Satellite Transceiver Bandwidth Efficiency via ISDN Multiplexing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current satellite transceiver systems, such as the Inmarsat Swift 64, are inefficient in bandwidth usage when handling voice and data communications, as they maintain an ISDN channel even when no voice calls are active, and can only support a limited number of voice channels due to inefficient packetization protocols.
Innovation Solution
The system dynamically switches between ISDN and MPDS modes based on call status, using ISDN for voice calls and MPDS for signaling and data when no calls are active, and divides ISDN channels into time slots to support multiple voice calls, optimizing bandwidth usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an ISDN channel is maintained for data transmission when no voice calls are active, then data communication capability is preserved, but bandwidth efficiency deteriorates due to wasted channel resources
Solution Approach 1:
The system dynamically switches between ISDN and MPDS communication modes based on real-time voice call status. When voice calls are active, the system uses ISDN mode; when no calls are active, it transitions to MPDS mode for data transmission. This dynamic adaptation eliminates the need to maintain an ISDN channel idle, thereby improving bandwidth efficiency while preserving data communication capability when needed.
2Adaptability or versatility
If ISDN channels are used for voice transmission with packetization protocols, then voice communication is enabled, but the number of supported voice channels is limited due to protocol overhead
Solution Approach 1:
The ISDN channel is segmented into multiple time slots, with each time slot capable of carrying a separate voice call. This time-division multiplexing approach allows a single ISDN channel to support multiple simultaneous voice conversations, thereby increasing the number of supported voice channels without requiring additional physical channels.
3Ease of operation
If ISDN channel is kept active for potential data transmission, then data communication readiness is maintained, but transmission cost increases due to connection-based charging
Solution Approach 1:
The system dynamically selects the appropriate communication mode based on operational needs. MPDS mode is used for data transmission when no voice calls are active, taking advantage of its pay-per-use pricing model that charges only for actual data transmitted. This eliminates the need to pay for maintaining an idle ISDN connection, thereby reducing transmission costs while maintaining data communication readiness through on-demand mode switching.
Data Source
AI summary
A method for communicating between an airborne mobile terminal and a terrestrial location via satellite, wherein the satellite communication channel is provided by an integrated services digital network (ISDN) connection for the voice data, and mobile packet data system (MPDS) connection for the signaling data. The ISDN connection is automatically disabled when no voice data is being transmitted, and multiple voice calls are multiplexed on a single ISDN channel.