Apparatus and associated method for communicating multimedia information upon a communication link

• US 6,466,585 B1
• Filed: 04/01/1999
• Issued: 10/15/2002
• Est. Priority Date: 04/01/1999
• Status: Expired due to Term

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Le, Khiem
• Primary Examiner(s): TON, DANG T
• Application Number:
  US09/283,808
• Time in Patent Office: 1,293 Days
• Field of Search: 370/465, 370/466, 370/389, 370/351, 370/352, 370/310, 370/350, 370/503, 370/349, 370/441, 370/442, 370/480, 370/341, 370/342, 370/343, 370/344, 370/345, 370/347, 370/335, 370/337, 370/336, 370/319, 370/320, 370/321, 370/403, 370/402, 370/401, 348/17
• US Class Current: 370/465
• CPC Class Codes: H04L 65/103 in the network
• CPC Class Codes: H04L 65/104 in the network
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1106 Call signalling protocols; H.323 and related
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04L 65/765 intermediate
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network

Abstract

Apparatus, and associated method, converts real-time multimedia information generated pursuant to an RTP protocol into a form amenable for transmission upon a radio channel, such as a radio channel defined in a cellular communication system. When converted, the informational content of the multimedia information is transmitted in a manner that achieves spectral efficiency and low, constant delay. Once transmitted over the radio channel, the multimedia information is converted back into form corresponding to the RTP protocol before being sent to the receiving station.

Claims

1. In a first communication station operable in a radio communication system in which multimedia information is communicated between the first communication station and a second communication station, an improvement of apparatus for converting packet-formatted data, of which the multimedia information is formed, into a radio-link format, amenable for transmission upon a radio link to the second communication station, said apparatus comprising:

a detector for detecting control-plane information associated with the packet-formatted data;

a requester coupled to receive indications of detection by said detector of the control-plane information, said requester for requesting allocation of a special channel defined upon the radio link extending between the first and second communication stations for communication of the multimedia information thereon; and

a format converter coupled to receive the packet-formatted data of which the multimedia information is formed, and responsive to allocation of the special channel requested by said requester, said format converter for converting the packet-formatted data into the radio-link format, thereafter to permit transmission, upon the special channel, of the multimedia information formatted in the radio-link format.

2. The apparatus of claim 1 wherein the indications of the control plane information to which said detector is coupled to receive comprise indications of selective assignation-requests for logical channels upon which to transmit the multimedia information.

3. The apparatus of claim 2 wherein the multimedia information comprises a first information-type and at least a second information-type, and wherein the indications of the selective assignation-requests comprise a request for selective assignation of a first logical channel upon which to transmit the multimedia information of the first information-type.

4. The apparatus of claim 3 wherein the first information-type of the multimedia information comprises real-time media.

5. The apparatus of claim 3 wherein the indications of the selective assignation-requests comprises a request for selective assignation of a second logical channel upon which to transmit the multimedia information of the second information-type.

6. The apparatus of claim 5 wherein the second information-type of the multimedia information comprises non-real-time media.

7. The apparatus of claim 5 wherein the packet-formatted data of which the multimedia information is formed further comprises user-plane information including the first information-type and the second information-type, the user-plane information to be generated selectively upon the first logical channel and at least the second logical channel subsequent to assignation of the first logical channel and at least the second logical channel requested.

8. The apparatus of claim 7 wherein the user-plane information is formatted according to real-time transport protocol.

9. The apparatus of claim 1 wherein the control-plane information, indications of which are detected by said detector, is formatted according to real-time transport protocol.

10. The apparatus of claim 1 wherein the radio communication system comprises a Time-Division, Multiple-Access (TDMA) communication system, and wherein said format converter converts the packet-formatted multimedia information into TDMA format for transmission over the special channel when it is allocated in response to the request by said requester.

11. The apparatus of claim 1 wherein the radio communication system comprises a Code-Division, Multiple-Access (CDMA) communication system, and wherein said format converter converts the packet-formatted multimedia information into CDMA format for transmission over the special channel when it is allocated in response to the request said requester.

