Robust telemetry repeater network system and method
A robust network telemetry repeater system exploits the repeater structure of data propagation and transmission and reception bi-directionality to increase network robustness. For example, multiple perceived receive attempts are created with no additional overhead. The system can be configured whereby nodes “hear” the transmissions of both adjacent and non-adjacent nodes forming implicit acknowledgement (“Acks”), and originating nodes can retransmit until implicit acknowledgments (“Acks”) are “heard,” indicating a successful link relay. Implicit acknowledgment can be applied to bidirectional networks, and bidirectional action can enable all nodes in the network to know the status of all other nodes.
1. A telemetry repeater network system, which includes:
multiple network nodes receiving and transmitting data;
a sensor associated with one or more of said multiple network nodes and providing output comprising signal data;
said telemetry repeater network system being configured whereby signals are received from both adjacent and non-adjacent nodes;
originating nodes determining successful reception by a destination node via a successful reception of a subsequent relay packet at the destination node, creating an implicit acknowledgment (Ack) of successful data packet reception;
formation of adaptive link management through an originating node gathering statistical information on link success rate or quality;
in response to said statistical information, said originating node taking one or more of the following actions to improve link robustness, conserve power, or increase data transmission rate: altering transmit power; altering baud rate; altering modulation; altering error correction scheme; altering transmission frequency; altering transmission medium; and altering power allocation or modulation or error correction as a function of transmission frequency or subcarrier frequency in the case of multi-carrier formats; and
said telemetry repeater network system using said statistical information to alter an Orthogonal Frequency Division Multiplexing (OFDM) signal modulation configuration.
2. The telemetry network system according to claim 1 , which includes:
said multiple network nodes being configured with a time division multiplexing scheme for adjacent and non-adjacent transmission reception;
said time division multiplexing being defined as time windows allocated for adjacent and non-adjacent node transmissions; and
said time division multiplexing providing a source of packet or data reception diversity, lessening a probability of packet loss due to short-term noise and channel events.
3. The telemetry network system according to claim 2 wherein:
said multiple network nodes have multiple receipts distributed over time of identical or similar signal or data content packets, with varying quality; and
resulting data of best quality is relayed; or signals are coherently combined to enhance signal-to-noise ratio (SNR) and recover higher quality data for relaying to other nodes.
4. The telemetry network system according to claim 3 wherein:
received data quality can be determined through the signal to noise ratio (SNR) measure of a received data packet and/or derived from an error detection and/or correction, signal detection or other quality encoding technique.
5. The telemetry network system according to claim 1 wherein:
said telemetry repeater network system has added node redundancy for improving robustness and network data net throughput; and
said telemetry repeater network system automatically bridging intermittent or failed adjacent nodes via signal reception from non-adjacent nodes, without internode control signaling.
6. The telemetry network system according to claim 1 , which is applicable to downhole drillstring networks comprising:
uplink, downlink and bidirectional networks; and
acoustic and electromagnetic (EM) repeater networks.