International Journal of Emerging Technology and Advanced Engineering Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 3, Issue 4, April 2013) 220 Wireless Communications from High Altitude Platforms Tarulata H. Chauhan 1 , Sudhir Agarwal 2 , Suchit Purohit 3 , Amit Kumar 4 1 PG student, 3 Lecturer, Rollwala Computer Center, Gujarat Univercity, Ahmedabad 2 Head, DCTD, Space Application Center, ISRO, Ahmedabad 4 Assistant Professor, Marwadi Education Foundation Group Of Institutions Abstract— The demand for wireless communication is increasing day by day. People want a high speed of communication in less time. No one is interested in use of bunch of wires. So we move to wireless communication. As technology increases a demand also increases. Now everyone wants a fast communication from anywhere to anyone. Even rural area also requires internet facility. It is too hard to establish a Base station for particular small village for broadband communication or any wireless communication. Even it’s too costly to launch a satellite for particular rural area. So Engineers made a intermediate way to satisfy both facilities of data transfer from terrestrial to satellite and satellite to terrestrial via HAP (High Altitude Platform). HAP is operated at altitude of 17-22km. HAP provides facilities of wireless communications. Keywords— High Altitude Platforms (HAPs), Broadband Communications, Wireless communications, Base station, Propagation. I. INTRODUCTION In current era demand for wireless communication is notoriously increases. A terrestrial and satellite system provides wireless communication services. Terrestrial systems are used in mobile applications while satellite systems are used where terrestrial system not reached. HAPs are airship or airplanes which altitudes at 17-22km above earth surface. HAPs have been proposed mobile services in stratosphere. It have advantages of both terrestrial as well as satellite. It also provides services like 3G, emergency services and Wi-MAX. HAP networks are provides different services like military application, earth monitoring, traffic monitoring and control. In terms of services, HAP offering low cost and high facility services. II. HAP DEFINITION HAPs are airships or airplanes in stratosphere, at 17- 22km altitude. III. HAP INFRASTRUCTURE Infrastructure of HAPs is categories in different types which are as follows: 1) Balloons :  The earliest aerial platforms were balloons.  It was filled by hydrogen.  It was used in military applications. Fig.1 Balloons[5] 2) Airships :  Airships are helium filled containers of the order of 100m or more in length.  Electric motors and propellers are used for station- keeping, and the airship flies against the prevailing wind.  Prime power is required for propulsion and station-keeping as well as for the payload and applications; it is provided from lightweight solar cells in the form of large flexible sheets. Fig.2 Airship[4]