1. A method of random access communications from a user element to an access point, the user element being operable to maintain a stack counter, the method comprising:
a) storing at least one packet in a buffer;
b) transmitting the packet for reception by the access point if the stack counter is zero;
c) receiving a feedback message from the access point wherein the feedback message is one of:
1) an idle message indicating that no transmissions were detected during the slot,
2) a successful transmission message indicating that a packet was successfully received during the slot, and
3) a collision message indicating that at least one packet was detected but could not be successfully received during the slot;
d) when the received feedback message is a successful transmission message and the stack counter is zero, removing the transmitted packet from the buffer;
e) when the received feedback message is a collision message, generating a random number and setting the stack counter to an amount determined by the generated random number; and
f) when the received feedback message is an idle message and the stack counter is greater than zero, decrementing the stack counter.
2. The method as defined in claim 1, further comprising repeating steps (b) to (f) as long as there is at least one packet in the buffer.
3. The method as defined in claim 1, wherein the user element is assigned a priority and step (e) comprises, when the received feedback message is a collision message, generating a random number and incrementing the stack counter by an amount determined by the generated random number in combination with the assigned priority.
4. The method as defined in claim 1, further comprising:
receiving a successful transmission message in a time slot in which no packet was transmitted from the user element; and
decrementing the stack counter in response to the received successful transmission message.
5. A user element for random access communications with an access point, the user element comprising:
a) a stack counter;
b) a buffer operable to store at least one packet;
c) a transmitter operable to transmit the packet for reception by the access point if the stack counter is zero;
d) a receiver operable to receive a feedback message from the access point wherein the feedback message is one of:
1) an idle message indicating that no transmissions were detected during the slot,
2) a successful transmission message indicating that a packet was successfully received during the slot, and
3) a collision message indicating that at least one packet was detected but could not be successfully received during the slot;
the buffer being operable, when the received feedback message is a successful transmission message and the stack counter is zero, to remove the transmitted packet from the buffer; and
the stack counter being operable:
(i) when the received feedback message is a collision message, to generate a random number and to set the stack counter to an amount determined by the generated random number; and
(ii) when the received feedback message is an idle message and the stack counter is greater than zero, to decrement the stack counter.
6. The user elements as defined in claim 5, wherein the stack counter is operable to repeat steps (i) to (ii) and the transmitter is operable to transmit a packet each time the stack counter is zero as long as there is at least one packet in the buffer.
7. The user elements as defined in claim 5, wherein the user element is assigned a priority and the stack counter is operable, when the received feedback message is a collision message, to generate a random number and to increment the stack counter by an amount determined by the generated random number in combination with the assigned priority.
8. The user elements as defined in claim 5, wherein the stack counter is further operable to decrement the stack counter in response to receipt of a successful transmission message in a time slot in which no packet was transmitted from the user element.
9. A method of facilitating random access communications at an access point comprising:
a) attempting to receive packets transmitted via a plurality of channels from a plurality of user elements during a time slot;
b) determining a number of successful channels in which packets were properly received during the time slot;
c) determining a number of unsuccessful channels in which packets were not properly received during the time slot; and
d) transmitting a feedback message to the plurality of user elements wherein the feedback message is selected from a group comprising:
1) a merge message when the ratio of successful channels to unsuccessful channels meets a merge message condition;
2) a split message when the ratio of successful channels to unsuccessful channels meets a split message condition, and
3) a stay message when the ratio of successful channels does not meet the merge message condition and does not meet the split message condition.
10. The method as defined in claim 9, wherein the merge message condition comprises the ratio of successful channels to unsuccessful channels exceeding a merge message threshold.
11. The method as defined in claim 9, wherein the split message condition comprises the ratio of successful channels to unsuccessful channels being less than a split channel threshold.
12. The method as defined in claim 9, further comprising transmitting to a user element a successful transmission message indicating that a packet was successfully received from the user element.
