"SPOT-1500" Gateway is designed to provide two-way 
            interconnection between THURAYA GMPCS and PSTN/PLMN. On PSTN side, 
            "SPOT-1500" interfaces PSTN via 1 E1 (G.703) channel in minimal 
            configuration. In start-up configuration, interface towards Thuraya 
            Space Segment provides 12 access channels serving up to 1000 users 
            at 6 mErl Busy Hour traffic per subscriber. "SPOT-1500" Gateway 
            supports both DSS1 or R2 signaling. Additional features of 
            "SPOT-1500" Gateway include incoming/outgoing calls charging, 
            user-defined change of signaling type and numbering plan, subscriber 
            profile addition and termination, monitoring of calls set-up and 
            routing.
 
            
            
Capacity upgrade
            As the number of subscribers or traffic density 
            grows, additional "SPOT-1500" Channel (CU) and Switching units (SU) 
            are to be installed into standard 19" rack and powered from the same 
            power supply unit (PSU). One rack can be used to accommodate several 
            Channel and Switching Units. PSTN interconnection capacity can be 
            increased by incremental addition of n*E1 channels.
            Making calls to PSTN/PLMN through "SPOT-1500" Gateway
            Call set-up procedure consists of 2 steps. When 
            making call to PSTN/PLMN telephone number, Thuraya subscriber dials 
            one of dedicated numbers allocated to "SPOT-1500" Gateway (step 1). 
            The Gateway provides Thuraya subscriber with one of free 30 channels 
            to the nearest PSTN/PLMN switch and lets dial destination number 
            (step 2).
            Receiving calls from PSTN/PLMN through "SPOT-1500" 
Gateway
            Similarly to mobile-originated calls set-up, 
            PSTN/PLMN subscriber dials one of access numbers allocated to 
            "SPOT-1500" Gateway (step 1), and the then the number of Thuraya 
            subscriber.
            Optionally, regional mobile satellite operator may 
            negotiate purchase or lease of PSTN numbering resource from operator 
            that provides interconnection to PSTN/PLMN switch. In this case any 
            PSTN/PLMN subscriber will reach Thuraya subscriber by dialing just 
            one telephone number. In this case for external world Thuraya 
            subscriber will have two numbers:
            +88216-XXX-XX-XX and PSTN number 
            +(XXX)-XX-XXX-XX-XX. In most cases this will result in significant 
            savings for calling party.
            Basic configuration and technical features
            Start-up configuration of "SPOT-1500" Gateway (1 CU) 
includes:
            
              - 
              
Switching Unit HW/SW 
               - 
              
Channel Unit with GPS Unit and LNA RF LNA/Power 
              amplifier 
               - 
              
19" rack/installation materials 
               - 
              
Outdoor antenna, cables and connectors 
               - 
              
Power Supply Unit 
               - 
              
Back-up power supply (optional)