Cellular Communication System Support for Limited Bandwidth Communication Devices

• US 20120327894A1
• Filed: 02/16/2012
• Published: 12/27/2012
• Est. Priority Date: 06/27/2011
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Bengt Lindoff, Erik Eriksson, Joakim Axmon, Leif Wilhelmsson, Wallén, Anders
• Inventors: Axmon, Joakim, Eriksson, Erik, Lindoff, Bengt, Wallén, Anders, Wilhelmsson, Leif
• Granted Patent: US 8,848,638 B2
• Time in Patent Office: Days
• US Class Current: 370/330
• CPC Class Codes: H04L 5/00 Arrangements affording multiple use of the transmission path
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 72/53 based on regulatory allocation policies

Abstract

A network node that serves a host cell in a cellular communication system transmits, at (a) first time interval(s), first control channel information on a control channel that extends over a first bandwidth of a radiofrequency spectrum. The first control channel communicates information necessary to enable a first type of communication device to receive data from the host cell. The first type of communication device can receive first bandwidth-wide signals. At (a) second time interval(s), second control channel information is transmitted on a second control channel of a first M-cell. The second control channel occupies a second bandwidth that is smaller than the first bandwidth. The second time interval(s) do(es) not coincide with any of the first time interval(s). A second type of communication device having reduced receive bandwidth capabilities compared to those of the first type of communication device is thereby made capable of being served by the node.

Claims

1. A method of operating a network node that serves a host cell in a cellular communication system, the method comprising:

at one or more first time intervals, transmitting first control channel information on a control channel that extends over a first bandwidth of a radiofrequency spectrum, wherein the first control channel communicates information that is necessary to enable a first type of communication device to receive data from the host cell, the first type of communication device being capable of receiving a signal having the first bandwidth of the radiofrequency spectrum; and

at one or more second time intervals, transmitting second control channel information on a second control channel of a first M-cell, wherein the second control channel occupies a second bandwidth of the radiofrequency spectrum, and wherein the second bandwidth is smaller than the first bandwidth, and wherein the one or more second time intervals do not coincide with any of the one or more first time intervals, whereby a second type of communication device having reduced receive bandwidth capabilities compared to those of the first type of communication device is made capable of being served by the network node.

2. The method of claim 1, wherein the second bandwidth of the radiofrequency spectrum is frequency-wise located within a frequency-wise location of the first bandwidth of the radiofrequency spectrum.

3. The method of claim 1, comprising transmitting information to the second type of communication device, wherein the information informs what the one or more second time intervals are.

4. The method of claim 1, comprising transmitting information to the second type of communication device, wherein the information informs on what part of the radiofrequency spectrum the second bandwidth of the radiofrequency spectrum is located.

5. The method of claim 4, wherein the information that informs on what part of the radiofrequency spectrum the second bandwidth of the radiofrequency spectrum is located is transmitted on a channel that occupies a third bandwidth of the radiofrequency spectrum, wherein the third bandwidth is smaller than the first bandwidth, and wherein a frequency-wise location of the second bandwidth of the radiofrequency spectrum differs from a frequency-wise location of the third bandwidth of the radiofrequency spectrum.

6. The method of claim 1, wherein an air interface of the cellular communication system is divided up into sequentially occurring frames, each of the frames comprising a plurality of sequentially occurring subframes, and wherein the one or more first time intervals occur at one or more subframes within a frame, and wherein the one or more second time intervals occur at one or more different subframes within the frame, wherein the one or more different subframes are not used for transmitting any information on the control channel that extends over the first bandwidth of the radiofrequency spectrum.

7. The method of claim 6, wherein the second control channel information transmitted in one of the one or more different subframes within the frame indicates one or more time intervals and/or frequencies within the one of the one or more different subframes that are used as respective one or more downlink physical data channels for the second type of communication device.

8. The method of claim 6, wherein the second control channel information transmitted in one of the one or more different subframes within the frame indicates one or more time intervals and/or frequencies within a later one of the one or more different subframes that are used as respective one or more downlink physical data channels for the second type of communication device.

9. The method of claim 6, comprising sending a signal to the first type of communication device that results in the first type of communication device not attempting to receive the first control channel during the one or more different subframes.