12. The apparatus of claim 1 wherein said detector, said requester, and said format converter form portions of an adaptation layer of the first communication station.

13. The apparatus of claim 12 wherein the second communication station further comprises an adaptation layer operable to convert radio-link-formatted multimedia information received at the second communication station into packet-data format.

14. The apparatus of claim 13 wherein the radio communication system comprises a cellular radio communication system, wherein the first communication station comprises a first terminal coupled together with a mobile station and wherein said detector, said requester, and said format converter form portions of the mobile station.

15. The apparatus of claim 14 wherein the second communication station comprises a second terminal coupled together with network infrastructure of the cellular communication system, and wherein said adaptation layer of the second communication station is formed at the network infrastructure.

16. A method for communicating multimedia information between a first and a second communication station in a radio communication system, said method comprising the steps of:

receiving in the first communication station, the multimedia information in packet-data form;

detecting control-plane information associated with the packet-formatted multimedia information;

requesting allocation of a special wireless channel defined upon a radio-link between the first communication station and the second communication station;

converting the packet-formatted multimedia information into a radio-link format, amenable for transmission upon the special wireless channel; and

transmitting the multimedia information upon the special wireless channel to the second communication station.

17. In a communication system having a first communication station operable at least to source real-time media in a selected format, an improvement of a first upstream adaptor portion for adapting the real-time media formatted in the selected format to facilitate communication of the real-time media upon a communication link, said first upstream adaptor portion comprising:

a first detector coupled to receive indications of the real-time media formatted in the selected format, said first detector for detecting when the real-time media is to be communicated upon the communication link;

a first requester coupled to receive indications of detection by said first detector of the real-time media to be communicated upon the communication link, said first requester for requesting allocation of a first special channel upon which to communicate the real-time media upon the communication link; and

a first converter coupled to receive the real-time media formatted in the selected format, said first converter for converting the real-time media formatted in the selected format into spectrally-efficient form for communication upon the first special channel.

18. The first upstream adaptor portion of claim 17 wherein said first detector and said first requester comprise portions of a control-plane adaptation layer.

19. The first upstream adaptor portion of claim 17 wherein the selected format in which the real-time media sourced by the first communication station is formatted into packets that include Internet Protocol, User Datagram Protocol, and Real-time Transport Protocol headers, and wherein the spectrally-efficient form into which said first converter converts the real-time media comprises a real-time media stream having at least selected ones of said headers removed.

20. In the communication system of claim 19 a further improvement of a first downstream adaptor portion for adapting the real-time media, communicated in the spectrally-efficient form upon the first special channel upon the communication link, to be formatted back into the selected format, said first downstream adaptor portion comprising:

a first reconverter coupled to receive the real-time media communicated upon the special channel of the communication link, said first reconverter for converting the real-time media into formatted form, formatted pursuant to the selected format.

21. The first downstream adaptor portion of claim 20 wherein said first reconverter comprises a regenerator for regenerating the real-time media formatted into the packets that include the Internet Protocol, User Datagram Protocol, and Real-time Transport Protocol header fields.

22. In the communication system of claim 21, the system further comprising a second communication station that is also operable at least to source real-time media in the selected format, a further improvement of a second upstream adaptor portion for adapting the real-time media sourced by the second communication station, said second upstream adaptor portion comprising:

a second detector coupled to receive indications of the real-time media sourced by the second communication station, said second detector for detecting when the real-time media sourced by the second communication station is to be communicated upon the communication link; and

a second requester coupled to receive indications of detection by said second detector of the real-time media sourced by the second communication station, said second requester for requesting allocation of a second special channel upon which to communicate the real-time media sourced by the second communication station upon the communication link.

23. The second upstream adaptor portion of claim 22 further comprising a second converter coupled to receive the real-time media sourced by the second communication station, said second converter for converting the real-time media sourced by the second communication station into spectrally-efficient form for communication upon the second special channel.

