Handover signaling in wireless networks

• US 10,568,085 B2
• Filed: 03/05/2018
• Issued: 02/18/2020
• Est. Priority Date: 12/04/2011
• Status: Active Grant

• Current Assignee: Comcast Cable Communications LLC (Comcast Corporation)
• Original Assignee: Comcast Cable Communications LLC (Comcast Corporation)
• Inventors: Dinan, Esmael Hejazi
• Primary Examiner(s): Chou, Albert T
• Application Number:
  US15/912,080
• Publication Number:
  US 20180359732A1
• Time in Patent Office: 715 Days
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 36/0005 Control or signalling for completing the hand-off
• CPC Class Codes: H04W 36/0072 of resource information of target access point
• CPC Class Codes: H04W 36/06 Reselecting a communication resource in the serving access point
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

A base station and a wireless device may communicate with one another regarding carrier types that may differ based on the presence or absence of certain reference signals. The communication may be, for example, related to a handover decision.

Claims

1. A method comprising:

receiving, by a second base station and prior to handover of a wireless device from a first base station, a handover request comprising an indication of at least one carrier type supported by the wireless device;

transmitting, by the second base station, to the first base station, and after receiving the handover request, at least one message comprising configuration information for communications between the wireless device and the second base station, wherein the configuration information comprises;

an identifier of a carrier of a first carrier type; and

an identifier of a carrier of a second carrier type,

wherein the carrier of the first carrier type comprises a reference signal in every downlink subframe of a plurality of downlink subframes, and

wherein the carrier of the second carrier type is without a reference signal in at least one downlink subframe of the plurality of downlink subframes; and

transmitting, by the second base station, to the wireless device, and employing the carrier of the first carrier type and the carrier of the second carrier type, information.

2. The method of claim 1, wherein the carrier of the second carrier type is without the reference signal, in the at least one downlink subframe, based on data being transmitted in fewer than all downlink subframes of the plurality of downlink subframes.

3. The method of claim 1, wherein the carrier of the second carrier type selectively comprises a reference signal based on data being transmitted in one or more of the plurality of downlink subframes.

4. The method of claim 1, wherein the carrier of the second carrier type supports fewer transmission modes than the carrier of the first carrier type.

5. The method of claim 1, wherein the carrier of the second carrier type employs a wireless-device-specific demodulation reference signal.

6. The method of claim 1, further comprising causing a downlink subframe, of the second carrier type, to become empty.

7. The method of claim 1, wherein the carrier of the second carrier type comprises a second downlink subframe in which a control channel is configured to start at a symbol after a first symbol in the second downlink subframe.

8. The method of claim 7, wherein in the second downlink subframe, no reference signal is transmitted between the first symbol in the second downlink subframe and the control channel in the second downlink subframe.

9. The method of claim 1, wherein transmitting the information comprise transmitting at least one of:

data;

configuration;

or

a message.

10. A second base station comprising:

one or more processors; and

memory storing instructions that, when executed by the one or more processors, cause the second base station to;

receive, prior to handover of a wireless device from a first base station, a handover request comprising an indication of at least one carrier type supported by the wireless device;

transmit, to the first base station and after receiving the handover request, at least one message comprising configuration information for communications between the wireless device and the second base station, wherein the configuration information comprises;

an identifier of a carrier of a first carrier type; and

an identifier of a carrier of a second carrier type,

wherein the carrier of the first carrier type comprises a reference signal in every downlink subframe of a plurality of downlink subframes, and

wherein the carrier of the second carrier type is without a reference signal in at least one downlink subframe of the plurality of downlink subframes; and

transmit, to the wireless device and employing the carrier of the first carrier type and the carrier of the second carrier type, information.

11. The second base station of claim 10, wherein the carrier of the second carrier type is without the reference signal, in the at least one downlink subframe, based on data being transmitted in fewer than all downlink subframes of the plurality of downlink subframes.

12. The second base station of claim 10, wherein the carrier of the second carrier type selectively comprises a reference signal based on data being transmitted in one or more of the plurality of downlink subframes.

13. The second base station of claim 10, wherein the carrier of the second carrier type supports fewer transmission modes than the carrier of the first carrier type.