10. The method of claim 1, wherein:

an air interface of the cellular communication system is divided up into sequentially occurring frames, each of the frames comprising a plurality of sequentially occurring subframes;

the one or more first time intervals occur during one or more subframes within a frame;

the one or more second time intervals occur at different times within the one or more subframes within the frame; and

none of the one or more first time intervals coincides with any of the one or more second time intervals.

11. The method of claim 1, comprising transmitting system information that informs the second type of communication device of one or more of:

random access parameters for use when accessing a random access channel of the first M-cell;

a subframe pattern of M-cells, wherein each M-cell associated with the subframe pattern is a reserved portion of the radiofrequency spectrum having the second bandwidth;

a subframe pattern of host cells; and

information from which the subframe pattern of host cells can be deduced.

12. The method of claim 1, comprising:

receiving a random access transmission; and

ascertaining that the random access transmission came from the second type of communication device and in response thereto, enabling the second type of communication device to locate an M-cell by sending information to the second type of communication device that identifies a time- and/or frequency-wise location of the second bandwidth of the radiofrequency spectrum.

13. The method of claim 1, comprising:

at one or more third time intervals, transmitting third control channel information on a third control channel of the first M-cell, wherein the third control channel information is intended for receipt by the second type of communication device, and wherein the one or more third time intervals do not coincide with any of the one or more first time intervals or any of the one or more second time intervals.

14. The method of claim 13, wherein an air interface of the cellular communication system is divided up into sequentially occurring frames, each of the frames comprising a plurality of sequentially occurring subframes, and wherein the one or more second time intervals occur at one or more subframes within a frame, and wherein the one or more third time intervals occur at one or more different time intervals within the subframe.

15. The method of claim 13, wherein an air interface of the cellular communication system is divided up into sequentially occurring frames, each of the frames comprising a plurality of sequentially occurring subframes, and wherein the one or more second time intervals occur at one or more subframes within a frame, and wherein the one or more third time intervals occur at one or more different time intervals within a different subframe within the frame.

16. The method of claim 1, wherein:

an air interface of the cellular communication system is divided up into sequentially occurring frames, each of the frames comprising a plurality of sequentially occurring subframes;

the one or more second time intervals occur during one or more subframes within a frame; and

the method comprises;

at one or more third time intervals, transmitting third control channel information on a third control channel of a second M-cell, wherein the third control channel occupies a third bandwidth of the radiofrequency spectrum, and wherein the third bandwidth is smaller than the first bandwidth, and wherein the one or more third time intervals occur during the one or more subframes within the frame and coincide with one or more of the second time intervals, whereby a different second type of communication device having reduced receive bandwidth capabilities compared to those of the first type of communication device is made capable of being served by the network node,

wherein a frequency-wise location of the second bandwidth of the radiofrequency spectrum does not overlap a frequency-wise location of the third bandwidth of the radiofrequency spectrum.

17. The method of claim 1, comprising:

using a first hybrid automatic repeat request (HARQ) protocol when communicating with the first type of communication device; and

using a second HARQ protocol when communicating with the second type of communication device,

wherein one or more timing requirements of the first HARQ protocol is/are different from one or more timing requirements of the second HARQ protocol.

18. The method of claim 1, comprising transmitting information that identifies capabilities related to the second type of communication device that the host cell supports.

19. A method of controlling a communication device in a cellular communication system, wherein the communication device has radio equipment that operates on no more than a predefined bandwidth of a radiofrequency spectrum, the method comprising:

operating the radio equipment to perform a cell search procedure in a first region of the radiofrequency spectrum, wherein the first region has a bandwidth that is no greater than the predefined bandwidth;

after finding a cell in the cellular communication system, tuning the radio equipment to cause the radio equipment to operate in a second region of the radiofrequency spectrum, wherein the second region has a bandwidth that is no greater than the predefined bandwidth;

while tuned to the second region of the radiofrequency spectrum, operating the radio equipment to receive system information being transmitted by the cellular communication system; and

tuning the radio equipment to cause the radio equipment to operate in a third region of the radiofrequency spectrum, wherein at least one of the second and third regions of the radiofrequency spectrum is different than the first region of the radio frequency spectrum.

20. The method of claim 19, wherein after finding the cell in the cellular communication system, tuning the radio equipment to cause the radio equipment to operate in the second region of the radiofrequency spectrum comprises:

receiving information transmitted in the first region of the radiofrequency spectrum, wherein the information directly or indirectly informs the communication device about a frequency-wise location of the second region; and

tuning the radio equipment to cause the radio equipment to operate in the second region of the radiofrequency spectrum.

