Asymmetric data transmission for use in a multi-modulation environment

• US 6,377,817 B1
• Filed: 04/18/2000
• Issued: 04/23/2002
• Est. Priority Date: 05/03/1999
• Status: Expired due to Term

• Current Assignee: Sisvel International S.A. (Fineur International S.A.)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Hamiti, Shkumbin, Jokinen, Harri, Nikula, Eero, Hakaste, Markus
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): Craver, Charles
• Application Number:
  US09/551,012
• Time in Patent Office: 735 Days
• Field of Search: 455/553, 455/403, 455/466, 455/108, 455/102, 455/188.1, 455/182.1, 455/173.1, 455/51, 455/136, 455/139, 370/252, 370/319-321, 370/324, 370/430, 370/503, 375/219, 375/268-270, 375/271
• US Class Current: 455/553.1
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0022 in which mode-switching is influenced by the user
• CPC Class Codes: H04L 1/0038 Blind format detection for detection of modulation format H04L27/0012
• CPC Class Codes: H04L 27/0012 arrangements for identifying the type of modulation
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A data transmission method and system for circuit switched and other services that can be employed in TDMA-based systems, and that supports the use of one or several types of modulation (e.g., 8-PSK modulation), in addition to a “normal” modulation (e.g., GMSK modulation) on a radio interface. An additional modulation/channel coding (e.g., one based on 8-PSK) may be used in the downlink transmission, while the normal modulation/channel coding (e.g., one based on GMSK) may be used in the uplink transmissions, under a variety of different conditions. A first condition arises where the radio conditions allow the use of the additional modulation in both directions, but the mobile station transmitter does not support it. A second condition arises where the radio conditions allow the use of the additional modulation in both directions, and the mobile station supports it, but the user requests a downlink-biased or uplink-biased data transmission service. A third condition arises where the mobile station supports the use of the additional modulation in both directions, but the uplink (or downlink) radio conditions do not permit the use of the additional modulation (e.g., because of link budget limitations.) Also, a lower data rate may be desired on the uplink in order to reduce the power consumption of the mobile station, and/or in the downlink direction to avoid unnecessary interference. This is especially true in the case that one direction or the other has less data to transmit, and the high speed data transmission mode is not required (even if supported).

Claims

1. A method for supporting data transmission services in a digital wireless communication system that operates with a first type of modulation between a mobile station and a wireless network, comprising steps of:

bidirectionally coupling a mobile station to the network through a radio interface; and

in a first case, applying a second, different type of modulation in a downlink direction from the network to the mobile station unless at least one of a plurality of conditions are found to apply, while

in a second case, applying a second, different type of modulation in an uplink direction from the mobile station to the network unless one of the plurality of conditions are found to apply,

wherein one of said conditions is that the second type of modulation is supported in the network, but is not supported in both directions by the mobile station.

2. A method as in claim 1, wherein another one of said conditions is that a user specifically requests a downlink biased data link service, which is also used by the mobile station in the uplink, and wherein the modulation type is implicitly detected by the network from received uplink mobile station transmissions.

3. A method as in claim 1, wherein another one of said conditions is that a user specifically requests an uplink biased data link service, which is also used by the mobile station in the downlink, and wherein the modulation type is implicitly detected by the network from received uplink mobile station transmissions.

4. A method as in claim 1, wherein another one of said conditions is that the mobile station supports the second type of modulation, but uplink conditions restrict the use of the second type of modulation, while another one of said conditions is that the mobile station supports the second type of modulation, but downlink conditions restrict the use of the second type of modulation.

5. A method as in claim 1, wherein an uplink data rate is caused to differ from a downlink data rate in order to at least one of reduce a power consumption of the mobile station, or to reduce an amount of interference in the downlink direction.

6. A method as in claim 1, wherein for any of the plurality of conditions the same L3 protocol is applied for data transmission in both the downlink and the uplink.

7. A method as in claim 1, wherein one of the modulation types is 8-PSK modulation, wherein another of the modulation types is GMSK modulation, and wherein the uplink and the downlink operate with the same or with different data rates.

8. A method as in claim 1, wherein the mobile station indicates to the network in a message that the second type of modulation is supported for both uplink transmission and downlink reception, or that the second type of modulation is supported for downlink reception only.

9. A method as in claim 8, wherein the message is Classmark_Change message.

10. A method as in claim 1, wherein the mobile station explicitly indicates to the network one of the following:

that downlink biased channel coding asymmetry is preferred, that uplink biased channel coding asymmetry is preferred, or that channel coding symmetry preferred.

11. A method as in claim 10, wherein the mobile station explicitly indicates to the network in a message having a Bearer Capability Information Element.

12. A method as in claim 1, wherein the mobile station explicitly indicates to the network one of two conditions for using an additional type of modulation, in addition to a normal type of modulation:

(a) the additional type of modulation is supported for uplink transmission and downlink reception;

or (b) the additional type of modulation is supported for downlink reception only.

