CONTENTS

 1 Introduction and background
2 Definitions
        2.1 Immediate and real-time
        2.2 Prioritization and pre-emptive access
        2.3 Other definitions
3 Identification of scenarios where real-time pre-emptive access would be applied
        3.1 Characteristics and requirements of AMS(R)S communications
        3.2 Conditions in which pre-emptive access would be applied
                  3.2.1 Characteristics of aeronautical traffic
                  3.2.2 Conditions of MSS networks to apply real-time pre-emptive access
                  3.2.3 Satellite network capacity design
                  3.2.4 Factors affecting the design of an AMS(R)S resource management process
        3.3 Possible scenarios for intersystem pre-emptive access
4 Investigation of potential methodologies and mechanisms
        4.1 Spectrum reserve pool
        4.2 Call set-up delay
        4.3 Unit of frequency transfer
        4.4 Intersystem data link and protocols for frequency transfer
        4.5 Standardization
        4.6 Current developments
5 Summary and conclusions
Annex 1 - Characteristics and requirements of AMS(R)S communications
1 Characteristics of AMS(R)S communications
2 Types of AMS(R)S communications and organization of flight information region
3 Required performance of AMS(R)S communications
        3.1 Requirements of AMS(R)S communications
        3.2 Transmission quality and reliability (availability)
        3.3 Service area and beams
Annex 2- Estimation of peak instantaneous aircraft count (PIAC)
1 Conditions of estimation
2 Target year�s PIAC
3 PIAC using satellite communications
Annex 3 - Example structure of MSS networks concerning real-time pre-emptive access