Electronic data communication systems

• US 20040131025A1
• Filed: 12/23/2003
• Published: 07/08/2004
• Est. Priority Date: 06/28/2001
• Status: Active Grant

• Current Assignee: Kings College London (University of London)
• Original Assignee: Kings College London (University of London)
• Inventors: Ghorashi, Seyed Ali, Aghvami, Abdol Hamid, Dohler, Mischa, Said, Fatin
• Granted Patent: US 7,594,010 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements
• CPC Class Codes: H04L 41/0893 Assignment of logical groups to network elements
• CPC Class Codes: H04L 41/0894 Policy-based network configuration management
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 52/46 in multi hop networks, e.g. wireless relay networks
• CPC Class Codes: H04W 84/22 with access to wired networks

Abstract

A method of transmitting data across an electronic data communication system comprising a plurality of terminals that can send and receive data in the form of electromagnetic waves to and from at least one of the terminals, which method comprises the steps of: (a) identifying at least one control terminal, at least one target terminal and at least two relaying terminals from the plurality of terminals; and (b) using the control terminal to instruct the at least two relaying terminals to receive and relay data intended for the at least one target terminal, so that the at least one target terminal can receive data directly from at least one terminal and from the at least two relaying terminals, thereby increasing capacity of the system.

Claims

1. A method of transmitting data across an electronic data communication system comprising a plurality of terminals that can send and receive data in the form of electromagnetic waves to and from at least one of the terminals, which method comprises the steps of:

(a) identifying at least one control terminal, at least one target terminal and at least two relaying terminals from the plurality of terminals; and

(b) using the control terminal to instruct the at least two relaying terminals to receive and relay data intended for the at least one target terminal, so that the at least one target terminal can receive data directly from at least one terminal and from the at least two relaying terminals, thereby increasing capacity of the system.

2. A method as claimed in claim 1, said method being initiated by the electronic data communication system reaching a predetermined capacity threshold or if data demanded by or sent from at least one of the plurality of terminals would breach said predetermined capacity threshold.

3. A method as claimed in claim 1 or 2, further comprising the steps of:

(c) determining the physical position of the at least one target terminal; and

(d) assigning the at least two relaying terminals by searching for a terminal that is within a range of the at least one target terminal such that relaying data from that terminal is deemed unlikely to reduce the capacity of the system.

4. A method as claimed in claim 3, said method further comprising the steps of grouping said relaying and target terminals together by the criteria in step (d) to form a group, and instructing the relaying terminals in the group to relay data to the at least one target mobile terminal in that group.

5. A method as claimed in claim 4, further comprising the steps of controlling the relaying power of said at least two relaying terminals so as to reduce effects of interference in the system.

6. A method as claimed in claim 5, wherein the relaying power is controlled so that each relaying terminal has a relaying range of between approximately 2 m and 100 m in any environment, and preferably between approximately 10 m and 20 m.

7. A method as claimed in any preceding claim, further comprising the step of verifying a membership status of each terminal before it can be used as a relaying terminal, said membership status determining whether or not that terminal can be so used.

8. A method as claimed in any preceding claim, further comprising the steps of:

(e) monitoring the capacity of the system after the at least two relaying terminals have begun relaying to the at least one target terminal to determine whether the system capacity is improved or degraded as a result;

(f) if the system capacity has been degraded, determining whether or not the addition of at least one additional relaying terminal would increase the system capacity; and

(g) if so, instructing the at least one additional relaying terminal to receive and relay data intended for the at least one target terminal; and

(h) further monitoring the capacity of the system and repeating steps (f) and (g) if the capacity of the system has been degraded.

9. A method as claimed in any preceding claim, further comprising the step of instructing the at least two relaying terminals to relay said data intended for the at least one target terminal by one of the following methods:

(1) relaying the entire part of the electromagnetic signal received including data for other terminals;

(2) relaying only that part of the electromagnetic signal containing data intended for the at least one target terminal;

or

(3) if the data is in packet form, storing said packets in a buffer for a predetermined time for transmission to the at least one target terminal if requested thereby.

10. A method as claimed in any preceding claim, further comprising the step of instructing the at least two relaying terminals to amplify at least the signal representing the data intended for the at least one target terminal.

11. A method as claimed in any preceding claim, further comprising the step of instructing the at least two relaying terminals to relay data to another at least two relaying terminals for onward transmission to a target terminal.

