Adaptive Coexistence Between Different Wireless Communication Systems

• US 20090262785A1
• Filed: 06/19/2008
• Published: 10/22/2009
• Est. Priority Date: 04/18/2008
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Wilhelmsson, Leif
• Granted Patent: US 8,072,896 B2
• Time in Patent Office: Days
• US Class Current: 375/133
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A first transceiver is operated in a first frequency band in the presence of a second transceiver operating in a second frequency band. Operation includes ascertaining an interference level at the first transceiver due to the second transceiver. A coexistence strategy for the second transceiver is dynamically selected by selecting a frequency division strategy if the ascertained interference level is less than a threshold level and selecting a time division strategy if the ascertained interference level is above the threshold level. The second transceiver is then caused to operate in accordance with the dynamically selected coexistence strategy.

Claims

1. A method of operating a first transceiver in a first frequency band in the presence of a second transceiver operating in a second frequency band, the method comprising:

ascertaining an interference level at the first transceiver due to the second transceiver;

dynamically selecting a coexistence strategy for the second transceiver by selecting a frequency division strategy if the ascertained interference level is less than a threshold level and selecting a time division strategy if the ascertained interference level is above the threshold level; and

causing the second transceiver to operate in accordance with the dynamically selected coexistence strategy.

2. The method of claim 1, wherein the frequency division strategy comprises filtering out interference.

3. The method of claim 1, wherein ascertaining the interference level at the first transceiver due to the second transceiver comprises ascertaining a transmit power level of the second transceiver.

4. The method of claim 1, wherein ascertaining the interference level at the first transceiver due to the second transceiver comprises ascertaining how close a transmit frequency of the second transceiver is to a receive frequency of the first transceiver.

5. The method of claim 1, wherein:

the first transceiver operates across a fixed bandwidth and the second transceiver utilizes frequency hopping; and

ascertaining the interference level at the first transceiver due to the second transceiver comprises ascertaining how many hop frequencies of the second transceiver are within a predefined distance from one or more receive frequencies of the first transceiver.

6. The method of claim 1, wherein ascertaining the interference level at the first transceiver due to the second transceiver comprises ascertaining an expected level of transmit activity of the second transceiver.

7. The method of claim 1, wherein the method is repeated periodically.

8. The method of claim 1, comprising:

determining whether a session will require more than one dynamic selection of a coexistence strategy and if so then periodically repeating the method, and otherwise making an initial dynamic selection of a coexistence strategy and then using the selected coexistence strategy throughout an entire communication session.

9. The method of claim 8, wherein determining whether a session will require more than one dynamic selection of a coexistence strategy comprises determining an anticipated length of the communication session.

10. The method of claim 1, comprising:

ascertaining an expected length of a communication session; and

comparing the expected length of the communication session with a threshold length,

wherein the method is not performed if the expected length of the communication session is less than the threshold length.

11. The method of claim 1, comprising:

selecting the threshold level as a function of a transmission scheme used by the first transceiver.

12. The method of claim 1, comprising:

ascertaining an interference level at the second transceiver due to the first transceiver;

dynamically selecting a coexistence strategy for the first transceiver by selecting the frequency division strategy if the ascertained interference level is less than a threshold level and selecting the time division strategy if the ascertained interference level is above the threshold level; and

causing the first transceiver to operate in accordance with the dynamically selected coexistence strategy.

13. An apparatus for operating a first transceiver in a first frequency band in the presence of a second transceiver operating in a second frequency band, the apparatus comprising:

logic configured to ascertain an interference level at the first transceiver due to the second transceiver;

logic configured to dynamically select a coexistence strategy by selecting a frequency division strategy if the ascertained interference level is less than a threshold level and selecting a time division strategy if the ascertained interference level is above the threshold level; and

logic configured to cause the second transceiver to operate in accordance with the dynamically selected coexistence strategy.

14. The apparatus of claim 13, wherein the frequency division strategy comprises filtering out interference.

15. The apparatus of claim 13, wherein the logic configured to ascertain the interference level at the first transceiver due to the second transceiver comprises logic configured to ascertain a transmit power level of the second transceiver.

16. The apparatus of claim 13, wherein the logic configured to ascertain the interference level at the first transceiver due to the second transceiver comprises logic configured to ascertain how close a transmit frequency of the second transceiver is to a receive frequency of the first transceiver.

17. The apparatus of claim 13, wherein:

the first transceiver operates across a fixed bandwidth and the second transceiver utilizes frequency hopping; and

the logic configured to ascertain the interference level at the first transceiver due to the second transceiver comprises logic configured to ascertain how many hop frequencies of the second transceiver are within a predefined distance from one or more receive frequencies of the first transceiver.

18. The apparatus of claim 13, wherein the logic configured to ascertain the interference level at the first transceiver due to the second transceiver comprises logic configured to ascertain an expected level of transmit activity of the second transceiver.

19. The apparatus of claim 13, wherein the apparatus is operated periodically so as to periodically make dynamic selections of the coexistence strategy.

20. The apparatus of claim 13, comprising:

logic configured to determine whether a session will require more than one dynamic selection of a coexistence strategy and if so then periodically repeat a dynamic coexistence strategy selection process, and otherwise make an initial dynamic selection of a coexistence strategy and then use the selected coexistence strategy throughout an entire communication session.

21. The apparatus of claim 20, wherein the logic configured to determine whether a session will require more than one dynamic selection of a coexistence strategy comprises logic configured to determine an anticipated length of the communication session.

22. The apparatus of claim 13, comprising:

logic configured to ascertain an expected length of a communication session; and

logic configured to compare the expected length of the communication session with a threshold length,

wherein the logic configured to dynamically select the coexistence strategy by selecting the frequency division strategy if the ascertained interference level is less than the threshold level and selecting the time division strategy if the ascertained interference level is above the threshold level is not operated if the expected length of the communication session is less than the threshold length.

23. The apparatus of claim 13, comprising:

logic configured to select the threshold level as a function of a transmission scheme used by the first transceiver.

24. The apparatus of claim 13, comprising:

logic configured to ascertain an interference level at the second transceiver due to the first transceiver;

logic configured to dynamically select a coexistence strategy for the first transceiver by selecting the frequency division strategy if the ascertained interference level is less than a threshold level and selecting the time division strategy if the ascertained interference level is above the threshold level; and

logic that causes the first transceiver to operate in accordance with the dynamically selected coexistence strategy.

25. A user equipment comprising:

a first transceiver that operates in a first frequency band; and

an apparatus for operating the first transceiver in the presence of a second transceiver operating in a second frequency band,

wherein the apparatus comprises;

logic configured to ascertain an interference level at the first transceiver due to the second transceiver;

logic configured to dynamically select a coexistence strategy by selecting a frequency division strategy if the ascertained interference level is less than a threshold level and selecting a time division strategy if the ascertained interference level is above the threshold level; and

logic configured to operate the second transceiver in accordance with the dynamically selected coexistence strategy.

26. The user equipment of claim 25, comprising:

the second transceiver.