13. An access point for receiving random access communications from an plurality of user elements, the access point comprising:
a) a receiver operable:
to attempt to receive packets transmitted via a plurality of channels from the plurality of user elements during a time slot;
to determine a number of successful channels in which packets were properly received during the time slot; and
to determine a number of unsuccessful channels in which packets were not properly received during the time slot; and
b) a transmitter operable to transmit a feedback message to the plurality of user elements wherein the feedback message is selected from a group comprising:
1) a merge message when the ratio of successful channels to unsuccessful channels meets a merge message condition;
2) a split message when the ratio of successful channels to unsuccessful channels meets a split message condition, and
3) a stay message when the ratio of successful channels does not meet the merge message condition and does not meet the split message condition.
14. The access point as defined in claim 13, wherein the merge message condition comprises the ratio of successful channels to unsuccessful channels exceeding a merge message threshold.
15. The access point as defined in claim 13, wherein the split message condition comprises the ratio of successful channels to unsuccessful channels being less than a split channel threshold.
16. The access point as defined in claim 13, wherein the transmitter is further operable to transmit to a user element a successful transmission message indicating that a packet was successfully received from the user element.
17. A method of random access communications from a user element to an access point, the user element being operable to maintain a stack counter, the method comprising:
a) storing at least one packet in a buffer;
b) transmitting the packet for reception by the access point if the stack counter is zero;
c) receiving a feedback message from the access point wherein the feedback message is one of:
1) a merge message when the ratio of successful channels to unsuccessful channels meets a merge message condition;
2) a split message when the ratio of successful channels to unsuccessful channels meets a split message condition, and
3) a stay message when the ratio of successful channels does not meet the merge message condition and does not meet the split message condition;
d) when the received feedback message is a split message, the stack counter is zero and the packet is not successfully transmitted, generating a random number and setting the stack counter to an amount determined by the generated random number;
e) when the received feedback message is one of a merge message and a stay message, the stack counter is zero and the packet is not successfully transmitted, maintaining the stack counter at zero.
18. The method as defined in claim 17, comprising repeating steps (b) to (f) as long as there is at least one packet in the buffer.
19. The method as defined in claim 17, wherein the user element is assigned a priority and step (e) comprises, when the received feedback message is a split message, generating a random number and incrementing the stack counter by an amount determined by the generated random number in combination with the assigned priority.
20. The method as defined in claim 17, further comprising:
receiving a split message when the stack counter is at least one; and
incrementing the stack counter in response to the received split message.
21. The method as defined in claim 17, further comprising:
receiving a stay message when the stack counter is at least one; and
maintaining the value of the stack counter in response to the received stay message.
22. The method as defined in claim 17, further comprising:
receiving a merge message when the stack counter is at least one; and
decrementing the stack counter in response to the received merge message.
23. The method as defined in claim 17, further comprising:
receiving a successful transmission message from the access point; and
removing the transmitted packet from the buffer in response to the successful transmission message.
24. The method as defined in claim 17, further comprising, before transmitting the packet, randomly selecting a channel for transmitting the packet.
25. The method as defined in claim 24, comprising randomly selecting a channel for transmitting a packet at each time slot in which a packet is to be transmitted.
26. A user element for random access communications with an access point, the user element comprising:
a) a stack counter;
b) a buffer operable to store at least one packet;
c) a transmitter operable to transmit the packet for reception by the access point if the stack counter is zero;
d) a receiver operable to receive a feedback message from the access point wherein the feedback message is one of:
1) a merge message when the ratio of successful channels to unsuccessful channels meets a merge message condition;
2) a split message when the ratio of successful channels to unsuccessful channels meets a split message condition, and
3) a stay message when the ratio of successful channels does not meet the merge message condition and does not meet the split message condition,
the stack counter being operable:
(i) when the received feedback message is a split message, the stack counter is zero and the packet is not successfully transmitted, to generate a random number and to set the stack counter to an amount determined by the generated random number; and
(ii) when the received feedback message is one of a merge message and a stay message, the stack counter is zero and the packet is not successfully transmitted, maintaining the stack counter at zero.
27. The user elements as defined in claim 26, wherein the stack counter is operable to repeat steps (i) to (ii) and the transmitter is operable to transmit a packet each time the stack counter is zero as long as there is at least one packet in the buffer.
28. The user elements as defined in claim 26, wherein the user element is assigned a priority and the stack counter is operable, when the received feedback message is a split message, to generate a random number and to increment the stack counter by an amount determined by the generated random number in combination with the assigned priority.