24. In the communication system of claim 23, a further improvement of a second downstream adaptor portion for adapting the real-time media, sourced by the second communication station and communicated in the spectrally-efficient form upon the second special channel, to be formatted back into the selected format, said second downstream adaptor portion having a second reconverter coupled to receive the real-time media communicated upon the second special channel, said second reconverter for converting the real-time media into formatted form, formatted pursuant to the selected format.

25. A method for adapting real-time media, formatted in a selected format and sourced at a first communication station operable in a communication system, to facilitate communication of the real-time media upon a communication link, said method comprising:

detecting when the real-time media is to be communicated upon the communication link;

requesting allocation of a special channel upon which to communicate the real-time media upon the communication link, and

converting the real-time media sourced by the first communication station into spectrally-efficient form, and

transmitting the real-time media, once converted during said operation of converting, upon the special channel.

26. In a communication system where multimedia information is transferred as packet-formatted data, an apparatus for converting the packet-formatted multimedia data into a communications-link format for transmission upon a communications link having bandwidth and spectrum efficiency limitations, said apparatus comprising:

an upstream adaptor and a downstream adaptor, each at respective ends of the communications link;

the upstream adaptor comprising;

a detector for detecting the initiation and termination of a real-time media session;

a requester coupled to the detector to receive indications of session initiation and termination by said detector, said requester for requesting allocation and de-allocation of a special channel upon the communications-link; and

a format converter coupled to receive the packet-formatted data for converting the packet-formatted data into the communications-link format, thereafter to permit transmission of the multimedia information, formatted in the communications-link format upon the special channel;

the downstream adaptor comprising;

a real-time manager to process the special channel allocation and de-allocation requests from the requester, and grant and release the special channel respectively;

a downstream format converter coupled to receive the communications-link formatted data for converting the communications-link-formatted data into packet format.

27. The apparatus of claim 26 wherein the application signaling protocol is such that the detector can detect the occurrence of selective assignation-requests and deassignation requests for logical channels upon which to carry real-time media.

28. The apparatus of claim 27 wherein the application signaling protocol is H.245, and the detector detects the occurrence of a real-time media logical channel opening and closing.

29. The apparatus of claim 26 wherein the downstream adaptor uses locally stored values, previously sent by the upstream adaptor, for regenerating Internet Protocol and User Datagram Protocol packet headers when converting the communications-link formated data to packet formatted data.

30. The apparatus of claim 26 herein the packet format of real-time media includes headers containing timestamps and sequence numbers.

31. The apparatus of claim 30 where the format converter of the upstream adaptor generates a real-time media stream with timing defined by the time stamps and sequence numbers received, and the special channel is such that the timing is preserved when received at the downstream converter.

32. The apparatus of claim 29 wherein the upstream adaptor needs to send initial time stamps and initial sequence numbers only at special channel allocation time;

the downstream adaptor subsequently regenerates a current time stamp and a current sequence number for each of the packets by using the initial time stamps and initial sequence numbers and an output of a local clock that increments monotonically and linearly in time.

33. The apparatus of claim 32 where the upstream adaptor updates the downstream adaptor with new relevant time stamps and initial sequence numbers whenever parameters that drive the determination of the time stamps and the sequence numbers have changed.

34. The apparatus of claim 26 wherein the packet format of real-time media in the user plane includes headers containing parameters other than timestamps and sequence numbers;

said parameters varying more slowly than said timestamps and said sequence numbers.

35. The apparatus of claim 34 where the downstream adaptor regenerates more slowly varying parameters by retrieving locally stored values, previously sent by the upstream adaptor at special channel allocation time, and updated by the upstream adaptor whenever the values change.

36. The apparatus of claim 35 wherein the real-time media in the user plane is formatted according to the Real-time Transport Protocol, and the more slowly varying parameters include the Synchronization Source (SSRC).

37. The apparatus of claim 26 wherein the communications link is a TDMA (time-division, multiple-access) radio link in which time frames formed of groups of time slots are defined, wherein channels defined in the TDMA communication system are defined, at least in part, by a time slot allocation in successive ones of the time frames, and wherein the request by said requester for allocation of the special channel comprises a request for allocation of at least one selected time slot upon which to transmit the multimedia information.

