Data communication protocol in an automatic meter reading system
An automatic meter reading (AMR) system includes a fixed or mobile reader and an endpoint interfaced to a utility meter. The fixed or mobile reader is capable of communicating with the endpoint via RF communication. The fixed or mobile reader sends a message to the endpoint that includes a response mode direction which directs the endpoint to respond to the reader via either a mobile network mode or a fixed network mode. The AMR system allows implementation of, and migration between, one-way, one-and-a-half-way, and two-way communications system modes without requiring reprogramming, reconfiguring the metering endpoints or going through a reconfiguration cycle before effecting a communication
1. In a system for automatic meter reading (AMR) of utility meters, a method for operating an endpoint to respond to wireless radio-frequency (RF) communications signals from a fixed or mobile reader, the RF communication signals including a preliminary portion and a command portion following the preliminary portion, the method comprising:
listening for an incoming RF communication signal in which the preliminary portion is indicative of a start of the command portion and includes one of a predefined first sequence and a predefined second sequence; and
detecting a presence of the first sequence or the second sequence in the preliminary portion of the RF communication signal;
responding to a detection of the first or the second sequence wherein:
responding to a detection of the first sequence includes processing the command portion of the RF communication signal; and
responding to a detection of the second sequence includes transmitting a first set of data via the AMR system without necessarily processing the command portion.
2. The method of claim 1 , wherein the responding to the detection of the second sequence excludes listening for any command portion.
3. The method of claim 1 , and further comprising:
transmitting a second set of data to the AMR system irrespective of any received preliminary portion of the RF communication signal.
4. The method of claim 3 , wherein the second set of data is the same set of data as the first set of data.
5. The method of claim 3 , and further comprising:
responding to a bubble-up event, wherein the second set of data is transmitted as part of the responding to the bubble-up event.
6. The method of claim 1 , wherein the listening, detecting, and responding are performed in response to a bubble-up event.
7. The method of claim 1 , wherein the instruction includes a command and control frame.
8. The method of claim 1 , wherein the first set of data includes utility meter data.
9. The method of claim 1 , wherein at least one of the first and the second sequences are pseudo noise (PN) sequences.
10. The method of claim 1 , wherein the preliminary portion of the RF communication signal is an information-bearing signal encoded with sequence inversion keying (SIK) of at least one pseudo noise (PN) sequence.
11. The method of claim 1 , and further comprising:
while listening for any command portion receiving the command portion; and
executing an instruction based on the command portion.
12. A utility meter endpoint, comprising:
a central processing unit (CPU);
a utility meter interface adapted to acquire utility meter information for the CPU from a utility meter;
a radio-frequency (RF) transceiver interfaced with the CPU and adapted to receive and transmit wireless radio-communications via an AMR system;
wherein the endpoint is configured to:
operate in a receiving mode that is receptive to incoming radio frequency (RF) communications signals from the AMR system that include a preliminary portion and a command portion following the preliminary portion, the preliminary portion being indicative of an AMR system to which the endpoint is responsive;
detect a preliminary portion of an incoming communication signal, the preliminary portion including one of a known first sequence and a known second sequence; and
determine, based on the preliminary portion, whether to respond to the incoming communication signal, wherein:
responding to a presence of the first sequence includes at least operating in a receiving mode that is receptive to the command portion; and
responding to a presence of the second sequence includes at least operating in a transmit mode to send a first set of data via the AMR system.
13. The utility meter endpoint of claim 12 , wherein the CPU and transceiver are configured to transmit a second set of data to the AMR system.
14. The utility meter endpoint of claim 13 , wherein the endpoint is configured to respond to a bubble-up event, wherein the second set of data is transmitted as part of the responding to the bubble-up event.
15. The utility meter endpoint of claim 12 , wherein the command portion includes a command and control frame.
16. The utility meter endpoint of claim 12 , wherein the first set of data includes utility meter data.
17. The utility meter endpoint of claim 12 , wherein the preliminary portion of the RF communication signal is encoded using sequence inversion keying (SIK).
18. The utility meter endpoint of claim 12 , wherein at least one of the first and the second sequences are pseudo noise (PN) sequences.
19. The utility meter endpoint of claim 12 , wherein the preliminary portion of the RF communication signal is a message-bearing signal encoded with sequence inversion keying (SIK) of at least one pseudo noise (PN) sequence.
20. The utility meter endpoint of claim 12 wherein the endpoint is capable of operating in all of a plurality of operational modes including a one-way utility meter reading mode, a one and halfway utility meter reading mode and a two-way utility meter reading mode.