14. The second base station of claim 10, wherein the carrier of the second carrier type employs a wireless-device-specific demodulation reference signal.

15. The second base station of claim 10, wherein the instructions, when executed by the one or more processors, further cause a downlink subframe, of the second carrier type, to become empty.

16. The second base station of claim 10, wherein the carrier of the second carrier type comprises a second downlink subframe in which a control channel is configured to start at a symbol after a first symbol in the second downlink subframe.

17. The second base station of claim 16, wherein in the second downlink subframe, no reference signal is transmitted between the first symbol in the second downlink subframe and the control channel in the second downlink subframe.

18. The second base station of claim 10, wherein the instructions, when executed by the one or more processors, cause the second base station to transmit the information by transmitting:

date;

configuration information;

or

a message.

19. A system comprising:

a first base station and a second base station,

wherein the first base station comprises;

one or more processors; and

memory storing instructions that, when executed by the one or more processors of the first base station, cause the first base station to transmit a handover request comprising an indication of at least one carrier type supported by a wireless device, and

wherein the second base station comprises;

one or more processors; and

memory storing instructions that, when executed by the one or more processors of the second base station, cause the second base station to;

receive, prior to handover of the wireless device from the first base station, the handover request;

transmit, to the first base station and after receiving the handover request, at least one message comprising configuration information for communications between the wireless device and the second base station, wherein the configuration information comprises;

an identifier of a carrier of a first carrier type; and

an identifier of a carrier of a second carrier type,

wherein the carrier of the first carrier type comprises a reference signal in every downlink subframe of a plurality of downlink subframes, and

wherein the carrier of the second carrier type is without a reference signal in at least one downlink subframe of the plurality of downlink subframes; and

transmit, to the wireless device and employing the carrier of the first carrier type and the carrier of the second carrier type, information.

20. The system of claim 19, wherein the carrier of the second carrier type is without the reference signal, in the at least one downlink subframe, based on data being transmitted in fewer than all downlink subframes of the plurality of downlink subframes.

21. The system of claim 19, wherein the carrier of the second carrier type selectively comprises a reference signal based on data being transmitted in one or more of the plurality of downlink subframes.

22. The system of claim 19, wherein the carrier of the second carrier type supports fewer transmission modes than the carrier of the first carrier type.

23. The system of claim 19, wherein the carrier of the second carrier type employs a wireless-device-specific demodulation reference signal.

24. The system of claim 19, wherein the instructions in the memory of the second base station, when executed by the one or more processors of the second base station, further cause a downlink subframe, of the second carrier type, to become empty.

25. The system of claim 19, wherein the carrier of the second carrier type comprises a second downlink subframe in which a control channel is configured to start at a symbol after a first symbol in the second downlink subframe.

26. The system of claim 25, wherein in the second downlink subframe, no reference signal is transmitted between the first symbol in the second downlink subframe and the control channel in the second downlink subframe.

27. The system of claim 19, wherein the instructions in the memory of the second base station, when executed by the one or more processors of the second base station, cause the second base station to transmit the information by transmitting:

data;

configuration information;

or

a message.

28. A method comprising:

transmitting, by a wireless device and to a first base station, a message indicating at least one type of carrier supported by the wireless device;

receiving, from the first base station, configuration information corresponding to a second base station, wherein the configuration information indicates that the second base station supports;

a carrier of a first carrier type; and

a carrier of a second carrier type,

wherein the carrier of the first carrier type comprises a reference signal in every downlink subframe of a plurality of downlink subframes, and

wherein the carrier of the second carrier type is without a reference signal in at least one downlink subframe of the plurality of downlink subframes; and

communicating with the second base station employing the carrier of the first carrier type and the carrier of the second carrier type.

29. The method of claim 28, wherein the carrier of the second carrier type is without the reference signal, in the at least one downlink subframe, based on data being transmitted in fewer than all downlink subframes of the plurality of downlink subframes.

30. The method of claim 28, wherein the carrier of the second carrier type selectively comprises a reference signal based on data being transmitted in one or more of the plurality of downlink subframes.