38. In a communication system where multimedia information is transferred between a multimedia mobile station consisting of a multimedia device and a mobile station (MS) adaptor and a multimedia remote terminal, an apparatus for converting packet-formatted multimedia data into a radio-link format, amenable for transmission upon a radio-link, and for converting the radio-link-formatted multimedia data back into packet-formatted data for delivery to the terminal and the mobile station, said apparatus comprising a mobile station (MS) adaptor and an Access Network Infrastructure (ANI) adaptor;

the MS adaptor comprising;

a detector for detecting when the MS or remote terminal intends to start a real-time media session, and when the real-time session is to be terminated;

the session can be for mobile originated, mobile terminated or both mobile originated and mobile terminated multimedia;

a requester coupled to receive indications of session start by said detector, said requester for requesting allocation of a special channel upon which to communicate the real-time media upon the radio-link;

the requester also requests deallocation of the special channel previously allocated, upon indications of session termination by said detector;

a format converter coupled to receive the mobile originated packet-formatted data of which the multimedia information is formed, and responsive to allocation of the special channel requested by said requester, said format converter for converting the packet-formatted data into the radio-link format, thereafter to permit transmission of the multimedia information, formatted in the radio-link format upon the special channel;

said format converter also coupled to receive the mobile terminated radio-link-formatted data of which the multimedia information is formed, and responsive to allocation of the special channel requested by said requester, said format converter for converting the radio-link-formatted data into the packet format, thereafter to permit delivery of the multimedia information to the mobile multimedia device in packet format;

the Access Network Infrastructure (ANI) adaptor comprising;

a real-time manager to process the special channel allocation and deallocation request from the requester, and grant and release the special channel respectively;

an ANI format converter coupled to receive the mobile originated radio-link formatted data of which the multimedia information is formed, and responsive to allocation of the special channel requested by said requester, said format converter for converting the radio-link-formatted data into the packet format, thereafter to permit delivery of the multimedia information to the remote terminal in packet format;

said format converter also coupled to receive the mobile terminated packet formatted data of which the multimedia information is formed, and responsive to allocation of the special channel requested by said requester, said format converter for converting the packet-formatted data into the radio-link format, thereafter to permit delivery of the multimedia information over the radio link.

39. The apparatus of claim 38 where the ANI adaptor needs to send the IP and UDP header values only at special channel allocation time;

the MS adaptor subsequently regenerates the IP and UDP headers of each of the packets for mobile terminated multimedia by retrieving locally stored values, previously sent by the ANI adaptor at special channel allocation time.

40. The apparatus of claim 38 wherein the MS adaptor needs to send the IP and UDP header values only at special channel allocation time;

the ANI adaptor subsequently regenerates the IP and UDP headers of each of the packets for mobile terminated multimedia by retrieving locally stored values previously sent by the MS adaptor at special channel allocation time.

41. The apparatus of claim 40 wherein the MS adaptor, upon determining that a handoff to a second ANI adaptor has occurred, sends the IP and UDP headers for mobile originated multimedia to the second ANI adaptor. The second ANI adaptor locally stores the values and retrieves them to regenerate IP and UDP headers of subsequent packets for mobile originated multimedia.

42. The apparatus of claim 38 wherein the packet format of real-time media in the user plane includes headers containing timerstamps and sequence numbers.

43. The apparatus of claim 42 where the MS and ANI format converter generates a real-time media stream with the timing defined by the time stamps and sequence numbers received, and the special channel is such that the timing is preserved when received at the ANI and MS converter respectively.

44. The apparatus of claim 43 where the ANI adaptor needs to send the initial time stamps and sequence numbers only at special channel allocation time;

the MS adaptor subsequently regenerates the current time stamp and sequence number for each of the packets by using the initial values and the output of a local clock that increments monotonically and linearly in time.