12. A method as claimed in any preceding claim, wherein data for each terminal has been multiplied by a different spreading code each having a chip rate allowing each terminal to extract its data using a copy of the spreading code, the method further comprising the steps of scrambling data intended for the at least one relaying terminal with a first scrambling code and instructing the at least one relaying terminal to de-scramble any data received under the first scrambling code.

13. A method as claimed in claim 12, further comprising the steps of scrambling data intended for the at least one target terminal with a second scrambling code and instructing the at least two relaying terminals to relay any data received under the second scrambling code to the at least one target terminal.

14. A method as claimed in claim 13, further comprising the steps of instructing the at least two relaying terminals to de-scramble data received under the second scrambling code, to scramble that data with the first scrambling code, and to relay that data to the at least one target terminal.

15. A method as claimed in claims 13 or 14, further comprising the steps of instructing transmission of data under said first scrambling code over a first frequency band, and instructing transmission of data under said second scrambling code over a second frequency band.

16. A method as claimed in any of claims 12 to 16, wherein the at least two relaying terminals form a group, the method further comprising the step of instructing each relaying terminal in the group to relay data for the at least one target terminal so that the path difference of each signal from each relaying terminal and/or control terminal at the at least one target terminal is out of synchronisation by an amount greater than the duration of one chip of the spreading code of the target terminal.

17. A method as claimed in claim 16, wherein said at least one target terminal lies outside said group, said method further comprising the step of instructing said group to relay data for the at least one target terminal to another group of relaying terminals nearer to the target terminal.

18. A method as claimed in any claims 12 to 17, wherein the at least two relaying terminals form a group, the method further comprising the step of instructing each relaying terminal in the group to relay data for the at least one target terminal so that the path difference of each signal from each relaying mobile terminal at the at least one target terminal is in synchronisation by an amount less than the duration of one chip of the spreading code of the target terminal.

19. A method as claimed in claim 18, wherein said at least one target terminal lies within said group, said method further comprising the step of instructing said group to relay data for the at least one target terminal to said at least one target terminal.

20. A method as claimed in claim 16 or 18, wherein said synchronisation is imposed by the data communication system, by natural delay or by organising each group of relaying terminals within a range of the at least one other terminal such that data relayed from that terminal does not reduce the capacity of the system.

21. A method as claimed in any of claims 12 to 20, further comprising the steps of identifying a first group of relaying terminals that lie within chip range of one another whereby the path difference of each signal from each relaying terminal at each other relaying terminal is in synchronisation by an amount less than or equal to the duration of one chip of each spreading code, and identifying a second group of relaying terminals that lie within chip range of one another whereby the path difference of each signal from each relaying terminal at each other relaying terminal is in synchronisation by an amount less than or equal to the duration of one chip of each spreading code, said first and second groups being organised so that they are out of chip range of one another.

22. A method as claimed in any of claims 1 to 11, the method further comprising the steps of instructing the data for each terminal to be transmitted during a time slot on a first frequency band, and instructing the at least two relaying terminals to relay data for the at least one target terminal at another time slot and on a second frequency different to said first frequency band.

23. A method as claimed in claim 22, further comprising the step of instructing the at least two relaying terminals to use an uplink (relaying terminal to control terminal) frequency band to relay data for the at least one target terminal.

24. A method as claimed in any of claims 12 to 22, further comprising the steps of instructing the at least two relaying terminals to de-code the data for the at least one target mobile terminal and to relay that data according to the relaying steps of claim 22 or 23.

25. A method as claimed in any of claims 1 to 11, further comprising the steps of instructing the at least two relaying terminals to relay data to the at least one target terminal during a number of time slots and/or over at least two sub-carrier frequencies, each of which are orthogonal to one another.

26. A method as claimed in claim 25, further comprising the step of instructing the at least two relaying terminals to utilise said at least two sub-carrier frequencies in a frequency band different to that over which the data was transmitted to the at least two relaying terminals.

27. A method as claimed in any of claims 12 to 23, further comprising the steps of instructing the at least two relaying terminals to relay data to the at least one target mobile terminal according to the relaying step of claim 25.

28. A method as claimed in any preceding claim, wherein data intended for the target terminal is encoded with space-time codes, transmitted from a terminal having a plurality of antenna elements, the method further comprising the step of instructing the at least one target terminal to receive data from the at least two relaying terminals and to use the different signals from each relaying terminal to take advantage of the space-time coding, the at least two relaying terminals effectively acting as respective antenna elements for the target terminal, such that communication channel between the terminal and the target terminal is similar to a multiple input multiple output channel.