31. The method of claim 28, wherein the carrier of the second carrier type supports fewer transmission modes than the carrier of the first carrier type.

32. The method of claim 28, wherein the carrier of the second carrier type employs a wireless-device-specific demodulation reference signal.

33. The method of claim 28, wherein the carrier of the second carrier type comprises a second downlink subframe in which a control channel is configured to start at a symbol after a first symbol in the second downlink subframe.

34. The method of claim 33, wherein in the second downlink subframe, no reference signal is transmitted between the first symbol in the second downlink subframe and the control channel in the second downlink subframe.

35. A wireless device comprising:

one or more processors; and

memory storing instructions that, when executed by the one or more processors, cause the wireless device to;

transmit, to a first base station, a message indicating at least one type of carrier supported by the wireless device;

receive, from the first base station, configuration information corresponding to a second base station, wherein the configuration information indicates that the second base station supports;

a carrier of a first carrier type; and

a carrier of a second carrier type,

wherein the carrier of the first carrier type comprises a reference signal in every downlink subframe of a plurality of downlink subframes, and

wherein the carrier of the second carrier type is without a reference signal in at least one downlink subframe of the plurality of downlink subframes; and

communicate with the second base station employing the carrier of the first carrier type and the carrier of the second carrier type.

36. The wireless device of claim 35, wherein the carrier of the second carrier type is without the reference signal, in the at least one downlink subframe, based on data being transmitted in fewer than all downlink subframes of the plurality of downlink subframes.

37. The wireless device of claim 35, wherein the carrier of the second carrier type selectively comprises a reference signal based on data being transmitted in one or more of the plurality of downlink subframes.

38. The wireless device of claim 35, wherein the carrier of the second carrier type supports fewer transmission modes than the carrier of the first carrier type.

39. The wireless device of claim 35, wherein the carrier of the second carrier type employs a wireless-device-specific demodulation reference signal.

40. The wireless device of claim 35, wherein the carrier of the second carrier type comprises a second downlink subframe in which a control channel is configured to start at a symbol after a first symbol in the second downlink subframe.

41. The wireless device of claim 40, wherein in the second downlink subframe, no reference signal is transmitted between the first symbol in the second downlink subframe and the control channel in the second downlink subframe.

42. A system comprising:

a wireless device and a first base station,

wherein the wireless device comprises;

one or more processors; and

memory storing instructions that, when executed by the one or more processors of the wireless, cause the wireless device to;

transmit, to the first base station, a message indicating at least one type of carrier supported by the wireless device;

receive, from the first base station, configuration information corresponding to a second base station, wherein the configuration information indicates that the second base station supports;

a carrier of a first carrier type; and

a carrier of a second carrier type,

wherein the carrier of the first carrier type comprises a reference signal in every downlink subframe of a plurality of downlink subframes, and

wherein the carrier of the second carrier type is without a reference signal in at least one downlink subframe of the plurality of downlink subframes; and

communicate with the second base station employing the carrier of the first carrier type and the carrier of the second carrier type, and

wherein the first base station comprises;

one or more processors; and

memory storing instructions that, when executed by the one or more processors of the first base station, cause the first base station to receive the message indicating the at least one type of carrier supported by the wireless device.

43. The system of claim 42, wherein the carrier of the second carrier type is without the reference signal, in the at least one downlink subframe, based on data being transmitted in fewer than all downlink subframes of the plurality of downlink subframes.

44. The system of claim 42, wherein the carrier of the second carrier type selectively comprises a reference signal based on data being transmitted in one or more of the plurality of downlink subframes.

45. The system of claim 42, wherein the carrier of the second carrier type supports fewer transmission modes than the carrier of the first carrier type.

46. The system of claim 42, wherein the carrier of the second carrier type employs a wireless-device-specific demodulation reference signal.

47. The system of claim 42, wherein the carrier of the second carrier type comprises a second downlink subframe in which a control channel is configured to start at a symbol after a first symbol in the second downlink subframe.

48. The system of claim 47, wherein in the second downlink subframe, no reference signal is transmitted between the first symbol in the second downlink subframe and the control channel in the second downlink subframe.