21. The method of claim 20, wherein the information additionally directly or indirectly informs the communication device about when the system information will be transmitted by the cellular communication system.

22. The method of claim 19, wherein the first and second regions of the radiofrequency spectrum are both located within a region of the radiofrequency spectrum that is allocated for use by the cellular communication system.

23. An apparatus for operating a network node that serves a host cell in a cellular communication system, the apparatus comprising:

circuitry configured to transmit, at one or more first time intervals, first control channel information on a control channel that extends over a first bandwidth of a radiofrequency spectrum, wherein the first control channel communicates information that is necessary to enable a first type of communication device to receive data from the host cell, the first type of communication device being capable of receiving a signal having the first bandwidth of the radiofrequency spectrum; and

circuitry configured to transmit, at one or more second time intervals, second control channel information on a second control channel of a first M-cell, wherein the second control channel occupies a second bandwidth of the radiofrequency spectrum, and wherein the second bandwidth is smaller than the first bandwidth, and wherein the one or more second time intervals do not coincide with any of the one or more first time intervals, whereby a second type of communication device having reduced receive bandwidth capabilities compared to those of the first type of communication device is made capable of being served by the network node.

24. The apparatus of claim 23, wherein the second bandwidth of the radiofrequency spectrum is frequency-wise located within a frequency-wise location of the first bandwidth of the radiofrequency spectrum.

25. The apparatus of claim 23, comprising circuitry configured to transmit information to the second type of communication device, wherein the information informs what the one or more second time intervals are.

26. The apparatus of claim 23, comprising circuitry configured to transmit information to the second type of communication device, wherein the information informs on what part of the radiofrequency spectrum the second bandwidth of the radiofrequency spectrum is located.

27. The apparatus of claim 26, wherein the information that informs on what part of the radiofrequency spectrum the second bandwidth of the radiofrequency spectrum is located is transmitted on a channel that occupies a third bandwidth of the radiofrequency spectrum, wherein the third bandwidth is smaller than the first bandwidth, and wherein a frequency-wise location of the second bandwidth of the radiofrequency spectrum differs from a frequency-wise location of the third bandwidth of the radiofrequency spectrum.

28. The apparatus of claim 23, wherein an air interface of the cellular communication system is divided up into sequentially occurring frames, each of the frames comprising a plurality of sequentially occurring subframes, and wherein the one or more first time intervals occur at one or more subframes within a frame, and wherein the one or more second time intervals occur at one or more different subframes within the frame, wherein the one or more different subframes are not used for transmitting any information on the control channel that extends over the first bandwidth of the radiofrequency spectrum.

29. The apparatus of claim 28, wherein the second control channel information transmitted in one of the one or more different subframes within the frame indicates one or more time intervals and/or frequencies within the one of the one or more different subframes that are used as respective one or more downlink physical data channels for the second type of communication device.

30. The apparatus of claim 28, wherein the second control channel information transmitted in one of the one or more different subframes within the frame indicates one or more time intervals and/or frequencies within a later one of the one or more different subframes that are used as respective one or more downlink physical data channels for the second type of communication device.

31. The apparatus of claim 28, comprising circuitry configured to send a signal to the first type of communication device that results in the first type of communication device not attempting to receive the first control channel during the one or more different subframes.

32. The apparatus of claim 23, wherein:

an air interface of the cellular communication system is divided up into sequentially occurring frames, each of the frames comprising a plurality of sequentially occurring subframes;

the one or more first time intervals occur during one or more subframes within a frame;

the one or more second time intervals occur at different times within the one or more subframes within the frame; and

none of the one or more first time intervals coincides with any of the one or more second time intervals.

33. The apparatus of claim 23, comprising circuitry configured to transmit system information that informs the second type of communication device of one or more of:

random access parameters for use when accessing a random access channel of the first M-cell;

a subframe pattern of M-cells, wherein each M-cell associated with the subframe pattern is a reserved portion of the radiofrequency spectrum having the second bandwidth;

a subframe pattern of host cells; and

information from which the subframe pattern of host cells can be deduced.

