Light monitoring system using a random phase multiple access system
Methods, systems, and apparatuses, including computer programs encoded on computer-readable media, for receiving monitor data from a lighting equipment monitor. A data stream is created based upon the monitor data. The data stream is spread with a common pseudo-noise (PN) code that is used by a plurality of nodes in communication with an access point. A frequency offset to the spread data stream based at least in part on a timing of the access point is applied. The spread data stream is transmitted with a randomly selected timing offset.
1. A method of monitoring lighting equipment, the method comprising:
receiving, at a processor, monitor data from a lighting equipment monitor;
creating a data stream based upon the monitor data;
spreading the data stream with a common pseudo-noise (PN) code, wherein the common PN code is used by a plurality of nodes in communication with an access point; and
transmitting the spread data stream at a first time based on a slot time and a first randomly selected timing offset, wherein the spread data stream is transmitted while at least a portion of a second spread data stream is transmitted, wherein the second spread data stream is spread with the common PN code, and wherein the second spread data stream is transmitted from a remote node at a second time based on the slot time and a second randomly selected timing offset.
2. The method of claim 1 , further comprising:
determining a light is not functioning properly based upon the monitor data; and
initiating a transmission of the spread data stream based upon the determination that the light is not functioning properly.
3. The method of claim 1 , wherein the lighting equipment monitor monitors an obstruction light.
4. The method of claim 1 , wherein the monitor data comprises data representing a voltage or a current used to power a light.
5. The method of claim 1 , further comprising receiving, from the access point, a monitor read schedule.
6. The method of claim 5 , wherein receiving the monitor data is based upon the received monitor read schedule.
7. The method of claim 1 , wherein transmitting the spread data stream is based upon a transmission schedule.
8. The method of claim 1 , further comprising receiving, from the access point, a transmission schedule.
9. The method of claim 8 , wherein transmitting the monitor data is based upon the received transmission schedule.
10. The method of claim 1 , wherein the first randomly selected timing offset is between zero and a spreading factor used to spread the data stream minus one.
11. The method of claim 1 , further comprising retransmitting the spread data stream with a third randomly selected timing offset if an acknowledgement is not received within a predetermined time period.
12. The method of claim 1 , wherein the common PN code comprises a gold code.
13. A lighting equipment monitor comprising:
a monitor configured to:
monitor lighting equipment; and
provide monitor data based upon the monitoring of the lighting equipment; and
a transmit apparatus comprising:
a pseudo-noise (PN) spreader configured to receive a data stream comprising the monitor data and spread the data stream with a common PN code, wherein the common PN code is used by a plurality of nodes in communication with an access point;
a delay module configured to generate a first randomly selected timing offset for the spread data stream; and
a transmitter configured to transmit the spread data stream at a first time based on a slot time and the randomly selected timing offset, wherein the spread data stream is transmitted while at least a portion of a second spread data stream is transmitted, wherein the second spread data stream is spread with the common PN code, and wherein the second spread data stream is transmitted from a remote node at a second time based on the slot time and a second randomly selected timing offset.
14. The lighting equipment monitor of claim 13 , further comprising a processor configured to:
determine a light is not functioning properly based upon the monitor data; and
initiate a transmission of the spread data stream based upon the determination that the light is not functioning properly.
15. The lighting equipment monitor of claim 13 , wherein the monitor monitors an obstruction light.
16. The lighting equipment monitor of claim 13 , wherein the monitor data comprises data representing a voltage or a current used to power a light.
17. The lighting equipment monitor of claim 13 , wherein the lighting equipment monitor is located below ground.
18. The lighting equipment monitor of claim 13 , further comprising a receiver configured to receive, from the access point, a monitor read schedule, wherein the monitor provides the monitor data based upon the monitor read schedule.
19. The lighting equipment monitor of claim 13 , wherein the first randomly selected timing offset is between zero and a spreading factor used to spread the data stream minus one.
20. The lighting equipment monitor of claim 13 , wherein the transmitter is further configured to retransmit the spread data stream with a third randomly selected timing offset provided by the delay module if an acknowledgement is not received within a predetermined time period.