45. The apparatus of claim 44 where the ANI adaptor updates the MS adaptor with new relevant values whenever the parameters that drive the determination of the time stamps and sequence numbers have changed;

an example of such parameters is the frequency of the clock to be used at the MS adaptor.

46. The apparatus of claim 45 wherein the real-time media in the user plane is formatted according to the RTP protocol;

timestamps and sequence numbers are RTP timestamps and RTP sequence numbers.

47. The apparatus of claim 43 where the MS adaptor needs to send the initial time stamps and sequence numbers only at special channel allocation time;

the ANI adaptor subsequently regenerates the current time stamp and sequence number for each of the packets by using the initial values and the output of a local clock that increments monotonically and linearly in time.

48. The apparatus of claim 47 where the MS adaptor updates the ANI adaptor with new relevant values whenever the parameters that drive the determination of the time stamps and sequence numbers have changed;

an example of such parameters is the frequency of the clock to be used at the ANI adaptor.

49. The apparatus of claim 48 wherein the real-time media in the user plane is formatted according to a Real-time Transport Protocol (RTP);

timestamps and sequence numbers are RTP timestamps and RTP sequence numbers.

50. The apparatus of claim 43 where the MS adaptor, upon determining that a handoff to a new ANI adaptor has occurred, sends the current value of the time stamp and sequence number for mobile originated multimedia to the new ANI adaptor.

51. The apparatus of claim 50 where the ANI adaptor regenerates packet format headers for mobile originated multimedia by calculating the time stamps and sequence numbers from the values sent by the MS adaptor at handoff time, and from a local clock that increments monotonically and linearly in time.

52. The apparatus of claim 38 wherein the packet format of real-time media in the user plane includes headers containing parameters other than timestamps and sequence numbers;

these parameters varying more slowly than timestamps and sequence numbers.

53. The apparatus of claim 52 where the MS adaptor regenerates more slowly varying parameters by retrieving locally stored values, previously sent by the ANI adaptor at special channel allocation time, and updated by the ANI adaptor whenever the values change.

54. The apparatus of claim 53 wherein the real-time media in the user plane is formatted according to a Real-time Transport Protocol (RTP), and the more slowly varying parameters include the Synchronization Source (SSRC).

55. The apparatus of claim 52 where the ANI adaptor regenerates more slowly varying parameters by retrieving locally stored values, previously sent by the MS adaptor at special channel allocation time, and updated by the MS adaptor whenever the values change.

56. The apparatus of claim 55 wherein the real-time media in the user plane is formatted according to a Real-time Transport Protocol (RTP);

more slowly varying parameters include the Synchronization Source (SSRC).

57. The apparatus of claim 38 where a special channel carrying real-time media can be multiplexed with other special channels carrying real-time media and/or other tapes of channels.

58. The apparatus of claim 38 where the multimedia device is integrated with the MS adaptor.

59. The apparatus of claim 58 wherein the packet format of real-time media in the user plane includes headers containing timestamps and sequence numbers.

60. The apparatus of claim 59 where the MS and ANI format converter generates a real-time media stream with the timing defined by the time stamps and sequence numbers received, and the special channel is such that the timing is preserved when received at the ANI and MS converter respectively.

61. The apparatus of claim 60 where the MS adaptor, upon determining that a handoff to a new ANI adaptor has occurred, sends the current value of the time stamp and sequence number for mobile originated multimedia to the new ANI adaptor.

62. The apparatus of claim 61 where the ANI adaptor regenerates packet format headers for mobile originated multimedia by calculating the time stamps and sequence numbers from the values sent by the MS adaptor at handoff time, and from a local clock that increments monotonically and linearly in time.

63. The apparatus of claim 58 wherein the packet format of real-time media in the user plane includes headers containing parameters other than timestamps and sequence numbers;

these parameters varying more slowly than timestamps and sequence numbers.

64. The apparatus of claim 63 where the ANI adaptor regenerates more slowly varying parameters by retrieving locally stored values, previously sent by the MS adaptor at special channel allocation time, and updated by the MS adaptor whenever the values change.