cellular) for far more functions, especially image and video. The answer may be a compound architecture of different AWT networks in a hierarchy of civil networks to overlap functions and coverage for redundancy. The security and emergency advantages of ad hoc deployment make AWTs attractive as the basis, because they offer all of the requirements featured above. The various networks in the hierarchy should inter-operate for applications requiring input from the different data flows on each network. To become self-healing the set of networks may also be self-organising. During the September 2005 Hurricane Katrina disaster, the only voice communication possible from the US President's plane when in the air to the Mayor of New Orleans was via a WiFi Internet connection still operating in the city - this key conversation was carried via a VoIP service provider.65 A recent EC/JRC/IPTS study on AWTs has proposed one form of combination of networks to create a security infrastructure with ad hoc capabilities for set up and topology and the overview of this compound architecture of different AWT networks is shown in Figure 2.16. 66 Other local loop and long distance infrastructure technologies Possible use of low earth orbit satellite system (LEOs): LEOs have failed before in mobile satellite services (MSS) ventures such as Iridium, Teledesic, etc. A new second generation is planned but appears just as likely to fail for the same reasons - demand against system cost. However a new launch model with hybrid oxygenation for flight propulsion systems for conventional take-off and landing (HOTOL) could make the difference for a third generation of LEO by 2015. Proposals for MSS are based on putting massive shoals of INFRASTRUCTURE TO 2030: TELECOM, LAND TRANSPORT, WATER AND ELECTRICITY - ISBN 92-64-02398-4 © OECD 2006 2. TELECOMS INFRASTRUCTURE TO 2030 Figure 2.16. A compound network for security - suggested integration of multiple AWT networks into a single security resource Alternative backup network Secondary resource net