FHSS Hopping Sequence Calculation via MAC Address and Epoch Tick
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In frequency-hopping spread spectrum (FHSS) wireless communications networks, especially in utility automatic meter reading (AMR)/automatic meter infrastructure (AMI) networks, there is a need to efficiently manage memory and reduce network overhead in conveying hopping sequences between devices, as existing methods either require significant memory allocation or additional network overhead.
Innovation Solution
A method is developed to calculate and use frequency hopping sequences without requiring additional network overhead, by determining a device's current channel based on its MAC address and pseudo-random hopping sequence, using a slot-to-channel conversion and fractional epoch tick, allowing devices to synchronize and transmit data efficiently without exchanging entire hopping sequence tables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hopping sequence tables are stored at each device for all neighboring devices, then transmitting devices can know receiving devices' hopping sequences, but memory requirements increase significantly
Solution Approach 1:
The patent extracts only the essential information needed from the hopping sequence table (current channel index and epoch tick) rather than storing the entire table. This allows devices to determine current hopping channels on-demand using lightweight stored parameters, dramatically reducing memory requirements while maintaining the ability to track neighboring device hopping sequences
Solution Approach 2:
Instead of storing complete hopping sequence tables, the patent uses simplified copies represented by just two parameters (channel index and epoch tick) that can regenerate the current channel state. This copying approach maintains functionality while minimizing memory usage
2Reliability
If hopping sequence tables are exchanged between transmitting and receiving devices, then transmitting devices can obtain receiving devices' hopping sequences, but additional network overhead is required
Solution Approach 1:
The patent extracts only the critical hopping sequence information (current channel index and epoch tick) that is necessary for synchronization, eliminating the need to exchange entire hopping sequence tables. This extraction reduces network overhead significantly while maintaining reliable hopping sequence knowledge
Solution Approach 2:
The patent transmits simplified copies of hopping sequence state (two parameters instead of full tables) between devices. This copying mechanism enables efficient information exchange with minimal network overhead while preserving the ability to reconstruct current channel states
3Quantity of substance
If the number of hopping sequences is constrained to reduce memory requirements, then memory usage decreases, but interference between nodes increases
Solution Approach 1:
The patent introduces dynamic epoch ticks that allow devices to shift their hopping sequences in time. This dynamic adjustment enables multiple devices to use the same hopping sequence table while maintaining different temporal patterns, reducing interference without requiring additional memory or constraining the number of sequences
Solution Approach 2:
The patent adds a temporal dimension to hopping sequence differentiation through epoch ticks. Instead of relying solely on different sequence tables (combinatorial approach), devices differentiate by introducing time offsets, effectively moving from a 2D sequence space to a 3D sequence-time space, which reduces interference while maintaining memory efficiency
Data Source
AI summary
A method for generating and using frequency-hopping sequences in frequency-hopping spread spectrum (FHSS) networks, such that no additional network overhead is required to convey a device's hopping sequence to another device, is disclosed. Furthermore, a method to maximize the number of unique hopping sequences, without increasing the random access memory (RAM) requirements on the network devices, is disclosed.