Distributed TDMA Scheduling for Directional Antenna MANETs
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Solution Overview
Problem
Conventional TDMA MANETs face inefficiencies due to lengthy guard times required for long-range communications, which restrict available time for other nodes to communicate, especially over hundreds of nautical miles, leading to reduced network efficiency.
Innovation Solution
A distributed scheduling process using directional antennas that dynamically selects transmit and receive time slots based on propagation delays and interference calculations, allowing each node to adjust its schedule independently to minimize interference and optimize communication time slots within a data epoch divided into mini-slots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If guard time is increased to accommodate long-range propagation delays, then communication reliability is improved, but network efficiency deteriorates
Solution Approach 1:
The patent segments the network into multiple zones based on propagation delay characteristics. Each zone has its own guard time allocation, allowing distant nodes to have longer guard times while nearby nodes use shorter guard times. This segmentation enables the system to maintain reliability for long-range communications without uniformly increasing guard times across the entire network, thus preserving overall efficiency.
Solution Approach 2:
The patent applies local quality by assigning different guard time characteristics to different spatial locations in the network. Nodes at greater distances from the reference point receive longer guard times, while closer nodes receive shorter guard times. This localized adaptation ensures that guard time is extended only where necessary to accommodate propagation delays, avoiding the efficiency penalty of uniform extension.
2Object-affected harmful factors
If centralized scheduling is used to coordinate TDMA time slots, then interference management is improved, but system complexity increases
Solution Approach 1:
The patent implements self-service by enabling each node to autonomously determine its own time slot allocations and guard times based on its position and propagation delay characteristics. Nodes independently calculate their scheduling parameters without requiring centralized coordination, which simplifies the overall system architecture while still effectively managing interference through distributed intelligence.
3Device complexity
If fixed guard times are used for all nodes, then scheduling simplicity is improved, but adaptability to varying propagation delays deteriorates
Solution Approach 1:
The patent introduces dynamics by making guard times variable rather than fixed. Each node's guard time is dynamically adjusted based on its distance from the reference point and its specific propagation delay characteristics. This dynamic adaptation allows the system to optimize performance for each node's unique conditions while maintaining a relatively simple scheduling framework that builds upon the conventional TDMA structure.
Data Source
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AI summary
Method and apparatus for scheduling time division multiple access (TDMA) communications among a plurality of peer nodes arranged to form a wireless ad hoc mobile network. The peer nodes communicate with each other using directional antennas and a TDMA process. The method includes a scheduling process for scheduling at least one transmit time slot during which a first one of the plurality of peer nodes transmits wireless data to a second one of the plurality of peer nodes.