouts

Propagation and diversity Consideration of rainfall and scattering statistics

Modulation and coding

Platform Station Keeping Propellers and thrusters technique

Payload power Sufficient power required for continuous coverage especially

in night


18/21

For communications and monitoring

applications

Integrated Network of some 10

airships to cover Japan

150 m class airship

Communications payload of 800 kg.

Some Current and Proposed Programs

Airships:

Sky Net

Sky Station


19/21

Some Existing Platforms: Aircrafts

Halo(Proteus 9)

Global Hawk

Predator

Military UAV


20/21

Conclusion The novelty of HAP communications calls for

some new concepts and researches in terms of

delivery of services and the platforms themselves

present some challenges and potential problems.

But A combination of technology push

from the providers of platforms and applications

pull from the demand for enhancedcommunications may provide significant

developments in HAPs for communication service

delivery in the near future


21/21

REFERENCES

http://www.elec.york.ac.uk/comms/wirelessnetwork

s.html

http://www.elec.york.ac.uk/comms/papers

http://www.airship.com

http://www.bakom.ch/en/funk/forschung/haps/

http://www.zdnet.co.uk/zdnetuk/news/communications/broadband

http://www.skylarc.com/papers.html
http://www.elec.york.ac.uk/commshttp://www.elec.york.ac.uk/commshttp://www.elec.york.ac.uk/comms/papershttp://www.airship.com/http://www.bakom.ch/en/funk/forschung/haps/http://www.zdnet.co.uk/zdnetuk/news/communications/broadbandhttp://www.zdnet.co.uk/zdnetuk/news/communications/broadbandhttp://www.skylarc.com/papers.htmlhttp://www.skylarc.com/papers.htmlhttp://www.zdnet.co.uk/zdnetuk/news/communications/broadbandhttp://www.zdnet.co.uk/zdnetuk/news/communications/broadbandhttp://www.bakom.ch/en/funk/forschung/haps/http://www.airship.com/http://www.elec.york.ac.uk/comms/papershttp://www.elec.york.ac.uk/commshttp://www.elec.york.ac.uk/comms

Documents

Wireless Communication in airship Engineering