System and device for evened frequency emission impact distribution using SIS channel sequencing by time-slotted transitions
Disclosed herein are wireless devices operable at intermediate wireless at ranges of thousands of meters, utilizing packets that include a preamble and a data payload. Devices may be such things as keypads, door latches, occupancy monitors, sprinkler controllers and other devices needing a communications link. A digital spread-spectrum frequency hopping rotation is used, wherein packet transmissions rotate through frequency sequences. A spectrum-impact-smoothed channel set is fashioned using sequences that each specify a unique preamble frequency relative to the other sequences and channels. The set is traversed as packets are transmitted, thereby distributing the focused radio-frequency emission impact of packets having long preambles over time. Traversal of the set is by way of time slots relative to a point of synchronization in a first packet. Detailed information on various example embodiments of the inventions are provided in the Detailed Description below, and the inventions are defined by the appended claims.
1. A pair of wireless communications devices operational at intermediate ranges, said devices utilizing a set of discrete radio frequencies upon which are organized a set of spectrum-impact smoothed (SIS) channels each having a distinct digital spread spectrum frequency sequence, each SIS channel specifying a unique frequency to be used in the transmission of a packet preamble relative to all of the other SIS channels within the set, each of said devices comprising:
a transceiver functional for wireless communication using the frequency sequence of the spectrum-impact-smoothed channels; and
an electronic circuit implementing a state machine immutable to power-transient events;
wherein said state machine of each device is configured to sequence through a set of states to implement the functions of:
(a) configuring said transceiver of the particular device to transmit or receive a packet on a channel having distinct communication parameters,
(b) exchanging a first packet with the other of said wireless devices using the first communications channel,
(c) establishing a point of synchronization in time relative to the first packet exchanged,
(d) observing a schedule of SIS channels, the schedule including a sequence of defined time slots relative to an established point of synchronization, wherein an SIS channel is repeated in the schedule of SIS channels,
(e) exchanging a plurality of streamed packets subsequent to the first packet, the streamed packets being exchanged on the SIS channels specified by the observed schedule, and
wherein each of said devices uses the same schedule of SIS channels in the course of streamed packet exchanges conducted through the sequencing of said state machines.
2. The pair of wireless communications devices as recited in claim 1 , wherein said state machine of each device is configured to sequence through a set of states to implement the function of exchanging a first packet containing a streaming directive.
3. The pair of wireless communications devices as recited in claim 2 , wherein said state machine of one of said devices is configured to acknowledge a first packet containing a streaming directive.
4. The pair of wireless communications devices as recited in claim 1 , wherein said state machine of each device is configured to sequence through a set of states to implement the function of observing a schedule of SIS channels including a sequence of defined time slots, wherein in the observed schedule each SIS channel is used in one time slot.
5. The pair of wireless communications devices as recited in claim 1 , wherein said state machine of each device is configured to sequence through a set of states to implement the function of observing a schedule of SIS channels including a sequence of defined time slots, wherein the observed schedule is bounded by the time in a sequence of SIS channels.
6. The pair of wireless communications devices as recited in claim 1 , wherein said state machine of each device is configured to sequence through a set of states to implement the function of observing a schedule of SIS channels including a sequence of defined time slots, wherein the observed schedule is bounded by an interval of communication inactivity.
7. The pair of wireless communications devices as recited in claim 1 , wherein said state machine of one of said devices is configured to observe an uncertainty period during which no packet transmission is initiated.
8. The pair of wireless communications devices as recited in claim 1 , wherein said state machine of each device is configured to sequence through a set of states to implement the function of establishing a point of synchronization in time relative to the end of the first packet exchanged.
9. A wireless communications device operational at intermediate ranges, said device utilizing a set of discrete radio frequencies upon which are organized a set of spectrum-impact-smoothed (SIS) channels each having a distinct digital spread spectrum frequency sequence, each SIS channel specifying a unique frequency to be used in the transmission of a packet preamble relative to all of the other SIS channels within the set, said device comprising:
a transceiver functional for wireless communication using the frequency sequence of the spectrum-impact-smoothed channels; and
an electronic circuit implementing a state machine immutable to power-transient events;
wherein said state machine of said device is configured to sequence through a set of states to implement the functions of:
(a) configuring said transceiver to transmit or receive a packet on a channel having distinct communication parameters,
(b) transmitting a first packet with the other of said wireless devices using the first communications channel,
(c) establishing a point of synchronization in time relative to the transmitted first packet,
(d) observing a schedule of SIS channels, the schedule including a sequence of defined time slots relative to an established point of synchronization, wherein an SIS channel is repeated in the schedule of SIS channels,
(e) transmitting a plurality of streamed packets subsequent to the first packet, the streamed packets being exchanged on the SIS channels specified by the observed schedule.
10. The wireless communications device recited in claim 9 , wherein said state machine is configured to sequence through a set of states to implement the function of transmitting a first packet containing a streaming directive.
11. The wireless communications device recited in claim 10 , wherein said state machine is configured to receive an acknowledgment packet from another wireless communications device immediately after transmission of a first packet containing a streaming directive.
12. The wireless communications device recited in claim 10 , wherein said state machine is configured to observe an uncertainty period during which no packet transmission is initiated.
13. The wireless communications device recited in claim 10 , wherein said state machine is configured to observe two uncertainty periods during defined time slots during which no packet transmission is initiated, the two uncertainty periods being located at the beginning and the end of the time slots.
14. The wireless communications device recited in claim 10 , wherein said state machine is configured to use a free-running counter in the observance of the schedule of SIS channels.
15. A wireless communications device operational at intermediate ranges, said device utilizing a set of discrete radio frequencies upon which are organized a set of spectrum-impact-smoothed (SIS) channels each having a distinct digital spread spectrum frequency sequence, each SIS channel specifying a unique frequency to be used in the transmission of a packet preamble relative to all of the other SIS channels within the set, said device comprising:
a transceiver functional for wireless communication using the frequency sequence of the spectrum-impact-smoothed channels;
a broadband helical microstrip antenna; and
an electronic circuit implementing a state machine immutable to power-transient events;
wherein said state machine of said device is configured to sequence through a set of states to implement the functions of:
(a) configuring said transceiver to transmit or receive a packet on a channel having distinct communication parameters,
(b) receiving a first packet with the other of said wireless devices using the first communications channel,
(c) establishing a point of synchronization in time relative to the received first packet,
(d) observing a schedule of SIS channels, the schedule including a sequence of defined time slots relative to an established point of synchronization, wherein an SIS channel is repeated in the schedule of SIS channels,
(e) receiving a plurality of streamed packets subsequent to the first packet, the streamed packets being exchanged on the SIS channels specified by the observed schedule.
16. The wireless communications device recited in claim 15 , wherein said state machine is configured to sequence through a set of states to implement the function of receiving and interpreting a first packet containing a streaming directive.
17. The wireless communications device recited in claim 16 , wherein said state machine is configured to transmit an acknowledgment packet to another wireless communications device immediately after reception of a first packet containing a streaming directive.
18. The wireless communications device recited in claim 15 , wherein said state machine is configured to use a countdown timer in the observance of the schedule of SIS channels.
19. The pair of wireless communications devices recited in claim 1 , wherein the devices comprise a broadband helical microstrip antenna.