29. A method as claimed in any preceding claim, further comprising the step of instructing the at least two relaying terminals to relay data intended for the at least one target terminal using wire, power line communication or another transmission standard for example Bluetooth, infrared, ultra wideband or HiperLAN2.

30. A computer program comprising instructions for carrying out a method as claimed in any preceding claim.

31. A computer readable storage medium having stored thereon a computer program as claimed in claim 30.

32. An apparatus for transmitting electromagnetic waves comprising a transmitter, controlling means for controlling emission of electromagnetic waves therefrom for wireless communication with at least one terminal, said controlling means being able to issue instructions to said at least one terminal remote from said transmitter for performing a method as claimed in any of claims 1 to 28 to increase capacity of said wireless communication.

33. An apparatus as claimed in claim 30, wherein said controlling means comprises computer means having a computer program as claimed in claim 28 stored thereon.

34. An apparatus as claimed in claim 32 or 33, said controlling means for controlling transmission of said instructions to a terminal for storage thereon so that it can operate the method on request of the controlling means.

35. An apparatus as claimed in claim 32, 33 or 34, wherein the apparatus is a base station controller, a radio network controller, a central controller or a portable terminal such as a mobile telephone, a portable computer or a personal digital assistant in a telecommunication system.

36. An apparatus as claimed in claim 32, 33, 34 or 35, wherein there are a plurality of said apparatus that can communicate with the at least two relaying terminals.

37. A subscriber identity module card for use in a portable terminal, such as mobile telephone, that is provided with a set of computer executable instructions in accordance with a method according to any of claims 1 to 29.

39. A method as claimed in claim 1, wherein said identification is performed on the basis of the relative physical positions of the plurality information relays and/or the at least one information silk with respect to one another.

52. A computer program comprising instructions for performing a method as claimed in any preceding claim.

53. A computer readable storage medium having stored thereon a computer program as claimed in claim 52.

38. A method of synchronising data transfer in an electronic data communication system comprising at least one information source and a plurality of information sinks each of which can send and receive data in the form of electromagnetic waves to and from the at least one at least one information source using a transmission access scheme, which method comprises the steps of:

(1) identifying a plurality of information relays from the plurality of information sinks; and

(2) instructing the plurality of information relays to receive and relay data intended for at least one of the plurality of information sinks;

wherein at step (1) the plurality of information relays is identified on the basis of ability to relay data such that it remains synchronous or has a deviation that can be tolerated by the at least one information sink.

40. A method as claimed in claim 38 or 39, further comprising the step of identifying two or more groups of information relays, the groups identified on the basis of their ability to relay data such that it remains synchronous as relayed from that group.

41. A method as claimed in claim 40, further comprising the step of instructing at least one group to relay data out of synchrony with another group.

42. A method as claimed in any of claims 38 to 41, further comprising the step of identifying the at least one information sink for which the data is intended as part of the plurality of information relays.

43. A method as claimed in claim 41 and 42, wherein the group that is instructed is the group containing the at least one information sink for which the data is intended.

44. A method as claimed in any of claims 38 to 43, wherein the step of identifying the plurality of information relays is carried out using a parameter of a signal to be transmitted, determining a threshold using said parameter and a known tolerated deviation in synchronisation of the transmission access scheme concerned, said threshold being a measure of the relative positions of the information relays in position or time, and accepting or rejecting potential information relays when compared with the threshold.

45. A method as claimed in claim 44, wherein said parameter is a measure of that part of the signal requiring synchronisation over the smallest time period.

46. A method as claimed in claim 44, wherein said parameter is a measure of the number of super-frames, frames, time-slot, symbol, bits or chips per unit time.

47. A method as claimed in any of claims 44 to 46, wherein the transmission access scheme is based on code division multiple access and said parameter is the number of chips per unit time of a spreading code, the deviation in synchronisation tolerated being of the order of one chip duration, the method further comprising the steps of determining said threshold by converting said one chip duration into a distance, the distance being an approximate measure within which data transmitted from information sources will remain synchronised within said deviation, and identifying information sources within approximately that distance of one another.

