S.H.A. Al-Samhi, N.S. Rajput / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 2,Mar-Apr 2012, pp.1508-1513 1508 | P a g e Interference Environment between High Altitude Platform Station and Fixed Wireless Access Stations S.H.A. Al-Samhi 1 , and N.S. Rajput 2 * 1,2* Department of Electronics Engineering, Institute of Technology, Banaras Hindu University, Varanasi 221005, India Abstract—High Altitude platform station (HAPS) technology is a new technology that can perform the tasks currently handled using terrestrial and satellite systems. Anew broadband telecommunication systems has been recently proposed for provision of fixed, mobile and personal services adopting the use of high altitude platform station placed in a fixed position in the stratospheric layer at heights from 17-25 km. This paper examines the interference between HAPS and FWA (fixed wireless access). Hence the characteristic of the interference from single HAPS toward FWA based station established appropriate separation distance and off axis angle of FWA to avoid harmful interferences. The effect of interference on FWA depend on the parameter as elevation angle of the HAPS, elevation angle HAPS ground station as well as that the azimuth angles of the FWA station .Calculations are done by using MATLAB software following the ITU recommendation. Result shows interference reduces when separation distance between HAPS ground station and FWA station increase as well as the off axis angle of FWA station gain large will help to reduce the interference. Key words: HAPS; FWA; Network and Component of HAPS; Interference between HAPS and FWA. I. INTRODUCTION High Altitude Platform station is the name of technology for providing wireless narrowband and broadband telecommunication services as well as broadcasting services with either airships or airplanes. HAPS is operating in the stratosphere at altitudes of typically 17-25km [1]. The platform position allows the HAPs-based system to provide better channel conditions than satellite. A Line Of Sight (LOS) condition is achievable in almost all the coverage area, thus less shadowing areas than terrestrial systems. Therefore, HAPs require much less transmission power for a given Quality of Services (QOS) [1]. Fundamentally, HAPs perform efficiently on tasks that are currently handled using terrestrial and satellite systems. Various applications of HAPs include telecommunication broadcasting services, surveillance, weather monitoring, remote sensing and so on [2,3]. HAPS bears the advantage of both satellite and terrestrial communication systems such as low cost, large coverage area, rapid deployment, board band capability, large system capacity, low propagation delay and clear line of sight signal paths offered by high elevation angles. In this paper, a scheme is proposed to mitigate co-channel interference from HAPS to FWA terminal, by taking into account the high directivity of antenna on the platform and by considering the off axis angle of FWA base station . This paper is divided into nine parts: Section I gives brief introduction about systems based on HAPS; in Section II architecture of HAPs is described. Altitude Platform of the HAPS, is covered in section III and Sections IV, describes the component of the HAPS communication systems. Coverage of HAPS in section V. HAPS spectrum allocation described in section VI and the interference from HAPS to FWA is described in Sections VII. Then, 4G services via HAPS described in section VIII. The result discussions are taken up in section IX. Finally, section X, conclusion of this work. II. HAPS NETWORK ARCHITECTURE The HAP-based based wireless systems could be the third infrastructure followed by terrestrial-based and satellite-based systems. These three systems could be integrated in the future to construct the more powerful network infrastructure by making up the weakness of each other. There are three proposed architectures for HAPS communication systems. The difference between them is mainly on network infrastructure involved as shown in Fig.1.HAPS has the capability of carrying a large variety of wireless communication payloads that can deliver high capacity broadband services to the end users. They are stand alone HAP system, integrated HAP terrestrial system and integrated terrestrial HAP satellite system [4, 5]. Fig.1. Architecture of HAPS 1. Stand alone HAP system HAPs are potential to be a standalone system in many applications, weather monitoring, and disaster surveillance as shown in Fig. 2. In rural or remote areas, it is rather expensive