High Altitude Platform Stations in Design Solutions for Emergency Services Israel R. Palma-Lázgare, José A. Delgado-Penín, CMC Group, TSC Department, Universitat Politècnica de Catalunya, Barcelona, Spain E-mail: {ipalma, delpen}@tsc.upc.edu ABSTRACT High Altitude Platform Stations (HAPS) are expected to conform a third major infrastructure for communications and broadcasting, after terrestrial and satellite systems. The proposal, which is maintained by many authors, is the use of HAPS as alternative wireless network provider that can partially replace or add capacity to damaged or overloaded wireless networks during a man-made or large- and small- scale natural disaster. During these critical phenomena, the telecommunications infrastructure and the required covera- ge for the emergency service operations might be unavaila- ble due to the destroyed area or overloading by the exces- sive communications demand. Along with satellites, high altitude platforms (HAPs) will be completely isolated from the effects of disasters on the ground. A couple of stratos- pheric-based network scenarios are considered as examples for a HAPS-aided disaster deployment assessing communi- cation viability and outlining issues in interoperability with existing networks. 1. INTRODUCTION The big three options in the use of telecommunications are by means of the terrestrial wire systems (copper wire, coax and fibre optic cable), terrestrial wireless systems and satellite communication systems [5]. In the last few years, a new set of options have been added in the form of high al- titude platform stations (HAPS) and unmanned aerial vehi- cles (UAVs) that operate as mobile telecom providers, mos- tly operating at stratospheric altitudes of ~20 km, or other low altitudes, above earth; in our days, it has been deeply studied that near-space platforms could be safely deployed at altitudes in the 17-25 km range. The origin of HAPS-ba- sed wireless systems comes principally from the military research, in such case are called UAVs, such as the Rover III that have assisted within the disaster recovery from Ka- trina, but these latter systems are being withdrawn from as commercial operation. Now, the issues of how HAPS-based systems, or solar-powered lighter-than-air (LTA) aircrafts, can be used to supplement communications and air survei- llance during emergencies is examined under the point of view of specialised organisations and research groups, e.g., Department of Homeland Security [15], and CAPANINA [9]. The purpose of this paper is to describe how HAPS can be used to provide emergency telecommunication coverage in a disaster scenario. A general classification is defined identifying the main points that need to be considered for such application. An empirical GSM-TETRA-UMTS HAPS-based disaster la- yout is introduced and together with their suitability is discus- sed. Finally, the conclusion of the paper is given. 2. HAPS & EMERGENCY AID LIAISON 2.1. HAPS Survey One major intention of this paper is to provide a contribution in the direction of describing the research activity performed (in particular at the European level) on HAPS-based com- munications [12], with particular attention to the two projects HeliNet and CAPANINA [9], both financed by the European Commission, in order to explore the use of HAPS for integra- ted communication services and broadband transmission. In the broad multiform communications, HAPS possesses all the potentialities to be proposed as a novel stratospheric segment in the wireless communications market. They are able to overcome the main drawbacks of satellite technology due to its reduced distance from the ground with respect to satellites, and its quasi-stationary situation in the sky. Addi- tionally, their costs for construction, deployment, launch, and maintenance can be kept in lower orders of magnitudes than those of satellites can, all these at an environmental sustaina- ble effort because of their solar power supplies. On the other hand, it is evident that HAPS cannot replace satellites, nor te- rrestrial radio links, for reasons of coverage, reliability, safety, and cost. In fact, satellites, HAPS, and terrestrial broadband systems have different but complementary characteristics. While satellites are more suited for coverage of very large areas and broadcast applications, HAPS are able to cover remote or sparsely populated areas at reduced costs, and to BURAN Nº 25 ABRIL 2010 