48. A method as claimed in any of claims 44 to 46, wherein the transmission access scheme is based on time division multiple access or orthogonal frequency division multiple access and said parameter is the number of symbols transmitted per unit time, the deviation in synchronisation tolerated being approximately ten percent of one symbol duration, the method further comprising the steps of determining said threshold by converting said ten percent of one symbol duration into a distance, the distance being an approximate measure within which data transmitted from information sources will remain synchronised within said deviation, and identifying information sources within approximately that distance of one another.

49. A method as claimed in any of claims 44 to 49, further comprising the step of increasing the magnitude of said parameter in response to an indication that the synchronisation of the link between the information source and the information sink is deteriorating, by an amount sufficient to improve the synchronisation.

50. A method as claimed in any of claims 38 to 49, further comprising the step of instructing at least one information relay to act as an information sink substantially simultaneously.

51. A method as claimed in any of claims 38 to 50, further comprising the step of instructing said plurality of information relays to relay either the entire part of the electromagnetic signal received after optionally amplifying and shifting the signal in frequency, or to relay the entire part of the electromagnetic signal received after optionally amplifying, de-coding and re-encoding with the same or a different code, and shifting in frequency.

54. An apparatus for synchronising an electronic data communication system comprising at least one information source and a plurality of information sinks each of which can send and receive data in the form of electromagnetic waves to and from the at least one at least one information source with a transmission access scheme, which apparatus comprises controlling means for controlling operation of a method as claimed in any of claims 38 to 51.

55. An apparatus as claimed as in claim 54, wherein said controlling means instruct operation of said method remotely from the apparatus, for example on a mobile terminal.

56. An apparatus as claimed in claim 54 or 55, wherein said controlling means comprises a central controller, a radio network controller or a master mobile terminal in an electronic telecommunication data system.

57. A subscriber identification module card comprising computer executable instructions for carrying out a method as claim in any of claims 38 to 51.

58. A method of transmitting data between at least one information source and at least one information sink using electromagnetic waves, which method comprises the steps of:

(a) identifying at least one information relay; and

(b) instructing the at least one information relay to relay data received from the information source intended for the information sink on an unused frequency band such that simultaneous communication can take place between the information source and sink whilst said information relay relays data to the information sink.

59. A method as claimed claim 58, wherein at step (b) said information relay is instructed to relay said data on a different frequency band to that which it was received on.

60. A method as claimed in claim 58 or 59, further comprising the step of instructing the information relay to utilise time slot or code to ensure orthogonality between the channels on which the data is relayed and that on which it is received.

61. A method as claimed in claim 58, 59 or 60, further comprising the step of instructing the information relay to relay data on its uplink frequency band.

62. A method as claimed in claim 61, wherein said information relay is instructed to re-program an uplink oscillator to relay on said uplink frequency band.

63. A method as claimed in any of claims 58 to 62, wherein said information source communicates with the information relay and the information sink on two different frequency bands for uplink and downlink, the method further comprising the step of instructing the information relay to relay on one of the downlink frequency bands.

64. A method as claimed in any of claims 58 to 63, wherein data is transmitted using a code division multiple access scheme by spreading data for u users, each of which call be an information source, sink and/or relay, with u distinct spreading codes, the method further comprising the step of instructing the users to relay u−

1 data streams to the remaining u−

1 users on a plurality of different frequency bands.

65. A method as claimed in claim 64, wherein the users are instructed to relay data on a u−

1 frequency bands.

66. A method as claimed in any of claims 58 to 65, wherein data is transmitted using a time division multiple access scheme by sending data to u users, each of which can be an information source, sink and/or relay, during appropriate time slots and frequency bands, the method further comprising the steps of instructing the users to relay u−

1 data streams to the remaining u−

1 on a plurality of different time slots and unused frequency bands.

67. A computer program comprising computer executable instructions for carrying out a method as claimed in any of claims 58 to 67.

68. A computer readable storage medium comprising a computer program as claimed in claim 67.

69. Apparatus comprising controlling means and transmitting means, said controlling means being operable to transmit signals for performing a method as claimed in any of claims 58 to 68.

70. Apparatus as claimed in claim 69, wherein said transmitting means comprises a plurality of antenna elements.

71. Apparatus as claimed in claim 69 or 70, further comprising receiving means and one or more programmable oscillators in addition to uplink and downlink oscillators for relaying signals received through said receiving means at an unused frequency band.

72. Apparatus as claimed in claim 69, 70 or 71, wherein said transmitter is a base station, a mobile terminal, mobile telephone or a portable computer.

73. A subscriber identity module card comprising computer readable instructions for performing a method as claimed in any of claims 58 to 66.