Dynamic bandwidth allocation in AD hoc wireless piconets

• US 20020167961A1
• Filed: 02/22/2002
• Published: 11/14/2002
• Est. Priority Date: 02/28/2001
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Haartsen, Jacobus C.
• Granted Patent: US 7,016,372 B2
• Time in Patent Office: Days
• US Class Current: 370/444
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

One of a number, n, of slave devices is selected for express or implicit polling by a master device in a communication system that transmits during individual ones of a number of sequentially occurring time slots. This is done by assigning a corresponding priority level to each slave device, wherein at least two slave devices are assigned different corresponding priority levels. A corresponding count parameter and a corresponding initial count value are assigned to each of the slave devices. For each of the slave devices, the corresponding count parameter is initialized to the corresponding initial count value. For each successive time slot, each of the count parameters is adjusted (e.g., by decrementing). A highest priority slave device whose corresponding count parameter has reached or passed a predetermined value is selected for polling.

Claims

1. A method of selecting one of a number, n, of slave devices by a master device in a communication system that transmits during individual ones of a number of sequentially occurring time slots, the method comprising:

assigning a corresponding priority level to each slave device, wherein at least two slave devices are assigned different corresponding priority levels;

assigning a corresponding count parameter to each of the slave devices;

assigning a corresponding initial count value to each of the slave devices;

for each of the slave devices, initializing the corresponding count parameter to the corresponding initial count value;

for each successive time slot, adjusting each of the count parameters; and

selecting a highest priority slave device whose corresponding count parameter has reached or passed a predetermined value.

2. The method of claim 1, wherein adjusting each of the count parameters comprises decrementing each of the count parameters by a predetermined adjustment amount.

3. The method of claim 2, wherein the predetermined adjustment amount is equal to one.

4. The method of claim 1, further comprising:

explicitly or implicitly polling the selected slave device; and

adjusting the corresponding count parameter of the selected slave device by an amount equal to the corresponding initial count value.

5. The method of claim 4, further comprising changing the initial count value of at least one slave device sometime after the selected slave has been explicitly or implicitly polled.

6. The method of claim 5, wherein changing the initial count value of at least one slave device after the selected slave has been explicitly or implicitly polled is performed as a function of a status of a buffer of one of the slave devices.

7. The method of claim 5, wherein changing the initial count value of at least one slave device after the selected slave has been explicitly or implicitly polled is performed as a function of a status of a buffer of said master device, wherein said buffer is associated with one of the slave devices.

8. The method of claim 5, wherein changing the initial count value of at least one slave device after the selected slave has been explicitly or implicitly polled comprises changing the initial count value by an amount that results in an exponential change.

9. The method of claim 4, further comprising reassigning the corresponding priority levels of at least two of the slave devices sometime after the selected slave has been explicitly or implicitly polled.

10. The method of claim 4, wherein:

an isochronous one of the slave devices provides an isochronous service having an isochronous transmission interval; and

for each message, the initial count value assigned to the isochronous one of the slave devices is adjusted to be a first count value at the start of each isochronous transmission interval, and the initial count value assigned to the isochronous one of the slave devices is changed to a second count value after a last packet associated with said each message is transmitted, wherein the first count value is not equal to the second count value.

11. The method of claim 10, wherein for each message, the second count value is selected such that the second count value ensures that the isochronous one of the slave devices will be explicitly or implicitly polled at the start of a next isochronous transmission interval.

12. The method of claim 1, further comprising:

determining whether a present slot is a synchronous connection oriented link slot, and if so, then delaying explicitly or implicitly polling the selected slave device until an occurrence of a slot that is not a synchronous connection oriented link slot.

13. The method of claim 12, further comprising:

suspending the adjusting of each of the count parameters if the present slot is a synchronous connection oriented link slot.

