Long Distance Wireless Communication Rural Connectivity using Tethered Aerostats

Principal Investigator: Prof. U.B. Desai

Co-Investigator: Prof. R. S. Pant

Aerospace Engineering Department,

IIT-Bombay

 

OBJECTIVE:

           The objective of this project is to design, fabricate and conduct field trials of Aerostats for setting up wireless communication in rural areas.

 

INTRODUCTION:

           Tethered aerostats are an outcome of Lighter-Than-Air Technology, where static lift production mechanism is based on Archimedes Principle. Thus, an aerostat does not require any additional energy to reach to a certain height; for a given volume of envelope that contains the lighter than air gas, displaced weight of air creates a vertically upward force (buoyant force) that leads to the lift. The volume is so designed that the displaced air should be able to produce sufficient lift to balance all the weight groups of the aerostat system, viz., Envelope, fin, nose battens, pivot mechanism, payload cart, tether, recovery system, gas filling ports, safety valves and many such systems. This is followed by the design aspects as suggested by other disciplines such as aerodynamics, aerostatics, materials, and manufacturing techniques that lead to a most desirable aerostat system design.

           Aerostats are used as a platform to house high-resolution sensors for applications such as aerial surveillance, regional atmospheric data collection and balloon-barrage system. Depending on the payload, range of surveillance, and operational time, these aerostats can be launched to a nominal altitude of 300m to 4600 m from sea level. So far kind of payload that were deployed successfully by some commercial aerostat companies are Surveillance radars of all sizes and capabilities, Signal Intelligence (SIGINT) collection equipment, Gyro-stabilized daylight, low-light level and infra-red video cameras, Direct television broadcast and relay, FM radio broadcast and relay, VHF/UHF, Ground Control Intercept (GCI) and microwave communications, Environmental monitoring equipment as referred from TCOM aerostats.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1.1: Conceptual Sketch of aerostat for raising the communication payload

 

           On the same lines, an innovative concept using such aerial platforms for raising some low cost wireless communication payload was conceived by undergraduate students of Electrical Engineering department of Indian Institute of Technology, Bombay. The objective of development of such low cost communication system was to check its feasibility in rural areas for knowledge sharing and community participation in most of the developmental trends that are followed in urban areas. Such a system can play a major upliftment program by bridging the gap between the communities that are beyond the range of present communication towers. A conceptual sketch of such communication system is shown in the Figure 1.1.

           As seen, data is transmitted to the router box on the aerostat by means of router board antenna which is situated roughly at 10 km from the aerostat launching spot. Router box on the aerostat, which is being powered by the PoE cable from the ground power supply received these signals and transmit it in the all directions by means of the Omni directional antenna. The receiver antenna at the client location which may be in the range of 10 to 30 km from the aerostat spot location can easily receive these signals. Thus, both data and telecommunication is achieved by such a noble technique which costs almost 8 to 10 times lesser than the tower networks. Other advantages of this technique are as below.

1. Very less infrastructure required

2. Relocation of the system to anywhere within operational range is possible. This include flood areas, earthquake areas, and other natural disaster affected areas where communication network is not yet established

3. Very less launching area is required

 

PROJECT COMMENCEMENT DATE: March 2006

DURATION: One and a Half year

PROGRAM ON AIRSHIP DESIGN AND DEVELOPMENT

PADD

Research And Development Projects