Communications Method, Particularly For a Mobile Radio Network

• US 20080145056A1
• Filed: 10/25/2004
• Published: 06/19/2008
• Est. Priority Date: 10/25/2004
• Status: Active Grant

• Current Assignee: Telecom Italia S.p.A.
• Original Assignee: Telecom Italia S.p.A.
• Inventors: Rossaro, Alberto, Gabba, Sara, Boldi, Mauro, Quasso, Roberto
• Granted Patent: US 8,855,489 B2
• Time in Patent Office: Days
• US Class Current: 398/96
• CPC Class Codes: H04J 14/0226 Fixed carrier allocation, e.g. according to service
• CPC Class Codes: H04J 14/0227 Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
• CPC Class Codes: H04J 14/0246 using one wavelength per ONU
• CPC Class Codes: H04J 14/0247 Sharing one wavelength for at least a group of ONUs
• CPC Class Codes: H04J 14/025 using one wavelength per ONU, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0252 Sharing one wavelength for at least a group of ONUs, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
• CPC Class Codes: H04J 14/0283 WDM ring architectures

Abstract

Communications method between a main station and processing nodes includes interconnecting the main station and the nodes in an optical path defining adjacent nodes and non-adjacent nodes, operatively grouping the nodes in a plurality of distinct sub-groups, each formed by non-adjacent nodes, at least one of said sub-groups including at least two nodes generating at the main station a multiplexed optical signal propagating along the path for serving the nodes, the multiplexed optical signal including a plurality of optical channel signals having a respective plurality of distinct carrier wavelengths, each carrier wavelength being associated with a respective sub-group of nodes, and serving each node of each sub-group of nodes with a respective portion of the optical channel signal having the associated carrier wavelength.

Claims

1-32. -32. (canceled)

33. A communications method between a main station and processing nodes, comprising:

interconnecting said main station and said nodes in an optical path defining adjacent nodes and non-adjacent nodes;

operatively grouping said nodes in a plurality of distinct sub-groups each formed by non-adjacent nodes, at least one of said sub-groups including at least two nodes;

generating at the main station a multiplexed optical signal propagating along said path for serving the nodes, said multiplexed optical signal comprising a plurality of optical channel signals having a respective plurality of distinct carrier wavelengths, each carrier wavelength being associated with a respective sub-group of nodes; and

serving each node of each sub-group of nodes with a respective portion of the optical channel signal having the associated carrier wavelength.

34. The communications method according to claim 33, further comprising, at each node, processing at least an optical power of the optical channel signal having the associated carrier wavelength.

35. The communications method according to claim 34, wherein the processing of the optical power comprises:

optically-to-electrically converting said optical channel signal to obtain a digital electric signal;

electrically processing the digital electric signal, and

electrically-to-optically converting a signal resulting from the electrical processing.

36. The communications method according to claim 35, wherein said electrically processing of the digital electric signal comprises electrically amplifying and re-shaping the digital electric signal.

37. The communications method according to claim 36, wherein said electrically processing and said electrically-to-optically converting are time-locked to said digital electric signal.

38. The communications method according to claim 33, wherein said optical path comprises optical links coupling pairs of adjacent nodes, said optical links being of the passive type.

39. The communications method according to claim 38, wherein said optical links comprise optical fibres.

40. The communications method according to claim 33, wherein the main station and the processing nodes are in a mobile radio communications system and each of said processing nodes is adapted to generate and receive radio signals serving at least a sector of a cell site of the mobile radio communications system.

41. The communications method according to claim 33, wherein each optical channel signal carries sub-data streams each destined to a corresponding node of the respective sub-group, the sub-data streams being organized according to a time division multiplexing technique.

42. The communications method according to claim 41 wherein the propagating of said multiplexed signal comprises:

generating a first optical channel signal having a first carrier wavelength and associated with a first sub-group of nodes, said first channel signal being associated with a first electrical digital signal comprising a plurality of sub-data streams, each node of the first sub-group being associated with at least one corresponding sub-data stream; and

sending said first channel signal together with the other channel signals on said optical path.

43. The communications method according to claim 42, wherein the serving of each node of each sub-group of nodes comprises:

processing at a first node, included in the first sub-group, the first channel signal for extracting a first sub-data stream;

generating from said extracted first sub-data stream a corresponding first downlink radio signal to be radiated; and

radiating said corresponding first downlink radio signal.

44. The communications method according to claim 43, wherein said processing at the first node further comprises:

receiving the multiplexed signal at an optical input of said first node;

selecting from the multiplexed signal the first optical channel signal;

converting said first optical channel signal in the first electrical signal; and

extracting from the first electrical signal the first sub-data stream to be processed, so as to generate the first downlink radio signal.

45. The method according to claim 44, further comprising:

receiving at an antenna input of said first node a first uplink radio signal;

processing said first uplink radio signal for generating a first uplink sub-data stream;

adding the first uplink sub-data stream to the first electrical signal as resulting from said extracting step for generating a second electrical signal;

converting the second electrical signal in an output optical signal having said first carrier wavelength; and

sending the output optical signal together with the other optical channel signals along said optical path.