29. The user elements as defined in claim 26, wherein the stack counter is further operable, on receipt of a split message when the stack counter is at least one, to increment the stack counter in response to the received split message.
30. The user elements as defined in claim 26, wherein the stack counter is operable, on receipt of a stay message when the stack counter is at least one, to maintain the value of the stack counter in response to the received stay message.
31. The user elements as defined in claim 26, wherein the stack counter is operable, on receipt of a merge message when the stack counter is at least one to decrement the stack counter in response to the received merge message.
32. The user elements as defined in claim 26, wherein:
the receiver is operable to receive a successful transmission message from the access point; and
the buffer is operable to remove the transmitted packet from the buffer in response to the successful transmission message.
33. The user elements as defined in claim 26, wherein the transmitter is operable, before transmitting the packet, to randomly select a channel for transmitting the packet.
34. The user elements as defined in claim 33, wherein the transmitter is operable to randomly select a channel for transmitting a packet at each time slot in which a packet is to be transmitted.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A lighting fixture comprised of:
an elongated tapered body having an axis of elongation extending in a first direction, with the body including a cavity having an opening therein;
a fixture mounting assembly for positioning the fixture with the cavity opening oriented to provide up-lighting;
a lamp mounting assembly for positioning a lamp in the cavity so it extends in the first direction with the lamp exposed upwardly; and
a louver assembly including a plurality of louvers spaced along the axis of elongation, with the louvers extending outward from the body cavity opening and transversely of the axis of elongation,
the louver assembly being operative to direct light outwardly in a substantially uniform pattern extending in the first direction and transversely of the first direction.
2. A lighting fixture as described in claim 1, wherein the body has an elongated opening on a side opposite to the louver assembly that extends in the first direction, the opening being operative to provide down-lighting.
3. A lighting fixture as described in claim 2, further including a light diffuser covering the elongated opening.
4. A lighting fixture as described in claim 1, wherein the louvers are comprised of partial disks, with the sizes of the louvers decreasing progressively from the center of the louver assembly to its ends.
5. A lighting fixture as described in claim 4, wherein the louvers have semi-circular perimeters.
6. A lighting fixture as described in claim 4, wherein the louvers have semi-elliptical perimeters, with the minor axes thereof extending vertically.
7. A lighting fixture as described in claim 4, wherein the louvers have semi-elliptical perimeters, with the major axes thereof extending vertically.
8. A lighting fixture as described in claim 4, wherein the louvers have polygonal perimeters.
9. A lighting fixture as described in claim 1, wherein the louvers decrease in size progressively from the center of the louver assembly to its ends.
10. A lighting fixture as described in claim 1, wherein the ratio of the spacing between the louvers and the thickness of the louvers is between about 7:1 and about 14:1.
11. A lighting fixture as described in claim 1, wherein the ratio of the spacing between the louvers and the thickness of the louvers is between about 10:1 and about 11:1.
12. A lighting fixture as described in claim 1, wherein the louver assembly is further comprised of an elongated supporting structure on which the louvers are mounted, the louver assembly being installable and removable as a single unit.
13. A lighting fixture as described in claim 12, wherein the supporting structure is comprised of an elongated partially tubular member having an inner surface that partially surrounds the area which receives the lamp and an outer surface on which the louvers are mounted in longitudinally spaced relationship.
14. A lighting fixture as described in claim 13, wherein the supporting structure is light transmissive.
15. A lighting fixture as described in claim 13, wherein the supporting structure is light transmissive, and the portions of the outer surface between the louvers are translucent.
16. A lighting fixture as described in claim 13, wherein the supporting structure has an arcuate outer surface, and the louvers each include an arcuate recess which receives the outer surface of the shell.
17. A lighting fixture as described in claim 13, wherein the louvers are comprised of partial discs having longitudinally spaced side faces and beveled peripheral faces.
18. A lighting fixture as described in claim 17, wherein the beveled faces all have a substantially constant bevel angle.
19. A lighting fixture as described in claim 17, wherein the beveled faces are angled toward the nearest end of the louver assembly.
20. A lighting fixture as described in claim 17, wherein the bevel angles increase progressively from the center of the louver assembly toward the ends of the louver assembly.