34. The apparatus of claim 23, comprising:

circuitry configured to receive a random access transmission; and

circuitry configured to ascertain that the random access transmission came from the second type of communication device and in response thereto, to enable the second type of communication device to locate an M-cell by sending information to the second type of communication device that identifies a time- and/or frequency-wise location of the second bandwidth of the radiofrequency spectrum.

35. The apparatus of claim 23, comprising:

circuitry configured to transmit, at one or more third time intervals, third control channel information on a third control channel of the first M-cell, wherein the third control channel information is intended for receipt by the second type of communication device, and wherein the one or more third time intervals do not coincide with any of the one or more first time intervals or any of the one or more second time intervals.

36. The apparatus of claim 35, wherein an air interface of the cellular communication system is divided up into sequentially occurring frames, each of the frames comprising a plurality of sequentially occurring subframes, and wherein the one or more second time intervals occur at one or more subframes within a frame, and wherein the one or more third time intervals occur at one or more different time intervals within the subframe.

37. The apparatus of claim 35, wherein an air interface of the cellular communication system is divided up into sequentially occurring frames, each of the frames comprising a plurality of sequentially occurring subframes, and wherein the one or more second time intervals occur at one or more subframes within a frame, and wherein the one or more third time intervals occur at one or more different time intervals within a different subframe within the frame.

38. The apparatus of claim 23, wherein:

an air interface of the cellular communication system is divided up into sequentially occurring frames, each of the frames comprising a plurality of sequentially occurring subframes;

the one or more second time intervals occur during one or more subframes within a frame; and

the apparatus comprises;

circuitry configured to transmit, at one or more third time intervals, third control channel information on a third control channel of a second M-cell, wherein the third control channel occupies a third bandwidth of the radiofrequency spectrum, and wherein the third bandwidth is smaller than the first bandwidth, and wherein the one or more third time intervals occur during the one or more subframes within the frame and coincide with one or more of the second time intervals, whereby a different second type of communication device having reduced receive bandwidth capabilities compared to those of the first type of communication device is made capable of being served by the network node,

wherein a frequency-wise location of the second bandwidth of the radiofrequency spectrum does not overlap a frequency-wise location of the third bandwidth of the radiofrequency spectrum.

39. The apparatus of claim 23, comprising:

circuitry configured to use a first hybrid automatic repeat request (HARQ) protocol when communicating with the first type of communication device; and

circuitry configured to use a second HARQ protocol when communicating with the second type of communication device,

wherein one or more timing requirements of the first HARQ protocol is/are different from one or more timing requirements of the second HARQ protocol.

40. The apparatus of claim 23, comprising circuitry configured to transmit information that identifies capabilities related to the second type of communication device that the host cell supports.

41. An apparatus for controlling a communication device in a cellular communication system, wherein the communication device has radio equipment that operates on no more than a predefined bandwidth of a radiofrequency spectrum, the apparatus comprising:

circuitry configured to operate the radio equipment to perform a cell search procedure in a first region of the radiofrequency spectrum, wherein the first region has a bandwidth that is no greater than the predefined bandwidth;

circuitry configured to tune the radio equipment after finding a cell in the cellular communication system, wherein the tuning causes the radio equipment to operate in a second region of the radiofrequency spectrum, wherein the second region has a bandwidth that is no greater than the predefined bandwidth;

circuitry configured to, while tuned to the second region of the radiofrequency spectrum, operate the radio equipment to receive system information being transmitted by the cellular communication system; and

circuitry configured to tune the radio equipment to cause the radio equipment to operate in a third region of the radiofrequency spectrum, wherein at least one of the second and third regions of the radiofrequency spectrum is different than the first region of the radio frequency spectrum.

42. The apparatus of claim 41, wherein the circuitry configured to tune the radio equipment to cause the radio equipment to operate in the second region of the radiofrequency spectrum comprises circuitry configured to perform, after finding the cell in the cellular communication system, the following:

receiving information transmitted in the first region of the radiofrequency spectrum, wherein the information directly or indirectly informs the communication device about a frequency-wise location of the second region; and

tuning the radio equipment to cause the radio equipment to operate in the second region of the radiofrequency spectrum.

43. The apparatus of claim 42, wherein the information additionally directly or indirectly informs the communication device about when the system information will be transmitted by the cellular communication system.

44. The apparatus of claim 41, wherein the first and second regions of the radiofrequency spectrum are both located within a region of the radiofrequency spectrum that is allocated for use by the cellular communication system.