46. The method according to claim 42, wherein each sub-data stream comprises a respective identification data for associating the sub-data stream with a corresponding node.

47. The method according to claim 42, wherein said plurality of sub-data streams are organized according to a transport standard-protocol selected from the group:

synchronous digital hierarchy, synchronous optical network, gigabit ethernet, and common public radio interface.

48. The method according to claim 33, wherein said optical path comprises an optical ring.

49. A communications network comprising:

a plurality of processing nodes interconnected in an optical path defining non-adjacent nodes and adjacent nodes; and

a main station connected to said optical path and adapted to generate a multiplexed optical signal to be propagated along said path for serving the nodes, said optical signal comprising a plurality of optical channel signals having a respective plurality of distinct carrier wavelengths;

said nodes being operatively grouped in a plurality of distinct sub-groups each formed by non-adjacent nodes, at least one of said sub-groups comprising at least two nodes, the network being configured so as to serve each sub-group of nodes with a respective portion of the optical channel signal having the associated carrier wavelength.

50. The network according to claim 49, wherein each node comprises a first apparatus adapted to process the optical power of the corresponding optical channel signal serving the respective node.

51. The network according to claim 50, wherein said first apparatus comprises:

an optical-to-electrical converter adapted to convert said optical channel signal to obtain a digital electric signal;

an electrical processing apparatus adapted to process the digital electric signal; and

an electrical-to-optical converter adapted to convert in optical form the signal resulting from the electrical processing apparatus.

52. The network according to claim 51, wherein said optical-to-electrical converter comprises an electrical amplifier and a re-shaping device of the digital electric signal.

53. The network according to claim 51, wherein said electrical processing apparatus and said electrical-to-optical converter are time-locked to said digital electric signal.

54. The network according to claim 49, wherein said optical path comprises optical links coupling each pair of adjacent nodes, said optical links being of the passive type.

55. The network according to claim 54, wherein said optical links comprise optical fibers.

56. The network according to claim 49, wherein the main station and the processing nodes are in a mobile radio communications system and each of said processing nodes is adapted to generate and receive radio signals serving at least a sector of a cell site of the mobile radio communications system.

57. The network according to claim 49, wherein each optical channel signal carries sub-data streams each destined to a corresponding node of the respective sub-group, the sub-data streams being organized according to a time division multiplexing technique.

58. The network according to claim 57, wherein the main station comprises:

equipment adapted to generate a first optical channel signal having a first carrier wavelength and associated with a first sub-group of non adjacent node, said first optical signal carrying information associated with a first electrical digital signal comprising a plurality of sub-data streams each associated with a corresponding node of the first sub-group; and

an optical multiplexer adapted to send said first optical channel signal together with the other optical channel signals on said optical path.

59. The network according to claim 58, wherein said first sub-group comprises a first node comprising:

a second apparatus adapted to process the first optical channel signal and extract a first sub-data stream;

a radio transmitter adapted to generate from the first sub-data stream a corresponding first downlink radio signal to be radiated; and

an antenna for radiating said first downlink radio signal.

64. The network according to claim 59, wherein:

said first node is connected to an output port of the main station by an optical fibre span having a first length, the first carrier wavelength associated with the first node having a first value of fiber attenuation coefficient,

said network comprising at least a second node associated with a further carrier wavelength and connected to the output port of the main station by an optical fibre connection comprising the first span and having a second length greater than the first length, the further carrier wavelength having a second value of fiber attenuation coefficient lower than said first value.

60. The network according to clam 59, wherein the first node further comprises:

an optical input port adapted to receive the multiplexed signal;

an optical add-and-drop device adapted to select from the multiplexed signal the first optical signal;

a first converting device adapted to convert said first optical signal in the first electrical signal; and

an electrical add-and-drop device adapted to extract from the first electrical signal the first sub-data stream to be processed so as to generate the first downlink radio signal.

61. The network according to claim 60, wherein said first node comprises:

a receiver device having an antenna input adapted to receive a first uplink radio signal and process said first uplink radio signal so as to generate a first uplink sub-data stream, the electrical add-and-drop device being adapted to add the first uplink sub-data stream to the first electrical signal so as to generate a second electrical signal;

a second converting device adapted to convert the second electrical signal in an output optical signal having said first carrier wavelength, the optical add-and-drop device being adapted to add the output optical signal to the multiplexed signal and send the multiplexed signal and send the multiplexed signal along said optical path.

62. The network according to claim 61, wherein each sub-data stream comprises respective identification data for associating the sub-data stream with a corresponding processing node.

63. The network according to claim 62, wherein said plurality of sub-data streams are organized according to a transport standard-protocol selected from the group:

synchronous digital hierarchy, synchronous optical network, gigabit ethernet, and common public radio interface.