21. A lighting fixture as described in claim 20, wherein the maximum bevel angle is about 50 degrees.
22. A lighting fixture as described in claim 20, wherein the louvers decrease progressively in size from the center of the louver assembly to its ends.
23. A lighting fixture as described in claim 22, wherein the intersections of the beveled faces and the side faces are bounded by a substantially smooth curve which defines an arcuate profile for the top of the louver assembly.
24. A lighting fixture as described in claim 22, wherein the louvers have semi-circular perimeters.
25. A lighting fixture as described in claim 22, wherein the louvers have semi-elliptical perimeters, with the major axes thereof extending vertically.
26. A lighting fixture as described in claim 25, wherein the louvers have semi-elliptical perimeters, with the minor axes thereof extending vertically.
27. A lighting fixture as described in claim 24, wherein the louvers have polygonal perimeters.
28. A lighting fixture as described in claim 1, wherein the louvers are comprised of partial discs having longitudinally spaced side faces and beveled peripheral faces.
29. A lighting fixture as described in claim 28, wherein the beveled faces are angled toward the nearest end of the louver assembly.
30. A lighting fixture as described in claim 28, wherein the bevel angles increase progressively from the longitudinal center of the louver assembly toward the end of the louver assembly.
31. A lighting fixture as described in claim 30, wherein the louvers decrease progressively in size from the center of the louver assembly to its ends.
32. A lighting fixture as described in claim 31, wherein the intersections of the beveled faces and the side faces are bounded by a substantially smooth curve which defines an arcuate profile for the top of the louver assembly.
33. A lighting fixture as described in claim 28, wherein the bevel angle is about 50 degrees.
34. A lighting fixture as described in claim 1, further including a reflector positioned to direct light upward from a lamp mounted in the fixture.
35. A lighting fixture as described in claim 12, wherein the supporting structure is comprised of a plurality of spaced tubular members that extend the length of the louver assembly.
36. A lighting fixture as described in claim 35, wherein the tubular members extend through openings in the individual louvers.
37. A lighting fixture as described in claim 35, wherein the tubular members are rods that extend through openings in the individual louvers.
38. A lighting fixture as described in claim 37, wherein the individual louvers include a recess that receives a lamp mounted in the lamp mounting assembly.
39. A lighting fixture as described in claim 38, further including a reflector positioned to direct light upward from a lamp mounted in the fixture.
40. A lighting fixture as described in claim 35, wherein the individual louvers include a recess that receives a lamp mounted in the lamp mounting assembly.
41. A lighting fixture as described in claim 1, wherein the fixture mounting assembly includes mounting members spaced along the axis of elongation of the fixture, the members extending downwardly for mounting the fixture on a surface spaced from a ceiling.
42. A lighting fixture as described in claim 41, further including a base to which the mounting members are attached.
43. A lighting fixture as described in claim 41, wherein the fixture is cantilevered on the mounting members
44. A lighting fixture as described in claim 43, further including a base to which the mounting members are attached.
45. A lighting fixture comprised of:
an elongated tapered body having an axis of elongation extending in a first direction, with the body including a cavity having an opening therein;
a fixture mounting assembly for positioning the fixture with the cavity opening oriented to provide lighting directed toward a surface;
a lamp mounting assembly that positions a lamp in the cavity so it extends in the first direction, with the lamp exposed to provide illumination toward the surface; and
a louver assembly including a plurality of louvers spaced along the axis of elongation, the louvers extending outward from the body cavity opening and transversely of the axis of elongation,
the louver assembly being operative to direct light toward the surface to be illuminated in a substantially uniform pattern extending in the first direction and transversely of the first direction.
46. A lighting fixture as described in claim 45, wherein the body has an elongated opening on a side opposite to the louver assembly and extending in the first direction, the opening being operative to provide illumination in a direction opposite to the light directed toward the surface to be illuminated.
47. A lighting fixture as described in claim 46, further including a light diffuser covering the elongated opening.
48. A lighting fixture as described in claim 45, wherein:
the surface to be illuminated is a wall; and
the fixture mounting assembly includes members spaced along the axis of elongation of the fixture, the members extending outwardly for attaching the fixture to the wall.