14. The method of claim 1, wherein:

the n slave devices include one or more synchronous slave devices and one or more non-synchronous slave devices; and

the corresponding priority levels are assigned to each slave device such that each of the one or more synchronous slave devices has a corresponding priority level that is higher than the corresponding priority level of any one of the one or more non-synchronous slave devices.

15. The method of claim 14, wherein the initial count values of the one or more synchronous slave devices are selected so as to ensure that the time slots utilized by the one or more synchronous slave devices are staggered with respect to one another.

16. The method of claim 15, further comprising:

after initializing the corresponding count parameter to the corresponding initial count value, adjusting the initial count values of the one or more synchronous slave devices so that they will equal a corresponding synchronous connection oriented link interval.

20. The apparatus of claim 19, wherein the logic that adjusts each of the count parameters comprises logic that decrements each of the count parameters by a predetermined adjustment amount.

21. The apparatus of claim 20, wherein the predetermined adjustment amount is equal to one.

22. The apparatus of claim 19, further comprising:

logic that explicitly or implicitly polls the selected slave device; and

logic that adjusts the corresponding count parameter of the selected slave device by an amount equal to the corresponding initial count value.

23. The apparatus of claim 22, further comprising logic that changes the initial count value of at least one slave device sometime after the selected slave has been explicitly or implicitly polled.

24. The apparatus of claim 23, wherein the logic that changes the initial count value of at least one slave device after the selected slave has been explicitly or implicitly polled performs this operation as a function of a status of a buffer of one of the slave devices.

25. The apparatus of claim 23, wherein the logic that changes the initial count value of at least one slave device after the selected slave has been explicitly or implicitly polled performs this operation as a function of a status of a buffer of said master device, wherein said buffer is associated with one of the slave devices.

26. The apparatus of claim 23, wherein the logic that changes the initial count value of at least one slave device after the selected slave has been explicitly or implicitly polled comprises logic that changes the initial count value by an amount that results in an exponential change.

27. The apparatus of claim 22, further comprising logic that reassigns the corresponding priority levels of at least two of the slave devices sometime after the selected slave has been explicitly or implicitly polled.

28. The apparatus of claim 22, wherein:

an isochronous one of the slave devices provides an isochronous service having an isochronous transmission interval; and

the apparatus further comprises logic that, for each message, adjusts the initial count value assigned to the isochronous one of the slave devices to be a first count value at the start of each isochronous transmission interval, and changes the initial count value assigned to the isochronous one of the slave devices to a second count value after a last packet associated with said each message is transmitted, wherein the first count value is not equal to the second count value.

29. The apparatus of claim 28, further comprising logic that, for each message, selects the second count value such that the second count value ensures that the isochronous one of the slave devices will be explicitly or implicitly polled at the start of a next isochronous transmission interval.

30. The apparatus of claim 19, further comprising:

logic that determines whether a present slot is a synchronous connection oriented link slot, and if so, then delays explicitly or implicitly polling the selected slave device until an occurrence of a slot that is not a synchronous connection oriented link slot.

31. The apparatus of claim 30, further comprising:

logic that suspends the adjusting of each of the count parameters if the present slot is a synchronous connection oriented link slot.

32. The apparatus of claim 19, wherein:

the n slave devices include one or more synchronous slave devices and one or more non-synchronous slave devices; and

the logic that assigns the corresponding priority levels to each of the slave devices assigns the corresponding priority levels such that each of the one or more synchronous slave devices has a corresponding priority level that is higher than the corresponding priority level of any one of the one or more non-synchronous slave devices.

33. The apparatus of claim 32, wherein the logic that assigns the corresponding initial count value to each of the slave devices uses initial count values that ensure that the time slots utilized by the one or more synchronous slave devices are staggered with respect to one another.

34. The apparatus of claim 33, further comprising:

logic that, after initializing the corresponding count parameter to the corresponding initial count value, adjusts the initial count values of the one or more synchronous slave devices so that they will equal a corresponding synchronous connection oriented link interval.

