Presence Signal Scheduling for Shared Medium Coexistence
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Solution Overview
Problem
Existing communication networks face challenges in managing the coexistence of different signaling protocols on a shared medium, leading to interference and inefficiencies in resource allocation, especially when devices with varying physical layer protocols share the same electrical wires.
Innovation Solution
The method involves transmitting unique presence signals by devices within specific time slots, synchronized to an alternating current line cycle, using a recurring schedule with unique phase sequences and coordinated resource sharing through time division or frequency division multiplexing, allowing devices to identify and synchronize with each other's signals despite phase shifts and zero crossing offsets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple signaling protocols share the same communication medium simultaneously, then resource utilization increases, but interference between protocols increases
Solution Approach 1:
The communication medium is segmented into distinct time slots, with each signaling protocol assigned to specific time slots. This temporal segmentation allows multiple protocols to share the medium without interference, as they transmit sequentially rather than simultaneously. The coordinator manages this segmentation by allocating time slots to different protocols based on their requirements.
Solution Approach 2:
The system implements periodic transmission cycles where different signaling protocols are activated in alternating time slots. Each protocol transmits during its designated period, creating a periodic pattern that ensures fair resource allocation while preventing interference. The coordinator schedules these periodic transmissions to optimize medium utilization.
2Adaptability or versatility
If devices use different physical layer protocols on the same medium, then protocol versatility increases, but synchronization difficulty increases
Solution Approach 1:
A coordinator device acts as an intermediary that manages synchronization between devices using different physical layer protocols. The coordinator receives synchronization indicators from various devices, processes this information, and generates appropriate resynchronization signals to maintain temporal alignment across heterogeneous protocols, thereby reducing the synchronization burden on individual devices.
Solution Approach 2:
The system implements a feedback mechanism where devices transmit synchronization indicators to the coordinator based on their local zero-crossing detection. The coordinator uses this feedback information to determine when resynchronization is needed and generates corresponding resynchronization signals, creating a closed-loop control system that maintains synchronization across diverse protocols.
3Reliability
If presence signals are transmitted continuously to ensure detection, then detection reliability increases, but energy consumption increases
Solution Approach 1:
Presence signals are transmitted periodically rather than continuously, with each signal sent at the beginning of its designated time slot. This periodic transmission ensures that receiving devices can detect the presence of transmitting devices at regular intervals while significantly reducing overall energy consumption compared to continuous transmission.
Solution Approach 2:
Presence signals are transmitted in advance at the start of each time slot before actual data communication begins. This preliminary action allows receiving devices to prepare for incoming communications and allocate resources appropriately, ensuring reliable detection without requiring continuous signal transmission throughout the entire communication cycle.
Data Source
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AI summary
A method is described for communicating among multiple devices over a shared communication medium. The method includes, in a schedule among multiple subsets of the devices that includes at least one respective time slot for each subset, transmitting from at least one of the devices in a given subset a presence signal associated with the given subset within a time slot for the given subset. A presence signal associated with a given subset is configured to indicate the presence of at least one device in the given subset. The method also includes communicating among devices in a given subset based on presence signals detected from one or more devices in at least one different subset.