13. A method as in claim 12, wherein the mobile station explicitly indicates to the network the one of the two conditions in a Classmark_Change message.

14. A method as in claim 1, wherein the mobile station explicitly indicates to the network a preference for asymmetric service using a first bit and a second bit in an Information Element.

15. A method as in claim 14, wherein the Information Element is a Bearer Capability Information Element.

16. A method as in claim 14, wherein the Information Element is a Bearer Capability Information Element in a Setup message.

17. A method as in claim 14, wherein the Information Element is sent in a WAIUR (Wanted Air Interface User Rate) message.

18. A method as in claim 1, wherein the mobile station explicitly indicates to the network a preference for one of asymmetric service or symmetric service using a first bit and a second bit in an Information Element as follows:

19. A method as in claim 18, wherein if both the first and the second bits are set, the network interprets the Information Element as specifying that channel coding symmetry preferred.

20. A method as in claim 1, and comprising a further step of switching to an asymmetric service during a call that was initiated as a symmetric call.

21. A method as in claim 20, wherein the mobile station explicitly indicates to the network a preference for switching to the asymmetric service using a first bit and a second bit in an Information Element as follows:

22. A method as in claim 21, wherein the Information Element is a Bearer Capability Information Element.

23. A method as in claim 1, and comprising a further step of switching to a symmetric service during a call that was initiated as an asymmetric call.

24. A method as in claim 23, wherein the mobile station explicitly indicates to the network a preference for switching to the symmetric service using a first bit and a second bit in an Information Element.

25. A method as in claim 24, wherein the Information Element is a Bearer Capability Information Element.

26. A digital wireless communication system that supports digital data communications and that operates with a first type of modulation between a mobile station and a wireless network, comprising:

a wireless interface for bidirectionally coupling the mobile station to the network; and

control circuitry operable

(a) in a first case for applying a second, different type of modulation in a downlink direction from the network to the mobile station unless at least one of a plurality of conditions are found to apply, while

(b) in a second case, applying a second, different type of modulation in an uplink direction from the mobile station to the network unless one of the plurality of conditions are found to apply,

wherein one of said conditions is that the second type of modulation is supported in the network, but is not supported in both directions by the mobile station.

27. A system as in claim 26, wherein another one of said conditions is that a user specifically requests one of a downlink biased data link service or an uplink biased data link service, which is also used by the mobile station in the uplink or the downlink, respectively, and at least the modulation type of which is detected by the network from received uplink mobile station transmissions, and wherein another one of said conditions is that the mobile station supports the second type of modulation, but either uplink or downlink conditions restrict the use of the second type of modulation.

28. A method as in claim 26, wherein for any of the plurality of conditions the same L3 protocol is applied for data transmission in both the downlink and the uplink.

29. A system as in claim 26, wherein one of the modulation types is 8-PSK modulation, and wherein another of the modulation types is GMSK modulation.

30. A system as in claim 26, wherein the mobile station explicitly indicates to the network in a Information Element that the second type of modulation is supported for both uplink transmission and downlink reception, or that the second type of modulation is supported for downlink reception only, and further explicitly indicates to the network that downlink biased channel coding asymmetry is preferred, or that uplink biased channel coding asymmetry is preferred, or that channel coding symmetry preferred.

31. A system as in claim 26, wherein said control circuitry switches to an asymmetric service during a call that was initiated as a symmetric call, or switches to a symmetric service during a call that was initiated as an asymmetric call.

32. A method for supporting data transmission services in a digital wireless communication system, comprising steps of:

bidirectionally coupling a mobile station to the network through a radio interface; and

explicitly signaling to the network a preference for one of asymmetric service or symmetric service using predetermined bits in an Information Element,

wherein the mobile station explicitly signals to the network one of two conditions for using a different type of modulation than a normal type of modulation;

(a) the additional type of modulation is supported for uplink transmission and downlink reception;

or (b) the additional type of modulation is supported for downlink reception only.

33. A method as in claim 32, wherein the Information Element is a Bearer Capability Information Element.

34. A method as in claim 32, wherein the Information Element is a Bearer Capability Information Element in a Setup message.

35. A method as in claim 32, wherein the mobile station explicitly signals to the network a preference for asymmetric service or symmetric service using a first bit and a second bit in an Information Element as follows:

36. A method as in claim 35, wherein if both the first and the second bits are set, the network interprets the Information Element as specifying that channel coding symmetry preferred.

37. A method as in claim 32, wherein implicit signalling is used to cause an uplink data rate to differ from a downlink data rate in order to at least one of reduce power consumption of the mobile station, or to reduce an amount of interference in the downlink direction.

38. A method as in claim 32, wherein implicit signalling is based on range considerations.