17. A method of selecting one of a number, n, of slave devices to be explicitly or implicitly polled by a master device in a communication system that transmits during individual ones of a number of sequentially occurring time slots, the method comprising:

assigning a different corresponding priority level to each of a number, n, of counters;

assigning a corresponding one of the counters to each of the slave devices;

assigning a corresponding initial count value to each of the slave devices;

for each of the slave devices, initializing the corresponding counter to the corresponding initial count value;

for each successive time slot, adjusting each of the counters;

identifying a highest priority counter whose contents have reached or passed a predetermined value; and

selecting for express or implicit polling the slave device corresponding to the identified counter.

18. A method of explicitly or implicitly polling one or more of a number, n, of slave devices by a master device in a communication system that transmits during individual ones of a number of sequentially occurring time slots, the method comprising:

a) assigning a different corresponding priority level to each of a number, n, of counters;

b) assigning a corresponding one of the counters to each of the slave devices;

c) assigning a corresponding initial count value to each of the slave devices;

d) for each of the slave devices, initializing the corresponding counter to the corresponding initial count value;

e) periodically adjusting each of the counters by an amount equal to a number of time slots that have occurred since a last adjusting of each of the counters;

f) identifying a highest priority counter whose contents have reached or passed a predetermined value;

g) selecting for express or implicit polling the slave device corresponding to the identified counter;

h) explicitly or implicitly polling the selected slave device;

i) adjusting the corresponding counter of the selected slave device by an amount equal to the corresponding initial count value; and

j) repeating steps e) through j).

19. An apparatus for selecting one of a number, n, of slave devices by a master device in a communication system that transmits during individual ones of a number of sequentially occurring time slots, the apparatus comprising:

logic that assigns a corresponding priority level to each slave device, wherein at least two slave devices are assigned different corresponding priority levels;

logic that assigns a corresponding count parameter to each of the slave devices;

logic that assigns a corresponding initial count value to each of the slave devices;

logic that, for each of the slave devices, initializes the corresponding count parameter to the corresponding initial count value;

logic that, for each successive time slot, adjusts each of the count parameters; and

logic that selects a highest priority slave device whose corresponding count parameter has reached or passed a predetermined value.

35. An apparatus for selecting one of a number, n, of slave devices to be explicitly or implicitly polled by a master device in a communication system that transmits during individual ones of a number of sequentially occurring time slots, the apparatus comprising:

logic that assigns a different corresponding priority level to each of a number, n, of counters;

logic that assigns a corresponding one of the counters to each of the slave devices;

logic that assigns a corresponding initial count value to each of the slave devices;

logic that, for each of the slave devices, initializes the corresponding counter to the corresponding initial count value;

logic that, for each successive time slot, adjusts each of the counters;

logic that identifies a highest priority counter whose contents have reached or passed a predetermined value; and

logic that selects for express or implicit polling the slave device corresponding to the identified counter.

36. An apparatus for explicitly or implicitly polling one or more of a number, n, of slave devices by a master device in a communication system that transmits during individual ones of a number of sequentially occurring time slots, the apparatus comprising:

a) logic that assigns a different corresponding priority level to each of a number, n, of counters;

b) logic that assigns a corresponding one of the counters to each of the slave devices;

c) logic that assigns a corresponding initial count value to each of the slave devices;

d) logic that, for each of the slave devices, initializes the corresponding counter to the corresponding initial count value;

e) logic that periodically adjusts each of the counters by an amount equal to a number of time slots that have occurred since a last adjusting of each of the counters;

f) logic that identifies a highest priority counter whose contents have reached or passed a predetermined value;

g) logic that selects for express or implicit polling the slave device corresponding to the identified counter;

h) logic that explicitly or implicitly polls the selected slave device;

i) logic that adjusts the corresponding counter of the selected slave device by an amount equal to the corresponding initial count value; and

j) logic that causes logic e) through j) to operate repetitively.